EN 843-6:2009

Advanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature - Part 6: Guidance for fractographic investigation

This Part of EN 843 contains guidelines to be adopted when evaluating the appearance of the fracture surface of an advanced technical ceramic. The purpose in undertaking this procedure can be various, for example, for material development or quality assessment, to identify normal or abnormal causes of failure, or as a design aid.
NOTE   Not all advanced technical ceramics are amenable to fractography. In particular, coarse-grained ceramics can show such rough surfaces that identifying the fracture origin may be impossible. Similarly, porous materials, especially those of a granular nature, tend not to fracture in a continuous manner, making analysis difficult.

Hochleistungskeramik - Mechanische Eigenschaften monolithischer Keramik bei Raumtemperatur - Teil 6: Leitlinie für die fraktographische Untersuchung

Dieser Teil von EN 843 enthält Leitlinien zur Bewertung des Bruchflächenaussehens keramischer Hochleistungswerkstoffe.
Eine Bruchflächenuntersuchung kann zu verschiedenen Zwecken durchgeführt werden,
z. B. zur Werkstoffentwicklung oder zur Qualitätsbeurteilung, zum Erkennen üblicher oder anomaler Ursachen
von Schadensfällen oder zur Hilfe bei der Konstruktion.
ANMERKUNG Nicht alle keramischen Hochleistungswerkstoffe sind für eine fraktographische Auswertung geeignet.
Besonders bei grobkörnigen keramischen Werkstoffen können die Oberflächen so rau sein, dass der Bruchursprung
möglicherweise nicht erkennbar ist. In ähnlicher Weise können auch poröse Werkstoffe eine fraktographische Auswertung
erschweren, besonders dann, wenn sie eine körnige Struktur haben und dazu neigen, nicht kontinuierlich zu brechen.

Céramiques techniques avancées - Propriétés mécaniques des céramiques monolithiques à température ambiante - Partie 6: Guide pour l'analyse fractographique

La présente partie de l'EN 843 contient des directives à adopter lors de l‘évaluation de l'aspect de la surface de rupture d'une céramique technique avancée. Ce mode opératoire peut avoir divers objets, par exemple, l'élaboration ou l'évaluation de la qualité d'un matériau, l'identification de causes anormales de défaillance ou une assistance à la conception. NOTE Les céramiques techniques avancées ne font pas toutes l’objet d’une fractographie. Les céramiques à grains grossiers en particulier peuvent présenter des surfaces d'une rugosité telle que l'identification de l'origine d'une rupture peut s'avérer impossible. De même, les matières poreuses, en particulier de nature granulaire, ont tendance à ne pas se rompre de façon continue, ce qui rend l'analyse difficile.

Sodobna tehnična keramika - Mehanske lastnosti monolitske keramike pri sobni temperaturi - 6. del: Vodilo za fraktografsko raziskavo

General Information

• Status: Published
• Publication Date: 11-Aug-2009
• Withdrawal Date: 27-Feb-2010
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: CEN/TC 184 - Advanced technical ceramics
• Drafting Committee: CEN/TC 184/WG 3 - Monolithic ceramics
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 05-Sep-2025
• Completion Date: 23-Sep-2025
• Ref Project: SIST EN 843-6:2009 - Advanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature - Part 6: Guidance for fractographic investigation

Relations

• Replaces: CEN/TS 843-6:2004 - Advanced technical ceramics - Monolithic ceramics. Mechanical properties at room temperature - Part 6: Guidance for fractographic investigation
• Effective Date: 22-Dec-2008

Overview

EN 843-6:2009 - “Advanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature - Part 6: Guidance for fractographic investigation” (CEN) provides practical, consensus guidance for examining and interpreting fracture surfaces of advanced technical (monolithic) ceramics. The standard describes when fractography is useful, limitations (e.g., coarse‑grained or highly porous ceramics may be unsuitable), and an evidence‑based procedure to locate and classify fracture origins and causes.

