Evolution and empirical modeling of compressive residual stress profile after milling, polishing and shot peening for TC17 alloy

Abstract

Compressive residual stress is important to improve the fatigue life of components. This paper proposed an empirical model to predict the compressive residual stress profile induced by the integration manufacturing processes (firstly milling, then polishing, finally shot peening). An exponential decay function was used to describe the compressive residual stress profile induced by milling process. Moreover, a sinusoidal decay function was proposed to describe the compressive residual stress profile induced by shot peening process. The integration manufacturing processes model was a deterministic function of the combination of exponential decay function, sinusoidal decay function, and their interaction term. Additionally, an impact coefficient was introduced to describe the influence of polishing process on compressive residual stress profile. The coefficients of the proposed models were related to the input machining parameters. Experiments of TC17 alloy were carried out utilizing response surface methodology and full factorial design to construct these models. Flank wear, tool inclination angle, axial depth of cut, shot peening intensity, and shot peening coverage were selected as five input machining parameters. According to the experimental results obtained, the evolution of compressive residual stress profile after the integration manufacturing processes was investigated, and the proposed models had been developed. The empirical model was validated by two extra experiments and a significantly good prediction was achieved.