Property Evaluation and Fabrication of WC-Co-Si3N4 Hard Materials by a Rapid Sintering Process

Abstract

Spark plasma sintering method (SPS) is a new rapid sintering method developed recently for the fabrication of ceramics and composites. This method provides an advantage for sintering high-temperature materials by applying high temperature and pressure in a short time using a direct pulsed current. In this study, Binderless-WC, WC-6 wt.%Co, WC-6 wt.%Co-1 wt.% Si3N4 and WC-6 wt.%Co-2.5 wt.% Si3N4 hard materials were densified using a horizontal ball-milled WC-Co, WC-Co-Si3N4 powders, and spark plasma sintering process (SPS process). Each SPSed Binderless-WC, WC-6 wt.%Co-1 wt.% Si3N4 and WC-6 wt.%Co-2.5 wt.% Si3N4 hard materials were almost completely dense with a relative density of up to 99.2 % after the simultaneous application of a pressure of 60 MPa. The average crystallite size of WC for Binderless-WC, WC-6 wt.%Co-1 wt.% Si3N4 and WC-6 wt.%Co-2.5 wt.% Si3N4 hard materials were about 41.8, 27.4, 30.8, and 38.2 nm, respectively. Mechanical properties, microstructure, and phase analysis of SPSed Binderless-WC, WC-6 wt.%Co-1 wt.% Si3N4 and WC-6 wt.%Co-2.5 wt.% Si3N4 hard materials were investigated.