Ab initio calculations of structural, elastic and thermal properties of TiCr2 and (Ti,Mg)(Mg,Cr)2 Laves phases

[Display omitted] •Structural stability, elastic and thermal properties of TiCr2 and (Ti,Mg)(Mg,Cr)2 are studied using ab initio calculations.•The preferred site of Mg alloy is also determined.•Elastic constants, mechanical parameters and Debye temperature are calculated and discussed. First principles calculations have been carried out to investigate the structural stability, mechanical and the thermal properties of TiCr2 and (Ti,Mg)(Mg,Cr)2 Laves phases. For pure TiCr2, results show that C15 (cubic) and C36 (hexagonal) phases are stable. When Mg is incorporated in substitution of Ti or Cr, the obtained total energies and formation enthalpies indicate that its preferred site is the Ti one. Also, the elastic properties reveal that (Ti,Mg)Cr2 is harder, more brittle and much stiffer than TiCr2.