Material removal and surface texture in the longitudinal ultrasonic vibration-assisted milling of GH4169D superalloy

GH4169D superalloy exhibits exceptional service performance, enhancing the capabilities of aeroengines. However, it also poses challenges to component machining. Ultrasonic vibration-assisted machining has demonstrated advantages in enhancing material machinability. However, comprehensive analyses that pertain to the tool cutting edge path, material removal mechanism, and surface texture in longitudinal ultrasonic vibration-assisted side-milling (LUVM) are rare. In this study, GH4169D superalloy was subjected to LUVM and conventional milling (CM) to investigate the material removal mechanism and surface texture generation. Furthermore, a noncutting time ratio model was proposed to predict the reduction in maximum milling force achieved by LUVM. Results indicated that compared with that of CM, the machining of LUVM was divided into milling and noncutting. The inclusion of noncutting contributed to a reduction in the maximum milling force during LUVM. However, as milling speed increased, noncutting time ratio decreased and subsequently diminished the advantage of LUVM. The chip morphology formed using LUVM exhibited a greater degree of curliness compared with that obtained using CM, facilitating chip breaking. The utilization of LUVM resulted in the formation of a thinner lamellar structure on the free surface of chips compared with the use of CM. The machined surface exhibited a distinct ultrasonic vibration texture in LUVM, which was characterized by a physics formula. The utilization of LUVM demonstrated a reduction in machined surface roughness Ra compared with the use of CM at a low milling speed. The findings of this study contribute to the prediction of the effects of LUVM on reducing maximum milling force and achieving control over chip morphologies and machined surface texture.