The Residual Stress and Deformation Control of TC4 Thin-Walled Outer Ring Components by Ultrasonic Regulation

Abstract

The deformation problem caused by the excessive residual stress has brought great challenges to the high-precision machining and geometrical stability of thin-walled components. Aiming to ensure the verticality within 0.012 mm after the processing and forming of a certain type of outer ring components, this paper firstly employs the ultrasonic critical refraction longitudinal wave (LCR wave) detection method to test the residual stress distribution in the key process. Additionally, the stress elimination effect of cryogenic stress relief treatment and the effect of residual stress on vertical deformation are analyzed. After that, combined with the self-developed ultrasonic stress relief (USR) equipment, the ultrasonic regulation treatment was used to replace the heat treatment stress relief process for the processing. The results show that after wire cutting and milling, excessive residual stress induces deformation of components, and USR method can eliminate machining residual stress more efficiently and quickly. As the whole component has torsional deformation along the cross section, the hole position at the upper and lower end faces is changed, which leads to the change in verticality. Finally, based on the results of X-ray diffraction (XRD), the potential microscopic mechanism of stress relief by ultrasonic treatment is analyzed. This study provides guidance for ultrasonic residual stress regulation to achieve the high-precision outer ring thin-walled components.