Theoretical Investigation On The Structural, Mechanical, Electronic And Thermodynamic Properties Of Cubic Ti3nial2c Compound

The structural, mechanical, electronic and thermodynamic properties of cubic Ti3NiAl2C compound are investigated by the first-principle method based on density functional theory, and compared with Ti2AlC, Ti3AlC2 and Ti3SiC2 compounds. The bulk modulus of cubic Ti3NiAl2C compound is lower than that of Ti3NiAl2C compound, but higher than that of Ti2AlC and Ti3AlC2 compounds. The ductility or brittleness of cubic Ti3NiAl2C compound is evaluated according to the B/G ratio and Poisson's ratio, and it is concluded that cubic Ti3NiAl2C compound is a brittle phase. However, its ductility is better than that of Ti2AlC, Ti3AlC2 and Ti3SiC2 compounds. The density of states shows that cubic Ti3NiAl2C compound exhibits metallic characteristics. The maximum width of the pseudo-gap is about 1eV, which indicates that cubic Ti3NiAl2C compound has strong covalent bonds. The Debye temperature, entropy, free energy, enthalpy and heat capacity of cubic Ti3NiAl2C compound are also calculated.