ASTM C1145-19

Standard Terminology of Advanced Ceramics

SCOPE
1.1 This terminology contains definitions and explanatory notes for the principal words, phrases, and terms used in advanced ceramics technology. The given definitions are technology specific and are directly applicable to the design, production, testing, analysis, characterization, and use of advanced ceramics for structural, electronic, coating, energy, chemical, nuclear, biomedical, and environmental applications.  
1.2 The purpose of the standard terminology is to provide a collected technical resource and reference that promotes a common understanding of the principal technical terms used within the advanced ceramics community and encourages the use of uniform terminology in specifications and reports.  
1.3 Definitions of terms appear in dictionary-definition form and include the term, part of speech (for example, n = noun; v = verb; adj = adjective), definition, and, when applicable, a delimiting phrase. Terms representing physical quantities have analytical dimensions stated immediately following the term (or letter symbol) in fundamental dimension form, using the following ASTM standard symbology for fundamental dimensions, shown within square brackets: [M] for mass, [L] for length, [T] for time, [θ] for thermodynamic temperature, and [nd] for non-dimensional quantities. Use of these symbols is restricted to analytical dimensions when used with square brackets, as the terms may have other definitions when used without the brackets.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2019
• ICS: 01.040.81 - Glass and ceramics industries (Vocabularies)
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: C28 - Advanced Ceramics
• Drafting Committee: C28.91 - Nomenclature and Editorial

Relations

• Replaces: ASTM C1145-06(2013)e1 - Standard Terminology of Advanced Ceramics
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1730-17(2022) - Standard Test Method for Particle Size Distribution of Advanced Ceramics by X-Ray Monitoring of Gravity Sedimentation
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1198-20 - Standard Test Method for Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio for Advanced Ceramics by Sonic Resonance
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1368-18 - Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Rate Strength Testing at Ambient Temperature
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1576-05(2017) - Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Flexural Testing (Stress Rupture) at Ambient Temperature
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1292-22 - Standard Test Method for Shear Strength of Continuous Fiber-Reinforced Advanced Ceramics at Ambient Temperatures
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1899-21 - Standard Test Method for Flexural Strength of Continuous Fiber-Reinforced Advanced Ceramic Tubular Test Specimens at Ambient Temperature
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1499-19 - Standard Test Method for Monotonic Equibiaxial Flexural Strength of Advanced Ceramics at Ambient Temperature
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1834-16 - Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Flexural Testing (Stress Rupture) at Elevated Temperatures
• Effective Date: 01-Jul-2019
• Referred By: ASTM F3187-16 - Standard Guide for Directed Energy Deposition of Metals
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1359-18e1 - Standard Test Method for Monotonic Tensile Strength Testing of Continuous Fiber-Reinforced Advanced Ceramics With Solid Rectangular Cross Section Test Specimens at Elevated Temperatures
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1358-18 - Standard Test Method for Monotonic Compressive Strength Testing of Continuous Fiber-Reinforced Advanced Ceramics with Solid Rectangular Cross Section Test Specimens at Ambient Temperatures
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1239-13(2018) - Standard Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Advanced Ceramics
• Effective Date: 01-Jul-2019
• Referred By: ASTM C1468-19a - Standard Test Method for Transthickness Tensile Strength of Continuous Fiber-Reinforced Advanced Ceramics at Ambient Temperature
• Effective Date: 01-Jul-2019
• Referred By: ASTM E3341-22 - Standard Guide for General Principles of Resilience
• Effective Date: 01-Jul-2019

Overview

ASTM C1145-19: Standard Terminology of Advanced Ceramics is a comprehensive international standard developed by ASTM International. It provides authoritative terminology for key words, phrases, and concepts used in the field of advanced ceramics. This resource is crucial for ensuring a shared technical language among professionals involved in the design, production, analysis, testing, and utilization of advanced ceramics across a wide range of industries.

Developed under the jurisdiction of ASTM Committee C28 on Advanced Ceramics, this standard is aligned with international principles established by the World Trade Organization’s Technical Barriers to Trade Committee. The terminology is designed to foster uniformity in technical documents, specifications, and industry communication globally.

Key Topics

• Technology-Specific Definitions: Terms are defined with direct relevance to advanced ceramics technology, addressing unique characteristics, materials, and processing methods.
• Analytical Notation: Certain terms, especially those representing physical quantities, include dimensional notation following ASTM symbology (e.g., [M] for mass, [L] for length).
• Material Science Terminology: Coverage includes fundamental ceramic material types, microstructures, and fabrication processes, such as matrix composites, cermets, and engineered porosity.
• Processing & Testing Vocabulary: Key definitions relate to processes like grinding, hot pressing, casting, and methods for evaluating strength, toughness, and other performance attributes.
• Fractography & Failure Analysis: Specialized terms support failure analysis and characterization, including fracture origins, flaw distributions, and fracture toughness.
• Dimensional and Mechanical Properties: Clarified notation for strength, stress, modulus, and other mechanical attributes ensures reliable communication in research and specification compliance.

Applications

ASTM C1145-19 serves as an essential reference across multiple sectors where advanced ceramics play a critical role, including:

• Structural Applications: Supporting design and manufacturing in aerospace, automotive, and civil engineering where high-performance ceramics provide mechanical strength and reliability.
• Electronics: Enabling precise specification of terms in the production and testing of ceramic substrates, capacitors, and insulators for electronic devices.
• Coatings and Surface Engineering: Informing terminology in advanced ceramic coatings for wear, protection, and functional applications.
• Energy and Environmental Technologies: Assisting in documenting processes and mechanisms for ceramics used in fuel cells, filters, membranes, and catalytic converters.
• Biomedical Devices: Providing a consistent language for product development, testing, and regulatory documents related to ceramic implants and medical devices.
• Nuclear and Chemical Processing: Ensuring clarity in the description and testing of ceramics used in harsh chemical or radiation environments.

This standard is invaluable for engineers, researchers, quality control technicians, specifiers, and regulatory professionals seeking accurate, harmonized communication regarding advanced ceramics.

Related Standards

• ASTM C28 Standards: Additional standards developed under the ASTM Committee C28 on Advanced Ceramics, covering methods for testing, characterization, and performance of ceramic materials.
• ASTM C1198, C1259, C1292, C1322, C1368, C1525, C1674: Cited reference standards related to specific technical aspects within advanced ceramics, including mechanical testing and microstructural analysis.
• ISO 20507: Standard international terminology for fine ceramics.
• ASTM C1624: Related terminology on ceramic coatings.
• ASTM C1495, C1274, C1239: Documents referenced for definitions related to grinding, adsorption, and statistical analysis in ceramics testing.

