Microstructure and Mechanical Properties of SUS304L Compact Produced by Shot-Blast SPD-PM Process

Abstract

In this research, shot-blaster apparatus is intended mechanical milling apparatus by using air blast shot peening method. Normally, Alumina or abrasive powder is used as media particle to clean the product surface in the shot-blaster apparatus. In this paper, SUS304L stainless steel powders, the most widely used austenite stainless steel, were intended as shot-blaster media. This SUS304L powder media hit the tungsten carbide by high pressure from air compressor so that is deformed severely. The SUS304L compact was made by spark plasma sintering process. The microstructure and mechanical properties of the SUS304L compacts compared with the conventional compacts prepared using initial powders. The SUS304L powders have plastic deformation on the particle surface after shot-blasting. The deformed powders fractions are increased with increasing shot-blasting time. However, deformed powders fractions are stable at about 70 to 75% after 18 ks of shot-blasting time. The bimodal structure of SUS304L compacts can produced by shot-blasting process because small grain areas are observed in the sintered compact prepared from shot-blasted powders. The tensile results reveal that the SUS304L compacts made by shot-blasted powders exhibit high strength and especially high ductility compared with the conventional SUS304L compact.