Analysis of Room-Temperature/High-temperature High-Cycle Fatigue Performance of Laser Additive Manufactured Ti65 Titanium Alloy

In this study, the microstructure, high-cycle fatigue performance, and the influence of stress concentration on the fatigue behavior of Ti65 titanium alloy were investigated under different laser powers using IPG fiber laser additive manufacturing. Fatigue life tests were conducted at both room temperature and high temperature (650 °C), comparing stress concentration coefficients of 1 and 3. The results indicate that different laser powers lead to significant differences in the microstructure of additive manufacturing samples across various directions. At room temperature, the fatigue limit of the high laser power specimens increased by 13.9%, and at high temperature, it increased by 8.78%. However, with a stress concentration coefficient of 3, the high laser power specimens exhibited slightly lower high-cycle fatigue performance compared to the low laser power specimens.