Synthesis of W–Zr–Ti Alloy via Combustion in the WO3–ZrO2–TiO2–Mg System

Abstract

We have studied the self-propagating high-temperature synthesis (SHS) process due to the combustion of a WO3 + ZrO2 + TiO2 + Mg multicomponent mixture. The ratio of the oxide phases and excess Mg content have been shown to have a significant effect on the phase composition of the synthesized material. Increasing the WO3 content of the starting mixture from 7.4 to 59.6% raises the adiabatic combustion temperature from 1560 to 3099 K and reduces the percentage of Zr and Ti metals in the synthesis product, which pass into the W〈Zr,Ti〉 solid solution. We have optimized the composition of the starting mixture, 50.6% WO3 + 6.9% ZrO2 + 4.5% TiO2 + 38% Mg, so that its combustion yields a semifinished product consisting of W〈Zr,Ti〉 alloy, MgO, and Mg. After acid leaching, we have obtained a single-phase W〈Zr,Ti〉 substitutional solid solution. Chemical analysis and X-ray diffraction data demonstrate that the alloy thus prepared is similar in composition to W0.66Zr0.17Ti0.17.