Effect of axial magnetic field on microstructure and corrosion properties of CrN films prepared by arc ion plating

The CrN films were prepared using magnetic field-enhanced arc ion plating on 2024 Al alloy substrates, and the effect of axial magnetic field intensity behind the cathodic target on microstructure, microhardness and corrosion properties of film was investigated. The results show that, with the increase of the magnetic field intensity, the complex structures of Cr₂N and CrN phase in the CrN films change to single phase of CrN, magnetic field has obvious effect on surface morphologies of film, the number of smaller particles reduces and the number of larger particles increases. When the magnetic field intensity is 7960 A/m, the microhardness and elastic modulus of the films reach the maximum values, which are 23.9 GPa and 392.6 GPa, respectively. The corrosion potentials of polarization curves firstly increase, and then decrease with the increase of the magnetic field intensity. The maximum value of the corrosion potential is obtained at the magnetic field intensity of 3184 A/m, namely, corresponding to the best corrosive resistance.