基于第一性原理的镍/碳化钨复合钎涂层界面分析

Ni/WC composite coating has been widely used in agricultural machinery, mould processing and new energy resources fields for its high hardness, high wear resistance and low friction coefficient. The first-principles calculation is used to study the Ni(111)/WC(0001) interface and Ni(111)/W₂C(0001) interface behavior in Ni/WC composite brazed coating of construction machinery. The influence of W₂C on the wear resistance of WC-reinforced Ni matrix composite brazed coatings is discussed. The calculation results reveal that the 5 atom-layers Ni(111) surface, 9 atom-layers WC(0001) surface and 9 atom-layers W₂C (0001) surface are selected to represent the block characteristics. Among the six stacking sequences, the highest Wad (adhesion work) is 7.42 J/m² at B site from C-terminated structure of Ni(111)/WC(0001) interface, then the interface bonding strength is the highest. The systematic analysis of the electronic structures at different interfaces shows that Ni atoms are more likely to bond with C atoms, the properties of bonds between Ni and C atoms are mainly ionic bonding, and the properties of metallic bonding between Ni atoms at the interface are much weaker than non-interface Ni atoms.W₂C phase should be strictly controlled at the coating interface. The theoretical basis is provided for the manufacture of high wear resistance, high hardness and high strength composite coatings.