Accession Number : ADA186443

Title :   Investigation of Microstructural Factors That Cause Low Fracture Toughness in Silicon Carbide Whisker/AL Alloy Composites.

Descriptive Note : Annual rept. 1 Sep 86-30 Sep 87,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE

Personal Author(s) : Wawner, F E ; Harris, C R

PDF Url : ADA186443

Report Date : Sep 1987

Pagination or Media Count : 106

Abstract : This investigation deals with factors influencing the fracture toughness in silicon carbide whisker aluminum alloy composites. There is an enormous amount of variables which can, independently or in combination, yield different properties in these materials. Chemical composition, manufacturing techniques and processing, along with the material's history, must all be considered for a complete understanding of the material's behavior. The approach employed here is to evaluate strength parameters in order to gauge the effectiveness of one variable, individually altered, while all other variables remain constant. For example, ultimate tensile strength was one parameter measured before and after a certain heat treatment. Any observed changes in strength were then investigated on a microstructural level, using electron microscopy and x-ray techniques. Ideally, an explanation for the phenomenon can be found and a model proposed to explain or predict the behavior. Keywords: Silicon carbide whiskers, Composites, Microstructure, Thermomechanical treatments.

Descriptors :   *ALLOYS, *COMPOSITE MATERIALS, *FRACTURE(MECHANICS), *SILICON CARBIDES, *TOUGHNESS, BEHAVIOR, CHEMICAL COMPOSITION, ELECTRON MICROSCOPY, GAGES, HEAT TREATMENT, HISTORY, MANUFACTURING, MATERIALS, MICROSTRUCTURE, STRENGTH(GENERAL), TENSILE STRENGTH, THERMOMECHANICS, WHISKERS(CRYSTALS), X RAYS

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE