| Carbon fiber reinforced plastic(CFRP)has many excellent mechanical properties such as light weight,high strength,fatigue resistance,etc.At the same time,the structural designability when used to manufacture parts is strong,so it is increasingly used in the manufacture of large aircraft parts.In order to ensure the reliability of the aircraft,metal parts are still used in the connection parts,to form a large and wide variety of metal and CFRP laminated structures.In order to ensure the processing quality and installation accuracy of the laminated structure,integrated hole making is usually adopted.During the integrated hole making process,it is usually faced with long metal chips scraping the hole wall and serious tool wear problems.For this reason,some scholars introduced low-frequency vibration assistance The drilling process solves the problems of metal chip breaking and heat dissipation,and improves the quality of hole and tool life,but most of them are researched on the laminated structure of the metal at the outlet.When CFRP is used as the export material,the CFRP of the export is in a weakly constrained state.The vibration causes the drill bit and the workpiece to intermittently contact and cut.The effect of the alternating load on the processing quality and tool wear is not yet clear.Therefore,based on the low-frequency vibration-assisted process,this paper conducts vibration drilling experiments on the Al / CFRP laminated structure,and explores the influence of low-frequency vibration on the processing quality and tool wear when CFRP is used as an export material;at the same time,the vibration hole design is based on the low-frequency vibration process.Test bench and perform performance tests.The main research contents and conclusions are as follows:(1)Vibration drilling can effectively break metal chip,avoid generating long chips to scratch the hole wall and material surface,and help to improve the processing quality of the upper aluminum alloy;in addition,different amplitudes are used for processing experiments,and it is found that the amplitude can be in a certain range The maximum axial force of drilling is increased to a certain extent,and the smaller amplitude has no obvious effect on the CFRP hole wall and outlet quality,but as the amplitude increases,the CFRP hole wall quality gradually deteriorates and the outlet tear increases.Therefore,in the process of Al / CFRP laminated structure processing with CFRP as an outlet,in order to achieve metal chip breaking and ensure the processing quality of the exported CFRP,the amplitude should be controlled between 0.025 and 0.5 mm.(2)During the drilling process,the cutting edge wear of the tool is asymmetric,the rake face wear is slower than the flank face;low frequency vibration can change the tool trajectory,significantly improve the shape of the chip,and promote the discharge of the chip and the loss of heat during the drilling process,reduce the temperature of the cutting edge,thereby reducing the chemical activity of various substances in the processing environment,effectively suppressing the chemical form of wear that occurs on the cutting edge and reducing tool wear.(3)The principle of mechanical low-frequency vibration drilling is analyzed,and the design idea of a low-frequency vibration test bedstand with adjustable frequency is proposed;at the same time,a portable low-frequency vibration hole-making device is designed,and the performance of the device is tested,and the processing process is stable,The processing quality is well.In this paper,through theoretical and experimental methods,the influence of low-frequency vibration technology on the processing quality and tool wear during the processing of Al / CFRP materials is analyzed.At the same time,low-frequency vibration hole-making equipment is designed,which is a high-level laminated structure for CFRP as an export material.Quality and efficient processing,and the development of low-frequency vibration hole-making equipment laid a certain foundation. |
PDF Full Text Request