Study On Micro-Hole Drilling Force And Drilling Heat Of Carbon Fiber Composites

Carbon fiber reinforced composites(CFRP)have been widely used in aerospace and other fields due to their high strength,toughness,corrosion resistance and good damping properties.They have gradually replaced the traditional metallic materials such as aluminum.In the field of aeronautics and space,by preventing the formation of the separation of the edge layer,a large number of tiny holes are drilled in the carbon fiber composite material components of the fuselage such as the nacelle,the wing,the tail surface and the like,so as to reduce air turbulence.In other words,by reducing the laminar flow to reduce fuel consumption.The carbon fiber composite material micro-drilling process by a lot of process parameters,such as speed,feed rate,processing methods.At present,in the research of drilling of carbon fiber composites,there are more and more scholars at home and abroad to study the conventional holes(more than 3mm in diameter,especially 8mm mostly),while few people study the drilling of small diameter holes.Therefore,it is necessary The theoretical and experimental researches on the cutting force,cutting heat and process parameters related to the drilling of micro-holes in carbon fiber composites are carried out.This thesis is divided into the following parts:(1)Study the basic drilling theory,including cutting deformation and chip formation and its influence factors,including cutting force,cutting heat and cutting temperature.(2)A carbon fiber reinforced composite material drilling temperature measuring platform was set up.The experiment of drilling small holes(2mm)of carbon fiber reinforced resin matrix composites under different technological parameters(different speed and feed speed)was carried out by using hard alloy twist drill.The temperature change during the drilling process,the influence law of the process parameters on the drilling temperature and the hole quality,and the surface quality of the hole.Firstly,the drilling temperature under different process parameters was measured by thermocouple.The curve of drilling temperature was analyzed,and the influence of process parameters on the drilling temperature was discussed.Then,the relationship between drilling temperature and speed and feed rate Expressions between speeds.(3)High-speed micro-hole drilling tests on carbon fiber composite plates were carried out.Three kinds of drilling methods were used,such as blind hole drilling,blind hole pecking(complete withdrawal)and through hole pecking(partially retracting)Parameters on the impact of drilling axial force,torque,using binary linear regression analysis method to establish and verify the drilling force model.(4)The mechanism for the tearing and burr defects in the drilling hole in micro hole drilling are analyzed,and the influence of the process parameters on the burr area,tearing factor,diameter of the hole and roundness error of the hole outlet is discussed.By strengthening the export side strength in drilling hole exit cutting system using drill plate,plate,AB coating so that a burr quantity is greatly reduced,the outlet significantly improve the drilling quality,practical significance.