Improving fatigue life of a titanium alloy through coupled electromagnetic treatments

•The mechanism of CEMT process regulating residual stress was studied by simulation and residual stress experiment.•The mechanism of improving fatigue performance by adjusting residual stress is analyzed theoretically.•Fatigue tests were carried out to verify the effectiveness of CEMT process in improving the fatigue properties of TC11.•The characteristics of fatigue fracture, grain boundary angles, and dislocation evolution were analyzed. TC11 titanium alloy is widely used in the manufacture of key components such as blades of gas turbine and aero engine because of its high specific strength and good processing performance. In the case of gas turbine or aero engine, the fatigue performance of TC11 will directly determine the life of the turbine or engine, and the surface residual stress generated on the alloy during manufacturing often affects the fatigue life of the material. In this study, a new method of coupled electromagnetic treatment (CEMT) was applied to regulate the surface residual stress of the alloy after manufacturing, so as to improve the fatigue life of the TC11. The results show that after the CEMT, the residual compressive stress in the length direction and width direction increased by 63.7% and 56.0% respectively, the fatigue life of the TC11 is increased by 39.9%. The microstructure analysis shows that after CEMT, the width of fatigue striations is significantly reduced. This paper proposes that CEMT can be used as an effective method to adjust the residual stress of materials and improve the fatigue life of titanium alloys. The research is also relevant for improvement of the fatigue life of other alloy materials.