Tool Life in Oblique Cutting as a Function of Computed Flank Contact Temperature

Abstract

The steps by which a tool life analysis applicable to orthogonal cutting can be extended to accommodate tool obliquity are detailed. By following these, a relation between tool-life, T , tool obliquity, λ , and a representative tool flank wear land contact temperature, θ fs , is obtained. A method is then described by which θ fs in oblique cutting can be computed. This is based on a recently developed procedure for estimating temperatures of obliquely moving heat sources on the rake face combined with the influence of constriction resistance occurring at the discrete contact points within the flank contact area. In this way, from a knowledge of the T − θ fs relation applicable to a given tool/workpiece combination cut orthogonally, tool lives at different tool obliquities are predicted and are shown to agree quite well with experimentally determined values. Finally, a comprehensive tool life expression independent of cutting parameters and of tool geometry is proposed and is verified using data obtained by cutting mild steel with H.S.S. tools.