Investigation on removal mechanism transformation and subsurface microscopic evolution of SiCp/Al composites under ultrasonic elliptical vibration cutting

SiCp/Al composites have traditionally proven difficult to manufacture due to poor surface quality, excessive tool wear, and subsurface damage. It has been established that ultrasonic elliptical vibration cutting (UEVC) technology is effective at increasing the materials machinability. However, there are currently no relevant investigations on the formation of the subsurface microstructure of SiCp/Al composites under UEVC conditions. To determine the removal method of SiCp/Al composites under UEVC, this work first conducts comparative tests to extensively investigate the correlations between chip morphology, tool wear and surface/subsurface morphology in conventional cutting (TC) and UEVC. Electron backscatter diffraction (EBSD) technique is then employed to investigate the evolution of the subsurface microstructure of SiCp/Al composites. According to the study, UEVC may successfully reduce mechanical stress during cutting, prevent material morphing, and prevent grain over-refinement. Compared to TC, UEVC can effectively suppress subsurface micro-damage and reduce residual stress in the subsurface by controlling the fracturing of SiC particles and their direction of fracture. Furthermore, it can reduce the texture strength of the Al matrix from 6 to 1.96, significantly weakening the deformation texture, effectively preventing dislocations from slipping and propagating, and reducing the creation of surface defects.