A first principle study on the basic properties of inclusions in aluminum alloy

The basic properties of aluminum alloy matrix and common inclusions of Al₂O₃, MgO, AlN, TiB₂, AlB₂, Al₄C₃ in aluminum alloy were studied by means of first principles calculation. The formation heat reveals that Al₂O₃ is the easiest to form, while MgO and AlB₂ are the most difficult to form. The absolute value of binding energy of Al₂O₃, AlN and TiB₂ are slightly larger than others, which suggests that TiB₂ is the most stable particle while AlB₂ is the most unstable one. TiB₂ holds the highest shear modulus, bulk modulus, Young's modulus and hardness. The hardness of Al₄C₃ is the closest one to aluminum alloy matrix, which indicates that TiB₂ has the largest impact on the strength, stiffness and processing performance of aluminum alloy. The anisotropy factor of AlN particles is the largest, and its influence on that of aluminum alloy is also the largest, then followed by AlB₂. The influence of Al₂O₃ and TiB₂ particles on the anisotropy of aluminum alloy is small. The impact of TiB₂ on the toughness of aluminum alloy is the greatest, followed by AlN, and Al₄C₃ is the smallest. The relative Fermi difference between Al₂O₃ and aluminum matrix is the largest, i.e. 1.4eV. AlB₂ particle is the smallest. The influence of the studied inclusions on corrosion properties of materials is in the order of Al₂O₃>MgO>TiB₂>Al₄C₃>AlN>AlB₂.