Microstructure And Properties Of GCr15 Bearing Steel Ions Implantation Carbon, Nitrogen And Tantalum By PBII

The strengthening effects and wear resistance of carbon, nitrogen and tantalum ions implantation of Gr15 steel are discussed by studying the evolution of nano-hardness and wear mechanism of the samples with different implantation sequence and dose.The composition and chemical structure of implanted layers were studied by X-ray photoelectron spectroscopy(XPS) and laser Raman spectroscopy respectively. The phases exist in the implanted layers were determined by grasing angle X-ray diffraction(GXRD). The Nano-impression apparatus were used to determine the nano-hardness and modulus of the implanted layers. The tribologocial behavior of the implanted layers was investigated by ball-disk friction wear testing machine under the condition of dry friction and laboratory ambient, and scanning electron microscopy(SEM) and metallographical were also used to investigate the wear machining.The results show that the properties of the DLC films for the sample with implantation sequence of nitrogen-carbon are better than the samples with implantation sequence of carbon-nitrogen. The highest hardness is with the nitrogen and carbon implantation dose of 3E17ions/cm2 whatever the implantation sequence, respectively. The adhesion abrasion resistance of samples with implantation sequence of nitrogen-carbon is better than the samples with implantation sequence of carbon-nitrogen during the friction tests without lubrication and the wear resistance increases with the increasing of carbon implantation dose. With friction pair GCr15 steel ball for the sample with implantation sequence of carbon-nitrogen, the wear machine is adhesive; for the sample with implantation sequence of nitrogen-carbon, the wear machine is abrasive. With friction pair Si3N4 ceramic ball at the beginning the wear machine is adhesive and abrasive one, then transisting into the adhesive or abrasive machine with the increasing of carbon and nitrogen implantation dose, respectively.The results also show that the new phase of TaC and Ta2C exited in the implanted layers for the samples with implated carbon, nitrogen and tantalum. Friction cofficient is also obvious decreased. The adhesion abrasion resistance of samples with implantation sequence of Ta-gas is better than the samples with implantation sequence of gas-Ta during the friction tests without lubrication. With friction pair GCr15 steel ball for the sample with implantation sequence of Ta-gas, the wear machine is abrasive. With friction pair Si3N4 ceramic ball its wear mechine is both abrasive and adhesive one at the beginning, then trasisting into abrasive one. The other is both abrasive and adhesive machine with whatwver friction pair.