High-speed micro-milling: Novel coatings for tool wear reduction

Tool wear affects dimensions and surface quality of the workpiece as well as tool life whose unpredictability is a major process constraint in micromilling. In this paper tool wear progression in seven different coatings is monitored during micromilling of hardened steel at high-speed under dry cutting conditions. A comparison among them and to a commercial solution is reported and the best one is selected.

► Seven new coatings for reducing tool wear have been developed and tested.
► New coatings show homogeneity, low cutting edge radius changes and small droplets.
► Silicon content seems to be the crucial for applying ultra high speed micromilling.
► Monolayer nanostructured with low silicon content is preferable for industrial use.
► Reliable performance, tool wear strongly reduced, breakage avoided.