Comparative Studies Of CrN_x And Cr_1-xV_x N Films Deposited By PEMS And CMS

Hard films could effectively improve the friction and wear performance of mechanical parts,however,different preparation processes have different effects on the structure and properties of hard films.In this paper,CrN_x and Cr_1-xV_xN films were deposited by conventional magnetron sputtering（CMS）and plasma enhanced magnetron sputtering（PEMS）.The influence of nitrogen flow rate(f_N2)on structures and properties of PEMS-CrN_x and CMS-CrN_x films,and the influence of V content on structures and properties of PEMS-Cr_1-xV_xN and CMS-Cr_1-xV_xN films were studied,respectively.The results are as follows:（1）As fN₂ increased,the deposition rates of PEMS-CrNx films reduced,while which decreased firstly and then raised gradually in CMS-CrN_x films.With an increase in f_N2,the phase transformation of PEMS-CrN_x films was found:Cr（N）→Cr（N）+Cr₂N→Cr₂N→Cr₂N+CrN→CrN,and the phase of CMS-CrN_x films transformed from a mixture of Cr and Cr₂N to a mixture of Cr and CrN.The FCC-CrN deposited by PEMS and CMS grew with（200）and（111）preferred orientations,respectively.The PEMS-CrN_x films were dense,which normally exhibited typical Zone T columnar structure in Mahieu model.However,the microstructure of CMS-CrN_x films with loose structure transformed from ZoneⅠb to ZoneⅠc,and then to transition between ZoneⅠc and T depending on f_N2,which density decreased firstly and then increased,and dropped finally.As f_N2 increased,the hardness and Young’s modulus of PEMS-CrN_x films increased firstly and then gradually decreased,and finally increased,while which increase first and then gradually decrease in CMS-CrN_x films.The effect of f_N2 on average friction coefficient were not obvious in both CrN_x films.With the increase of f_N2,the wear rates of PEMS-CrN_x films increased firstly and then gradually decreased,and finally increased,which increased firstly and then gradually decreased in CMS-CrN_x films.（2）With an increase in V content,the deposition rates increased firstly and then reduced in both Cr_1-xV_xN films.The V content had no effect on phase structure of PEMS-Cr_1-xV_x N films,and CMS-Cr1-x VxN films transformed from a mixture of Cr（V）N and Cr to a mixture of Cr（V）N and VN_0.81 with increasing V content.The Cr（V）N deposited by PEMS and CMS grew with（200）and（111）preferred orientations,respectively.The PEMS-Cr1-xVxN films with dense structure exhibited typical Zone T columnar structure in Mahieu model,and the CMS-Cr1-xVxN films exhibited porous columnar-type structure.which were the transition of ZoneⅠc and T.The density of CMS-Cr1-xVxN films increased firstly and then gradually decreased depending on f N₂.With the increase of V content,the hardness and Young’s modulus of PEMS-Cr1-xVxN films decreased firstly and then remained basically unchanged,while which in CMS-Cr_1-xV_x N films raised first and then dropped gradually.As V content increased,the average friction coefficient of annealed PEMS-Cr_1-xV_xN increased gradually and then decreased,while the effect of V content on average friction coefficient was not obvious in annealed CMS-Cr_1-xV_xN films.The wear rates showed rising trend in both annealed Cr_1-xV_x N films with an increase in V content.