Employing ASTM C1145-19 as a primary reference ensures consistency, accuracy, and compliance across the global ceramics industry, paving the way for seamless exchange of technical information and the advancement of advanced ceramics technology.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1145 − 19
Standard Terminology of
Advanced Ceramics
This standard is issued under the fixed designation C1145; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope adhesive failure, n—detachment and separation of a coating
from the substrate with cracking and debonding at the
1.1 This terminology contains definitions and explanatory
coating-substrate interface. (C1624)
notes for the principal words, phrases, and terms used in
advanced ceramics technology. The given definitions are tech-
adsorbate,n—materialthathasbeenretainedbytheprocessof
nology specific and are directly applicable to the design,
adsorption. (C1274)
production, testing, analysis, characterization, and use of
adsorbent, n—any solid having the ability to concentrate
advanced ceramics for structural, electronic, coating, energy,
significant quantities of other substances on its surface.
chemical, nuclear, biomedical, and environmental applications.
(C1274)
1.2 The purpose of the standard terminology is to provide a
collected technical resource and reference that promotes a
adsorption, n—process in which molecules are concentrated
common understanding of the principal technical terms used
onasurfacebychemicalorphysicalforces,orboth. (C1274)
within the advanced ceramics community and encourages the
adsorption isotherm, n—relation between the quantity of
use of uniform terminology in specifications and reports.
adsorbate and the equilibrium (relative) pressure of the
1.3 Definitionsoftermsappearindictionary-definitionform
adsorptive, at constant temperature. (C1274)
and include the term, part of speech (for example, n = noun;
DISCUSSION—Typically, the amount adsorbed is presented on an
v = verb; adj = adjective), definition, and, when applicable, a 3
isotherm as volume in cm STP (Standard Temperature and Pressure,
delimiting phrase. Terms representing physical quantities have
that is, 273.15 K and 101325.02 Pa) normalized per mass of sample.
analytical dimensions stated immediately following the term
adsorptive, n—any substance available for adsorption.
(or letter symbol) in fundamental dimension form, using the
(C1274)
following ASTM standard symbology for fundamental
dimensions, shown within square brackets: [M] for mass, [L]
advanced ceramic,n—ahighlyengineered,highperformance,
for length, [T] for time, [θ] for thermodynamic temperature,
predominately non-metallic, inorganic, ceramic material
and [nd] for non-dimensional quantities. Use of these symbols
having specific functional attributes. (C1198, C1259,
is restricted to analytical dimensions when used with square
C1292, C1322, C1368, C1525, C1576, C1674)
brackets, as the terms may have other definitions when used
agglomerate, n—as used in fractography, a cluster of grains,
without the brackets.
particles, platelets, or whiskers, or a combination thereof,
1.4 This international standard was developed in accor-
present in a larger solid mass.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
aggregate, n—a dense mass of particles held together by
Development of International Standards, Guides and Recom-
strong intermolecular or atomic cohesive forces. It is stable
mendations issued by the World Trade Organization Technical
to normal handling and ordinary mixing techniques includ-
Barriers to Trade (TBT) Committee.
ing high-speed stirring and ultrasonics. (C242)
2. Terminology
aliquot, n—a representative portion of a whole that divides the
whole leaving a remainder. (C1274)
absorbed moisture, n—water held within the materials and
having physical properties not substantially different from
back-face strain, n—the strain as meaured with a strain gage
ordinary water at the same temperature and pressure.
mounted longitudinally on the compressive surface of the
specimen, opposite the crack or notch mouth (often this is
This terminology is under the jurisdiction of ASTM Committee C28 on
the top surface of the specimen as tested). (C1421)
Advanced Ceramics and is the direct responsibility of Subcommittee C28.91 on
Nomenclature and Editorial.
base exchange, n—a surface property exhibited by collodial
Current edition approved July 1, 2019. Published July 2019. Originally approved
inorganic materials, usually clays, whereby absorbed surface
in 1989. Last previous edition approved in 2013 as C1145 – 06 (2013). DOI:
10.1520/C1145-19. cations are replaced by other cations.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1145 − 19
baseline flexure strength, n—in the context of this standard, organic in nature. These components are combined on a
refers to the flexure strength value obtained after application macroscale to form a useful engineering material possessing
of a grinding procedure specified in this standard. (C1495) certain properties or behavior not possessed by the indi-
DISCUSSION—Fortheadvancedceramicstowhichthisthisstandardis
vidual constituents. (C1275)
applicable, the baseline flexure strength is expected to be a close
approximation to the inherent flexure strength. cermet, n—a composite material or article comprised of a
ceramic and a metal or metal alloy, interdistributed in any of
blanchard grinding, n—a type of rotary grinding in which the
various geometrical forms but intimately bonded together.
workpiece is held on a rotating table with an axis of rotation
that is parallel to the (vertical) spindle axis. (C1495)
channel porosity, n—porosity in the porous ceramic compo-
nent that is defined by the large, open longitudinal honey-
body, n—the structural portion of a ceramic article, or the
comb channels. Channel porosity generally has cross-
material or mixture from which it is made. (C242)
sectional dimensions on the order of 1 millimeter or greater.
(C1674)
breaking force, [F], n—the force at which fracture occurs in a
test specimen. (C1674)
chatter, n—an undesirable pattern created on the surface of a
DISCUSSION—In this test method, fracture consists of breakage of the
work piece, usually at regularly spaced intervals, due to an
test bar into two or more pieces or a loss of at least 50 % of the
out-of-round, out-of-balance condition or due to an induced
maximum force carrying capacity.
natural frequency, or its harmonics, or both, in a grinding
brittle fracture, n—fracture that takes place with little or no
machine.
preceding plastic deformation. (C1322)
cohesive failure, n—material damage and cracking in the
bundle, n—a collection of parallel fibers. Synonym, tow.
coating or in the substrate, separate and distinct from
(C1557)
detachment and adhesive debonding at the coating-substrate
interface. (C1624)
calcine, v (calcination, n)—firing or heating a granular or
particulate solid at less than fusion temperature, but suffi-
colloidal particle, n—a dispersed particle with a linear dimen-
cient to remove most of its chemically combined volatile
sion of 5 to 100 nm.
matter (that is, H O, CO ) and otherwise to develop the
2 2
desired properties for use.
comminution, n—the act or process of reduction in particle
size, usually but not necessarily by grinding or milling.
capillary action, n—the phenomenon of intrusion of a liquid
into interconnected small voids, pores, and channels in a
competing failure modes, n—distinguishably different types
solid, resulting from surface tension.
of fracture initiation events that result from concurrent
(competing) flaw distributions. (C1239)
casting, drain (hollow casting), v—forming ceramic ware by
introducing a body slip into an open, porous mold, and then
complete gage section, n—the portion of the specimen be-
draining off the remaining slip when the cast piece has
tween the two outer bearings in four-point flexure and
reached the desired thickness. (C242)
three-point flexure fixtures. (C1161, C1674)
DISCUSSION—The complete four-point flexure gage section is twice
cell pitch, (p), [L], n—the unit dimension/s for the cross-
the size of the inner gage section. Weibull statistical analysis only
section of a cell in the honeycomb component.The cell pitch
includes portions of the specimen volume or surface which experience
p is calculated by measuring the specimen dimension of
tensile stresses.
interest, the cell count in that dimension, and a cell wall
thickness, wherep=(d–t)/n. (C1674) compositional inhomogeneity, (CI), n—as used in
DISCUSSION—The cell pitch can be measured for both the height and fractography, a volume-distributed flaw that is a microstruc-
width of the cell; those two measurements will be equal for a square
tural irregularity related to the nonuniform distribution of an
cell geometry and uniform cell wall thickness and will be unequal for
additive, a different crystalline or glass phase or in a
