Research On Influence Of Magnetic Field Characteristics Of Cathodic Arc Source On Macro-particles And Utilization Of Targets

Arc ion plating technology is a vacuum coating technology that uses vacuum arc discharge on an evaporation source,with merits of high ion energy,high deposition rate,good adhesion for deposited coatings,higher density of coatings,high ionization rate and so on.It is widely used in hard coatings,decorative coatings,metal coatings and optoelectronic coatings.However,the problems of macro-particles pollution and low cathode target utilization had always limited the development of arc ion plating technology.As the core component of arc ion plating technology,cathodic arc source has played an important role in arc ion plating system.In this paper,based on the arc discharge mechanism of the cathodic arc source,the "simulation+experiment" research method had adopted to control the movement of the cathode spot by magnetic field,and the problems of macro-particles pollution and low cathode target utilization in the process of preparing the coatings are improved.The previous investigations show that the horizontal magnetic field intensity affects the velocity of cathode spot motion,and the vertical magnetic field intensity has the influence on the position of cathode spot.In this paper,the axis-symmetric magnetic field was optimized to adjust the vertical magnetic field at each position of the cathode surface to the same intensity value,so that the arc spot was evenly distributed over the entire cathode surface.As the melting points of the target decreases,the vertical magnetic field intensity needs to be increased to maintain the cathode spot motion that moved on the entire cathode surface.With the horizontal magnetic field increased,the velocity of cathode spot increased significantly,and the cathode spot motion changed from a fuzzy agglomerate motion to a clear circular motion.The velocity and the range of cathode spot motion affected the heat distribution of the cathode surface,thereby affecting the quality of the deposited coatings.With the velocity and the range of the cathode spot increased,the quality of the coatings was improved,the number of micro-particles was significantly reduced,and the element content of N in the coatings was increased while the element content of metal was declined.The thickness of the coatings prepared by different cathode targets shows different changes due to the different melting points.The better the surface quality of the coatings prepared by the low melting point cathode target,the lower the deposition rate.The thickness of the coatings prepared by the high melting point cathode target increased with the range of cathode spot motion.The crystal structure of coatings prepared under optimized magnetic field didn’t change with the variation of the magnetic field component,and had stability.According to the experimental results of coatings under static magnetic field,the control mechanism and method of cathode spot motion of dynamic magnetic field are determined.The distribution of cathode spot on the cathode surface is controlled by changing the frequency and amplitude of the square wave of electromagnetic coil,the temperature distribution of cathode surface and target etching were uniformized.Finally,the surface quality of the coatings and the utilization rate of the cathode were greatly improved.