STRUCTURE AND MECHANICAL PROPERTIES OF Ti-Cr-Al-Nb AND Ti-Cr-Al-Nb-V MULTICOMPONENT ALLOYS

Abstract

The empirical and semi-empirical models were used to analyze the phase-structural state of five- and fourcomponent alloys of the Ti-Cr-Al-Nb-V system. Two compositions of lightweight alloys were selected for experimental study: Ti60Cr11Al7Nb11V11 and Ti60Cr11Al7Nb22 (at. %). Ingots of these alloys were obtained by argonarc melting method, and they were subjected to homogenization, deformation by rolling and subsequent annealing at different temperatures. The influence of annealing temperature on the phase-structural state of the alloys, their hardness, and mechanical properties during tensile tests has been studied experimentally. It was found that the change of phase composition and grain size during annealing in the temperature range of 700…900 ºC practically does not affect the hardness and tensile strength of alloys. Annealing at 900 ºC transforms the alloys into a singlephase state with bcc lattice and significantly increases the elongation to fracture, which is about 30% for both alloys. In addition, the yield strength and tensile strength of the five-component alloy are noticeably higher than those of the four-component alloy.