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A first-principles investigation on the electronic structure, mechanical, and thermal properties of Zr-Si compounds has been investigated to prompt the development of new materials. The influence of Si content on mechanical and thermal properties is clarified. All the Zr-Si compounds are strikingly incompressible under uniaxial stress along x, y, and z axes. β-ZrSi possesses the strongest resistance to shape change and uniaxial tensions. α-ZrSi presents better performance of the resistance to volume change. The bulk modulus first increases and then decreases with the increase of the Si concentration. All the compounds exhibit brittle behavior. These zirconium silicides have relatively low bulk and shear modulus, but the shear anisotropy is strongly dependent on diverse directions. Debye temperature increases linearly with the increase of Si content. ZrSi 2 shows the best capacity of thermal conductivity. The minimum thermal conductivity in all the crystallographic directions is progressively increased with the increase of Si content except for β-ZrSi in the [010] direction.

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The phase equilibria in the Al–Mo–Y system have been experimentally investigated at 873 K. The existence of 10 binary compounds and 1 ternary phase Al43Mo4Y6 has been confirmed by using X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray analysis. A new ternary phase Al4Mo2Y with space group I4/mmm (No. 139) has been found at 873 K. The structure, phase stability, elastic properties and densities of state of the Al4Mo2Y compound have been theoretically investigated by using first-principles calculations. The result of cohesive energy proves that Al4Mo2Y is stable. The elastic constants, bulk modulus, shear modulus, Young's modulus, the ratio of bulk modulus/shear modulus and Poisson's ratio of Al4Mo2Y are presented. According to the phase-disappearing method, the solubility of Al in Mo, AlMo3 and Al8Mo3 phase is determined to be about 16 at.%, 7.5 at.% and 1 at.%, respectively.

The phase stability, mechanical, electronic, and thermodynamic properties of In-Zr compounds have been explored using the first-principles calculation based on density functional theory (DFT). The calculated formation enthalpies show that these compounds are all thermodynamically stable. Information on electronic structure indicates that they possess metallic characteristics and there is a common hybridization between In-p and Zr-d states near the Fermi level. Elastic properties have been taken into consideration. The calculated results on the ratio of the bulk to shear modulus (B/G) validate that InZr3has the strongest deformation resistance. The increase of indium content results in the breakout of a linear decrease of the bulk modulus and Young’s modulus. The calculated theoretical hardness ofα-In3Zr is higher than the other In-Zr compounds.