Exploration of D022-Type Al3TM(TM = Sc, Ti, V, Zr, Nb, Hf, Ta): Elastic Anisotropy, Electronic Structures, Work Function and Experimental Design

Abstract

The structural properties, elastic anisotropy, electronic structures and work function of D022-type Al3TM (TM = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta) are studied using the first-principles calculations. The results indicate that the obtained formation enthalpy and cohesive energy of these compounds are in accordance with the other calculated values. It is found that the Al3Zr is the most thermodynamic stable compound. The mechanical property indexes, such as elastic constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and Vickers hardness are systematically explored. Moreover, the calculated universal anisotropic index, percent anisotropy and shear anisotropic factors of D022-type Al3TM are analyzed carefully. It demonstrates that the shear modulus anisotropy of Al3La is the strongest, while that of Al3Ta is the weakest. In particular, the density of states at Fermi level is not zero, suggesting that these phases have metal properties and electrical conductivity. More importantly, the mechanisms of correlation between hardness and Young’s modulus are further explained by the work function. Finally, the experimental design proves that D022-Al3Ta has an excellent strengthening effect.

Probing the electronic, elastic, mechanical and anisotropic features of ZrTiX4 alloys via density functional theory

“…Also, ν = 0.26 is a significant checkpoint for the ductile-brittle classifications of materials. So, ν ≥ 0.26 signifies the ductility, while values of ν lower than 0.26 (ν ≤ 0.26) mean that the investigated material is brittle [37]. Additionally, for isotropic materials, ν must be in the numerical range of −1 ≤ ν ≤ 0.5 [35].…”