Effect of Machining Parameters on the Residual Stress Distribution and Surface Roughness in Ti-6-Al-4V Alloy

The residual stress and the surface roughness are the critical input when conducting the safety analysis of the aero-engine components because the surface integrity of the machining process may affect the fatigue life of the aero-engine components. To obtain the residual stress distribution and surface roughness, the analytical and finite element method have been developed to obtain the stress and temperature fields. However, the analytical and finite element methods are based on many assumptions and fail to predict accurately. Thus, there is an absence of models that can be used to predict the residual distribution. Therefore, this paper established the database of residual stress and surface roughness in Ti-6-Al-4V alloy under different machining parameters to provide the core input to the safety or reliability analysis of the critical components. Specifically, the machining parameters of Ti-6-Al-4V alloy refer to the actual manufacturing process, and the cutting speed ranges from 30 to 95 m/min, the cutting feed ranges from 0.05 to 0.2 mm/r, and the cutting depth ranges from 0.01 to 0.5 mm. Results show that the cutting process on the Ti-6-Al-4V alloy mainly generates compressive residual stress ranging from −550 MPa to −300 MPa, and the residual stress layer depth is around 200–600 μm. The surface residual stress mainly depends on the cutting feed rate, while the residual stress depth is related to the cutting speed. The surface roughness Ra ranges from 0.388 to 4.430 μm, mainly depending on the feed rate.