Key topics and requirements

• Scope and applicability: Guidance for fractographic investigation of advanced technical ceramics to support material development, quality assessment, failure analysis and design.
• Terminology: Definitions for cracks, flaws, fracture origin, agglomerates, inclusions, pores, delaminations, hackle, mirror and mist regions, etc.
• Apparatus and magnification:
  • Hand lens (3–8×), optical microscope (approx. 5–50×) with photomicrography, directed illumination.
  • Scanning electron microscope (SEM), preferably with energy‑dispersive X‑ray (EDX) analysis for chemical identification.
  • Preparation tools: diamond saw for cross‑sections, ultrasonic bath, dry oil‑free compressed air.
• Recommended procedure (typical steps):
  • Collection, storage and contamination control of fragments (avoid direct handling; use clean, dry containers).
  • Cleaning (solvents such as acetone or ethanol with ultrasonic bath) and careful drying.
  • Visual inspection and optical microscopy to locate likely fracture origin and classify surface features.
  • SEM inspection for detailed morphology and EDX to detect compositional inhomogeneities at origins.
  • Use of fracture‑mechanical information (e.g., origin size vs fracture stress) to support conclusions.
  • Reporting: structured documentation of findings and conclusions.
• Limitations: Explicit note that fractography may be impossible for coarse‑grained, granular or very porous ceramics.

Applications and users

EN 843-6:2009 is intended for:

• Materials scientists and ceramic engineers conducting fracture analysis and microstructural development.
• Quality assurance and failure‑investigation teams in industries using advanced ceramics (aerospace, medical devices, electronics, wear components).
• Testing laboratories and consultants performing ceramic mechanical testing and forensic fractography. Practical uses include identification of manufacturing defects (pores, agglomerates, inclusions), machining or handling damage, oxidation pitting, and support for design improvements.

Related standards

• EN 843 series (Parts 1–5): methods for flexural strength, elastic properties, subcritical crack growth, hardness, and statistical analysis.
• EN ISO/IEC 17025: competence of testing and calibration laboratories - cited as a normative reference for laboratory practice.

Keywords: EN 843-6:2009, fractography, advanced technical ceramics, fracture surface analysis, fractographic investigation, SEM EDX, fracture origin identification, ceramic failure analysis.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Hochleistungskeramik - Mechanische Eigenschaften monolithischer Keramik bei Raumtemperatur - Teil 6: Leitlinie für die fraktographische UntersuchungCéramiques techniques avancées - Propriétés mécaniques des céramiques monolithiques à température ambiante - Partie 6: Guide pour l'analyse fractographiqueAdvanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature - Part 6: Guidance for fractographic investigation81.060.30Sodobna keramikaAdvanced ceramicsICS:Ta slovenski standard je istoveten z:EN 843-6:2009SIST EN 843-6:2009en,de01-oktober-2009SIST EN 843-6:2009SLOVENSKI
STANDARDSIST-TS CEN/TS 843-6:20041DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 843-6August 2009ICS 81.060.30Supersedes CEN/TS 843-6:2004
English VersionAdvanced technical ceramics - Mechanical properties ofmonolithic ceramics at room temperature - Part 6: Guidance forfractographic investigationCéramiques techniques avancées - Propriétés mécaniquesdes céramiques monolithiques à température ambiante -Partie 6: Guide pour l'analyse fractographiqueHochleistungskeramik - Mechanische Eigenschaftenmonolithischer Keramik bei Raumtemperatur - Teil 6:Leitlinie für die fraktographische UntersuchungThis European Standard was approved by CEN on 16 July 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre:
Avenue Marnix 17,
B-1000 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 843-6:2009: ESIST EN 843-6:2009

Crack patterns in ceramic bodies . 14 Annex B (informative)
Examples of general features of fracture surfaces . 17 Annex C (informative)
Examples of procedure for fracture origin identification. 19 C.1 Single large pores . 20 C.2 Agglomerates . 22 C.3 Large grains . 24 C.4 Compositional inhomogeneities . 26 C.5 Delaminations . 28 C.6 Handling damage . 30 C.7 Machining damage . 31 C.8 Oxidation pitting . 33 C.9 Complex origins . 35 C.10 No obvious origins . 36 Annex D (informative)
Use of fracture mechanical information to aid fractography. 37 D.1 Fracture stress and origin size . 37 D.2 Fracture stress and fracture mirror size . 40 Annex E (informative) Example layout of reporting pro-forma . 42 Bibliography . 44
 Part 4: Vickers, Knoop and Rockwell superficial hardness  Part 5: Statistical analysis  Part 6: Guidance for fractographic investigation
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
distinct microstructural discontinuity arising during or after manufacture caused by the action of thermal and/or mechanical stress and leading to the generation of new surfaces which do not completely separate 3.1.2 flaw inhomogeneity which, through stress concentration, can act as a strength defining feature NOTE The term flaw used in this sense does not imply that the component is defective. 3.1.3 fracture process of propagation of a crack through a test-piece or component 3.1.4 fracture origin source from which failure commences 3.2 Terms classifying inherently volume-distributed fracture origins 3.2.1 agglomerate unintentional microstructural inhomogeneity usually of altered density, for example a cluster of grains of abnormal size, particles, platelets or whiskers, resulting from non-uniformity in processing SIST EN 843-6:2009

