The Effect of Solution Heat Treatment Temperature on Phase Transformations, Microstructure and Properties of Ti-25Ta-xZr Alloys Used as a Biomaterial

This paper describes a study of the effect of solution heat treatment temperature (500, 750 and 1000 degrees C) on the phase transformations, microstructure, microhardness and Young's modulus of Ti-25Ta-xZr alloys, aimed at biomedical applications. The Ti-25Ta-xZr alloys ingots were melted in an arc furnace with five different compositions (x = 0, 10, 20 30 and 40 wt.%) in order to produce samples with alpha '', beta + alpha '' and beta phase. The results showed that both the microstructure and mechanical properties of the studied alloys can be tailored according to the temperatures used for solution in the Ti-25Ta-xZr system. Usually, higher solution heat treatment temperatures increase hardness due to the higher phase stabilization in single-phase alloys, while in the alpha '' + beta alloys or predominantly beta, hardness decreases due to the suppression of phase alpha ''. However, the elastic modulus of the alloys decreases when solution heat treatment is performed at 1000 degrees C. In general, solution heat treatment performed at higher temperatures stabilizes more the beta phase, optimizing the lower modulus of the alloys.