Defects Study on Drilling of Carbon Fiber Reinforced Polymer (CFRP) Laminates

The new developed carbon fiber reinforced polymer laminates are widely used in main structural components of big commercial aircrafts. Generally drilling is the final operations in manufacturing structure, which is the most important operation during assembly. Defects such as burrs and delamination always appear in the process of drilling, which makes it hard to control the drilling quality. In this research, the drilling defects of T800 CFRP laminates are evaluated by using a brad point drill and a multifacet drill in terms of drilling forces, burr defect and delamination detection. The results show that the spindle speed is the most significant factor affecting the delamination defect followed by the feed rate. High speed drilling and low feed rate could improve the surface quality and reduce the delamination. The multifacet drill showed excellent drilling performance than the brad point drill and generated smaller defects.