Strength and Microstructure of Ceramics

reportActive / Technical Report | Accession Number: ADA217752 | Open PDF

Abstract:

Results of a study program on the toughness properties of monophase ceramics are summarized. In situ observations of crack propagation in alumina and other monophase ceramics show crack interface bridging to be the principal source of increasing toughness with crack size, i.e. R-curve behavior. Fracture mechanics models describing this behavior, in the particular context of strength, are developed. Results of strengths tests confirming the essential predictions of the theory are presented. Results of wear and fatigue tests are also described. The model has strong implications concerning the controlled processing of ceramics for optimum toughness and strength properties. Keywords Strength mechanics Fracture resistance Brittleness Heat treatment Toughening Mechanical properties.

Author(s):
Lawn, Brian R. ; Alpert, C. J. ; Bennison, S. J. ; Chan, H. M. ; Cho, S-j ; Cook, R. F. ; Fairbanks, C. J. ; Harmer, M. P. ; Hockey, B. J. ; Marshall, D. B.
Author Organization(s):
NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD CERAMICS DIV
Descriptive Note:
Final technical rept. 1987-1989
Pagination:
0240

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFOSR-TR-90-0013
Contract/Grant Number(s):
AFOSR-ISSA-87-0034, AFOSR-ISSA-88-0005
Task Number(s):
A2
Project Number(s):
2306
Monitor Series:
TR-90-0013, AFOSR
 Subject Terms
Joint Capability Areas:
JCA_4.6_Engineering; JCA_4.6.1_General Engineering; JCA_5_Command and Control; JCA_5.3_Planning; JCA_1.2.7_Experimentation; JCA_1.2.5_Lessons Learned; JCA_1.2.6_Concepts; JCA_1.3.2_Personnel Management; JCA_5.4_Decide; JCA_1.2.3_Educating; JCA_5.4.5_Intuit; JCA_4.5.4_Requirements Definition; JCA_4.5_Operational Contract Support; JCA_1.2.1_Training; JCA_1.2.2_Exercising; JCA_4.4.1_Food Service; JCA_4.4_Logistics Services; JCA_5.2.2_Develop Knowledge and Situational Awareness; JCA_5.2_Understand
Modernization Areas:
Microelectronics
Communities of Interest:
Energy and Power Technologies
Descriptor(s):
*CRACK PROPAGATION, *CERAMIC MATERIALS, *MICROSTRUCTURE, MECHANICAL PROPERTIES, OPTIMIZATION, SIZES(DIMENSIONS), PREDICTIONS, INTERFACES, PROCESSING, RESISTANCE, CRACKS, THEORY, TOUGHNESS, STRENGTH(MECHANICS), FRACTURE(MECHANICS), HEAT TREATMENT, BRITTLENESS, ALUMINUM OXIDES, WEAR, CONTROL, FATIGUE TESTS(MECHANICS), TEST AND EVALUATION, MATHEMATICAL MODELS
Field(s)/Group(s):
Ceramics, Refractories and Glass, Mechanics
Keyword(s):
MONOPHASE CERAMICS, TOUGHENING, PE61102F, WUAFOSR2306A2
Report Date:
1989 Nov 01