Low cycle fatigue behaviour of Ti-13Nb-13Zr alloy in ultrasonic shot peened and stress relieved condition

Abstract

This study examined the effects of ultrasonic shot peening (USSP) and stress relieving treatment at 400 °C (USSP-SR) on low cycle fatigue behaviour of Ti-13Nb-13Zr alloy. The Un-USSP, USSP and USSP-SR samples were characterized for microstructure, surface roughness, hardness and low cycle fatigue. The surface microstructure of the USSP and USSP-SR specimens was refined to ∼ 35 nm. At strain amplitudes of 0.55 to 0.90 %, USSP nearly tripled fatigue life; however, the enhancement was lower in the stress relieved condition but still higher than Un-USSP, except at the highest strain amplitude of 0.90 %, where it was 20 % less than Un-USSP.