Study On Process Control Of High-speed Dry Milling CF/PEEK Facing High Surface Machining Quality

Carbon fiber reinforced thermoplastic composites(CFRTP)not only have the advantages of traditional carbon fiber composites(CFRP)such as high specific strength,high specific stiffness and corrosion resistance,but also have good toughness,recovery,weldability and other characteristics,which leads to great application potential in aerospace and military industries.However,there are many unique surface defects in CFRTP processing relative to traditional metal materials on account of its characteristics of heterogeneity and anisotropy.In addition,CFRTP has high hardness and low interlayer strength,which makes it a refractory material and poor surface quality after processing.Few researches are reported on account of studies on the characterization and regulation of CFRTP surface defects are still in the initial stage.Therefore,this paper,a clean and efficient process,high-speed dry cutting process,was used to milling CF/PEEK,a typical composite material in CFRTP,to study the milling process control for high quality machined surfaces.It is of great significance which can provide theoretical support for high quality clean cutting of emerging aerospace composites.The main work is as follows:Firstly,the experimental planning was carried out based on the four-factor hybrid horizontal orthogonal experimental design and the CF/PEEK high-speed dry cutting experimental platform was built.Two kinds of continuous unidirectional CF/PEEK with fiber direction of 0° and 90° were selected to carry out high-speed dry milling experiments.Combined with the workpiece detection results,the damage types of the processed surface were analyzed and the evaluation method of surface damage degree was determined.Then,the characterization quantities used to quantify the surface shape accuracy,fractal dimension and surface complexity were added to the evaluation system on the basis of the three-dimensional surface parameters.The characterization results of each group of tests were calculated and dimension reduction was carried out based on principal component analysis(PCA)to establish a concise and effective surface quality evaluation system for CF/PEEK high-speed dry cutting machining and the correlation between the evaluation system and surface damage was analyzed.Finally,the influence of cutting heat on the surface quality of CF/PEEK was analyzed and the influence of various process parameters on the characterization of quantity were compared.Regression models under 0 ° and 90 ° fiber direction angles were established respectively.Map response surface diagrams were drawn to reflect the influence of cutting parameters on the machining surface quality.Optimization based on the regression model was carried out to obtain the global optimal process parameters combination.