Experimental Investigation of Phase Equilibria in the Cr-Mo-Hf Ternary System

In this study, the phase equilibria of the Cr-Mo-Hf ternary system at 1100 and 1300 °C were experimentally investigated by means of back-scattered electron, electron probe microanalysis and x-ray diffraction. The two C15 phases (α(HfMo 2 ) and α(HfCr 2 )) link up with each other from Mo-Hf side to Cr-Hf side across the isothermal sections both at 1100 and 1300 °C. The isothermal section at 1300 °C consists of one three-phase region and three two-phase regions, while no ternary compound is found. One single-phase region of bcc(βHf) not connected with Mo-Hf binary boundary is found unexpectedly at 1100 °C, which results in the appearance of two extra three-phase regions.