TiN Film Formation by Linear and Novel Winding Filtered-Arc Deposition*

Protective coatings on cutting tools are expected to improve machining efficiency and tool life. A vacuum arc deposition (VAD) system has been used in industry as forming protective coatings. VAD system produces dense films with excellent adhesion due to the highly ionized ions in the plasma, but the macro-particles (MPs) adhesion sometimes causes low-quality.  For reduction of MPs adhesion, a filtered arc deposition (FAD) system with magnetically plasma transportation function has been employed.

In this study, we attempted to form TiN films by two types of FAD systems having an electromagnetic coil on the outside of the connection duct (duct coil). One was a traditional linear-FAD (L-FAD) with a cylindrical anode as a part of FAD system. The other was newly designed winding-FAD (W-FAD) with a winding shape anode. The anode was composed of C-ring-shaped copper plates assembled into a coiled shape. Therefore, the anode in W-FAD generated magnetic field by arc current itself to transport the vacuum arc plasma tunneling the anode as well as to block the flying MPs. As a result, it was found that the number of MPs on the 1-micron thick film prepared by W-FAD were excellently few compared to that on the film prepared by L-FAD.