Characteristics Of High Pulsed Current Arc Discharge And Deposition Of AlCrN Thin Films

Thin film technique is widely used in traditional manufacturing industry which could effectively improve the hardness,friction performance,and corrosion resistance of the material surface.Vacuum cathodic arc deposition is characterized of high ionization rate and high deposition rate,however there are large macroparticles on the coating surface.The pulse cathodic arc can significantly reduce the number of large particles and improve ionization degree,and the DC component can keep the arc stable.In this paper,pulse cathodic arc ion plating is used to enhance the ionization of the gas vapors and increase the substrate current to obtain high performance of AlCrN thin films.The discharge test showed that the substrate current increased with the increase of pulse current.With the increase of pressure and bias voltage,the substrate current increased.Substrate current produced by vacuum cathode pulse arc ion plating is much higher than the DC cathodic arc.The results of spectral properties showed that the spectral intensity increased with the pluse current increasing.As the bias increase,the spectral intensity increased.With the pressure increase,the spectral intensity of metal ion decreased and the spectral intensity of the gas increased.The AlCrN films were deposited by vacuum pulse cathodic arc ion plating and conventional DC arc ion plating respectively.The effects of pulse current and N2 gas pressure on the micro morphology,phase composition,nano hardness and and film-substrate adhesion were investigated.The film surface prepared by pulsed arc source was much better and the microstructure was more compact.The size of macroparticles on the surface decreased gradually with the increase of pulse current and pressure.And the columnar crystal became denser.Large particles increased when the pulse frequency increases to a high degree.The results of XRD showed that the diffraction peaks prepared by pulsed cathodic arc were obvious.The crystal orientations were mainly(111),(311)and(200)diffraction peaks;The nano-hardness and film-substrate adhesion of the films produced by pulse cachodic arc are higher than those produced by DC cathodic arc.Under bias voltage of-40 V,coil current of 0.5A,pulse current frequency of 20 kHz and N2 pressure of 3.0Pa,AlCrN films possessed the best comprehensive performance.