Effect of hard phase content on the mechanical properties of TiC-316 L stainless steel cermets

Abstract

The dense TiC-316 L stainless steel cermets with different TiC content were fabricated via conventional powder metallurgy (PM) process. The effects of TiC content on the microstructure and mechanical properties of TiC-316 L stainless steel cermets are studied. Scanning electron microscopy (SEM) is employed to observe the microstructure, fracture morphology, and crack propagation of cermets. The binder mean free path (MFP) and hard phase contiguity are analyzed based on the stereological principles. The relative density, hardness and transverse rupture strength (TRS) of the cermets are measured by the Archimedes' principle, Rockwell scale hardness tester and three-point flexural test, respectively. The average TiC grain size decreases first and then increases with the increase of hard phase content. At a content of 80 wt%, the maximum relative density (99.1%), hardness (88.9 HRA) and TRS (1373 MPa) are obtained. During crack propagation, both intergranular and transgranular fractures exist, of which the intergranular fracture prevail and coarse grains are more prone to transgranular fracture.