Effect of Nano-Y2O3 Addition on Microstructure and Tensile Properties of High-Nb TiAl Alloy Prepared by Spark Plasma Sintering

Abstract

Nano-Y2O3 reinforced Ti-47.7Al-7.1Nb-(V, Cr) alloy was fabricated by a powder metallurgy route using spark plasma sintering (SPS), and the influence of nano-Y2O3 contents on the microstructure and mechanical properties were investigated systematically. The results revealed that the ultimate tensile strength and elongation of the alloy were 570 ± 28 MPa and 1.7 ± 0.6% at 800 °C, 460 ± 23 MPa and 6.1 ± 0.4% at 900 °C with no nano-Y2O3, 662 ± 24 MPa and 5.5 ± 0.5% at 800 °C, and 466 ± 25 MPa and 16.5 ± 0.8% at 900 °C with 0.05 at% nano-Y2O3 addition, respectively. Due to the fine-grain strengthening and the second-phase strengthening, both tensile strength and elongation of the high-Nb TiAl alloy were enhanced with the addition of nano-Y2O3.