a rectangular cell geometry.
multiphase material, the nonuniform distribution of a second
phase.
cell wall thickness, (t), [L], n—the nominal thickness of the
wallsthatformthecellchannelsofthehoneycombstructure.
compound flaw distributions, n—any form of multiple flaw
(C1674)
distribution that is neither pure concurrent nor pure exclu-
sive. A simple example is where every test specimen
censored strength data, n—strength measurements (that is, a
contains the flaw distribution A, while some fraction of the
sample) containing suspended observations such as that
produced by multiple competing or concurrent flaw test specimens also contains a second independent flaw
distribution B. (C1239)
populations. (C1239)
ceramic matrix composite, n—material consisting of two or concurrent flaw distributions, n—type of multiple flaw dis-
more materials (insoluble in one another), in which the tribution in a homogeneous material where every test speci-
major, continuous component (matrix component) is a men of that material contains representative flaws from each
ceramic, while the secondary component(s) (reinforcing independent flaw population. Within a given test specimen,
component) may be ceramic, glass-ceramic, glass, metal, or all flaw populations are then present concurrently and are
C1145 − 19
competing with each other to cause failure. This term is bath that will cause a 30 % drop in the average flexural
synonymous with “competing flaw distributions.” (C1239) strength. (C1525)
cross-feed, n—increment of displacement or feed in the
‘constant applied stress time-to-failure’ curve, n—a curve
cross-feed direction. (C1495)
fitted to the values of time to failure at each of several
applied stresses. (C1576)
cross-feed direction, n—direction in the plane of grinding
DISCUSSION—In the ceramics literature, this is often called a “static
which is perpendicular to the principle direction of grinding.
fatigue” curve.
(C1495)
‘constant applied stress time-to-failure’ diagram, n—a plot
deairing, n—the process of removing entrapped air or ab-
of constant applied stress against time to failure. Constant
sorbed air from a mass or slurry, usually by application of a
applied stress and time to failure are both plotted on
vacuum.
logarithmic scales. (C1576)
depth of penetration, n—(1) the distance a penetrant has
continuous fiber-reinforced ceramic matrix composite
entered into a solid material as measured from the surface of
(CFCC), n—ceramic matrix composite in which the rein-
the material; (2) the maximum depth at which a magnetic or
forcingphaseconsistsofacontinuousfiber,continuousyarn,
ultrasonic indication can be measured in a test specimen.
or a woven fabric. (C1275)
diamond paste,n—diamond dust dispersed in a paste or slurry
coolant, n—usually a liquid that is applied to the workpiece or
for use as a grinding or polishing compound.
wheel, or both, during grinding for cooling, removal of
diamond tool, n—any tool in which the working area is inset
grinding swarf, and for lubrication. (C1495)
with diamonds or diamond dust.
coolant flow rate, n—volume of coolant per unit time deliv-
diamond wheel, n—a bonded grinding wheel in which the
ered to the wheel and workpiece during grinding. (C1495)
abrasive grains are crushed and sized natural or synthetic
crack, (CK), n—as used in fractography, a volume-distributed
diamonds.
flaw that is a plane of fracture without complete separation.
discontinuous fiber-reinforced composite, n—a ceramic ma-
crack deflection, n—a toughening mechanism in advanced
trix composite material reinforced by chopped fibers.
ceramics or ceramic matrix composites characterized by
dish grinder, n—a grinding machine equipped with a dish-
fracture surface roughening and crack tilting/twisting during
shaped abrasive wheel as a grinding mechanism
propagation around grains or a reinforcing component
caused by stress fields around the grains or component
dish wheel, n—dish-shaped abrasive grinding wheel.
developed through mismatches in thermal expansion or
disk feeder, n—a rotating disk beneath the opening of a bin
mechanical properties (such as elastic modulus), or both,
which delivers material from the bin at a specified rate by
between grains or between reinforcement and matrix.
controlling the rate of rotation of the disk and the size of the
crack orientation, n—a description of the plane and direction
gate opening of the bin.
of a fracture in relation to a characteristic direction of the
disk grinder, n—a grinding machine equipped with a large
product.This identification is designated by a letter or letters
abrasive disk as the work mechanism.
indicating the plane and direction of crack extension. The
letter or letters represent the direction normal to the crack
disk wheel,n—a bonded abrasive wheel mounted on a plate so
plane and the direction of crack propagation. (C1421)
that grinding may be done on the side of the wheel.
creep, n—the time-dependent part of a strain resulting from
down-feed, n—increment of displacement or feed in the down
stress. feed direction. (C1495)
down-feed direction—direction perpendicular to the plane of
creep-feed grinding, n—a mode of grinding characterized by
a relatively large wheel depth-of-cut and correspondingly grinding for a machine configuration in which the grinding
wheel is located above the workpiece. (C1495)
low rate of feed. (C1495)
down-grinding, n—a condition of down-grinding is said to
critical scratch load (L ), n—applied normal force at which
CN
hold when the velocity vector tangent to the surface of the
a specific, well-defined, recognizable damage/failure event
wheel at points of first entry into the grinding zone has a
occurs or is observed in the scratch test of a specific coating
component normal to and directed into the ground surface of
on a specific substrate. (C1624)
the workpiece. (C1495)
DISCUSSION—The subscript N is used to identify progressive failure
events. For example, L is often used to identify the first level of
C1
drag, n—the resistance of the foot or base of a ceramic article
cohesive failure in the coating itself; L is often used to identify first
C2
to shrinkage during firing time due to friction with the slab
adhesive failure between the coating and the substrate. Multiple
or sagger on which it rests.
subscripts can be used for progressive levels of distinct damage in a
specific coating-substrate systems.
dressing, n—(1) the process of restoring the efficiency of an
critical temperature difference, ∆T , n—temperature differ- abrasive grinding wheel by removal of dulled grains; (2)
C
ence between the furnace and the ambient temperature water reshaping the faces of grinding wheels to special contours.
C1145 − 19
dressing, n—a conditioning process applied to the abrasive electrical contact, n—any physical contact between two or
surface of a grinding wheel to improve the efficiency of more parts which will permit the flow of electricity between
grinding. (C1495) the parts.
DISCUSSION—Dressingmayaccomplishoneormoreofthefollowing:
electric furnace,n—afurnaceorkilninwhichthemainsource
(1) removal of bond material from around the grit on the surface of the
of heat is provided by electrical means.
grinding wheel causing the grit to protrude a greater distance from the
surrounding bond, (2) removal of adhered workpiece material which
electrophoresis, n—the movement of colloidal particles or
interferes with the grinding process, removal of worn grit, (3) removal
macromolecules through a solution under the action of an
of bond material thereby exposing underlying unworn grit, and (4)
electromotive force applied through electrodes in contact
fracture of worn grit thereby generating sharp edges.
with the solution.
drum dryer, n—a heated, rotating drum in which tumbling or
emissivity,n—theratiooftheradiationgivenoffbythesurface
cascading raw materials are dried.
of a body to the radiation given off by a perfect black body
drying oven, n—a closed unit in which specimens are dried by
at the same temperature.
heating.
emulsification, n—the process of dispersing an immiscible
drying shrinkage, n—the contraction of a moist body during
liquid in another liquid.
thedryingprocess,expressedaslinearpercentoftheoriginal
endothermic reaction,n—achemicalreactioninwhichheatis
length or volume percent of the original volume.
absorbed.
drying, vacuum, n—the technique of expediting the removal
endurance, thermal, n—the ability of a ceramic product to
of moisture from a material or body by the use of a vacuum
withstand thermal shock or to withstand deterioration during
in conjunction with a conventional drying system.
exposure to high temperatures.
dry milling, n—the process of reducing the particle size of a
engineered porosity, n—porosity in a component that is
substance by milling without the use of a liquid medium.
deliberately produced and controlled for a specific function
dry screening, n—the process of separating small sizes of
