First-Principles Investigations of the Structural, Anisotropic Mechanical, Thermodynamic and Electronic Properties of the AlNi2Ti Compound

Abstract

Abstract:In this paper, the electronic, mechanical and thermodynamic properties of AlNi 2 Ti are studied by first-principles calculations in order to reveal the influence of AlNi 2 Ti as an interfacial phase on ZTA (zirconia toughened alumina)/Fe. The results show that AlNi 2 Ti has relatively high mechanical properties, which will benefit the impact or wear resistance of the ZTA/Fe composite. The values of bulk, shear and Young's modulus are 164.2, 63.2 and 168.1 GPa respectively, and the hardness of AlNi 2 Ti (4.4 GPa) is comparable to common ferrous materials. The intrinsic ductile nature and strong metallic bonding character of AlNi 2 Ti are confirmed by B/G and Poisson's ratio. AlNi 2 Ti shows isotropy bulk modulus and anisotropic elasticity in different crystallographic directions. At room temperature, the linear thermal expansion coefficient (LTEC) of AlNi 2 Ti estimated by quasi-harmonic approximation (QHA) based on Debye model is 10.6 × 10 −6 K −1 , close to LTECs of zirconia toughened alumina and iron. Therefore, the thermal matching of ZTA/Fe composite with AlNi 2 Ti interfacial phase can be improved. Other thermodynamic properties including Debye temperature, sound velocity, thermal conductivity and heat capacity, as well as electronic properties, are also calculated.

Interfacial Bonding and Abrasive Wear Behavior of Iron Matrix Composite Reinforced by Ceramic Particles

“…The Vicker’s hardness of Ni 3 Ti, TiO and AlNi 2 Ti was 12.5 GPa, 16.1 GPa and 9.2 GPa, respectively. These testing values are very close to the theoretical hardness reported in [30,31,32,33,34,35]. The hardness of these interfacial phases are much higher than common white cast iron (~5.5 GPa), but lower than the ZTA ceramic (12–20 GPa [19,20]).…”