Phase stability and mechanical properties of sigma phase in Co–Mo system by first principles calculations

摘要: Abstract First principles calculations are applied to study the phase stability and mechanical properties of sigma in cobalt–molybdenum (Co–Mo) system. Formation enthalpies have been used for evaluation stability, compared among selected configurations. Based on most energetically stable configurations, a ground-state line is sketched out Co–Mo phase. Magnetic effects electronic structures also explored explain compositional dependence stability. The elastic constants polycrystalline moduli calculated exhibit similar trends as formation enthalpies. A significant degree anisotropy predicted, which can shed light brittle nature rapid crack propagation