Microstructure and Abrasive Wear Resistance of Mo2C Doped Binderless Cemented Carbide

Xiuqi Zan,Kailin Dong,Jun Shu,Kaihua Shi,Jun Liao

doi:10.3389/fmats.2020.00191

Abstract

A series of binderless cemented carbides with various Mo2C addition amounts(0~6wt.%) were prepared by sintering and then HIPed at 2000℃ under an isostatic pressure of 70MPa. The microstructure and abrasive wear resistance of the obtained samples were systemically investigated. The grain size does not change with the increase of Mo2C addition amount, while the abrasive wear resistance of the cemented carbide increases obviously. The data of the abrasive wear test show the wear volume loss of the cemented carbide reduces from 7.32cm3/105r to 0.02cm3/105r when the Mo2C addition amount change from 0wt.% to 6.0wt.%. The superior abrasion resistance of samples with higher Mo2C content and the smoother appearance of the worn surfaces with no pronounced pullout of grains compared with other samples were result from the forming of (W,Mo)C because of the intermixing between WC and Mo2C after sintering at a high temperature.

Highlights

WC-Co cemented carbides have a wide range of industrial applications, being used in cutting tools, forming tools, impact resistant mold, and wear resistant parts due to their exceptionally high hardness, wear resistance, and good toughness (Shi et al, 2014; García et al, 2019)
The results show that the increase of Mo content can reduce the solubility of WC in the liquid phase, so that the grain growth is refined and the hardness of the cemented carbide is significantly improved
The Bragg peaks for “WC” of the sintered samples tend to shift toward higher angles with increasing Mo2C addition amount, as shown in X-ray diffraction (XRD) patterns (Figures 1A,B)

Summary

INTRODUCTION

WC-Co cemented carbides have a wide range of industrial applications, being used in cutting tools, forming tools, impact resistant mold, and wear resistant parts due to their exceptionally high hardness, wear resistance, and good toughness (Shi et al, 2014; García et al, 2019). Typical WC-Co cemented carbides contain less than 30 wt% cobalt, and the WC grain size ranges from submicron levels to a few microns (Wu et al, 2016) The binding phase such as Co is good for fracture toughness and strength increase, but at the same time, it will reduce the hardness, corrosion resistance, and wear resistance. The results show that a small amount of Mo addition can refine WC grains, improve the relative density and hardness of the cemented carbide, but reduce the bending strength of the cemented carbide. There has been relatively little investigation of the effect of Mo/Mo2C addition on the microstructure and properties of binderless cemented carbide. The effect of Mo2C doping amount on microstructure and abrasive wear properties of the as-prepared samples were studied.

RESULTS AND DISCUSSION

CONCLUSIONS

DATA AVAILABILITY STATEMENT