Study On Milling Process And Surface Quality Of CFRP

Carbon fiber reinforced polymer(CFRP)has excellent performance and is widely used in the aerospace field.With the development of science and technology,the application scope of CFRP in automobile,high-speed rail and other areas continues to expand,and the characteristics and advantages of CFRP continue to be reflected,but as a typical difficult-to-machining material,it is easy to appear defects such as burr,delamination and tearing.After the forming of CFRP parts,it is generally necessary to milling the edges of CFRP to remove the residual material and get the desired shape.The milling process parameters which are efficient and can avoid defects are the focus of many pieces of literatures,but there are few literatures on the milling mechanism and experimental process research on the side of CFRP.Based on the milling process,this paper studies the milling mechanism and process of CFRP side,which can improve the milling efficiency on the premise of ensuring the milling surface quality,milling accuracy and reducing milling defects.The specific research contents of this paper are as follows:(1)The research status of CFRP milling at home and abroad is summarized,the purpose and content of the research are analyzed and planned,and the CFRP milling steps and methods are established;based on the cutting principle,and milling kinematics theory,the mechanism of CFRP milling and the causes of defects are analyzed.(2)Using the response surface method,the horizontal values of several milling process parameters are determined,the experimental scheme is designed,and the empirical research is carried out.Taking the minimum milling radial force as the experimental goal,the best parameter combination is obtained.First of all,the finite element analysis of the CFRP milling process is carried out by using the optimal combination of parameters,and the stress,radial force,interlayer damage and morphology of the workpiece are analyzed.Secondly,the optimum parameters are verified by experiments,the relevant results are measured,and the factors affecting milling quality are discussed.After analysis,the process parameters are obtained as follows: spindle speed 4173r/min,cutting depth 1mm,feed speed 300mm/min.Through measurement and analysis,it is found that defects are more likely to occur at the entrance and exit than at the middle part of the cutting process.(3)To further improve the surface quality,variable parameter machining is introduced based of cemented carbide tool machining.Through measurement and analysis,it is concluded that the better process parameters of cemented carbide tool machining are as follows: the spindle speed at the inlet and outlet is 6000 rpm,the cutting depth is 1mm,the feed speed is 200 mm,the middle part is the spindle speed is4000 rmin,the cutting depth is 1mm,and the feed speed is 300mm/min.The surface quality at the inlet and outlet is further improved by using the variable parameter processing technology.After the cemented carbide tool experiment,the PCD tool,which is more suitable for machining CFRP,is introduced,and the surface quality is further improved by using the same machining parameters.The feasibility of variable parameter machining is proved.In this paper,through milling mechanism analysis,experimental research and process simulation,the influence rules of relevant parameters are obtained,and the better side milling process parameters are obtained.This analysis method can provide reference for other machining process research of CFRP.