TB6 titanium alloy is widely used in aviation because of its high strength-to-weight ratio and extraordinary hot deformation behavior

which is the main material to manufacture the primary structure of helicopter rotor systems as well as the landing gears. To ensure the parts meet the requirement of fatigue properties

finish milling parameters have been optimized based on the integrity of machined surface. The experiment results show that feed per tooth fz has an obvious influence on the roughness R a and residual stress σH of the machined surface. When fz increases

the surface roughness increases linearly. Meanwhile

the amplitude of the residual stress also increases with the increase of fz . The microhardening rate is mainly effected by the cutting speed vc. The increase of vc leads to the decrease of the micro-hardening rate. On the other hand

it can be obtained that the cutting width ae has a great influence on the machined surface residual stress. When ae increases

the amplitude of surface residual stress reduces obviously. According to improving the fatigue properties

low cutting speed vc

small cutting width ae and high feed per tooth fz should be adopted. At the same time

the appropriate cutting depth ap can be utilized under the premise of meeting all the design requirements

such as the surface roughness and machining efficiency.