New tool coatings for light metal cutting

New carbon based coatings have been developed for cutting light metals such as aluminum. These coatings can be used either directly on the tool or as topcoating combined with another hard base coating. Cutting tests show that the coating gives good performance for materials that tend to stick to the cutting tools, such as aluminum alloys, because of the substantial reduction of appearance of the so-called built up edge (BUE). This results in a longer life time of the tool and smoother surface finish of the cut made in the workpiece material. Especially in dry machining and deep hole drilling this coating performed very well. An overview of the properties and initial cutting results of this coating is presented. This paper also presents the results from recent industrial field tests carried out by a leading European aerospace manufacturer. Cutting forces, BUE formation and surface roughness data are presented to explain the cutting process during dry machining.