Research on flexible adaptive CNC polishing process and residual stress of blisk blade

Abstract

Flexible adaptive polishing process can be used to polish blisk. In order to verify the feasibility of polishing blisk and improve the surface integrity of blisk, this paper analyzes residual stress and its effect on deformation. Firstly, the formation mechanism of residual stress and deformation was analyzed. Secondly, the influence of polishing process on surface profile was analyzed and qualitatively analyzed the non-interference polishing of blisk polishing. Thirdly, the effects of polishing process on surface residual stress, residual stress of depth layer, and residual stress uniformity were analyzed. Fourthly, the empirical model of surface residual stress to polishing process parameters was established, and the sensitivity and stable range of the process parameters were analyzed. Finally, the influence of polishing process on deformation was quantitatively analyzed by FEA and experimental testing though contrasting polishing and milling process. The results show that the surface residual stress is reduced by 60 Mpa by flexible polishing process and can be reduced by more than 80 Mpa if appropriate polishing process parameters are used, and the surface residual stress is mostly sensitive to spindle speed, followed by compression depth, granularity, and feed rate. Flexible polishing process can make the surface residual stress become more uniform. Flexible polishing process has no effect on the change rule in the depth direction of residual stress. The second deformation of polished blisk blade is less than the milled blisk blade’s. Flexible polishing process can effectively improve surface integrity and be widely used for polishing blisk.