local variations in chemical composition, usually manifest as agglomerates (3.2.1), or as areas denuded of or enriched in dispersed phases, or as changes in grain size 3.2.3 delamination
generally planar crack within a material arising from the method of manufacture 3.2.4 inclusion discrete inhomogeneity, usually as a result of inorganic contamination by a foreign body not removed during firing 3.2.5 large grain grain which is of abnormally large size as a result of poor particle size control or accelerated grain growth, and which can act as a flaw (3.1.2) 3.2.6 pore cavity or void within a material, which may be isolated or continuously interconnected with others 3.2.7 porous region zone of enhanced porosity, usually three-dimensional in nature and resulting from inhomogeneity or organic contamination in processing 3.2.8 porous seam zone of enhanced porosity, usually linear or planar in nature and resulting from inhomogeneity or organic contamination in processing 3.3 Terms classifying inherently surface-distributed fracture origins 3.3.1 chip small flake of material removed from a surface or an edge of an item or its fracture surface 3.3.2 handling damage scratches, chips or other damage resulting from contact between items, test-pieces or fracture surfaces, not present normally 3.3.3 machining damage result of removal of small chips (see 3.3.1) or the formation of scratches at, or cracks near, the surface resulting from abrasive removal of material 3.3.4 open pore void connected to the external surface, usually by virtue of machining 3.3.5 pit surface depression or surface connected shallow pore, usually resulting from manufacturing conditions or interaction with the external environment SIST EN 843-6:2009

The accumulation of additional information about the conditions of fracture (stresses, forces, temperature, time under stress, likelihood of impact, etc.) is highly desirable for achieving justifiable conclusions. 5 Apparatus 5.1 Preparation and cleaning facilities 5.1.1 Cutting wheel, for large specimens. A diamond-bladed saw.
NOTE This is needed to cut small samples for microscope observation, particularly in the scanning electron microscope SIST EN 843-6:2009

NOTE As an alternative to photomicrographic facilities, a camera with appropriate lenses and a macrophotography stand. 5.2.3 Illumination system, a light source that can be positioned to the side of the test-piece to provide contrast on the fracture surface. 5.2.4 Scanning electron microscope (SEM), preferably with energy-dispersive X-ray (EDX) analysis equipment fitted. SIST EN 843-6:2009

Location of originCollection and cleanfragmentsHistory of fractureObjectionActon:Deduction:Result:Visual inspectionPrimary fracturefaceBinocular macroscopeinspectionIdentify features and locate originTentativeclassification oforiginMore ?Mechanicalnature of originSEM inspection.Origin size,
fracturemechanicsMechanicalcircumstancesof fractureMore ?Chemicalnature of originReportOverallconclusionsChemical causes of failure EDX analysis.Origin chemicalinhomogeneityNoNoYesYes
Figure 1 — Flow chart for general fractographic procedure SIST EN 843-6:2009

