RHENIUM INTERACTION WITH METALS AND FORMATION OF INTERMETALLIC COMPOUNDS

Interaction of rhenium with transition metals of the IV-VIII groups has been analyzed. The advantages of rhenium as an alloying element for construction steels and especially for steels used in special machinery have been demonstrated. Besides being heat and boil resistant, like tungsten, molybdenum and tantalum alloys, Re alloys are also uniquely plastic which is due to separation of carbon from brittle carbides and formation of solid rhenium and carbon solutions. It has been demonstrated that rhenium and elements of the eighth group form solid solutions with unlimited solubility. In the rhenium systems, there are twenty intermetallic compounds with σ and χ phases. Besides these phases, rhenium also forms λ phases (Laves’s phase) with elements of the IVth group. Being a metal with tight hexagonal structure, rhenium has high solubility, up to 65 at.%, with metals of the Vth and VIth groups that have a volumcentric cubic structure. Rheniums solubility is quite low (0,5...4,0%) in hexagonal α modifications of polymorph metals of IVth group and, at the same time, the solubility in volumecentric β modificiation of the same metals reaches (for titan) 50 at.%. Re has high thermal stability. It has higher strength than tungsten, and considerably higher than Mo at 1200oC.