Microstructure and Mechanical Properties of Spark Plasma Sintered Si3N4/WC Ceramic Tools

Authors :: Zhenhua Wang
Jiheng Jia
Liyan Cao
Yulin Wang
Ning Sun
Source :: Materials, Vol 12, Iss 11, p 1868 (2019), Materials, Volume 12, Issue 11
Publication Year :: 2019
Publisher :: MDPI AG, 2019.
Abstract: Silicon nitride (Si3N4) based ceramic tools exhibit good machinability in cutting materials such as gray cast iron, ductile iron, malleable cast iron, and superalloys due to excellent high-temperature mechanical properties. In this paper, high-performance Si3N4-based ceramic tools containing tungsten carbide (WC) and cobalt (Co) were studied. Effects of the WC content and Co content on mechanical properties and a microstructure of Si3N4-based ceramic materials were analyzed. Results showed that Si3N4-based ceramic material containing 10 wt % WC and 1 wt % Co had the best comprehensive mechanical properties at a sintering temperature of 1650 &deg<br />C and holding time of 6 min, achieving Vickers hardness, fracture toughness, and room temperature bending strength of 16.96 GPa, 7.26 MPa&middot<br />m1/2, and 1132 MPa, respectively. The microstructure of Si3N4-based ceramic tool material is uniform without obvious abnormal growth. The Si3N4-based ceramic tool was mainly composed of &alpha<br />Si3N4, &beta<br />Si3N4, and WC phases.

Tools