Abstract:
The technology of ultrasonic rolling strengthening titanium alloy at room/medium temperature is proposed and studied. Combining experiments and finite element analysis methods, the influence mechanism of ultrasonic vibration rolling and ultrasonic vibration warm rolling on the residual stress and strain distribution of the titanium alloy surface modification layer was compared and investigated. The results show that: compared with ultrasonic vibration rolling, the ultrasonic vibration warm rolling process can cause more serious plastic deformation of the surface and near surface materials, and introduce a deeper residual compressive stress layer near the surface of the material to obtain better surface strengthening. The further increase of compressive stress and strain benefits from the combined effect of high-frequency mechanical shock and warm plasticity. During the ultrasonic rolling process, ultrasonic excitation fundamentally changes the way the stress propagates in the material, forming a dynamic stress wave and oscillating and propagating far away from the material surface and the application of the temperature field accelerates the formation and dynamics of this stress wave spread.