THE STRUCTURAL AND MECHANICAL PROPERTIES OF CrN_x THIN FILMS PREPARED BY REACTIVE MAGNETRON SPUTTERING

CrN_x films were prepared using reactive magnetron sputtering in order to analyze the structural and mechanical features regarding to N₂ partial pressure variations.XRD diffraction patterns revealed that only Cr phase with strong（111） orientation was observed for 0% nitrogen partial pressure,the mixed Cr₂N and Cr phase appeared at 20% nitrogen partial pressure,while for 40% N₂ partial pressure no crystal structure feature was seen.Further increasing the nitrogen partial pressure to 60% or above,only CrN phase appeared.SEM results showed a columnar-type structure lying in the transition zone between T and I zones of Thornton Model for the films.The Cr film（0% N₂ partial pressure） showed a low friction coefficient against the steel ball,but much higher against the Si₃N₄ ball.The friction coefficient of the CrN_x films is low in the range of nitrogen partial pressure from 20% and 40%,and then reached about 0.70.The obviously changes was not observed with the N₂ partial pressure further increasing.