Optimizing WC-10Co cemented carbides with high-entropy (Ti, Cr, V, Nb, Mo)(C, N) inhibitor: Microstructure, mechanics, and wear resistance

Abstract

Cemented carbides play a pivotal role in diverse industrial sectors, and controlling abnormal grain growth and regulating the homogeneity of the Co binder phase are the key challenges to improve their properties. In this study, WC-10Co alloy was prepared for the first time by low-pressure sintering technique using (Ti, Cr, V, Nb, Mo)(C, N) high entropy powder as an inhibitor, focusing on the effect of trace additions of (Ti, Cr, V, Nb, Mo)(C, N) on the microstructure and mechanical properties of the alloy as well as friction and wear properties. The results show that under the conditions of sintering at 1420 ℃, a pressure of 3 MPa, and a holding time of 1 h, the alloy with 0.2 wt% high-entropy inhibitor exhibited the best comprehensive properties, with a flexural strength of 3752 MPa, a Vickers hardness of 1679 HV₃₀, and a fracture toughness of 13.07 MPa·m^1/2. During the stable stage of tribological testing, the average friction coefficient reached 0.6195, and the wear rate was as low as 1.34 × 10⁻⁷ mm³/(N·m). The toughening and strengthening mechanism of the (Ti, Cr, V, Nb, Mo)(C, N) - modified alloy is mainly attributed to the significant refinement of WC grains, WC lattice contraction, and the formation of Co-based solid solutions by the high-entropy inhibitor. However, excessive addition deteriorates the overall performance. This study provides experimental data and technical insights for the development of a new generation of cemented carbides with high strength, high toughness, and excellent wear resistance.