Performance and limitation of hybrid PECVD (hard coating)—PVD magnetron sputtering (MoS2/Ti composite) coated inserts tested for dry high speed milling of steel and grey cast iron

Abstract

In the industry, High Speed Machining (HSM) is recognised as one of the key manufacturing technologies for higher productivity and lower production costs. Existing cutting tools are coated to improve the tool life and the performance. These coatings are all based on the principle that the coating is much harder than the work piece material. The objective of this paper is to present the new coatings for cutting tools based on a new approach: Low friction self-lubricant MoS2/Ti composite coatings (MoST) deposited by PVD magnetron sputtering technique. Dry machining (DM) is an important objective in machining industry to reduce environmental- and production costs. DM using MoST is possible in some cases: because of the low friction, the use of coolant is not necessary. Also, better chip evacuation and a smoother cutting process will occur, which can lead to higher accuracy of products. The paper included an assessment of machining performance of state of the art PECVD coated inserts (grade, geometry, coating). The consortium included manufacturers of milling machines and lathes, a coating company, a tool manufacturer, a university and two research institutes. Partners have contributed their particular expertise to the paper. The main results obtained with these new "hybrid" inserts are: (1) Tools with MoST can be used in dry milling operations at normal cutting speeds; (2) MoST coatings reach good tool life (1.5-2 times longer than 'State of the art' tools) at normal cutting speeds.