Theoretical prediction on the interfacial bonding properties of MoAlB(010)/Cu(100) interface

MoAlB ceramics, renowned for its superior mechanical characteristics, robust oxidation resistance, and exceptional thermal conductivity, has demonstrated successful applications as a reinforcing phase in metal matrix composites. However, Recent investigations have revealed that that during the sintering process, Al atoms present in MoAlB diffuse into the copper matrix, thereby compromising the performance of copper-based composites. In this work, the work of adhesion, interfacial energy and electronic structure of MoAlB/Cu interface were investigated using first-principle calculations, aiming to enhance the understanding of the diffusion phenomenon observed. The results indicate that the surface energy of Al1 (B2) and Al2 (Al1) slabs is relatively lower, and following the complete relaxation of the slabs, there is a pronounced tendency for Al atoms to detach from MoAlB. The results of adsorption work suggest that HCP sites exhibit a more stable interface stacking sequence. The calculation results pertaining to interfacial energy demonstrate that the Al/Cu interface exhibits a lower interfacial energy, thus facilitating its formation. Furthermore, a detailed analysis of the electronic structure of the Al1(Mo2)-HCP and Al2(Al1)-HCP interfaces reveals the formation of Cu–Al bonds at the interface, hinting at a potential tendency for Al atoms to diffuse into the Cu matrix.