Investigating the nanomechanical and thermal characteristics of Ti20-Al20-V20-Fe20-Ni20 HEA developed via SPS for high energy applications

Abstract

Ti6Al4V is one of the most popular alloys used in the aerospace, biomedical and high temperature/strength applications due to its high strength, low weight, high oxidation resistance and low CTE. But its low shear strength undermines its performance in some critical engineering applications. This work was aimed at developing high entropy alloy of Ti-Al-V-Fe-Ni at equiatomic level using spark plasma sintering technique which would be able to address the above weakness of Ti64. The powders were blended, sintered at varying temperatures from 700 °C to 1100 °C and characterized. Results showed that HEA sintered at 1100 °C possessed the best nanomechanical, thermal and microstructural properties while that sintered at 700 °C had the weakest properties. The developed alloy had elastic modulus improvement of about 667% over Ti6Al4V and about 51% over Ti6Al4V-0.55B alloys. It had creep resistance of 1.5%, densification of 98.94%, porosity of 1.06% and very high resistance to oxidation. It was concluded that the developed alloy can perform much better than Ti64 in high temperature and high strength applications.