Standard Guide for Testing the Thermal Properties of Advanced Ceramics

SCOPE
1.1 This guide covers the thermal property testing of advanced ceramics, to include monolithic ceramics, particulate/whisker-reinforced ceramics, and continuous fiber-reinforced ceramic composites. It is intended to provide guidance and information to users on the special considerations involved in determining the thermal properties of these ceramic materials.
1.2 This guide is based on the use of current ASTM standards for thermal properties where appropriate and on the development of new test standards where necessary.
1.3 It is not the intent of this guide to rigidly specify particular thermal test methods for advanced ceramics. Guidance is provided on how to utilize the most commonly available ASTM thermal test methods, considering their capabilities and limitations.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C 1470 – 00
Standard Guide for
Testing the Thermal Properties of Advanced Ceramics
This standard is issued under the fixed designation C 1470; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope C 201 Test Method for Thermal Conductivity of Refracto-
ries
1.1 This guide covers the thermal property testing of ad-
C 202 Test Method for Thermal Conductivity of Refractory
vanced ceramics, to include monolithic ceramics, particulate/
Brick
whisker-reinforced ceramics, and continuous fiber-reinforced
C 408 Test Method for Thermal Conductivity of Whiteware
ceramic composites. It is intended to provide guidance and
Ceramics
information to users on the special considerations involved in
C 518 Test Method for Steady-State Heat Flux Measure-
determining the thermal properties of these ceramic materials.
ments and Thermal Transmission Properties by Means of
1.2 This guide is based on the use of current ASTM
the Heat Flow Meter Apparatus
standards for thermal properties where appropriate and on the
C 767 Test Method for Thermal Conductivity of Carbon
development of new test standards where necessary.
Refractories
1.3 It is not the intent of this guide to rigidly specify
C 1044 PracticeforUsingtheGuarded-Hot-PlateApparatus
particular thermal test methods for advanced ceramics. Guid-
or Thin-Heater Apparatus in the Single-Side Mode
ance is provided on how to utilize the most commonly
C 1045 Practice for Calculating Thermal Transmission
available ASTM thermal test methods, considering their capa-
Properties from Steady-State Heat Flux Measurements
bilities and limitations.
C 1113 Test Method for Thermal Conductivity of Refracto-
1.4 This standard does not purport to address all of the
ries by HotWire (Platinum ResistanceThermometerTech-
safety concerns, if any, associated with its use. It is the
nique)
responsibility of the user of this standard to establish appro-
C 1114 TestMethodforSteady-StateThermalTransmission
priate safety and health practices and determine the applica-
Properties by Means of the Thin-Heater Apparatus
bility of regulatory limitations prior to use.
C 1132 Practice for Calibration Practice for Heat Flow
2. Referenced Documents Meter Apparatus
E 1225 Test Method for Thermal Conductivity of Solids by
2.1 ASTM Standards:
Means of the Guarded-Comparative-Longitudinal Heat
2.1.1 Specific Heat:
Flow Technique
C 351-92b Test Method for Mean Specific Heat of Thermal
E 1530 Test Method for Evaluating the Resistance to Ther-
Insulation
mal Transmission of Thin Specimens of Materials by the
D 2766-95 Test Method for Specific Heat of Liquids and
Guarded Heat Flow Meter Technique
Solids
2.1.3 Thermal Expansion:
E 1269-95 Test Method for Determining Specific Heat Ca-
C 372 Test Method for Linear Thermal Expansion of Por-
pacity by Differential Scanning Calorimetry
celain Enamel and Glaze Frits and Fired CeramicWhitew-
2.1.2 Thermal Conductivity:
are Products by the Dilatometer Method
C 177 Test Method for Steady-State Heat Flux Measure-
C 1300 Test Method for Linear Thermal Expansion of
ments and Thermal Transmission Properties by Means of
Glaze Frits and Ceramic Whiteware Materials by the
the Guarded-Hot-Plate Apparatus
Interferometric Method
C 182 Test Method for Thermal Conductivity of Insulating
E 228 Test Method for Linear Thermal Expansion of Solid
Firebrick
Materials With a Vitreous Silica Dilatometer
E 289 Test Method for Linear Thermal Expansion of Rigid
Solids with Interferometry
This guide is under the jurisdiction of ASTM Committee C28 on Advanced
E 831 Test Method for Linear Thermal Expansion of Solid
Ceramics and is the direct responsibility of Subcommittee C28.03 on Physical
Materials by Thermomechanical Analysis
Properties and Performance.
Current edition approved May 10, 2000. Published October 2000.
