Accession Number : ADA311169

Title :   High Temperature Behavior of Metal Matrix Composites.

Descriptive Note : Final rept. 15 Jul 92-29 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/Ti-alloy matrix composite was also conducted and the mechanical properties of as-cycled composite were assessed. The minor degradation of the as-cycled 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 metal-ceramic 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 Von-Mises 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