COMPRESSIVE BEHAVIOR AND DEFORMATION-MODE MAP OF AN OPEN CELL ALUMINA

被引:66
作者
DAM, CQ
BREZNY, R
GREEN, DJ
机构
[1] Department of Materials Science and Engineering, The Pennsylvania State University, Pennsylvania 16802, University Park
基金
美国国家科学基金会;
关键词
Ceramic Materials--Mechanical Properties - Materials Testing--Fracture - Porous Materials--Thermal Conductivity - Space Shuttles--Materials;
D O I
10.1557/JMR.1990.0163
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Compressive behavior of an open cell, porous ceramic has been examined and compared to a prior theoretical model. The study involved (i) microstructural characterization, (ii) crushing strength and Young's modulus measurements, and (iii) construction of a deformation-mode map. Initially, the crushing behavior was found to be different than predicted theoretically. Weaker struts throughout the material fractured during the loading and this damage was accumulated until a macroscopic crack or cracks propagated through the material at the crushing stress. Further work showed the discrepancy was related to the uniformity of loading in these porous materials. The use of compliant faces on the loading rams improved the loading uniformity, leading to a substantial reduction in the experimental scatter and increasing the likelihood of unstable crack propagation events rather than damage accumulation. Both crushing strength and Young's modulus were found to be dependent on cell size, but this was considered to be a result of strut cracking at the smallest cell size. A deformation-mode map was constructed using the average stress/strain values at critical points such as the onset of crushing, the minimum crushing stress, and the densification stress. Although some of the details of the deformation map were different from that expected theoretically, the map did appear to be a useful guide to the compressive behavior. © 1990, Materials Research Society. All rights reserved.
引用
收藏
页码:163 / 171
页数:9
相关论文
共 15 条
[1]   THE MECHANICAL-PROPERTIES OF CELLULAR SOLIDS [J].
ASHBY, MF .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1983, 14 (09) :1755-1769
[2]   FRACTURE-BEHAVIOR OF OPEN-CELL CERAMICS [J].
BREZNY, R ;
GREEN, DJ .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1989, 72 (07) :1145-1152
[3]   EVALUATION OF STRUT STRENGTH IN OPEN-CELL CERAMICS [J].
BREZNY, R ;
GREEN, DJ ;
DAM, CQ .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1989, 72 (06) :885-889
[4]  
BREZNY R, UNPUB
[5]  
Gibson L, 1988, CELLULAR SOLIDS STRU
[6]   THE MECHANICS OF 3-DIMENSIONAL CELLULAR MATERIALS [J].
GIBSON, LJ ;
ASHBY, MF .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1982, 382 (1782) :43-&
[7]  
GREEN DJ, 1986, FRACTURE MECHANICS C, V8, P39
[8]  
GREEN DJ, 1984, IND MATERIALS SCI EN, P123
[9]   ELASTIC BEHAVIOR OF OPEN-CELL ALUMINA [J].
HAGIWARA, H ;
GREEN, DJ .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1987, 70 (11) :811-815
[10]  
HAGIWARA H, 1986, THESIS PENNSYLVANIA