Atmosphere influence in sintering process of stainless steels matrix composites reinforced with hard particles

This paper studies the change in properties of powder metallurgy 316L stainless steel, depending on kind of added reinforcement and its amount and the sintering atmosphere. Used reinforcements have been AlCr2, Cr2Ti, VC and SiC and the amounts were 1.5 and 3% (vol.). All materials have been manufactured mixing the powders with a 0.6% (wt.) of wax, compacting at 700 MPa, and sintering at 1230 degreesC. In order to analyze the sintering atmosphere, three different media were used: 75%H-2-25%N-2, pure H-2 and vacuum. The properties of the 24 different composites materials are evaluated and compared with the base stainless steel sintered in the same conditions. The study carried out includes sintering density, tensile strength, hardness, corrosion and wear and microstructural analysis. Intermetallics seem to be a good solution to improve the studied properties. (C) 2002 Elsevier Science Ltd. All rights reserved.