Study On The Key Technology And Properties Of Ta-C Films Deposited By Filtered Cathode Arc Deposition

As the key technology of filtered cathode arc deposition(FCVA),suppressing the macroparticles and reducing the stress of ta-C films have been studied in this paper.Films deposited on 316 L stainless steel or silicon(100)were prepared with titanium as a transition.The influences of magnetic filtered coil current,baffle aperture and pluse bias on macroparticles were investigated by experiments and the ones of arc source magnetic field distribution on the movement of arc spot and macroparticles was analyzed by ANSYS.In addition,the changes of residual stress,hardness,adhesion strength and friction properties of ta-C films before and after annealing were studied.The thermal stress distribution of stainless steel based Ti/ta-C films were simulated by ANSYS.The reasons for the excessive residual stress of ta-C films and the reduction methods were also explored.The main contents of the full text are as follows:(1)The content of macroparticles increases with the increase of the baffle aperture and the current of the magnetic filter coil,the decrease of the pulse bias.(2)By using the finite element method,the result shows that with the increase of diameter and height of the center of permanent magnet,the maximum transverse magnetic field of the graphite target surface increases,the macroparticles is lower;as the coil current increases,the zero point of longitudinal magnetic flux density moves towards the center at the target surface gradually and the motion of the arc spot is more stable.It provides a new way to effectively control the content of macroparticles.(3)Through the orthogonal test,it is found that the arc spot motion is stable and the content of macroparticles is reduced when the diameter of the central permanent magnet is 18 mm,the height is 55 mm,the coil current is 2A.(4)The thermal stress distribution of Ti/ta-C composite films on 316 L stainless steel has been studied by the finite element method.The influence of the thickness of the film and substrate on the thermal stress has been studied.The error between results and the theoretical calculation is small,which provides a theoretical basis for control of the Ti/taC films thickness.(5)The residual stress of Ti/ta-C films at different deposition temperatures has been studied experimentally.Combined with the results of thermal stress analysis,it is concluded that the intrinsic stress caused by film defects and impurities is the main factor for the residual stress of ta-C films deposited by filtered cathode arc deposition.(6)The change regulation of residual stress in Ti/ta-C films has been explored by high vacuum annealing.The residual stress of films is the lowest at annealing temperature of 200℃,while the hardness,adhesion strength,friction coefficient and bond structure change little when compared with those unannealed ones.