2.1.4 Thermal Diffusivity:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
C 714 Test Method for Thermal Diffusivity of Carbon and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Graphite by a Thermal Pulse Method
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1470–00
E 1461 Test Method for Thermal Diffusivity of Solids by L , where DL is the observed change in length DL=L – L ,
0 2 1
the Flash Method and L , L , and L are the lengths of the specimen at reference
0 1 2
2.1.5 Emittance/Emissivity: temperature T and test temperatures T and T . (E 228)
0 1 2
E 408 TestMethodsforTotalNormalEmittanceofSurfaces 3.1.9 mean coeffıcient of linear thermal expansion, a [T ],
L
Using Inspection Meter Techniques
n—the change in length, relative to the length of the specimen,
E 423 Test Method for Normal Spectral Emittance at El- accompanying a unit change of temperature measured across a
evated Temperatures of Nonconducting Specimens
specified temperature range (T to T ). (C 372)
1 2
2.1.6 General Standards:
3.1.10 particulate reinforced ceramic matrix composite,
C 373 Test Method for Water Absorption, Bulk Density,
n—a ceramic matrix composite reinforced by ceramic particu-
Apparent Porosity, andApparent Specific Gravity of Fired
lates. (C 1145)
–1 –2 –1
Whiteware Products
3.1.11 specific heat (specific heat capacity), C[mL T u ],
C 1145 Terminology of Advanced Ceramics
n—the quantity of heat required to provide a unit temperature
E 122 Practice for Choice of Sample Size to Estimate a
increase to a unit mass of material. (E 1142)
–1 –1
Measure of Quality for a Lot or Process
3.1.12 thermal conductivity, l [mLT u ], n—the time rate
E 473 Terminology Relating to Thermal Analysis
of heat flow, under steady conditions, through unit area, per
E 1142 Terminology Relating toThermophysical Properties
unit temperature gradient in the direction perpendicular to the
C 1045 Practice for Calculating Thermal Transmission
area. (E 1142)
2 –1
Properties from Steady-State Heat Flux Measurements
3.1.13 thermal diffusivity, [L T ], n—the property given by
the thermal conductivity divided by the product of the bulk
3. Terminology
density and heat capacity per unit mass. (E 1461)
3.1 Definitions:
3.1.14 thermodilatometry, n—a technique in which a di-
3.1.1 advanced ceramic, n—a highly engineered, high-
mension of a substance under negligible load is measured as a
performance, predominantly nonmetallic, inorganic, ceramic
function of temperature while the substance is subjected to a
material having specific functional attributes. (C 1145)
controlled temperature program in a specified atmosphere.
3.1.2 ceramic matrix composite, n—a material consisting of
(E 473)
two or more materials (insoluble in one another), in which the
3.2 Units for Thermal Properties:
major continuous component (matrix component) is a ceramic,
Property SI Units Abbreviation
whilethesecondarycomponent/s(reinforcingcomponent)may
Specific heat capacity joules/(gram-kelvin) J/(g·K)
be ceramic, glass-ceramic, glass, metal, or organic in nature.
Thermal Conductivity watts/(metre-kelvin) W/(m·K)
2 2
Thermal diffusivity metre/second m/s
These components are combined on a macroscale to form a
–1
Thermal expansion metre/(metre-kelvin) K
useful engineering material possessing certain properties or
Emittance/emissivity no dimensions —
behavior not possessed by the individual constituents.
(C 1145)
4. Summary of Guide
3.1.3 coeffıcient of linear thermal expansion, a[T ], n—the
4.1 Five thermal properties (specific heat capacity, thermal
change in length, relative to the length of the specimen,
conductivity, thermal diffusivity, thermal expansion, and
accompanying a unit change of temperature, at a specified
emittance/emissivity)arepresentedintermsoftheirdefinitions
temperature. [This property can also be considered the instan-
and general test methods. The relationship between thermal
taneous expansion coefficient or the slope of the tangent to the
properties and the composition, microstructure, and processing
DL/L versus T curve at a given temperature.] (E 1142)
of advanced ceramics is briefly outlined, providing guidance
3.1.4 continuous fiber-reinforced ceramic composite
on which material characteristics have to be considered in
(CFCC), n—aceramicmatrixcompositeinwhichthereinforc-
evaluating the thermal properties.Additional sections describe
ing phase(s) consists of continuous filaments, fibers, yarns, or
samplingconsiderations,testspecimenpreparation,andreport-
knitted or woven fabric. (C 1145)
ing requirements.
3.1.5 differential scanning calorimetry (DSC), n—a tech-
4.2 Current ASTM test methods for thermal properties are
nique in which the difference in energy inputs into a specimen
tabulated in terms of test method concept, testing range,
and a reference material is measured as a function of tempera-
specimen requirements, standards/reference materials, capa-
turewhilethesubstanceandreferencematerialaresubjectedto
bilities, limitations, precision, and special instructions for
a controlled temperature program. (E 1269)
monoliths and composites.