and engineered performance. The porosity can be micropo-
granular or powdered solids from coarser particles by rous (micron and submicron pores in the body of the
passing them through a screen of desired mesh size while in ceramic) or macroporous (millimeter and larger) cells and
the dry state. channels in the ceramic. The porosity commonly has physi-
cal properties (volume fraction, size, shape, structure,
dual-drum mixer, n—a mixer consisting of a long drum
architecture, dimensions, etc.) that are produced by a con-
containing two compartments separated by a bulkhead with
trolled manufacturing process. The porosity in the compo-
a swinging chute extending through the unit.
nent has a direct effect on the engineering properties and
performanceandoftenhastobemeasuredforqualitycontrol
durability, n—the property of an article of being resistant to
and performance verification. (C1674)
physical or chemical damage, or both, under the usual
conditions of service, and of being useful over extended
equibiaxial flexural strength, [F/L ],n—maximum stress that
periods of time and use.
a material is capable of sustaining when subjected to flexure
between two concentric rings. This mode of flexure is a
dust pressing, n—the process of forming ceramic bodies of
cupping of the circular plate caused by loading at the inner
1.5 % or less water content by pressing in a mold.
load ring and outer support ring. The equibiaxial flexural
effective gage section, n—that portion of the test specimen
strength is calculated from the maximum-load of a biaxial
geometry that has been included within the limits of inte-
test carried to rupture, the original dimensions of the test
gration (volume, area, or edge length) of the Weibull
specimen, and Poisson’s ratio. (C1499)
distribution function. In tensile test specimens, the integra-
equibiaxial flexural strength, [F/L ], n—the maximum stress
tion may be restricted to the uniformly stressed central gage
that a material is capable of sustaining when subjected to
section,oritmaybeextendedtoincludetransitionandshank
flexure between two concentric rings. (C1368)
regions. (C1239)
erosion resistance, electrical, n—the resistance of electrical
elastic limit, n—the greatest stress that a material is capable of
insulating materials to erosion by the action of electrical
sustaining without permanent strain remaining upon com-
discharges.
plete release of the stress. (C1259)
–2 estimator, n—well-defined function that is dependent on the
elastic limit, [FL ], n—the greatest stress that a material is
observations in a sample. The resulting value for a given
capable of sustaining without permanent strain remaining
sample may be an estimate of a distribution parameter (a
upon complete release of the stress. (C1198)
point estimate) associated with the underlying population.
elastic modulus, n—the ratio of stress to strain below the
The arithmetic average of a sample is, for example, an
proportional limit. (C1259)
estimator of the distribution mean. (C1239)
–2
elastic modulus, [FL ], n—the ratio of stress to strain below exclusive flaw distributions, n—type of multiple flaw distri-
the proportional limit. (C1198) bution created by mixing and randomizing test specimens
C1145 − 19
from two or more versions of a material where each version fluid-energy mill, n—a size-reduction apparatus in which
contains a different single flaw population. Thus, each test grinding is achieved by the collision of the particles being
specimen contains flaws exclusively from a single ground in a high-velocity steam of air, steam, or other fluid.
distribution, but the total data set reflects more than one type
fluorescent penetrant, n—an inspection penetrant which fluo-
of strength-controlling flaw. This term is synonymous with
resces or glows in ultraviolet light.
“mixtures of flaw distributions.” (C1239)
fluxing agent, n—any substance which will promote fusion of
exothermic reaction, n—a chemical reaction in which heat is
ceramic materials.
evolved.
four-point- ⁄3-point flexure, n—a configuration of flexural
extraneous flaws, n—strength-controlling flaws observed in
strength testing where a test specimen is symmetrically
some fraction of test specimens that cannot be present in the
loaded at two locations that are situated one third of the
component being designed. An example is machining flaws
overall span away from the outer two support bearings.
in ground bend test specimens that will not be present in
(C1341)
as-sintered components of the same material. (C1239)
four-point- ⁄4-point flexure, n—configuration of flexural
extrude, v—to shape a plastic body by forcing the body
strength testing where a specimen is symmetrically loaded at
through a die.
two locations that are situated one quarter of the overall
extruder, n—a device, such as a pug mill, that forces plastic
span, away from the outer two support bearings. (C1161)
bodies through a die of appropriate shape and size in a
fractional open frontal area, (OFA), [ND], n—a fractional
continuous column.
ratio of the open frontal area of the honeycomb architecture,
feed, gravity, n—the movement of materials from one con-
calculated by dividing the total frontal area of the open
tainer to another container or location by force of gravity.
channels by the full frontal area of the full size specimen, as
a whole. (C1674)
filament, n—a long flexible thread of small cross section,
DISCUSSION—The fractional open frontal area of the full size speci-
usually extruded or drawn.
men can be calculated from the shape and dimensions of the cells and
the wall thickness between cells.
film, n—a thin coating or layer of a substance over the surface
of another material.
fractionation, elastic, n—a process in which soft aggregate is
separated from harder aggregate by hurling the composite
fineness, n—a measurement number designating the particle
aggregate against a steel plate, the hard particles rebounding
size of a material, usually reported as passing a screen of a
farther from the plate than the softer, more friable particles.
particular standard size.
fines, n—the portions of a powder composed of particles fractography, n—means and methods for characterizing a
smaller than a specified size. fractured specimen or component. (C1322)
finish grinding, n—the completion of a grinding operation to fractography, n—analysis and characterization of patterns
obtain a desired surface appearance or accurate dimensions. generated on the fracture surface of a test specimen. Frac-
tography can be used to determine the nature and location of
firing expansion, n—the increase in the dimensions of a
the critical fracture origin causing catastrophic failure in an
substance or product during thermal treatment.
advanced ceramic test specimen or component. (C1239)
fissures, n—surface defects consisting of narrow openings or
fracture origin, n—the source from which brittle fracture
cracks.
commences. (C1239, C1322)
fixed-feed grinding, n—the process of feeding a material to be
fracture, spontaneous, n—cracking or chipping which occurs
ground to a grinding wheel at a given rate or in specific
without immediately apparent external causes.
increments.
fracture strength (F/L ), n—tensile stress that the material
flaw, n—structural discontinuity in an advanced ceramic body
sustains at the instant of fracture. Fracture strength is
that acts as a highly localized stress raiser. (C1322)
calculated from the force at fracture during a tension test
DISCUSSION—The presence of such discontinuities does not necessar-
carried to rupture and the original cross-sectional area of the
ily imply that the ceramic has been prepared improperly or is faulty.
test specimen. (C1337)
–2
flexural strength, [FL ], n—a measure of the ultimate
DISCUSSION—In some cases, the fracture strength may be identical to
strength of a specified beam in bending. (C1161, C1211,
the tensile strength if the load at fracture is the maximum for the test.
C1684)
Factors such as load train compliance and fiber pull-out behavior may
influence the fracture strength.
–2
flexural strength, σ , [FL ], n—a measure of the strength of
f
a specified beam specimen in bending determined at a given fracture toughness, n—a generic term for measures of resis-
tance to crack extension.
stress rate in a particular environment. (C1368)
fluid carrier, n—a fluid in which particles are suspended to fully articulating fixture, n—a flexure fixture designed to be
facilitate their movement or application. used either with flat and parallel specimens or with uneven
C1145 − 19
or nonparallel specimens. The fixture allows full indepen- grinding damage, n—any change in a material that is a result
dent articulation, or pivoting, of all rollers about the speci- of the application of a surface grinding process. Among the
menlongaxistomatchthespecimensurface.Inaddition,the types of damage are microcracks, dislocations, twins, stack-
