Study On Quality Of CFRP Drilled With Brazed Diamond Core Drill

Limited to the development level of common drilling tools, low machining quality, short tool life,low machining efficiency have been the most remarkable problems during drilling Carbon fiberreinforced plastics (CFRP), which is the representative of high performance but difficult-to-cutengineering materials. In view of this, brazed diamond core drill with regularly distributed diamondgrits are developed for drilling of Carbon fiber reinforced plastics3234/G803PV based on the idea of“design and manufacture the cutting tools according to actual materials”. The machining quality andhole exit temperature of CFRP laminates drilled with brazed diamond core drill are researched atdifferent grits assignment of core drill and drilling parameters.The main research works completed are as follows:(1) The effects of grits assignment of core drill and drilling parameters on hole exit machiningquality, hole diameter precision and hole wall roughness in CFRP laminates drilled with brazeddiamond core drill are studied. The optimal grits assignment of core drill and drilling parameters havebeen proposed to improve the hole diameter accuracy and to achieve low-defect drilling of CFRPlaminates with brazed diamond core drill.(2) A temperature measurement system is designed to test the hole exit drilling temperature ofCFRP laminates. The effects of grits assignment of core drill and drilling parameters on hole exittemperature in CFRP laminates drilled with brazed diamond core drill are studied. The empiricalequations of hole exit drilling temperature are established.(3) In order to calculate the hole exit drilling temperature of CFRP laminates, A heat affectedsimulation model is builded, which has a dependable accuracy proved by experimental data. Based onthis model, the thermal deformation of hole diameter caused by drilling heat is analysed with finitemethod.