Application of GOV (flow peening) process to improve surface quality of Ti-6Al-4V of aerospace material

Ti-6Al-4V is a difficult-to-cut material with wide applications due to its superior mechanical features. Non-traditional surface treatment methods namely abrasive flow machining and shot peening are applied to obtain desired surface quality. GOV (flow peening) process having advantages of surface quality and strength improvement (compressive residual stress generation) of AFM and shot peening respectively was developed. In this paper, the effects of the GOV process parameters (number of cycles, steel ball size, and media ratio) on the material surfaces were investigated to evaluate surface roughness (Ra), material removal amount and white layer thickness. The surface roughness, Ra value was decreased from 2.17 µm to 0.80 µm. In addition, 4.4 mg of material corresponds to total amount of white layer was removed (verified by SEM images). GOV process can be used to improve surface quality by decreasing surface roughness and removing white layer without any excess chip removal.