APPLICATION OF TERNARY PHASE-DIAGRAMS TO THE DEVELOPMENT OF MOSI2-BASED MATERIALS

A review of the literature reveals ternary phase diagram data for a number of systems involving MoSi2. Although incomplete, this literature provides the initial basis for a rational approach to alloy design. For example. one can assess the high temperature stability of various artificially introduced reinforcements, such as niobium or SiC in an MoSi2 matrix and the possibilities for the development of stable two-phase microstructures in quasibinary alloys in the MoSi2-TiSi2 and MoSi2-TaSi2 systems. Revised phase diagrams for these latter systems are presented that indicate the absence of the C11b-to-C40 high temperature polymorphic transformation in pure MoSi2.