Research On Key Technology Of Two Dimensional Ultrasonic Vibration Polishing Of CoCrMo Alloy

The CoCrMo alloy has excellent friction properties,high corrosion resistance and good biocompatibility,so it is used for artificial joints.However,as a refractory material,traditional mechanical methods are difficult to obtain excellent surface morphology.But two-dimensional ultrasonic vibration polishing solves the problems of low removal efficiency and poor roughness.Therefore,the paper studies structural characteristics of the ultrasonic vibration polishing device,analyzes the movement mechanism and establishes the polishing force and material removal model.Then,the effect of processing parameters on CoCrMo alloys surface morphologies and removal rates is explored.The main research contents of this paper are as follows:(1)Structures of a two-dimensional ultrasonic polishing device is studied.The trajectory is simulated and the size parameters of the groove are optimized by finite element.Then,the position model of single abrasive particles in contact with workpiece was established.(2)The principle of impulse impact of ultrasonic vibration was studied,and the mechanical model of ultrasonic vibration polishing was established based on kinetic energy theorem.Then the expression of indentation width was established according to Hertz contact theory,and the vibration polishing removal model was established based on the trajectory of abrasive particles.(3)The advantages of ultrasonic vibration polishing CoCrMo alloy were explored through experiments,and the influence of different processing parameters on the surface quality was analyzed.Then,the effect of ultrasonic vibration polishing on hydrophilic and hydrophobic properties of CoCrMo alloy was investigated.