upper or lower pairs are free to pivot to distribute force ing faults, voids, and transformed phases. (C1495)
evenly to the bearing cylinders on either side. (C1161)
DISCUSSION—Although they do not represent internal changes in
DISCUSSION—A three-point fixture has the inner pair of bearing microstructure, chips and surface pits, which are a manifestation of
cylinders replaced by a single bearing cylinder. microfracture, and abnormally large grinding striations are often
referred to as grinding damage. Residual stresses that result from
fundamental adhesion, n—summation of all interfacial inter-
microstructural changes may also be referred to as grinding damage.
molecular interactions between a film or coating and its
grinding direction, n—when used in reference to flexure test
substrate. (C1624)
bars, refers to the angle between the long (tensile) axis of the
furnace, arc-image, n—a furnace in which high temperatures
flexure bar and the path followed by grit in the grinding
are produced by focusing radiation from high-temperature
wheel as they move across the ground surface. See longitu-
arcs into the furnace chamber.
dinal grinding direction and transverse grinding direction.
(C1495)
furnace, image, n—a furnace in which high temperatures are
generated by focusing radiation from a high-temperature
grit depth-of-cut, n—nominal maximum depth that individual
source, such as the sun or an electric arc.
grit on the grinding wheel penetrate the workpiece surface
during grinding. Synonymous with undeformed chip
furnace, recuperative, n—a furnace equipped with a heat
thickness. (C1495)
exchanger in which heat is conducted from the combustion
products through a system of ducts or through flue walls in
hackle, n—as used in fractography, a line or lines on the crack
a manner so as to preheat the air as it enters the burner to
surface running in the local direction of cracking, separating
unite with the fuel.
parallel but non-coplanar portions of the crack surface.
(C1322)
furnace, regenerative, n—a furnace having a cyclic heat
exchanger which alternately receives heat from gaseous
handling damage, (HD), n—as used in fractography,
combustion products and transfers heat to the air or gas of
scratches, chips, cracks, etc., due to the handling of the
the fuel mixture before combustion takes place.
specimen/component.
furnace, solar, n—an image-type furnace in which solar
homogeneous, adj—the condition of a material in which the
radiation is focused into a relatively small area as a source of
relevant properties (composition, structure, density, and so
heat producing extremely high temperatures.
forth) are not a function of position for sample size used, so
furnace, thermal gradient, n—a tubular furnace in which a
that a small sample taken from any location in an original
controlled temperature gradient is maintained along its
body is representative of the whole. Practically, the geo-
length.
metricaldimensionsofthesamplemustbelargewithrespect
to the size of the individual grains, crystals, components,
fuse, v—to melt or join by the use of heat.
pores or microcracks.
fusion casting, n—the process of forming items by casting
homogeneous,n—conditionofamaterialinwhichtherelevant
molten materials in mold.
properties (composition, structure, density, etc.) are uniform,
fusion point, n—the temperature or range of temperatures at so that any smaller sample taken from an original body is
which melting or softening, as a result of partial melting, of representative of the whole. Practically, as long as the
a composition, will occur. geometrical dimensions of a sample are large with respect to
thesizeoftheindividualgrains,crystals,components,pores,
fusion test, n—any test to determine the temperature or range
or microcracks, the sample can be considered homogeneous.
of temperatures at which fusion takes place, or to determine
(C1499)
the flow or other properties of a material at fusion tempera-
tures.
honeycomb cellular architecture, n—an engineered compo-
nent architecture in which long cylindrical cells of defined
gel, n—a semisolid system consisting of a network of solid
geometric cross-section form a porous structure with open
aggregates in which liquid is held.
channels in one dimension and a nominal closed-cell archi-
tecture in the remaining two dimensions. The cross sectional
grain boundary (GB), n—as used in fractography, a volume-
geometry of the honeycomb cells can have a variety of
distributedflawthatisaboundaryfacet
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: C1145 − 06 (Reapproved 2013) C1145 − 19
Standard Terminology of
Advanced Ceramics
This standard is issued under the fixed designation C1145; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—New definitions were added editorially in July 2018.
1. Scope
1.1 This terminology contains definitions and explanatory notes for the principal words, phrases, and terms used in advanced
ceramics technology. The given definitions are technology-specific technology specific and are directly applicable to the design,
production, testing, analysis, characterization, and use of advanced ceramics for structural, electronic, coating, energy, chemical,
nuclear, biomedical, and environmental applications.
1.2 The purpose of the standard terminology is to provide a collected technical resource and reference that promotes a common
understanding of the principal technical terms used within the advanced ceramics community and encourages the use of uniform
terminology in specifications and reports.
1.3 Definitions of terms appear in dictionary-definition form and include the term, part of speech (for example, n = noun; v =
verb; adj = adjective), definition, and, when applicable, a delimiting phrase. Terms representing physical quantities have analytical
dimensions stated immediately following the term (or letter symbol) in fundamental dimension form, using the following ASTM
standard symbology for fundamental dimensions, shown within square brackets: [M] for mass, [L] for length, [T] for time, [θ] for
thermodynamic temperature, and [nd] for non-dimensional quantities. Use of these symbols is restricted to analytical dimensions
when used with square brackets, as the terms may have other definitions when used without the brackets.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Terminology
absorbed moisture, n—water held within the materials and having physical properties not substantially different from ordinary
water at the same temperature and pressure.
adhesive failure, n—detachment and separation of a coating from the substrate with cracking and debonding at the
coating-substrate interface. (C1624)
adsorbate, n—material that has been retained by the process of adsorption. (C1274)
adsorbent, n—any solid having the ability to concentrate significant quantities of other substances on its surface. (C1274)
adsorption, n—process in which molecules are concentrated on a surface by chemical or physical forces, or both. (C1274)
adsorption isotherm, n—relation between the quantity of adsorbate and the equilibrium (relative) pressure of the adsorptive, at
constant temperature. (C1274)
DISCUSSION—
Typically, the amount adsorbed is presented on an isotherm as volume in cm STP (Standard Temperature and Pressure, that is, 273.15 K and 101325.02
Pa) normalized per mass of sample.
adsorptive, n—any substance available for adsorption. (C1274)
This terminology is under the jurisdiction of ASTM Committee C28 on Advanced Ceramics and is the direct responsibility of Subcommittee C28.91 on Nomenclature
and Editorial.
Current edition approved Feb. 1, 2013July 1, 2019. Published March 2013July 2019. Originally approved in 1989. Last previous edition approved in 20062013 as
C1145 – 06.C1145 – 06 (2013). DOI: 10.1520/C1145-06R13E01.10.1520/C1145-19.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1145 − 19
advanced ceramic, n—a highly engineered, high performance, predominately non-metallic, inorganic, ceramic material having
specific functional attributes. (C1198, C1259, C1292, C1322, C1368, C1525, C1576, C1674)
agglomerate, n—as used in fractography, a cluster of grains, particles, platelets, or whiskers, or a combination thereof, present
in a larger solid mass.
aggregate, n—a dense mass of particles held together by strong intermolecular or atomic cohesive forces. It is stable to normal
handling and ordinary mixing techniques including high-speed stirring and ultrasonics. (C242)
aliquot, n—a representative portion of a whole that divides the whole leaving a remainder. (C1274)
back-face strain, n—the strain as meaured with a strain gage mounted longitudinally on the compressive surface of the specimen,
opposite the crack or notch mouth (often this is the top surface of the specimen as tested). (C1421)
base exchange, n—a surface property exhibited by collodial inorganic materials, usually clays, whereby absorbed surface cations
