The structural, elastic and thermodynamic properties of intermetallic phases in Mg–Sn–Si–Ca(Sr) alloys: A first-principles study

Abstract

The structural, elastic and thermodynamic properties of Mg2Si, Mg2Sn, CaMgSi and MgSnSr phases in Mg–Sn–Si–Ca(Sr) alloys have been investigated by implementing first-principles calculations. Formation enthalpies and cohesive energies show that MgSnSr has the strongest alloying ability and CaMgSi has the highest structural stability. The bulk modulus B, shear modulus G, Young’s modulus E, G/B, Poisson ratio [Formula: see text], anisotropy index A[Formula: see text] are estimated after evaluating the elastic constants. The mechanical properties are further analyzed and discussed. Finally, the Gibbs free energy and Debye temperature of these phases are calculated by means of the quasi-harmonic Debye model in temperature ranging from 0 K to 1000 K.