Study On Deposition Of Hard-films On The Internal Wall Of Deep Tubes By Arc Ion Plating

Hard coating technology has received more intention since the longevity of the cutter tools coated with TiN films was successfully improved in 1970s.Through the development of the last several decades,the hard outer surface of the membrane technology has made remarkable progress,greatly promote the development of the industrial automation,a good economic benefit.However,in practice to work within the workpiece surface is not less than the outside surface of the workpiece face such as the cylinder engine,pipeline transport,ion accelerator control,artillery tube.These parts often wall wear,corrosion and other forms of destruction,deposited in pipe wall corrosion resistance,abrasion resistance;High Temperature in the film is of great significance.But rarely seen in domestic and foreign publications related technical reports,Therefore wall coating technology development is a very urgent task.Our workgroup have done a lot of work on the researching of films deposition on the internal wall of deep tubes by AIP(arc ion plating).In this study,TiN film deposition on inner wall of the tubes(Φ50×200×5mm bar tube,Φ50×300×5mm open tube) was carried out with AIP.In order to increase the depth of the film in the deep tube,we will use the high temperature permanent-magnet to control the plasma to go into the tube.Then,film thickness,XRD,SEM,hardness etc.were carried out.The results of films hardness show that whether in the open tube or in the bar tube the sample's nanohardness is above 20GPa at any depth.According to the standard of HK hardness larger than 20GPa,the microhardness shows that,the ratio of depth and diameter could be 2.0 by the films deposition on the internal wall of deep tubes technology.According to the film thickness measured,the deposition rate can be calculated:it is 0.45μm/h at 150mm depth in the bar tube,but≥0.84μm/h in the open tube.XRD results show that the film is pure TiN.And the preferring orientation changes from (111) to(220) while the increase of the tube depth.At the end of the thesis,the best method of films deposition on internal wall of deep tube, was applied on hard-film deposition on the internal wall of the mold for skinning.And film coated mold's service life is much longer.The method also was applied on the film of CrN deposition on the PEMFC's bipolar plate.It makes the internal wall of the trenches in the bipolar plate also coat with compact and uniform film.The electrical conductivity and inoxidizability of the bipolar plate both are enhanced greatly.