Interfacial Characteristics and Wetting Behaviors of Wc Cemented Carbide With Cocrnicufe as a Binder

Abstract

A new ultra-fine WC cemented carbide is fabricated by mechanical ball milling and spark plasma sintering (SPS), in which the CoCrNiCuFe high entropy alloy (HEA) is used as the binder of WC carbide. The microstructure and mechanical properties of WC-10wt.%HEA cemented carbides were studied using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), DSC-TG, Vickers hardness, friction and wear tester, and compression testing. The results show that the CoCrNiCuFe can inhibit the growth of WC grain in the particles. The WC particles are wetted by HEA binder through the adsorption of Cr atoms at the solid-liquid interface. The interface characteristics of the WC/HEA system include the main part of the FCC(111)//HCP(1010) interface is stable with ionic bonds and the secondary part of the interfacial reaction due to the formation of (Fe, Co)3W3C phase. The WC-10wt.% HEA cemented carbide exhibited the excellent properties as a result of the diffusion of HEA has good wettability on the WC grains and the strengthening effect on the WC/WC interface. The density, hardness and fracture toughness values of WC-10wt.% HEA cemented carbide are 98.7%, 1988.60 HV30, 10.98 MPa·m1/2, and the compressive strength values at room temperature and 800 ℃ are 3307 MPa and 1747 MPa, respectively.

Keywords: Cemented carbide, Microstructure, Mechanical properties, Wetting, Interface