Controls And Mechanical Properties Of Interface Between Diamond-like Carbon Film And Substrate

Diamond-like carbon(DLC)with comprehensive performance of low friction coefficient,high hardness,good abrasion resistance and high chemical stability gets wordwide excellent scientific research workers' and enterprises' attention.But because of the influence of DLC's preparation method and its limitation of the micro structure,its internal stress is very high and the adhesion strength is low.This paper adopts the industrial chamber of H1300 mm×?1700 mm type with PACVD method for DLC films,this configuration is simple and inexpensive.In order to improve bonding strength of DLC films,Cr C is added as the transition layer between the film and substrate,preparation parameters and multilayer structure of Cr C transition layer are researched.In order to further improve the DLC films' binding strength for mechanical properties,WC transition layer was prepared by hybrid PACVD and PVD processes comparing with the traditional preparation system on the differences of structure and mechanical properties.The main research contents are as follows:Cr C transition layer was prepared by unbalanced magnetron sputtering.The results show that when the acetylene flow rate is 55 sccm,Cr/C ratio reached 1:1,Cr C film reaches the highest hardness and the DLC film adhesion strength and the wear resistance is better than the other group;when Cr C film thickness is 0.815 ?m,the DLC film achieves the optimal combination and bearing capacity;when substrate bias voltage is 100 V for Cr C film,the Cr C/DLC film has excellent comprehensive mechanical properties.This experiment through the periodic controls of acetylene flow rate successfully prepares the(Cr/Cr C)x multilayer structure transition layer with the thickness more than1 ?m.(Cr/Cr C)x multilayer structure refines the grain size of Cr C monolayer and improves binding strength.When the modulation cycle is 175 nm,the hardness of the films is 13.678 GPa,more than a single layer of Cr(8.858 GPa)and Cr C layer(10.374GPa).Bearing capacity and wear resistance of(Cr/Cr C)x/DLC film are improved comparing to Cr C/DLC.The poisoning points of WC target is higher,WC transition layer is prepared by hybrid PACVD and PVD model which is different from the traditional magnetron sputtering.New WC transition layer compared to traditional transition layer has the depthen combination in structure and composition with DLC layer,so the binding layer is smooth without space.And the new WC transition layer is compact,the hardness reaches 17.721 GPa,while maintaining high toughness.Compared to the traditional method,the new WC/DLC film has been greatly improved in the combination of strength and bearing capacity.Even in the frictional environment of high pressure stressand shear stress,the DLC film also maintains very high stability.This paper selects large industrial equipment,diamond-like carbon film is prepared by PACVD method with adding transition layer to improve the adhesion strength of DLC film.Researching the parameters of preparation of transition layer and putting forward a new transition layer preparation model are providing a new way for large-scale producted diamond-like carbon films with low cost and excellent comprehensive properties.