Crystal chemistry and Calphad modeling of the σ phase

摘要: Abstract This article is a comprehensive review devoted to the phase diagram and crystal structure properties of χ intermetallic compound. An extensive study available literature has been performed completed by key experimental measurements in following systems: Fe–Re, Mn–Mo, Mn–Re, Mn–Ru, Mn–V, Mo–Re, Nb–Os, Nb–Re, Re–Ti, Re–Zr. The an important Frank–Kasper (topologically close-packed) whose presence certain systems implications process industrial materials such as Ni-based super-alloys. As binary phase, it exists mainly transition metal Tc, Re Os with elements groups 3–6, rare earths-Mg (αMn) solid solutions. It peculiarity exist three ordered variants corresponding different prototypes αMn, Ti5Re24 Mg17Al12. Particular attention paid way composition compounds accommodated atom mixing on sites. In our work, occupancy parameters four crystallographic sites have obtained Rietveld analysis X-ray powder diffraction data. investigation made function when possible. addition compounds, particular emphasis placed ordering modelling Calphad method. Different models are reviewed recommendations for future thermodynamic assessments.