are replaced by other cations.
baseline flexure strength, n—in the context of this standard, refers to the flexure strength value obtained after application of a
grinding procedure specified in this standard. (C1495)
DISCUSSION—
For the advanced ceramics to which this this standard is applicable, the baseline flexure strength is expected to be a close approximation to the inherent
flexure strength.
blanchard grinding, n—a type of rotary grinding in which the workpiece is held on a rotating table with an axis of rotation that
is parallel to the (vertical) spindle axis. (C1495)
body, n—the structural portion of a ceramic article, or the material or mixture from which it is made. (C242)
breaking force, [F], n—the force at which fracture occurs in a test specimen. (C1674)
DISCUSSION—
In this test method, fracture consists of breakage of the test bar into two or more pieces or a loss of at least 50 % of the maximum force carrying
capacity.
brittle fracture, n—fracture that takes place with little or no preceding plastic deformation. (C1322)
bundle, n—a collection of parallel fibers. Synonym, tow. (C1557)
calcine, v (calcination,n)—firing or heating a granular or particulate solid at less than fusion temperature, but sufficient to remove
most of its chemically combined volatile matter (that is, H O, CO ) and otherwise to develop the desired properties for use.
2 2
capillary action, n—the phenomenon of intrusion of a liquid into interconnected small voids, pores, and channels in a solid,
resulting from surface tension.
casting, drain (hollow casting), v—forming ceramic ware by introducing a body slip into an open, porous mold, and then draining
off the remaining slip when the cast piece has reached the desired thickness. (C242)
cell pitch, (p), [L], n—the unit dimension/s for the cross-section of a cell in the honeycomb component. The cell pitch p is
calculated by measuring the specimen dimension of interest, the cell count in that dimension, and a cell wall thickness, where
p = (d – t )/n. (C1674)
DISCUSSION—
The cell pitch can be measured for both the height and width of the cell; those two measurements will be equal for a square cell geometry and uniform
cell wall thickness and will be unequal for a rectangular cell geometry.
cell wall thickness, (t), [L], n—the nominal thickness of the walls that form the cell channels of the honeycomb structure. (C1674)
censored strength data, n—strength measurements (that is, a sample) containing suspended observations such as that produced
by multiple competing or concurrent flaw populations. (C1239)
C1145 − 19
ceramic matrix composite, n—material consisting of two or more materials (insoluble in one another), in which the major,
continuous component (matrix component) is a ceramic, while the secondary component(s) (reinforcing component) may be
ceramic, glass-ceramic, glass, metal, or organic in nature. These components are combined on a macroscale to form a useful
engineering material possessing certain properties or behavior not possessed by the individual constituents. (C1275)
cermet, n—a composite material or article comprised of a ceramic and a metal or metal alloy, interdistributed in any of various
geometrical forms but intimately bonded together.
channel porosity, n—porosity in the porous ceramic component that is defined by the large, open longitudinal honeycomb
channels. Channel porosity generally has cross-sectional dimensions on the order of 1 millimeter or greater. (C1674)
chatter, n—an undesirable pattern created on the surface of a work piece, usually at regularly spaced intervals, due to an
out-of-round, out-of-balance condition or due to an induced natural frequency, or its harmonics, or both, in a grinding machine.
cohesive failure, n—material damage and cracking in the coating or in the substrate, separate and distinct from detachment and
adhesive debonding at the coating-substrate interface. (C1624)
colloidal particle, n—a dispersed particle with a linear dimension of 5 to 100 nm.
comminution, n—the act or process of reduction in particle size, usually but not necessarily by grinding or milling.
competing failure modes, n—distinguishably different types of fracture initiation events that result from concurrent (competing)
flaw distributions. (C1239)
complete gage section, n—the portion of the specimen between the two outer bearings in four-point flexure and three-point flexure
fixtures. (C1161, C1674)
DISCUSSION—
The complete four-point flexure gage section is twice the size of the inner gage section. Weibull statistical analysis only includes portions of the
specimen volume or surface which experience tensile stresses.
compositional inhomogeneity, (CI), n—as used in fractography, a volume-distributed flaw that is a microstructural irregularity
related to the nonuniform distribution of an additive, a different crystalline or glass phase or in a multiphase material, the
nonuniform distribution of a second phase.
compound flaw distributions, n—any form of multiple flaw distribution that is neither pure concurrent nor pure exclusive. A
simple example is where every test specimen contains the flaw distribution A, while some fraction of the test specimens also
contains a second independent flaw distribution B. (C1239)
concurrent flaw distributions, n—type of multiple flaw distribution in a homogeneous material where every test specimen of that
material contains representative flaws from each independent flaw population. Within a given test specimen, all flaw populations
are then present concurrently and are competing with each other to cause failure. This term is synonymous with “competing flaw
distributions.” (C1239)
‘constant applied stress-time to failure’ stress time-to-failure’ curve, n—a curve fitted to the values of time to failure at each
of several applied stresses. (C1576)
DISCUSSION—
In the ceramics literature, this is often called a “static fatigue” curve.
‘constant applied stress time-to-failure’ diagram, n—a plot of constant applied stress against time to failure. Constant applied
stress and time to failure are both plotted on logarithmic scales. (C1576)
continuous fiber-reinforced ceramic matrix composite (CFCC), n—ceramic matrix composite in which the reinforcing phase
consists of a continuous fiber, continuous yarn, or a woven fabric. (C1275)
coolant, n—usually a liquid that is applied to the workpiece or wheel, or both, during grinding for cooling, removal of grinding
swarf, and for lubrication. (C1495)
coolant flow rate, n—volume of coolant per unit time delivered to the wheel and workpiece during grinding. (C1495)
crack, (CK), n—as used in fractography, a volume-distributed flaw that is a plane of fracture without complete separation.
crack deflection, n—a toughening mechanism in advanced ceramics or ceramic matrix composites characterized by fracture
surface roughening and crack tilting/twisting during propagation around grains or a reinforcing component caused by stress
C1145 − 19
fields around the grains or component developed through mismatches in thermal expansion or mechanical properties (such as
elastic modulus), or both, between grains or between reinforcement and matrix.
crack orientation, n—a description of the plane and direction of a fracture in relation to a characteristic direction of the product.
This identification is designated by a letter or letters indicating the plane and direction of crack extension. The letter or letters
represent the direction normal to the crack plane and the direction of crack propagation. (C1421)
creep, n—the time-dependent part of a strain resulting from stress.
creep-feed grinding, n—a mode of grinding characterized by a relatively large wheel depth-of-cut and correspondingly low rate
of feed. (C1495)
critical scratch load (L ), n—applied normal force at which a specific, well-defined, recognizable damage/failure event occurs
CN
or is observed in the scratch test of a specific coating on a specific substrate. (C1624)
DISCUSSION—
The subscript N is used to identify progressive failure events. For example, L is often used to identify the first level of cohesive failure in the coating
C1
itself; L is often used to identify first adhesive failure between the coating and the substrate. Multiple subscripts can be used for progressive levels
C2
of distinct damage in a specific coating-substrate systems.
critical temperature difference, ΔT , n—temperature difference between the furnace and the ambient temperature water bath that
C
will cause a 30 % drop in the average flexural strength. (C1525)
cross-feed, n—increment of displacement or feed in the cross-feed direction. (C1495)
cross-feed direction, n—direction in the plane of grinding which is perpendicular to the principle direction of grinding. (C1495)
deairing, n—the process of removing entrapped air or absorbed air from a mass or slurry, usually by application of a vacuum.
