Machining Process and Fatigue Test of TC4 Titanium Alloy Strain Fatigue Specimens

In order to efficiently obtain fatigue specimens that can meet the high requirements in the aerospace material testing field, a practical and efficient machining process for strain fatigue round bar specimen of TC4 titanium alloy was proposed with reference to relevant standards. The surface integrity of the fatigue specimen of TC4 titanium alloy was evaluated by physical parameters such as surface roughness, surface processing marks, surface state and surface residual stress. Finally, the strain fatigue test was carried out by hydraulic servo test system to characterize its fatigue performance. The results show that the fatigue specimens processed by using the machining technology can meet the higher requirements of fatigue specimens in the aerospace material testing field. The residual compressive stress on the specimen surface can increase the fatigue performance of TC4 titanium alloy to some extent. At the same time, it can efficiently obtain stable and reliable surface quality in large-scale specimen preparation. It can provide reference for laboratories to effectively control the processing quality of fatigue specimens.