A study of the cutting-induced heating effect on the machined surface in ultra-precision raster milling of 6061 Al alloy

In ultra-precision machining, the heating effect on a workpiece induced by cutting process itself plays an important role in the machining process as it affects tool life, machining accuracy, and the surface quality of the workpiece. This paper discusses the cutting-induced heating effect in ultra-precision raster milling based on the study of the time-temperature-dependent precipitation of 6061 aluminum alloy. Experiments are designed to estimate the temperature variation of the workpiece in ultra-precision machining by comparing the change in the size of precipitates in isothermal heat treatment with those in raster milling process under different depth of cut. Microscopical examination under a scanning electron microscope (SEM) revealed that the temperature on the raster-milled surface is much higher than 500°C. In the last part of this paper, the heat generation of the workpiece in the process of ultra-precision raster milling is simulated by finite element method, the result of which is found to be consistent with that from SEM.