CFRP board drilling performance studying for carbide drill bit with DLC coating
The drill bit for carbon fiber reinforced plastics machining facing the issues like short running life and bad machining quality.Carbide drill bits with DLC coating would be a good solution to increase the life of drill bits which with lower frictional co-efficient and higher surface hardness.4 groups of samples had been studied like uncoated carbide drill bits,monolayer DLC coat-ing,Cr/W-DLC/DLC and Cr/CrN/DLC composite coating.By comparing the frictional coefficient,surface hardness and roughness of different coatings,the data showed that all the drill bits with DLC coating had advantage of low frictional coefficient and could improve the surface roughness.The data of cutting torque force,cutting temperature,cutting speed and frank wear from 4 groups of samples'drilling testing showed that the composite coating of Cr/CrN/DLC provided best service life and much more stable performance,its service life was 2.65 times of the drills without coating.