Mechanical and Oxidation Characteristics of Ti20-Al16-V16-Fe16-Ni16-Cr16 High-Entropy Alloy Developed via Spark Plasma Sintering for High-Temperature/Strength Applications

Ti6Al4V is one of the most useful alloys because of its high strength, low weight, high oxidation resistance and low CTE. However, it is weak in shear strength which has affected its performance. This research was aimed at developing high-entropy alloy of Ti-20-Al-16-V-16-Fe-16-Ni-16-Cr-16 at near equi-molar level via spark plasma sintering technique which would possess better mechanical and oxidation characteristics than Ti64. The powders were blended, sintered at varying temperatures from 700 to 1100 degrees C and characterized. Results showed that HEA sintered at 1000 degrees C possessed the best mechanical, oxidative and microstructural properties, while that sintered at 700 degrees C had the least mechanical and thermal properties. The developed HEA had elastic modulus improvement of about 336% over Ti6Al4V and about 277% over Ti6Al4V-0.55B alloys. It had creep resistance of 2.47% at loading of 300 mN and 4.38% at loading of 500 mN, densification of 98.86%, porosity of 1.14% and a parabolic oxidation profile. It was concluded that the developed alloy has superior mechanical and oxidation properties than Ti64 and so can perform better in applications where high strength at high temperature is required.