Cr and Fe Replacement to Optimize -Al(MnCrFe)Si Phase Stability, Electronic Structure and Mechanical Properties

The stability, electronic properties, mechanical properties and elastic anisotropy of [alpha]-AlSiMnCrFe compounds were calculated by first-principles calculation method. The formation enthalpy and cohesive energy of the AlSiMnCrFe compounds were not more than zero, which indicates that these compounds had thermodynamically stable structures. The [Al.sub.102][Si.sub.12][Mn.sub.16][Cr.sub.2][Fe.sub.6] had the lowest formation enthalpy, showing that this compound had better stability than other-the AlSiMnCrFe compounds. The main types of bonding bonds of the AlSiMnCrFe compounds were metal bonds, covalent bonds and ionic bonds. The [Al.sub.102][Si.sub.12][Mn.sub.16][Cr.sub.8] had the biggest bulk modulus with the value 104.3 GPa; the [Al.sub.102][Si.sub.12][Mn.sub.16][Fe.sub.8] had the biggest Yong's modulus and shear modulus with the value 156.9 GPa and 63.6 GPa, respectively. From the 3D surface map and projection map of elastic modulus, it can be seen that the AlSiMnCrFe compound had the elastic anisotropy.