Microstructure and tensile properties of a cost-affordable and ultrahigh-strength metastable β titanium alloy with a composition of Ti-6Al-1Mo-1Fe-6.9Cr

A cost-affordable and ultrahigh-strength metastable beta titanium alloy with a composition of Ti-6Al-1 Mo1 Fe-6.9Cr has been designed by high-throughput diffusion couple technique. The alloy was heat treated along different regimes to investigate the effects of heat treatments on phase transformation, microstructure evolution, and tensile properties. The results showed that the aging strength of the alloy after solution treatment at 840 degrees C was higher than that at 800 degrees C due to the more alpha s precipitation during aging, while solution treatment at 840 degrees C and aging caused slight decrease of tensile ductility because of the lower alpha(p)-phase fraction during solution treatment. Moreover, the formation TiCr2 Laves phase at aging temperatures above 540 degrees C resulted in remarkable reduction of tensile ductility. Owing to the multiple-hierarchy alpha precipitations dispersed into the beta matrix, two excellent strength-ductility combinations were successfully obtained for the alloys after solution treatment at 800 degrees C/840 degrees C and aging at 470 degrees C with the ultimate tensile strength and tensile elongation values of 1395 MPa/16.0% and 1614 MPa/9.7%, respectively. (C) 2021 Published by Elsevier B.V.

Automated summary

A cost-affordable and ultrahigh-strength metastable beta titanium alloy has been designed by high-throughput diffusion couple technique. The effects of heat treatments on phase transformation, microstructure evolution, and tensile properties were investigated. Excellent strength-ductility combinations were obtained by choosing appropriate heat treatment schemes.