An analysis of the effects of nanolayered nitride coatings on the lifetimes and wear of tungsten carbide micromilling tools

D. Zdebski (a), D.M. Allen (a), D.J.Stephenson (a), J. Hedge (a), C. Ducros (b) and F. Sanchette (b)

(a) Precision Engineering Centre, Cranfield University, Bedford MK43 0AL, UK
(b) CEA Grenoble, Labatoire des Technologies des Surfaces, 17 rue des Martyrs 38054 Grenoble CEDEX, France

Abstract

Micromilling is becoming increasingly important for a wide range of manufacturing tasks in the general field of microengineering, such as milling small channels in micromoulds designed for the fabrication of microfluidic devices by microinjection moulding of polymers. However, micromilling tools, often less than 1mm in diameter, are rather delicate, fracturing when forces become excessive and, consequently, micromilling can become an expensive process. In an attempt to increase tool lifetimes and reduce costs, micromilling forces have been measured with a microdynamometer and the effects of chromium nitride/titanium nitride and titanium aluminium nitride/titanium nitride coatings have been evaluated as an aid to decreasing tool wear and extending the lifetime of tungsten carbide micromilling tools. The surface finish of the milled workpiece has also been measured to monitor how tool wear affects the resultant milled surface.