The Effect of Cathodic Arc Guiding Magnetic Field on the Growth of (Ti0.36Al0.64)N Coatings

Coatings

Frank Mücklich¹  Tun-Wei Hsu²  Bilal Syed²  AnaB. B. Chaar²  Magnus Odén²  Mats Johansson-Jöesaar²  Gérard Henrion³  LarsJ. S. Johnson⁴  JonM. Andersson⁵ 

[1] Department of Materials Science and Engineering, D3.3 Saarland University, D-66123 Saarbrücken, Germany;Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden;Institute Jean Lamour, Campus ARTEM, University of Lorraine, CNRS, F-54011 Nancy, France;Sandvik Coromant, SE-126 80 Stockholm, Sweden;Seco Tools AB, SE-737 82 Fagersta, Sweden;

关键词: physical vapor deposition;    magnetic field;    optical emission spectroscopy;    coatings;    grain size;   

DOI  :  10.3390/coatings9100660

来源: DOAJ

【 摘 要 】

We use a modified cathodic arc deposition technique, including an electromagnetic coil that introduces a magnetic field in the vicinity of the source, to study its influence on the growth of (Ti_0.36Al_0.64)N coatings. By increasing the strength of the magnetic field produced by the coil, the cathode arc spots are steered toward the edge of the cathode, and the electrons are guided to an annular anode surrounding the cathode. As a result, the plasma density between the cathode and substrate decreased, which was observed as a lateral spread of the plasma plume, and a reduction of the deposition rate. Optical emission spectroscopy shows reduced intensities of all recorded plasma species when the magnetic field is increased due to a lower number of collisions resulting in excitation. We note a charge-to-mass ratio decrease of 12% when the magnetic field is increased, which is likely caused by a reduced degree of gas phase ionization, mainly through a decrease in N₂ ionization. (Ti_0.36Al_0.64)N coatings grown at different plasma densities show considerable variations in grain size and phase composition. Two growth modes were identified, resulting in coatings with (i) a fine-grained glassy cubic and wurtzite phase mixture when deposited with a weak magnetic field, and (ii) a coarse-grained columnar cubic phase with a strong magnetic field. The latter conditions result in lower energy flux to the coating’s growth front, which suppresses surface diffusion and favors the formation of c-(Ti,Al)N solid solutions over phase segregated c-TiN and w-AlN.

【 授权许可】

Unknown