1、Designation: C1322 05b (Reapproved 2010)C1322 15Standard Practice forFractography and Characterization of Fracture Origins inAdvanced Ceramics1This standard is issued under the fixed designation C1322; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 The objective of this practice is to provide an efficient and consistent methodo
3、logy to locate and characterize fracture originsin advanced ceramics. It is applicable to advanced ceramics whichthat are brittle; that is, the material adheres to Hookes Law upto fracture. fracture that takes place with little or no preceding plastic deformation. In such materials, fracture commenc
4、es froma single location which is termed the fracture origin. The fracture origin in brittle ceramics normally consists of some irregularityor singularity in the material which acts as a stress concentrator. In the parlance of the engineer or scientist, these irregularities aretermed flaws or defect
5、s. The latter word should not be construed to mean that the material has been prepared improperly or issomehow faulty.1.2 Although this practice is primarily intended for laboratory test piece analysis, the general concepts and procedures may beapplied to component failurefracture analyses as well.
6、In many cases, component failurefracture analysis may be aided by cuttinglaboratory test pieces out of the component. Information gleaned from testing the laboratory pieces (for example, flaw types,general fracture features, fracture mirror constants) may then aid interpretation of component fractur
7、es. For more information oncomponent fracture analysis, see Ref (1 and 2).21.3 This practice supersedes Military Handbook 790.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish a
8、ppropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3C162 Terminology of Glass and Glass ProductsC242 Terminology of Ceramic Whitewares and Related ProductsC1036 Specification for Flat GlassC1145 Termi
9、nology of Advanced CeramicsC1161 Test Method for Flexural Strength of Advanced Ceramics at Ambient TemperatureC1211 Test Method for Flexural Strength of Advanced Ceramics at Elevated TemperaturesC1239 Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Ad
10、vanced CeramicsC1499 Test Method for Monotonic Equibiaxial Flexural Strength of Advanced Ceramics at Ambient TemperatureC1678 Practice for Fractographic Analysis of Fracture Mirror Sizes in Ceramics and GlassesF109 Terminology Relating to Surface Imperfections on Ceramics2.2 MilitaryNIST Standard:4M
11、ilitary Handbook 790,NIST Special Publication SP 960-16 Fractography and CharacterizationGuide to Practice forFractography of Ceramics and Glasses of (2Fracture )Origins in Advanced Structural Ceramics, 19921 This practice is under the jurisdiction ofASTM Committee C28 on Advanced Ceramics and is th
12、e direct responsibility of Subcommittee C28.01 on Mechanical Propertiesand Performance.Current edition approved July 15, 2010July 1, 2015. Published November 2010October 2015. Originally approved in 1996. Last previous edition approved in 20052010as C1322 05b (2010).1. DOI: 10.1520/C1322-05BR10.10.1
13、520/C1322-15.2 The boldface numbers in parentheses refer to the list of references at the end of this standard.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the st
14、andards Document Summary page on the ASTM website.4 Available from Army Research Laboratory-Materials Directorate, Aberdeen Proving Ground, MD 21005.National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.This document is not a
15、n 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. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate.
