| SiCp/Al composites are widely used in the automotive industry,aerospace,defense and military and electronic packaging due to their high specific strength,high specific modulus and excellent wear resistance,corrosion resistance and thermophysical properties.However,hard Si C particles are not evenly distributed in SiCp/Al composites,resulting in serious tool wear,poor machining quality and low machining efficiency during conventional cutting.In order to improve the machinability of SiCp/Al composites,reduce processing costs and improve the quality of the processing surface,a single-excited twodimensional ultrasonic vibration turning device that can realize vibration-assisted processing is first developed.Secondly,the simulation and experimental research are combined to explore the temperature field in laser ultrasonic assisted processing.Then,finite element simulation was used to compare and analyze the stress-strain distribution and surface formation process of SiCp/Al composites in the microstate under different processing methods.Finally,the process parameters affecting cutting force and surface morphology are analyzed experimentally,which provides an effective method for the highquality processing of SiCp/Al composites.The specific research content is as follows:(1)Research and development of single-excitation two-dimensional ultrasonic vibration turning device.According to the design theory of luffing rod and ultrasonic transducer,the structural design of each component of the single-excitation twodimensional ultrasonic vibration turning device is carried out,and the dimensional parameters of the corresponding components are calculated.Based on the calculated dimensions,the three-dimensional modeling is carried out and the simulation is carried out,and the rationality of the design is verified by modal analysis and harmonious response analysis,so as to complete the development of single-excitation two-dimensional ultrasonic vibration turning device.The R&D prototype was tested to ensure that the single-excitation 2D ultrasonic vibration turning device designed met the design requirements.(2)Based on the heat conduction theory,a transient heat transfer model of laser ultrasound-assisted turning SiCp/Al composites was established and finite element analysis was carried out.The temperature field after pulsed laser heating was simulated by A baqus software,and the dependence of the surface temperature field and cross-sectional temperature field of pulsed laser irradiation SiCp/Al composites on laser power,laser movement speed,spot diameter and pulse frequency was explored.The infrared temperature measurement method is used to measure the surface temperature of the laser ultrasonic assisted turning process,and the relationship between the simulated value and the experimental value is analyzed,which provides a basis for the selection of laser parameters for subsequent experiments.(3)Finite element simulation analysis for different processing methods.A twodimensional microscopic finite element model based on the random distribution of polygonal Si C particles was established by Abaqus software to simulate the ultrasonic vibration-assisted turning and laser ultrasound-assisted turning processes of SiCp/Al composites.By comparing and analyzing the stress-strain distribution and the improvement of cutting force by pulsed laser under pulsed laser conditions,as well as the removal mechanism and surface morphology of SiCp/Al composites under the two processing methods,it was verified that the laser ultrasonic assisted turning method by finite element simulation could significantly improve the processability of SiCp/Al composites.(4)Carry out experimental research on laser ultrasound-assisted turning of 20%SiCp/Al composite materials.A laser ultrasonic assisted turning experimental platform was built to conduct experimental research on laser ultrasonic assisted turning and ultrasonic vibration-assisted turning of 20% SiCp/Al composites,and the influence of workpiece speed,feed,cutting depth and laser power on cutting force and surface roughness was explored.The removal mechanism of SiCp/Al composites under laser-assisted turning and the reasons for the reduction of surface roughness,surface defects and smaller cutting force during processing were analyzed by comparing the surface defects under the two processing methods,and the optimal process parameters were obtained based on the experimental results of laser ultrasound-assisted turning of 20% SiCp/Al composites. |
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