Tool wear in high speed machining

Abstract
High speed machining has received an important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due to the high temperature at the tool-workpiece interface. There are three major processes of wear : abrasion wear, adhesion wear and diffusion wear. The last one is predominant at large temperature. Chemical diffusion produces a transfer of the tool constituents towards the chip. The loss of some of those constituents reduces the tool mechanical resistance and its efficiency. That is why an important objective of metal cutting research has been the assessment of tool wear and the evaluation of tool-life. This paper describes diffusion wear and presents an analytical model which allows to calculate the concentration of the diffused substances. The mass which is lost by the tool is obtained according to the cutting conditions such as cutting speed, rake angle and depth of cut. The model includes the physical and chemical parameters of the tool and of the workpiece.