Phase Equilibria in the Quaternary Ni-Re-Nb-Cr System at 1375 K Determined Using the Graph Method

Phase equilibria in the quaternary Ni-Re-Nb-Cr system at 1375 K have been determined by using the graph method combined with equilibrated alloys that were characterized with electron probe microanalysis and x-ray diffraction techniques. Three 4-phase equilibria, alpha + beta(Cr) + lambda + sigma, alpha + beta(Nb) + lambda + chi, and alpha + gamma + sigma + Re, and three nonprojected 3-phase equilibria, alpha + lambda + chi, alpha + lambda + sigma and alpha + sigma + chi, have been experimentally established. In addition, the graph method suggested the existence of the following four other 4-phase equilibria in this system at 1375 K, alpha + beta(Cr) + gamma + sigma, alpha + beta(Nb) + lambda + mu, alpha + lambda + sigma + chi, and alpha + sigma + chi + Re.