First principles calculation on mechanical and thermal properties of intermetallic compounds in Al-Y alloys

The mechanical and thermal properties of the intermetallic compounds AlY, Al2Y and Al3Y in the Al-Y alloys were theoretically calculated based on density functional theory (DFT) and first principles, using the software of CASTEP. First, the structures of the five intermetallic compounds were optimized and the equilibrium lattice constants were obtained. On this basis, their formation enthalpy, cohesive energy and elastic constant were calculated and the results were analyzed in theory. It can be conculded that among the five intermetallic compounds of different structures, the ability of alloying of the main strengthening phase Al2Y is the strongest, and the structure is relatively stable, while its brittleness is the strongest.