PHASE-EQUILIBRIA IN VANADIUM-RICH ALLOYS OF THE V-NI-AL SYSTEM

Vanadium-rich alloys of the V-Ni-Al system were studied by the methods of metallographic,x-ray diffraction, and electron beam microprobe ana lysis. The boundaries of the phases, and the vertices of the conoidal triangle alpha beta sigma, in the vanadium corner of the 1200 degrees C isothermal section were determined. The maximum solubility of alumin um in the a-phase is 6 at. %. The homogeneity range of the NiAl-based beta-phase is very broad; the maximum solubility of vanadium in beta r eaches 41.5 at. %. The maximum solubility of nickel in the vanadium so lid solution is 25 at. %. Alloys containing 15-20 % Al and 20-30% Ni e xhibit a tendency to dispersion harden and, therefore, might serve as a basis for the development of a new generation of radiation-resistant materials.