3.1.6 discontinuous fiber-reinforced ceramic composite,
n—a ceramic matrix composite reinforced by chopped fibers.
5. Significance and Use
(C 1145)
3.1.7 emittance (emissivity), e (nd), n—the ratio of the 5.1 The high-temperature capabilities of advanced ceramics
radiant flux emitted by a specimen per unit area to the radiant areakeyperformancebenefitformanydemandingengineering
flux emitted by a black body radiator at the same temperature applications. In many of those applications, advanced ceramics
and under the same conditions. Emittance ranges from 0 to 1, will have to perform across a broad temperature range. The
with a blackbody having an emittance of 1.00. (E 423) thermal expansion, thermal diffusivity/conductivity, specific
3.1.8 linear thermal expansion, [nd], n—the change in heat, and emittance/emissivity are crucial engineering factors
length per unit length resulting from a temperature change. in integrating ceramic components into aerospace, automotive,
Linear thermal expansion is symbolically represented by DL/ and industrial systems
C1470–00
5.2 This guide is intended to serve as a reference and equilibrium. The increase in temperature of the calorimeter
information source for testing the thermal properties of ad- liquid/container is a measure of the amount of heat in the test
vanced ceramics, based on an understanding of the relation- specimen.
ships between the composition and microstructure of these
7.1.5 In any calorimetry test, the experimenter must recog-
materials and their thermal properties.
nize that phase changes and other thermo-physical transforma-
5.3 The use of this guide assists the testing community in
tions in the material will produce exothermic and endothermic
correctlyapplyingtheASTMthermaltestmethodstoadvanced
events which will be captured in the test data. The thermal
ceramics to ensure that the thermal test results are properly
events must be properly identified and understood within the
measured, interpreted, and understood. This guide also assists
context of the material properties, chemistry, and phase com-
the user in selecting the appropriate thermal test method to
position across the temperature range of interest.
evaluate the particular thermal properties of the advanced
7.2 Thermal Conductivity:
ceramic of interest.
7.2.1 Thermal conductivity is a measurement of the rate of
5.4 The thermal properties of advanced ceramics are critical
heat flow through a material for a given temperature gradient.
data in the development of ceramic components for aerospace,
It is normalized for thickness and cross-sectional area to give
automotive, and industrial applications. In addition, the effect
amaterialspecificvalue.Thethermalconductivityofaceramic
of environmental exposure on thermal properties of the ad-
is used in determining the effectiveness of a ceramic either as
vanced ceramics must also be assessed.
a thermal insulator or as a thermal conductor. The SI units for
thermal conductivity are watts/(metre·K). As with other ther-
6. Procedure
malproperties,thermalconductivitychangeswithtemperature,
6.1 Review Sections 7-10 to become familiar with thermal
so that a thermal conductivity value for a material must be
property concepts and thermal testing issues for advanced
associated with a specific test temperature.
ceramics, specimen preparation guidance, and reporting rec-
7.2.2 In electrically nonconductive ceramics, thermal con-
ommendations.
ductivity occurs by lattice vibration (phonon) conductivity and
6.2 Review the test method text and tables in Section 11 for
by radiation (photon) at higher temperatures (>500°C). Ther-
the property you need to determine. Use the text and tables to
mal conductivity decreases when the mean free path of the
help select the most appropriate ASTM test method for
phonons and photons decreases. Lattice imperfections, differ-
evaluating the thermal property of interest for the specific
ences in atomic weight between anions and cations, non-
advanced ceramic.
stoichiometric compositions, solid solutions, amorphous
6.3 Performthethermalpropertytestinaccordancewiththe
atomic structures, porosity, and grain boundaries all act as
selected ASTM test method, but refer back to the guide for
scattering sites for phonons and reduce the thermal conductiv-
directions and recommendations on material characterization,
ity of the material.
sampling procedures, test specimen preparation, and reporting
7.2.3 Thermal conductivity is commonly measured by
results.
steady-state methods, that is, heat flow techniques, heat flux
7. Thermal Properties and Their Measurement
meter techniques, guarded hot-plate techniques, and calorim-
7.1 Specific Heat Capacity: etery techniques. It can also be determined by transient
techniques (hot wire and flash diffusivity).
7.1.1 Specificheatcapacityistheamountofenergyrequired
to increase the temperature by one unit for a unit mass of
7.2.4 Incomparativeheatflowtechniques,thetestspecimen
material.Itisafundamentalthermalpropertyforengineersand
is subjected to a known heat flow and the temperature
scientists in determining the temperature response of materials
differential is measured across the dimension of interest. The
to changes in heat flux and thermal conditions.The SI units for
test system and the specimen are configured with insulation
specific heat capacity are joules/(gram·K). Since the specific
and heaters to min
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