Investigation on surface quality of milling Ti6Al4V alloy thin-walled parts based on ice fixation

Due to poor structural stiffness, high heat production during processing, easily producible plastic deformation, part processing accuracy, and processing efficiency, thin-walled titanium alloy parts are challenging to mill. Based on the fundamental concepts of ice-covered cold action and stress-free clamping of workpieces under freezing, this paper focuses on the challenging issues in the machining of titanium alloy thin-walled parts and suggests a novel, high-precision milling technique for ice-covered constrained thin-walled parts of titanium alloy. Designing ice-covered fixation and non-ice-covered fixation milling tests allowed researchers to confirm the method's efficacy. The effects of the machining parameters, coated tool, tool path, and workpiece freezing temperature on the milling temperature, milling force, flatness/parallelism, and surface roughness of the workpiece were carefully examined. The research results show that the ice-covered restraint method effectively suppresses the phenomenon of titanium alloy burning and glowing during the milling process and reduces the temperature in the tool tip-workpiece contact area by 64.90% compared with the traditional method. The dimensional accuracy and surface quality of the workpiece are significantly improved. Flatness and parallelism are reduced by 19.49-34.29% and 8.75-23.33%, respectively, and surface roughness is reduced by 13.07-34.86%. Surface roughness and milling forces are not feed speed sensitive, but spindle speed has a significant impact on both. Low-friction AiTiN-coated tools produce surfaces with the least amount of surface roughness, milling forces, and flatness. Surface roughness, parallelism, and flatness of the workpiece can all be enhanced by longitudinal or transverse travel. Workpiece freezing temperature - 15 degrees C working condition has the most significant effect on suppressing workpiece processing deformation and improving surface quality. The findings of the study offer a new common solution for the efficient and high-precision machining of thin-walled structural parts with a wide variety of applications.