Comparison of Tribological Behaviors of Ti-Si-N Coatings Prepared by Magnetically Controlled Sputtering and Pulsed Chemical Vapor Deposition

Two types of Ti-Si-N coatings were deposited W18Cr4V high speed steel and 1Cr18Ni9Ti stainless steel, respectively, making use of pulsed chemical vapor deposition (PCVD) and magnetically controlled sputtering, respectively. The resulting coatings were coded as C-type Ti-Si-N coating and P-type Ti-Si-N coating, respectively. The hardness of the coatings was measured, while their friction and wear behaviors sliding against AISI-52100 steel at ambient and elevated temperatures in a ball-on-disc configuration were evaluated on a high temperature friction and wear tester. Moreover, the worn surface morphologies of various coatings at different sliding conditions were observed on a scanning electron microscope. It was found that the coatings had the largest hardness at Si content about 10at%. The wear-resistance of the two types of coatings at room and high temperatures was independent on their hardness. The PCVD Ti-Si-N coating showed better wear-resistance at elevated temperature than the magnetically-controlled-sputtered one. The differences in the tribological behaviors of the two types of Ti-Si-N coatings were attributed to their differences in the film-substrate bonding strengths and hardness, while the decreased friction coefficients of the coatings at elevated temperature than at ambient condition was attributed to the lubricity of the oxide layer on the worn coating surfaces.