| Arc ion plating is one of the most widely used vacuum coating technologies in industry.Thanks to its high ionization rate(even up to 100%),excellent plasma diffraction.The prepared coatings are uniform,dense,good adhesion,and have a very large market share in both functional films and decorative coatings.For example,the wear-resistant coating on the cutting tools,anti-corrosion coating,rose gold on furniture ornaments,champagne gold and other colors are very popular.The high deposition rate allows the technology to produce large quantities of products quickly and efficiently.The most serious problem of arc ion plating is the emission of macroparticles.Macroparticles limit the application of this technology in optical films and other fields.This defect of protective coating affect the service life,increasing the roughness of the hard coating on the cutting tools and reducing the surface accuracy.So a large number of researchers focus on the reduction of macroparticles.From using magnetic field to control arc spots movement,to magnetic filters and parameter optimization,even target poisoning.In the previous works,our group realized the control of the radial scaling movement of the arc spots on the target surface,which made the target surface evenly etched and reduced the molten pool,thus reducing the macroparticles.In this work,the cathode arc source is redesigned.Under the premise of arc spot scaling motion,nitrogen is introduced near the cathode to poison the target evenly so as to further reduce the size of molten pools and reduce the generation of macroparticles.The law of cathode target poisoning was studied by different gas introductions.The EDS analysis of cathode target surface showed that during conventional gas introduction,the content of nitrogen atoms in the target surface increased gradually with the increase of nitrogen flow,from 35.0%at 15 sccm to 3 8.8%at 35 sccm.While the nitrogen content of the target surface was between 38.4%-40.6%in the whole range of the experiment,which proved that the gas introduction ring could effectively poison the cathode surface.Combined with the number of macroparticles and the degree of target poisoning,the critical value of poisoning was found to be 3 8%.In which the best effect on the inhibition of macroparticles was achieved.In conventional way,with the increase of nitrogen flow,the number of macroparticles decreased and the size decreased.In the gas-introduction ring mode,the number of macroparticles is basically maintained at 2000/m2.With the increase of nitrogen flow rate,although the conventional method can reach a similar number of macroparticles,the nitrogen flow is relatively large and the deposition rate decreases to 175 nm/min,while the gas-introduction ring method can maintain a relatively high deposition rate(250 nm/min)and the number of macroparticles is very small at a low nitrogen flow rate.It is verified that near cathode gas-introduction can be a new method for rapid deposition of titanium nitride coating with good quality. |
