Effect of rare-earth elements on the interface of WC/α-Fe cemented carbide: A first-principles calculation

Abstract

The fundamental effects of rare-earth elements doping on cohesion properties of WC (101¯0)/α-Fe (100) interfaces were investigated by first-principles calculation. The WC/Fe interface has six interface structures, including W-AS-Fe, W-HS-Fe, W-BS-Fe, C-AS-Fe, C-HS-Fe, and C-BS-Fe interfaces. The C-BS-Fe interface is the most stable among all interface structures, with a maximum interface energy of 10.50 J/m2, due to the dominant FeCr covalent bond. Rare-earth elements (Sc, Y, La, Pr, Nd, Eu, Gd, and Dy) doped at three kinds of positions of the C-BS-Fe interface were investigated. The results show that the interfacial structural strength can be enhanced by Sc and Pr doping to Fe positions, and Nb can play a role in interfacial strengthening no matter which position is doped. Besides, the strengthening effect is the best when the subsurface Fe atomic position is replaced, which is on account of the formation of the FeNd metal bond and the NdC bond.