depth of penetration, n—(1) the distance a penetrant has entered into a solid material as measured from the surface of the material;
(2) the maximum depth at which a magnetic or ultrasonic indication can be measured in a test specimen.
diamond paste, n—diamond dust dispersed in a paste or slurry for use as a grinding or polishing compound.
diamond tool, n—any tool in which the working area is inset with diamonds or diamond dust.
diamond wheel, n—a bonded grinding wheel in which the abrasive grains are crushed and sized natural or synthetic diamonds.
discontinuous fiber-reinforced composite, n—a ceramic matrix composite material reinforced by chopped fibers.
dish grinder, n—a grinding machine equipped with a dish-shaped abrasive wheel as a grinding mechanism
dish wheel, n—dish-shaped abrasive grinding wheel.
disk feeder, n—a rotating disk beneath the opening of a bin which delivers material from the bin at a specified rate by controlling
the rate of rotation of the disk and the size of the gate opening of the bin.
disk grinder, n—a grinding machine equipped with a large abrasive disk as the work mechanism.
disk wheel, n—a bonded abrasive wheel mounted on a plate so that grinding may be done on the side of the wheel.
down-feed, n—increment of displacement or feed in the down feed direction. (C1495)
down-feed direction—direction perpendicular to the plane of grinding for a machine configuration in which the grinding wheel
is located above the workpiece. (C1495)
down-grinding, n—a condition of down-grinding is said to hold when the velocity vector tangent to the surface of the wheel at
points of first entry into the grinding zone has a component normal to and directed into the ground surface of the workpiece.
(C1495)
drag, n—the resistance of the foot or base of a ceramic article to shrinkage during firing time due to friction with the slab or sagger
on which it rests.
dressing, n—(1) the process of restoring the efficiency of an abrasive grinding wheel by removal of dulled grains; (2) reshaping
the faces of grinding wheels to special contours.
dressing, n—a conditioning process applied to the abrasive surface of a grinding wheel to improve the efficiency of grinding.
(C1495)
C1145 − 19
DISCUSSION—
Dressing may accomplish one or more of the following: (1) removal of bond material from around the grit on the surface of the grinding wheel causing
the grit to protrude a greater distance from the surrounding bond, (2) removal of adhered workpiece material which interferes with the grinding process,
removal of worn grit, (3) removal of bond material thereby exposing underlying unworn grit, and (4) fracture of worn grit thereby generating sharp
edges.
drum dryer, n—a heated, rotating drum in which tumbling or cascading raw materials are dried.
drying oven, n—a closed unit in which specimens are dried by heating.
dry milling, n—the process of reducing the particle size of a substance by milling without the use of a liquid medium.
dry screening, n—the process of separating small sizes of granular or powdered solids from coarser particles by passing them
through a screen of desired mesh size while in the dry state.
drying shrinkage, n—the contraction of a moist body during the drying process, expressed as linear percent of the original length
or volume percent of the original volume.
drying, vacuum, n—the technique of expediting the removal of moisture from a material or body by the use of a vacuum in
conjunction with a conventional drying system.
dry milling, n—the process of reducing the particle size of a substance by milling without the use of a liquid medium.
dry screening, n—the process of separating small sizes of granular or powdered solids from coarser particles by passing them
through a screen of desired mesh size while in the dry state.
dual-drum mixer, n—a mixer consisting of a long drum containing two compartments separated by a bulkhead with a swinging
chute extending through the unit.
durability, n—the property of an article of being resistant to physical or chemical damage, or both, under the usual conditions of
service, and of being useful over extended periods of time and use.
dust pressing, n—the process of forming ceramic bodies of 1.5 % or less water content by pressing in a mold.
effective gage section, n—that portion of the test specimen geometry that has been included within the limits of integration
(volume, area, or edge length) of the Weibull distribution function. In tensile test specimens, the integration may be restricted
to the uniformly stressed central gage section, or it may be extended to include transition and shank regions. (C1239)
elastic limit, n—the greatest stress that a material is capable of sustaining without permanent strain remaining upon complete
release of the stress. (C1259)
–2
elastic limit, [FL ], n—the greatest stress that a material is capable of sustaining without permanent strain remaining upon
complete release of the stress. (C1198)
elastic modulus, n—the ratio of stress to strain below the proportional limit. (C1259)
–2
elastic modulus, [FL ], n—the ratio of stress to strain below the proportional limit. (C1198)
electric furnace, n—a furnace or kiln in which the main source of heat is provided by electrical means.
electrical contact, n—any physical contact between two or more parts which will permit the flow of electricity between the parts.
electric furnace, n—a furnace or kiln in which the main source of heat is provided by electrical means.
electrophoresis, n—the movement of colloidal particles or macromolecules through a solution under the action of an electromotive
force applied through electrodes in contact with the solution.
emissivity, n—the ratio of the radiation given off by the surface of a body to the radiation given off by a perfect black body at the
same temperature.
emulsification, n—the process of dispersing an immiscible liquid in another liquid.
endothermic reaction, n—a chemical reaction in which heat is absorbed.
endurance, thermal, n—the ability of a ceramic product to withstand thermal shock or to withstand deterioration during exposure
to high temperatures.
engineered porosity, n—porosity in a component that is deliberately produced and controlled for a specific function and
engineered performance. The porosity can be microporous (micron and submicron pores in the body of the ceramic) or
macroporous (millimeter and larger) cells and channels in the ceramic. The porosity commonly has physical properties (volume
C1145 − 19
fraction, size, shape, structure, architecture, dimensions, etc.) that are produced by a controlled manufacturing process. The
porosity in the component has a direct effect on the engineering properties and performance and often has to be measured for
quality control and performance verification. (C1674)
equibiaxial flexural strength, [F/L ], n—maximum stress that a material is capable of sustaining when subjected to flexure
between two concentric rings. This mode of flexure is a cupping of the circular plate caused by loading at the inner load ring
and outer support ring. The equibiaxial flexural strength is calculated from the maximum-load of a biaxial test carried to rupture,
the original dimensions of the test specimen, and Poisson’s ratio. (C1499)
equibiaxial flexural strength, [F/L ], n—the maximum stress that a material is capable of sustaining when subjected to flexure
between two concentric rings. (C1368)
erosion resistance, electrical, n—the resistance of electrical insulating materials to erosion by the action of electrical discharges.
estimator, n—well-defined function that is dependent on the observations in a sample. The resulting value for a given sample may
be an estimate of a distribution parameter (a point estimate) associated with the underlying population. The arithmetic average
of a sample is, for example, an estimator of the distribution mean. (C1239)
exclusive flaw distributions, n—type of multiple flaw distribution created by mixing and randomizing test specimens from two
or more versions of a material where each version contains a different single flaw population. Thus, each test specimen contains
flaws exclusively from a single distribution, but the total data set reflects more than one type of strength-controlling flaw. This
term is synonymous with “mixtures of flaw distributions.” (C1239)
exothermic reaction, n—a chemical reaction in which heat is evolved.
extraneous flaws, n—strength-controlling flaws observed in some fraction of test specimens that cannot be present in the
component being designed. An example is machining flaws in ground bend test specimens that will not be present in as-sintered
components of the same material. (C1239)
extrude, v—to shape a plastic body by forcing the body through a die.
extruder, n—a device, such as a pug mill, that forces plastic bodies through a die of appropriate shape and size in a continuous
column.
