Comparative study of material damage and tool wear mechanisms during drilling of CFRP/Ti stack

The usage of CFRP and Ti stacks in the aerospace industry has widely increased due to its mechanical properties and improved structural functions but at the same time, different mechanical and thermal properties of the CFRP and Ti makes the process difficult. Major apprehensions in the drilling of CFRP/Ti stacks include rapid tool wear and poor hole quality. Typically, the surface quality of the holes in the drilling of CFRP/Ti stack is poor due to delamination, the progression of hole diameter in CFRP and burr formation in Ti. Moreover, the flank wear on the tool also influences the surface quality of the hole produced. Therefore, the present study is mainly focused on the influence of cutting parameters on cutting forces, hole quality and tool wear characteristics. Drilling was performed on CFRP/Ti stack using coated and uncoated carbide tools. The obtained results revealed a significant correlation between tool wear and delamination characteristics.