Effects of a Small Amount of Additional Carbides on High-Temperature Strength of TiC-Mo₂C-Ni Cermets

Abstract

Effects of a small amount of additional carbides such as V₄C₃, Cr₃C₂, ZrC, NbC, HfC, TaC, and WC on the transverse-rupture strength of TiC-20%Mo₂C-20%Ni cermet were studied mainly at 900°C.
It was found that the strength of the cermet was particularly improved by the addition of ZrC or HfC, and the most suitable amount of addition was about 1.5% in ZrC and 2.7-5.3% in HfC. The reason was suggested to be in the fact that the titanium carbide phase in the cermet was most solution-hardened by the addition of those carbides, leading to the strength increase of carbide skeletons or to the low plastic-defor-mability of cermet at elevated temperatures.