Friction in machining — Comparison of rake and flank wear-land friction

Metal cutting studies were carried out to study the nature of the friction present at the tool-chip and tool-work contact surfaces in the presence of progressing flank wear. The distribution of the friction stresses was obtained during the machining of metallic lead with photoelastic model tools having a prehoned land simulating flank wear. The validity of the binomial law of friction along the rake contact surfaces and along the flank contact surfaces was verified and compared. The effects of increasing wearland upon the rake and flank contact phenomena were studied for correct evaluation of the role of friction upon the flank wear of tools. The studies have indicated the dominant influence of flank wear (particularly in the early stages) upon the two contact processes. It was found that the proportional contribution of the adhesive component of the friction coefficient was greater in the case of tool-chip contact, although the overall average coefficient of friction was higher along the flank wear-land.