16、In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 C
17、EN Standard:5EN 843-6 Advanced Technical Ceramics. Mechanical Properties of Monolithic Ceramics at Room Temperature. Guidance forFractographic Investigation, European Standards Committee (CEN), 20103. Terminology3.1 Definitions:3.1.1 GeneralThe following terms are given as a basis for identifying fr
18、acture origins that are common to in advancedceramics. It should be recognized that origins can manifest themselves differently in various materials. The photographs inAppendix X1 show examples of the origins defined in 3.11 and 3.203.23. Terms that are contained in other ASTM standards arenoted at
19、the end of the each definition. The specific origin types listed in 3.11 through 3.23 are the most common types in advancedceramics, but by no means cover all possibilities. NISTSpecial Publication SP960-16(2)includes many more origin types. Section3.24 provides guidance on how to characterize or de
20、fine other origin types. Some common origin types are identified in 3.12through 3.23. These origin flaws are distributed throughout the bulk (inherently volume-distributed) or are distributed on anexterior surface (inherently surface-distributed). The distinction is very important for Weibull statis
21、tical analysis and size scalingof strength as discussed in Practice C1239. Section 7.2 provides guidance on interpretation3.2 advanced ceramic, na highly engineered, high-performance, predominately nonmetallic, inorganic, ceramic materialhaving specific functional attributes. C11453.3 brittle fractu
22、re, nfracture that takes place with little or no preceding plastic deformation.3.4 flaw, nstructural discontinuity in an advanced ceramic body that acts as a highly localized stress raiser.NOTE 1The presence of such discontinuities does not necessarily imply that the ceramic has been prepared improp
23、erly or is faulty.3.5 fractography, nmeans and methods for characterizing a fractured specimen or component. C11453.6 fracture mirror, nas used in fractography of brittle materials, a relatively smooth region in the immediate vicinity of andsurrounding the fracture origin.3.7 fracture origin, nthe s
24、ource from which brittle fracture commences. C11453.8 grain boundary, n (GB)as used in fractography, a volume-distributed flaw that is a boundary facet between two or moregrains.NOTE 2This flaw is most apt to be strength limiting in course-grainedcoarse-grained ceramics.3.9 hackleas used in fractogr
25、aphy, a line or lines on the crack surface running in the local direction of cracking, separatingparallel but non-coplanar portions of the crack surface.3.10 mist, nas used in fractography of brittle materials, markings on the surface of an accelerating crack close to its effectiveterminal velocity,
26、 observable first as a misty appearance and with increasing velocity reveals a fibrous texture, elongated in thedirection of crack propagation.3.11 Inherently Volume-Distributed Common Origins:3.12 agglomerate, n, (A)as used in fractography, a volume-distributed flaw that is a cluster of grains, par
27、ticles, platelets, orwhiskers, or a combination thereof, present in a larger solid mass. C11453.13 compositional inhomogeneity, n, (CI)as used in fractography, a volume-distributed flaw that is a microstructuralirregularity related to the nonuniform distribution of the primary constituents or an add
28、itive or second phase. C11453.14 crack, n, (CK)as used in fractography, a volume- or surface-distributed flaw that is a surface of fracture without completeseparation. C11453.15 inclusion, n, (I)as used in fractography, a volume-distributed flaw that is a foreign body that has a composition differen
29、tfrom the nominal composition of the bulk advanced ceramic. C11453.16 large grain(s), n, (LG)as used in fractography, a volume- or surface-distributed flaw that is a single (or cluster of) grain(s)having a size significantly greater than that encompassed by the normal grain size distribution. C11453
30、.17 pore, n, (P(V)as used in fractography, a volume-distributed flaw that is a discrete cavity or void in a solid material.C11453.18 porous region, n, (PR)as used in fractography, a volume-distributed flaw that is a 3-dimensional zone of porosity ormicroporosity. C11453.19 porous seam, n, (PS)as use
31、d in fractography, a volume-distributed flaw that is a 2-dimensional area of porosity ormicroporosity. C11455 The American Ceramic Society, Westerville, OH 1984.Available from European Committee for Standardization (CEN), Avenue Marnix 17, B-1000, Brussels, Belgium,http:/www.cen.eu.C1322 1523.20 Inh
32、erently Surface-Distributed Origins:3.20 handling damage, n, (HD)as used in fractography, surface-distributed flaws that include scratches, chips, cracks, etc., dueto the handling of the specimen/component. C11453.21 machining damage, n, (MD)as used in fractography, a surface-distributed flaw that i
33、s a microcrack(s), chip(s),striation(s), or scratch(es), or a combination of these, created during the machining process. C1145NOTE 3Machining may result in the formation of surface or subsurface damage, or both.3.22 pit, n, (PT)as used in fractography, a surface-distributed flaw that is a cavity cr
