Phase diagram of the Cu-Ni-Mn system

Part of the phase diagram of the Cu-Ni-Mn system from 0 to 20% Ni and from 30 to 50% Mn is refined with the help of a theoretical analysis and based on the experimental data. It is shown that the assumption that a line exists in the Cu-Ni-Mn ternary system along which the alloys with a zero crystallization range are arranged is erroneous. Only the alloys in the Cu-Mn and Ni-Mn binary systems have a zero crystallization range. The primary assumption that it is impossible to represent the nonequilibrium crystallization by Petrov-Scheil in the absence of a minimum line in the Cu-Ni-Mn system was not confirmed because previous studies were performed for a model system in which a convex liquidus line was present in the polythermal section connecting the minima in binary systems. In this study it is shown that this line is concaved towards lowering the temperature.