Research On Temperature Field Simulation Of Arc Source Internal Cooling System For Vacuum Arc Ion Plating Application

Vacuum arc ion plating technology applies arc discharge to evaporation sources.This coating technology is widely used in many fields,such as decorative coatings,hard coatings,super-hard metal films and optoelectronic films.Arc ion plating technology has the advantages of high ion density,good adhesive strength and high deposition rate,however,large particle pollution is still a major problem that restricts its further development.A major cause of this phenomenon is that the arc spot is too concentrated to overheat the target material,thereby forming a molten pool and causing the so-called particle pollution.The effective methods to reduce particle pollution include some methods,such as controlling the arc spot motion area and velocity,increasing the ionization rate and improving the cooling structure.Among them,improvement of the internal cooling structure of the arc source has great significance.In the early stage of this thesis,a numerical model was established for the arc source of vacuum arc ion plating,where the cooling system inside the arc source was accutately included.The fluid-solid coupling analysis of the cooling system was carried out and the surface temperature distribution is consistent with the actual test data.Firstly,the basic principles of arc ion plating and the basic theory of fluid dynamics were analyzed.Two heat source boundaries were set for temperature field simulation analysis,and the calculated results were compared and analyzed.The main research contents lie on two aspects:target surface temperature decreased by the heat transfer characteristics of the cold structure and surface temperature increased by the trajectory of the arc spot.All the comparative researches are carried out through experimental data,magnetic field simulation and temperature field simulation.Secondly,effect of different boundary conditions on the target surface temperature distrubution is analyzed.The influences of cooling water inlet speed,inlet temperature,cooling back plate thickness,and target material on the temperature field distribution are analyzed.The cooling structure of the source was further improved based on the research result.According to the result,it can be seen that different boundaries have little effect on the target surface temperature distribution.Finally,magnetic field distribution on the target surface is simulated and experimentally tested.The influence of magnetic field distribution on the arc spot motion trajectory and the target surface temperature distribution is studied.The circular arc spot motion behavior was simulated and compared with the experimental test results.It can be seen that the film quality becomes better when the arc spot occurs on the entire target surface and seldom ont the central area.