34、eated on the specimen/component surfaceduring the reaction/interaction between the material and the environment, for example, corrosion or oxidation. C11453.23 surface void, n, (SV)as used in fractography, a surface-distributed flaw that is a cavity created at the surface/exterior asa consequence of
35、 the reaction/interaction between the material and the processing environment, for example, surface reaction layeror bubble that is trapped during processing. C11453.24 Miscellaneous Origins:3.25 unidentified origin, n, (?)as used in this practice, an uncertain or undetermined fracture origin.3.26 O
36、ther terms or fracture origin types may be devised by the user if those listed in 3.11 andthrough 3.203.23 are inadequate.In such instances the user shall explicitly define the nature of the fracture origin (flaw) and whether it is inherently volume- orsurface-distributed. Additional terms for surfa
37、ce imperfections can be found in Terminology F109 and supplementary fractureorigin types for ceramics and glasses may be found in The Ceramic Glossary and Terminology C162 and Terminology C242 andin a Specification C1036. Examples of additional terms are hard agglomerate, collapsed agglomerate, hard
38、 agglomerate (CEN843-6) poorly bonded region, glassy inclusion, chip, or closed chip.closed chip, chip (CEN 843-6), delamination (CEN 843-6),grain boundary cracks, chatter cracks, sharp impact cracks, blunt impact cracks, C-cracks (ball bearings), baseline microstructuralflaws (BMF), or mainstream m
39、icrostructural flaws (MMF). See the ”Guide to Practice for Fractography of Ceramics and Glasses”(2) for discussion and examples.3.27 The word “surface” may have multiple meanings. In the definitions above, it refers It may refer to the intrinsic spatialdistribution of flaws. The word “surface” also
40、may refer to the exterior of a test specimen cut from a bulk ceramic or component,or alternatively, the original surface of the component in the as-fired state. It is recommended that the terms original-surface oras-processed surface be used if appropriate.4. Summary of Practice4.1 Prior to testing
41、mark the specimen or component orientation and location to aid in reconstruction of the specimen/component fragments. Marker lines made with a pencil or felt tip marker may suffice. See Fig. 1.4.2 Whenever possible, test the specimen(s)/component(s) to failurefracture in a fashion that preserves the
42、 primary fracturesurface(s) and all associated fragments for further fractographic analysis.4.3 Carefully handle and store the specimen(s)/component(s) to minimize additional damage or contamination of the fracturesurface(s), or both.4.4 Visually inspect the fractured specimen(s)/component(s) (1 to
43、10) in order to determine crack branching patterns, anyevidence of abnormal failurefracture patterns (indicative of testing misalignments), the primary fracture surfaces, the location ofthe mirror and, if possible, the fracture origin. Specimen/component reconstruction may be helpful in this step. L
44、abel the pieceswith a letter or numerical code and photograph the assembly if appropriate.4.5 Use an optical microscope (10 to 200) to examine both mating halves of the primary fracture surface in order to locateand, if possible, characterize the origin. Repeat the examination of pieces as required.
45、 If the fracture origin cannot be characterized,then conduct the optical examination with the purpose of expediting subsequent examination with the scanning electronmicroscope (SEM).4.6 Inspect the external surfaces of the specimen(s)/component(s) near the origin for evidence of handling or machinin
46、g damageor any interactions that may have occurred between these surfaces and the environment.4.7 Clean and prepare the specimen(s)/component(s) for SEM examination, if necessary.4.8 Carry out SEM examination (10 to 2000) of both mating halves of the primary fracture surface.4.9 Characterize the str
47、ength-limiting origin by its identity, location, and size. When appropriate, use the chemical analysiscapability of the SEM to help characterize the origin.4.10 If necessary, repeat 4.6 using the SEM.4.11 Keep appropriate records, digital images, and photographs at each step in order to characterize
48、 the origin, show its locationand the general features of the fractured specimen/component, as well as for future reference.C1322 1534.12 Compare the measured origin size to that estimated by fracture mechanics. If these sizes are not in general agreement thenan explanation shall be given to account
49、 for the discrepancy.4.13 For a new material, or a new set of processing or exposure conditions, it is highly recommended that a representativepolished section of the microstructure be photographed to show the normal microstructural features such as grain size andporosity.size, porosity, and phase distribution.NOTE 1Keep appropriate records, digital images, and photographs at each step to assist in the origin characterization and for future reference.Keep appropriate records, digital images, and photographs at each step to assist in the origin