NOTE Storage in paper or plastic containers can lead to pick-up of contamination. Glass vials minimise risks, but can damage surfaces if the specimen is loose in the vial. It is recommended to avoid the use of tape or mouldable compounds as the adhesive is difficult to remove once contaminating the fracture surface. Avoid handling with naked hands; use tweezers or surgical gloves to avoid contamination from body oils.
Cleaning facilities are required to allow removal of such contamination without damaging further the fracture surface. It is recommended that solvents such as acetone or ethyl alcohol are used in conjunction with a laboratory ultrasonic bath to remove soluble or loose contamination. Dry the specimens using compressed air. 6.3 Visual inspection 6.3.1 Examine visually all the available fragments using a good light source and a hand lens as appropriate.
6.3.2 Label all fragments with an indelible marker at positions that are remote from the surfaces of interest. Make a sketch of the labelled fragments for future reference.
6.3.3 Where there are several fragments, use the pattern of cracks to identify the originating fracture surface (the primary fracture):
NOTE 1 Annex A contains some examples of crack patterns in test-pieces and components.
NOTE 2 It is recommended not to attempt to fit the fracture pieces tightly together since this may induce further damage on the fracture surfaces which will impede subsequent investigations. 6.3.4 Examine the primary fracture surface for evidence of an origin of the fracture. This may be identified by tracing back any radiating ridges or grooves. NOTE 1 Annex B shows some examples of fracture surface patterns which may aid this step. However, it should be noted that: 1) Not all ceramic materials show clear fracture markings. High strength fine-grained or amorphous materials show fracture features the best. In contrast, the roughness of the fracture surface in coarse-grained or weaker materials may be too great, and obscures the fracture markings. 2) Features such as mist or hackle can be absent as a consequence of the size of the test-piece or the level of fracture stress. These features only develop if the crack reaches a sufficient velocity within the test-piece cross-section. An example is the case of subcritical crack growth, or in the fracture of small test-bars. SIST EN 843-6:2009

11 Table 1 — Visibility of fracture origins Origin name Comment Identifiable by optical microscopy or SEM Examples in annex C or D Pore (3.2.6) Large single pores are often irregular in shape, and can act as fracture origins, especially when close to or connected to the surface, e.g. when exposed by virtue of machining. Optical, although SEM better for translucent materials C1.1, C1.2 Porous region (3.2.7) A zone of closely spaced pores distributed in three dimensions can be difficult to identify positively except at high magnification. SEM unless large
Porous seam (3.2.8) A zone of closely spaced pores distributed in a planar or near planar arrangement may result from incomplete compaction, or inadvertent organic matter, or a closed delamination. SEM unless large
Delamination (3.2.3) or green-body crack (3.1.1),
A planar or near planar open cavity resulting from fracture during pressing of the green shape, or during ejection from a die cavity, which does not heal completely in firing. Usually identifiable as being at an angle to the general plane of fracture, and as having a different internal surface topography from a fractured region.
Optical or SEM C5.2 Inclusion (3.2.4) An inhomogeneity of different chemical composition from that of the ceramic material which is often linked with a pore or locally modified grain size, but which may become obvious only with backscattered electron SEM or energy dispersive X-ray imaging. SEM for chemical information, optical only if large and discoloured C4.2 Large grain(s) (3.2.5) A single or a group of abnormally large grains is usually caused by a compositional inhomogeneity, excessive firing temperature, or occasionally from poor milling of powders. SEM or optical if large C3.1 Agglomerate (3.2.1) A dense cluster of grains distinguishable from the rest of the microstructure, but often surrounded by a porous seam created by differential shrinkage on sintering. SEM C2.1, C2.2 Compositional inhomogeneity (3.2.2) A region where there is a local change in composition modifying the microstructure or creating a void. SEM for chemical information C4.1 Surface chip (3.3.1) Damage at the external surface, often along an edge, can initiate cracking, and is usually identified by additional local damage. Fracture may initially be out of plane of final fracture. Optical or SEM D2 Surface crack (3.1.1) A pre-existing crack which can result from mechanical or thermal damage or during handling in production can be hard to identify, but is usually out of the plane of final fracture. Optical or SEM C9 Surface pit (3.3.5) A cavity at the surface resulting from external influences, e.g. oxidation, requires examination of the relationship between the fracture origin and the external surface. Optical or SEM C8.1, C8.2 Open pore (3.3.4) A cavity at the surface which results from the processing method used to prepare the component or test-piece can typically be distinguished from a pit by its depth or by surface morphology similar to normal surface.
Optical or SEM D1 Machining damage (3.3.3) Surface or sub-surface shallow damage such as chips or cracks can be produced by machining, leading to apparently extended fracture origins, often of semi-elliptical shape.
SEM C7.1, C7.2 Handling damage (3.3.2) Scratches or other abnormal damage resulting from abnormal handling during processing. Optical or SEM C6 SIST EN 843-6:2009
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