Effect of Cr3C2 addition on the microstructure, magnetic and mechanical properties of TiC–TiN–WC–C–Ni cermets

Abstract

This study explored the effect of Cr3C2 content (0, 0.5, 1, 1.5, and 2 mol%) on the microstructure, magnetic properties and mechanical behavior of TiC–10TiN–6WC–4C–(15,30) Ni (mol%) cermets after vacuum sintering. The results show that just Ti-based carbonitride ceramic grains and Ni-based binder phase were presented in the experimental cermets, and the mean size of ceramic grains reduced with the increase of Cr3C2 content. By adding Cr3C2 into cermets, the Cr concentration in binder phase obviously raised. However, Ti concentration in binder phase decreased continuously as Cr3C2 content increased, while the W concentration remained nearly constant. Saturation magnetization and remanence of cermets decreased with increasing Cr3C2 content, which was primarily ascribed to the increased amounts of antiferromagnetic Cr element in the Ni-based binder phase. When Cr3C2 content exceeded 0.5 mol%, cermets became paramagnetic at room temperature. Cermets with 15 and 30 mol% Ni had Curie temperatures of roughly 138 K and 28 K by 2 mol% Cr3C2 addition, respectively. Therefore, Cr3C2 addition is very effective in suppressing the ferromagnetism of cermets. Moreover, transverse rupture strength and hardness of cermets first raised and then declined with the addition of Cr3C2.