Comparative Study of Al/SiC<sub>p</sub> Composites Manufactured by Direct and Underwater Explosive Compaction

Abstract

Abstract. Aluminum matrix composites containing of 10, 20 and 30 vol% SiC particles were processed by direct and underwater explosive compaction methods. Optical microscopic examination hardness and bending strength measurements were carried out. It is observed that there was different distribution of SiC particles in recovered compacts by direct and underwater explosive compaction. In direct method, distribution of SiC particles at center and at periphery of the cross-section was different but in underwater (except some insignificant area at top and corners of the compact samples) microstructure was uniform. The micro hardness of compacts increased with increasing SiC particle volume fraction in both method and highest bending strength obtained for composite including 10-20 vol% SiC particles. Introduction Aluminum-matrix composites (AMCs) possess many advantages such as high strength, high stiffness and excellent wear resistance, which make them increasingly being cited as candidate materials in many industrial applications [1-3]. Particulate-reinforced aluminum matrix composites are most promising and also economically viable [4-6]. There are many methods for fabrication of AMCs. Dynamic consolidation, such as explosive compaction is a route that involves a very rapid and intense deposition of shock energy at powder particle surfaces and used to produce densification to a solid piece and has been intensively attractive method for the compaction of powdered materials and composites since 1980s[7,8]. This process offers several unique advantages over the static compaction methods in conventional powder metallurgy [9]. Among advantages achieved is high density (or full theoretical density) and prevention of undesirable microstructural changes such as reaction between the constituents in silicon carbide- aluminum composites. Shock wave can be gnerated by the detonation of an explosive that surrounds the powders (direct method)[10] or by explosive capsule that put on a water container as transmitting medium above powder container (underwater method)[11]. Normally researchers have studied shock wave compaction of favorite powders by one of these routes. In this investigation we tried compare some microstructure characteristics of Al/SiC