Liquid-phase sintering of medical-grade P558 stainless steel using a new biocompatible eutectic additive

One of the effective approaches to reduce residual pores in powder metallurgy parts is activated liquid-phase sintering process using proper additives. In this work, for the first time, a new biocompatible additive (Mn-11.5 wt.% Si, a eutectic alloy) is experimented for liquid-phase sintering of nanocrystalline/amorphous P558 stainless steel powders. It is realized that by increasing the sintering aid content and temperature, the density is effectively increased: a sharp densification progress when the sintering temperature increases from 1000 degrees C to 1050 degrees C and a slower densification rate when it exceeds 1050 degrees C. This preliminary study opens up the development of high-density medical-grade stainless steels produced by powder metallurgy, where suitable additives can lower sintering temperature and time, which is promising for retarding grain growth and commercial applications. (C) 2012 Elsevier B.V. All rights reserved.