Liquidus surface projection and vertical sections of the phase diagram for the Mo–Mo5SiB2–TiC pseudo-ternary system

Abstract

TiC-reinforced Mo–Si–B alloys (designated as MoSiBTiC alloys) exhibit great potential for application in the aerospace industry, due to their high melting point, moderate density and attractive high-temperature strength and creep resistance. Nevertheless, further material design and industrialization requires more systematic understanding of the phase diagram and solidification paths of Mo–Mo₅SiB₂–TiC pseudo-ternary system. In this study, an advanced ultra-high temperature thermal analysis method employing blackbody radiation and an electromagnetic levitation technique for in situ observation of the solidification process, were utilized to experimentally investigate the solidification process and reaction temperature of alloys in the vicinity of the Mo–Mo₅SiB₂–TiC ternary eutectic point. On the basis of the experimental results, three vertical sections of phase diagram at 9 mol% Mo₅SiB₂, 10 mol% TiC, and 70 mol% Mo_ss isopleths in the Mo–Mo₅SiB₂–TiC pseudo-ternary system were established. The liquidus surface projection on the Mo–Mo₅SiB₂–TiC system has also been reconstructed, with the addition of a new Mo₂B primary phase region and a larger Mo₅SiB₂ primary phase region than previously reported.