Surface integrity in high-speed milling of Titanium alloy TC11

The study focuses on the machined surface integrity of titanium alloy TC11 under different cutting conditions. Residual stress, surface roughness and microstructure were investigated. Three cutting speeds were selected as 376.8 m/min, 471 m/min, and 565.2m/min. In addition, three different cooling methods including dry, emulsion liquid and oil mist were selected. The results show that the surface residual stresses are compressive under all cutting condition. The compressive residual stresses decrease with the milling speed increasing both in feed and stepover directions. When the milling speed increases, surface roughness increases obviously. The lowest residual stress and surface roughness are obtained when the emulsion liquid is used as cooling method. The microstructure of surface layer is not obvious changed; phase transition and undesirable deformation of grain are not found under all cutting condition. Emulsion liquid cooling is the best cooling method in high-speed milling of titanium alloy with uncoated cemented carbide tool.