A Study of Coatings on Experimental Thrust and Torque in Drilling

The paper presents results of a systematic study of tool coatings on drilling performance of twist drills. It looks at data reported in open literature sources as well as the author’s own experimental results. The findings are discussed in terms of cutting forces, namely thrust, torque (and power) in drilling and advantages of advanced surface coatings from a competitive point of view. Moreover the searched literature did not provide any empirical thrust and torque equations for coated drills. An alternative way to solve this problem has been offered through analytical approach based on the mechanics of cutting analysis, and required to carry out the fundamental approach to the effects of coating in machining which is considered further in this paper with reference to cathodic arc evaporated TiN, TiCN and TiAlN coated general purpose twist drills when dry machining a Type Bisalloy 360 steel work-material