Microstructure and microhardness of ZrO2 reinforced PM 316L austenitic stainless steel composites sintered in ambient and argon atmosphere

Abstract

The present study examines the microstructure and microhardness of zirconia (ZrO2) reinforced PM 316L austenitic stainless steel matrix composites. ZrO2 was added in a proportion of 1 wt% to 3 wt%. Powders were compacted into a disc of 11mm diameter and 2mm thick at 70kN. Compacts were sintered in an ambient and argon atmosphere at 1250oC for 30 minutes. Sintered compacts were then analyzed for microhardness using Vickers hardness testing machine, and microstructure was examined using a scanning electron microscope. The study revealed that the reinforcement of ZrO2 significantly enhanced the microhardness of PM 316L SS matrix composites with a microstructure consisting of irregular porosity and zirconia encapsulating the 316L SS particles.