Effect of Cr3C2 content on the microstructure and properties of Mo2NiB2-based cermets

Abstract

Abstract Four series of Mo2NiB2-based cermets with Cr3C2 addition of between 0 and 7.5 wt.% in 2.5 wt.% increments were studied by means of scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffractometry. The transverse rupture strength and hardness were also measured. It was found that Cr3C2 completely dissolved in Mo2NiB2-based cermets. Cr3C2 addition improved the wettability of the Ni binder phase on the Mo2NiB2 hard phase, which resulted in a decrease in the porosity and an increase in the phase uniformity. The cermets with 2.5 wt.% Cr3C2 content showed relatively fine grains and almost full density. A high Cr3C2 content resulted in the formation of M 6C (M = Mo, Cr, Ni) phase. In addition, energy dispersive X-ray spectroscopy results showed that the content of Mo in the binder decreased with increasing Cr3C2 content. The cermets with 2.5 wt.% Cr3C2 addition exhibited the highest transverse rupture strength of 2210 MPa, whereas the cermets without Cr3C2 addition exhibited the highest hardness.