Research On Chip Formation Mechanism And Tool Wear In CFRP Internal Chip Removal Drilling

Carbon fiber reinforced polymer(CFRP)is widely used in aerospace,automobile manufacturing and other fields because of its high specific strength and greater specific rigidity among lightweight materials.When assembling CFRP laminates with other components,it is inevitable to carry out mechanical processing,among which hole processing is the main one.However,there are many problems in the ordinary hole processing of CFRP,such as machining defects,serious tool wear and low collection efficiency of powder chips,which seriously affect the quality of hole processing and machining efficiency.For special structure drill and new drilling technology,there are differences between drilling mechanism and wear type in drilling process.Therefore,based on the internal chip removal drilling technology,this paper researches and analyzes the drilling mechanism,tool wear law and failure form in the process of CFRP drilling.The main research contents of this paper include the following aspects:(1)This paper studies the drilling mechanism of CFRP,analyzes the chip formation process with different sharpness under different fiber direction angles,explores the generation mechanism and influencing factors of drilling axial force and drilling temperature in drilling process,and analyzes the change law of drilling force and drilling temperature in drilling process.(2)The suction type internal chip removal tool handle is designed,and the experimental platform for the drilling process of CFRP internal chip removal is established.Under certain drilling parameters,select reasonable drill parameters to carry out the experimental research on the CFRP drill wear.Collect data of drilling axial force,drilling temperature and wear value in the experimental process.(3)The range analysis method is used to analyze the experimental data,andthe influences of drill diameter,drill sharp angle and clearance angle on the axial force,transverse edge width,blunt circle radius of cutting edge and wear band width of flank face are studied.The optimal drill parameter selection method in actual drilling of CFRP is put forward.(4)This paper studies the problem of tool wear in the internal chip removal drilling of CFRP,and analyzes the change of axial force and tool wear in drilling process by using the experimental comparative analysis method.Based on the representation method of tool wear characteristics,the tool wear mechanism and failure form of the internal chip removal drill are analyzed by studying the tool wear variation law of the internal chip removal drill.