Investigation on the effect of alloying elements on the Ti2AlC/TiAl interfacial properties: First-principles prediction and experimental verification

In the present work, the effect of alloying elements Cr, Nb, Mo, V on the Ti2AlC/TiAl interfacial properties was studied via first-principles calculation. The results showed that all the alloying elements (Cr, Nb, Mo, V) have the trend to aggregate to the Ti2AlC and increase the interfacial strength by the decrease of interfacial distance after relaxation, the alloying element Cr has the largest enhancement effect due to the shortest interfacial distance and formation of Ti-Cr covalent bond. Then the site preference of alloying element Cr in the Ti2AlC/TiAl interface was experimentally verified by the HADDF-STEM and EDS elemental maps. These results could provide theoretical guidance for the design of Ti2AlC/TiAl composite with high performance.