Cutting force, tool life and surface integrity in milling of titanium alloy Ti-6Al-4V with coated carbide tools

Titanium alloys are widely used in aeronautics that demands a good combination of high strength, good corrosion resistance and low mass. The mechanical properties lead to challenges in machining operations, such as high process temperature as well as rapidly increasing tool wear. In this work, three carbide end mills have been used in machining of titanium alloy Ti-6Al-4V. The first tool is coated with TiAl; the second and the third are coated with multi-layers or with a single layer of TiAlN. The cutting force and the tool life have been experimentally investigated and put into relationship with the process parameters under dry cutting condition. The quality of the machined surfaces has been evaluated by measuring the roughness of the machined surfaces. Finally, the correlation among cutting force variation, tool wear propagation and surface roughness has been analyzed and discussed. These three tools demonstrate to be able to maintain their hardness and other mechanical properties at the high cutting temperatures that they encountered.