| Silicon carbide particle reinforced aluminum matrix composite(SiCp/Al)has the characteristics of low density,high strength,high specific modulus,high thermal conductivity,low thermal expansion coefficient,high wear resistance and corrosion resistance,and has been widely used in automotive,electronics,aerospace and other fields.With the rapid development of science and technology,the application requirements of SiCp/Al composites are increasing.SiCp/Al composite is composed of aluminum matrix and silicon carbide(SiC)particle reinforced phase.The physical properties of the two phases are very different,which makes SiCp/Al composite become a typical difficult material to process.Conventional processing SiCp/Al is difficult,the surface quality is poor after processing,difficult to achieve the ideal processing effect.Vibration assisted lapping is a method that combines conventional lapping and vibration with vibration auxiliary device to grind workpiece.The method can reduce lapping force,reduce lapping head wear and improve surface quality,and is suitable for SiCp/Al processing.The main contents of SiCp/Al vibration assisted lapping are as follows:(1)A vibration auxiliary lapping device is developed.Based on the theory of flexible mechanism,a vibration-assisted lapping device was designed.The static and dynamic models of the device were established by the compliance matrix method and Lagrange method.The device was simulated and optimized by finite element analysis method,and the device was processed by wire cutting.Finally,the performance of the device is tested,including the natural frequency,resolution,output displacement,motion trajectory,etc.,to ensure that the device can meet the requirements of practical applications.(2)The removal characteristics of vibration assisted lapping of SiCp/Al composite were analyzed by finite element simulation.The finite element model of single particle vibration assisted lapping SiCp/Al was established to study the material chipping form,removal mechanism and surface defects during vibration assisted lapping of SiCp/Al composite,and to explore the influence of process parameters on the surface formation of SiCp/Al composite during vibration assisted lapping.(3)Study on lapping force assisted by SiCp/Al vibration.According to the chip forming characteristics of SiCp/Al vibration assisted lapping,the lapping force was divided into chip forming force,particle crushing force and friction force,and a SiCp/Al vibration assisted lapping force model was established.By analyzing the processing characteristics of vibration-assisted lapping device,the relationship between lapping particles and workpiece surface motion is explored based on the principle of kinematics,and the chip forming force of SiCp/Al cutting by single lapping particle is expressed.Combining with the energy conservation law and the number of effective lapping particles,the chip forming force,particle breaking force and friction force are obtained.Finally,the three parts are pursued and the total lapping force is obtained.(4)Experimental study on SiCp/Al vibration assisted lapping.SiCp/Al conventional lapping and vibration assisted lapping comparative experiment,explore the change law of lapping force after conventional lapping and vibration,analyze the influence law of process parameters on lapping force,and the surface of the workpiece after processing using white light interferometer topography detection,the quality of the two processing methods are compared.The variation of workpiece surface roughness with process parameters was investigated,and finally the validity of vibration assisted lapping method was verified. |
