Simulation And Experimental Study Of TiN_x Coating Prepared By DC Magnetron Sputtering At Room Temperature

TiN_xcoating is widely used in surface protection,photoelectric materials,decorative coating and many other fields,and usually can be prepared by magnetron sputtering method.However,there are problems of loose structure and amorphfication of TiN_xcoatings which were prepared by DC magnetron sputtering method at room temperature with TiN ceramic targets,which are caused by the low temperature of deposited particles.At the same time,conventional solutions will increase the process complexity and coating preparation cost,which is not conducive to industrial production.Therefore,a fast and simple solution for industrial production is urgently needed.Firstly,the glow discharge process was simulated by using the finite element method.Secondly,according to the distribution state and the sheath theory,the method of adjusting the"target-substrate distance"is improved,and the influence of the"target-substrate distance"on the ion temperature and density of the matrix surface was studied by the simulation model.Finally,the coating preparation experiment was implemented to verify the effectiveness of the simulation optimization,and compared the improved process method with the conventional method.The main research contents are as follows:1)A physical model of magnetized DC glow discharge was established.A fluid model was used to obtain the spatial distribution characteristics of charged particles.The simulation results show that outside the dissociation zone,the charged particle density decreases rapidly with the increasing distance of the charged particles and the cathode target,and the charged particles density are low on both sides and high in the middle.2)Simulation and optimization method of charged particle parameters based on adjusting the"target-substrate distance".Based on the distribution state of the charged particles’parameters and the sheath theory,the"target-substrate distance"can affect the ion parameters of the matrix surface.With the help of the plasma discharge simulation model and the univariate analysis method,the influence of the"target-substrate distance"on the matrix surface ion temperature and density were further studied.The simulation results show that with the decrease of the target-substrate distance,the ion temperature and density of the matrix surface both rise first and then decrease.When the target distance is50 mm,both reach a large value.3)Experimental validation of coating preparation based on the optimized"target-substrate distance"parameter.Using the parameters optimized by simulation,the results showed that the crystallinity,structural density and hardness of the TiN_xcoating prepared on the YG8 cemented carbide matrix,with the parameters of the target base distance is 50 mm,sputtering power is 50 W and the background pressure is 0.7 Pa,are significantly improved before the optimization.In addition,the nanohardness is 27.82 GPa,which meet the use requirements.4)The improved process method is compared with the conventional process method.Compared with the methods of conventional heat treatment and adding matrix negative bias,it is found that the improved process method in this paper can effectively reduce the implementation cost of the experiment,and improve the hardness and crystallinity of the coating,which has a high industrial application value.