Friction Drilling: A Chipless Hole-Making Process

This paper summarizes the research on friction drilling, a chipless hole making process using the rotating conical tool. Extensive research in experiment, modeling, tool wear, and metallurgical analysis of friction drilling tool and workpiece has been carried out to demonstrate the feasibility of this technology for hole-making in thin metals. The experimentally measured thrust force and torque were analyzed and compared with analytical and finite element modeling results for validation. The microstructures and indentation hardness were characterized on the cross-section of friction drilled holes for different work-materials. For brittle cast metals, effects of workpiece temperature, spindle speed, and feed rate were analyzed. The wear of a tool, which is made of hard carbide material, for friction drilling of carbon steel workpiece, was also studied to demonstrate the capability of a durable tool in the production environment.