Investigation of the surface integrity when cryogenic milling of Ti-6Al-4V using a sub-zero metalworking fluid

Abstract

In this paper a novel cooling strategy is presented using a sub-zero metalworking fluid when milling Ti-6Al-4V. The metalworking fluid, composed of water and ethane-1,2-diol, was applied to the process at varied supply temperatures. An analysis of the occurring forces and temperatures, as well as the resulting surface integrity, is carried out. The surface integrity is characterized by microhardness measurements in the surface layer of the workpiece. Additionally, the surface topography is characterized using optical measuring techniques. The results are compared to those obtained using dry milling and when using a conventional cryogenic CO2 cooling strategy.