feed, gravity, n—the movement of materials from one container to another container or location by force of gravity.
filament, n—a long flexible thread of small cross section, usually extruded or drawn.
film, n—a thin coating or layer of a substance over the surface of another material.
fineness, n—a measurement number designating the particle size of a material, usually reported as passing a screen of a particular
standard size.
fines, n—the portions of a powder composed of particles smaller than a specified size.
finish grinding, n—the completion of a grinding operation to obtain a desired surface appearance or accurate dimensions.
firing expansion, n—the increase in the dimensions of a substance or product during thermal treatment.
fissures, n—surface defects consisting of narrow openings or cracks.
fixed-feed grinding, n—the process of feeding a material to be ground to a grinding wheel at a given rate or in specific increments.
flaw, n—structural discontinuity in an advanced ceramic body that acts as a highly localized stress raiser. (C1322)
DISCUSSION—
The presence of such discontinuities does not necessarily imply that the ceramic has been prepared improperly or is faulty.
–2
flexural strength, [FL ], n—a measure of the ultimate strength of a specified beam in bending. (C1161, C1211, C1684)
–2
flexural strength, σ , [FL ], n—a measure of the strength of a specified beam specimen in bending determined at a given stress
f
rate in a particular environment. (C1368)
fluid carrier, n—a fluid in which particles are suspended to facilitate their movement or application.
fluid-energy mill, n—a size-reduction apparatus in which grinding is achieved by the collision of the particles being ground in a
high-velocity steam of air, steam, or other fluid.
fluorescent penetrant, n—an inspection penetrant which fluoresces or glows in ultraviolet light.
C1145 − 19
fluxing agent, n—any substance which will promote fusion of ceramic materials.
four-point- ⁄3-point flexure, n—a configuration of flexural strength testing where a test specimen is symmetrically loaded at two
locations that are situated one third of the overall span away from the outer two support bearings. (C1341)
four-point- ⁄4-point flexure, n—configuration of flexural strength testing where a specimen is symmetrically loaded at two
locations that are situated one quarter of the overall span, away from the outer two support bearings. (C1161)
fractional open frontal area, (OFA), [ND], n—a fractional ratio of the open frontal area of the honeycomb architecture, calculated
by dividing the total frontal area of the open channels by the full frontal area of the full size specimen, as a whole. (C1674)
DISCUSSION—
The fractional open frontal area of the full size specimen can be calculated from the shape and dimensions of the cells and the wall thickness between
cells.
fractionation, elastic, n—a process in which soft aggregate is separated from harder aggregate by hurling the composite aggregate
against a steel plate, the hard particles rebounding farther from the plate than the softer, more friable particles.
fractography, n—means and methods for characterizing a fractured specimen or component. (C1322)
fractography, n—analysis and characterization of patterns generated on the fracture surface of a test specimen. Fractography can
be used to determine the nature and location of the critical fracture origin causing catastrophic failure in an advanced ceramic
test specimen or component. (C1239)
fracture origin, n—the source from which brittle fracture commences. (C1239, C1322)
fracture, spontaneous, n—cracking or chipping which occurs without immediately apparent external causes.
fracture strength (F/L ), n—tensile stress that the material sustains at the instant of fracture. Fracture strength is calculated from
the force at fracture during a tension test carried to rupture and the original cross-sectional area of the test specimen. (C1337)
DISCUSSION—
In some cases, the fracture strength may be identical to the tensile strength if the load at fracture is the maximum for the test. Factors such as load
train compliance and fiber pull-out behavior may influence the fracture strength.
fracture toughness, n—a generic term for measures of resistance to crack extension.
fully articulating fixture, n—a flexure fixture designed to be used either with flat and parallel specimens or with uneven or
nonparallel specimens. The fixture allows full independent articulation, or pivoting, of all rollers about the specimen long axis
to match the specimen surface. In addition, the upper or lower pairs are free to pivot to distribute force evenly to the bearing
cylinders on either side. (C1161)
DISCUSSION—
A three-point fixture has the inner pair of bearing cylinders replaced by a single bearing cylinder.
fundamental adhesion, n—summation of all interfacial intermolecular interactions between a film or coating and its substrate.
(C1624)
furnace, arc-image, n—a furnace in which high temperatures are produced by focusing radiation from high-temperature arcs into
the furnace chamber.
furnace, image, n—a furnace in which high temperatures are generated by focusing radiation from a high-temperature source, such
as the sun or an electric arc.
furnace, recuperative, n—a furnace equipped with a heat exchanger in which heat is conducted from the combustion products
through a system of ducts or through flue walls in a manner so as to preheat the air as it enters the burner to unite with the fuel.
furnace, regenerative, n—a furnace having a cyclic heat exchanger which alternately receives heat from gaseous combustion
products and transfers heat to the air or gas of the fuel mixture before combustion takes place.
furnace, solar, n—an image-type furnace in which solar radiation is focused into a relatively small area as a source of heat
producing extremely high temperatures.
furnace, thermal gradient, n—a tubular furnace in which a controlled temperature gradient is maintained along its length.
C1145 − 19
fuse, v—to melt or join by the use of heat.
fusion casting, n—the process of forming items by casting molten materials in mold.
fusion point, n—the temperature or range of temperatures at which melting or softening, as a result of partial melting, of a
composition, will occur.
fusion test, n—any test to determine the temperature or range of temperatures at which fusion takes place, or to determine the flow
or other properties of a material at fusion temperatures.
gel, n—a semisolid system consisting of a network of solid aggregates in which liquid is held.
grain boundary (GB), n—as used in fractography, a volume-distributed flaw that is a boundary facet between two or more grains.
(C1322)
DISCUSSION—
This flaw is most apt to be strength limiting in course-grained ceramics.
grinding axis, n—any reference line along which the workpiece is translated or about which it is rotated to effect the removal of
material during grinding. (C1495)
grinding damage, n—any change in a material that is a result of the application of a surface grinding process. Among the types
of damage are microcracks, dislocations, twins, stacking faults, voids, and transformed phases. (C1495)
DISCUSSION—
Although they do not represent internal changes in microstructure, chips and surface pits, which are a manifestation of microfracture, and abnormally
large grinding striations are often referred to as grinding damage. Residual stresses that result from microstructural changes may also be referred to
as grinding damage.
grinding direction, n—when used in reference to flexure test bars, refers to the angle between the long (tensile) axis of the flexure
bar and the path followed by grit in the grinding wheel as they move across the ground surface. See longitudinal grinding
direction and transverse grinding direction. (C1495)
grit depth-of-cut, n—nominal maximum depth that individual grit on the grinding wheel penetrate the workpiece surface during
grinding. Synonymous with undeformed chip thickness. (C1495)
hackle, n—as used in fractography, a line or lines on the crack surface running in the local direction of cracking, separating parallel
but non-coplanar portions of the crack surface. (C1322)
handling damage, (HD), n—as used in fractography, scratches, chips, cracks, etc., due to the handling of the specimen/
component.
homogeneous, adj—the condition of a material in which the relevant properties (composition, structure, density, and so forth) are
not a function of position for sample size used, so that a small sample taken from any location in an original body is
representative of the whole. Practically, the geometrical dimensions of the sample must be large with respect to the size of the
individual grains, crystals, components, pores or microcracks.
homogeneous, n—condition of a material in which the relevant properties (composition, structure, density, etc.) are uniform, so
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