High temperature deformation behavior of 20 vol.% metal matrix composite

Abstract

The SiC whisker reinforced aluminum matrix composites are attractive materials for aerospace or automotive structural components due to high specific strength and high specific modulus with good thermal stability. However, the SiC whisker reinforced composites generally have the major drawback of poor formability because of low ductility and poor fracture toughness in comparison with matrix alloys. Therefore, the enhancement of ductility in metal matrix composites remains as a major obstacle to the expansion of the industrial application. In this paper, the high temperature deformation behavior of a 20 vol. % SiC[sub w]/2024Al composite, fabricated by the vacuum hot pressing process, has been investigated. The tensile deformation behavior of the SiC[sub w]/2024Al composite was observed at temperatures ranging from 475--575 C with initial strain rates ranging from 10[sup [minus]3]--1.7s[sup 1]. The effect of extrusion on high temperature deformation behavior was investigated. The microstructural parameters, such as the orientation and aspect ratio of SiC whiskers and the grain size of the 2024Al matrix, are related with the high temperature deformation behavior of SiC[sup w]/2024Al composites.