
Accession Number : ADA311169
Title : High Temperature Behavior of Metal Matrix Composites.
Descriptive Note : Final rept. 15 Jul 9229 Feb 96,
Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF MECHANICAL ENGINEERING
Personal Author(s) : Taya, M. ; Lee, J. K. ; Dunn, M. L. ; Walker, G. ; Mori, T.
PDF Url : ADA311169
Report Date : 28 MAY 1996
Pagination or Media Count : 130
Abstract : When a metal matrix composite(MMC) is subjected to combined creep and thermal cycling loading, dimensional change is known to occur. This project is aimed at elucidating the mechanisms of a MMC subjected to creep/thermal cycling both experimentally and theoretically. The target MMCs is SiC particulate/Al matrix composite. The experimental results of dimensional change of SiCp/Al composite indicates that larger the maximum temperature(Tmax), and larger creep applied stress, the larger dimensional change is observed. The analytical model based on dislocation punching can explain the experimental results well. Thermal cycling of SCS6 fiber/Tialloy matrix composite was also conducted and the mechanical properties of ascycled composite were assessed. The minor degradation of the ascycled composite was observed only under the condition that Tmax is equal to or higher than 600C. Analytical modeling of relaxation of CTE mismatch strain that exists at the metalceramic interface was also developed by using variational principle and Eshelby's method. Complete relaxation can be found by minimizing the total potential energy. As a example, a complete relaxation of a creeping MMC is that the VonMises stress in the metal matrix becomes zero, i.e., hydrostatic state of stress.
Descriptors : *THERMAL PROPERTIES, *HIGH TEMPERATURE, *LOADS(FORCES), *METAL MATRIX COMPOSITES, *CYCLES, *CREEP, STRESSES, MATHEMATICAL MODELS, MECHANICAL PROPERTIES, DEGRADATION, INTERFACES, COMPOSITE MATERIALS, MATRIX MATERIALS, CERAMIC MATERIALS, DISLOCATIONS, ALUMINUM, HEATING, HYDROSTATICS, RELAXATION, POTENTIAL ENERGY, SILICON CARBIDES, TITANIUM ALLOYS, VARIATIONAL PRINCIPLES.
Subject Categories : Laminates and Composite Materials
Inorganic Chemistry
Mechanics
Thermodynamics
Distribution Statement : APPROVED FOR PUBLIC RELEASE