Analysis on CFRP Hole Making with Brazed Diamond Core Drill.

The high hardness of carbon fiber in carbon fiber reinforced plastics (CFRP) leads to quick wear, low durability of drills, and poor machining quality in drilling process. Appling brazed diamond core drill to drilling CFRP can improve drill durability and increase machining quality. In order to optimize the setting of diamond grits on core drill, the diamond grits are orderly set to make core drill, and the maximum undeformed chip thickness are changed through changing the diamond quantity. The influences of maximum unde[ormed chip thickness on thrust force, surface roughness of hole wall and quality of hole entrance and exit are compared under the same machining parameters. The moving model of diamond grits is set up to analyze the forming process of machined surface. The results and analysis show that the drilling quality is influenced by chip storage space and the maximum undeformed chip thickness. If the chip storage space is sufficient, the thrust force decreases and the drilling quality improves with the decreasing maximum undeformed chip thickness. [ABSTRACT FROM AUTHOR]