Research On The Influential Factors Of Processing Quality In High-speed Drilling Of Carbon Fiber Reinforced Composite

Carbon Fiber Reinforced Composites is a kind of widely used material.Drilling is the most common method by which more than half amont of the materials was processed.However,it is easy to occur defects such as tool wear,delamination and tear in the drilling process because of the low laminar strength,anisotropy,high strength and low thermal conductivity,which influence the durability of cutting tool and machining quality badly.At present,the study of drilling CFRP is still in its infancy,lacking systematic theory to guide practical production.Therefore,it's meaningful to study the influence factors of processing quality in drilling CFRP for the theoretical research and practical application.The paper used high-speed drilling method and carried out the relevant experimental studies on the influential factors of processing quality in drilling CFRP.The main works and achievements have been done as followed:(1)The experiment platform was designed to measure the force and temperature of drilling CFRP.The embedded thermocouple method combined with LabVIEW software was adopted to obtain the temperature signal.The measurement of drilling force was based on Kistler dynamometer and Dyno Ware software.(2)The defects formation reasons,drilling deformation and chip formation mechanism of drilling CFRP were studied.The tear of high-speed drilling CFRP and the effect of process factors on the hole roughness were analyzed.The binary nonlinear regression model was established to predict the extent of drilling defects through experimental data.Result had showed that the accuracy of established regression model was high and it can predict the size of hole defect effectively.(3)The white confocal 3D profile meter and electronic microscope were used to observe the topography of hole wall surface.The result showed that there was more tiny chip in the inlet side and less chip in the outlet side.The hole wall quality was better in the middle area,but there was small amount of pits and uncut fiber.(4)The orthogonal test method was used to analyze the effect of spindle speed,feed rate and point angle on drilling force and temperature.The drilling force and temperature had direct relationship with hole quality.The fitting curve method was used to study the effect of force and temperature on the hole quality.The result showed that tear increased with the increase of the drilling force and the drilling force had less effect on the hole wall roughness.Tear and roughness decreased with the increase of drilling temperature.(5)The method of single factor analysis was used to study the effect of splind speed and feed rate on the tool wear.The VB value had used to represent the value of tool wear and the curve of the influence of splinde speed and feed rate on the VB value was drawed.The result showed that the VB value increased with the increase of splind speed and feed rate,the impact degree of feed rate was greater than the impact of splind speed.The fitting curve method was used to study the relationship between tool wear and hole quality.The fitted curve of linear equation was built.The result showed that the equation had excellent accuracy.