Research On High Speed Drilling Of Carbon Fiber Composites

Carbon fiber reinforced plastics (CFRP) have been widely used in the aerospace,energy and other fields, because of it is characterized by high strength.It is a kind ofdifficult-to-machine material because of its characteristics such as high strength, highhardness, and anisotropy. Currently, the hole technology on its carbon fiber compositematerial is interested by many researchers. In this paper, two kinds of drills are usedto drill unidirectional T800carbon fiber composite materials, and make some researchon its drilling force, drilling temperature and hole quality, for providing technicalguidance for the kind of material drilling. The dissertation includes the followingaspects:(1)The YG6X carbide twist drill and CoroDrill854diamond coated drill havebeen used in the T800carbon fiber composite plastics drilling experiment. This thesishas analyzed the drilling process of two kinds of drill, at the same time, the variationof the processing parameters with the drilling axial force was investigated, and twokinds of drill’s drilling thrust in drilling process were discussed. We established thetwo bit of cutting force and cutting temperature model by using a binary linearregression analysis method. The results show that under the same parameters, thedrilling force of diamond coated carbide drill40%smaller than carbide twist drill.(2) Comparative analyzed the influence of processing parameters with thedrilling temperature, the results showed that: carbide drill drilling temperature risewith the speed increases; down With the greater of the speed. Diamond coated drilldrilling temperature decreases with an increase in speed, feed rate has little effect onits temperature changes.(3)The thesis has discussed the reasons why the defects of hole’s entrance andexit generated when used two kinds of drills. The effects of processing parameters onthe qualities of hole’s entrance and exit have been studied. At the same time, thequalities of holes’ entrance and exit of two kinds of drills been compared. Themorphologies of holes’ wall have been observed, and the effects of the angularseparation between fiber direction and cutting direction on the roughness of the holes’wall, and then the characteristics of morphologies of holes’ wall generated and theroughness of the holes’ wall by the two kind drills have been compared, and measuredthe hole roundness of the two kind drills, then discovered that we can obtain the highquality holes efficiently when used the diamond coating drill.