A plasma electrolytic nitrocarburising （PEN/C） process was performed on stainless steel 316L to improve the surface properties for using as medical implants. A bath was optimised to reduce the required voltage to 15...A plasma electrolytic nitrocarburising （PEN/C） process was performed on stainless steel 316L to improve the surface properties for using as medical implants. A bath was optimised to reduce the required voltage to 150 volts. Aqueous urea-based solutions with 10% NH4Cl were prepared with slightly different amounts of Na2CO3 to optimise the electrolyte composition. The surface and the cross-section morphologies were studied by scanning electron microscopy. The microstructure and the chemical composition of samples were investigated by X-ray diffraction （XRD） and energy dispersive X-ray （EDX） techniques. The microstructure of the outer layer of the coatings was found to be a complex oxide containing Cr and Fe. The wear properties of the samples were examined by using a pin on disk wear test with Ringer＇s solution and were compared with their wear properties in the ambient atmosphere. The Ringe（s solution acted as a lubricant, reducing friction coefficient. Hardness and roughness were also studied. The bath with the composition of 10% NH4CI and 3% Na2CO3 exhibited the best tribological properties. The results showed that the tribological properties of treated samples were improved and the wear mechanism was abrasion of the pin.展开更多
基金supported by the Research Committee of Shiraz University under grant No.88-GR-ENG-62,which is gratefully appreciated
文摘A plasma electrolytic nitrocarburising （PEN/C） process was performed on stainless steel 316L to improve the surface properties for using as medical implants. A bath was optimised to reduce the required voltage to 150 volts. Aqueous urea-based solutions with 10% NH4Cl were prepared with slightly different amounts of Na2CO3 to optimise the electrolyte composition. The surface and the cross-section morphologies were studied by scanning electron microscopy. The microstructure and the chemical composition of samples were investigated by X-ray diffraction （XRD） and energy dispersive X-ray （EDX） techniques. The microstructure of the outer layer of the coatings was found to be a complex oxide containing Cr and Fe. The wear properties of the samples were examined by using a pin on disk wear test with Ringer＇s solution and were compared with their wear properties in the ambient atmosphere. The Ringe（s solution acted as a lubricant, reducing friction coefficient. Hardness and roughness were also studied. The bath with the composition of 10% NH4CI and 3% Na2CO3 exhibited the best tribological properties. The results showed that the tribological properties of treated samples were improved and the wear mechanism was abrasion of the pin.
