Research On Influencing Characteristics Of Parameters In Laser And Ultrasonic Vibration Assisted Cutting Of Tungsten Carbide

Tungsten carbide has excellent comprehensive performance as a kind of typical difficult-to-machine materials,such as high hardness,wear resistance,good strength and toughness,heat resistance,corrosion resistance,etc.Their most prominent characters are high brittleness and low fracture toughness,the elastic limit of the material is very close to the strength of the material,When the material is subjected to the load more than the elastic limit,the fracture damage occurs,which produces cracks and pits on the machined surface,and seriously affects the surface quality and performance of the material.According to the previous research of ultrasonic machining hard and brittle materials,the method of two dimensional ultrasonic vibration and laser heating assisted precision machining is proposed through combing the precise machining technology and the special processing theory in this paper,which achieves the ultra-precision machining of tungsten cobalt carbide.The motion characteristics of ultrasonic vibration cutting was analyzed,and the theoretical model of cutting force was established in this paper.Theoretical model of laser heating temperature field was established according to the theory of heat conduction,the laser heating parameters influence on the temperature field was analyzed by the method of combing finite element simulation and experimental verification,and the empirical model of temperature field of laser heating was built.Based on the self-developed two-dimensional ultrasonic vibration device,orthogonal cutting experiment and single factor experiment were performed in laser heating conditions,The effects of laser parameters and three cutting elements on the three direction force and machined surface roughness were analyzed,and the empirical model of cutting force and roughness value were established then.A series of parameters of the laser assisted heating were identified through experimental research,the influences of three elements of cutting parameter and laser power on cutting force and the influence degree were analyzed,empirical formula of cutting force in the laser heating and two-dimensional ultrasonic vibration aided cutting was established using the regression analysis method,which has high reliability and accuracy through the inspection and analysis,and provides a certain theoretical basis for the reasonable choice of cutting parameters and the optimal control of cutting force.The influence characteristics of three factors of cutting and laser power on the machined surface roughness were analyzed through the same orthogonal experiment and single factor experiment,surface roughness prediction model under the conditions of laser heating and two-dimensional ultrasonic vibration assisted cutting was built based on response surface method,the interaction characteristics between process parameters were analyzed according to response surface diagrams,which lays a foundation for optimal control of surface quality.