Nickel-containing stainless steels have been widely applied in watch and jewelry production, and their re- sponses to the Nickel Directive become a universal concern in the industry. The nickel release rates and corro...Nickel-containing stainless steels have been widely applied in watch and jewelry production, and their re- sponses to the Nickel Directive become a universal concern in the industry. The nickel release rates and corrosion be- haviors of types 316L, 304, 303 and 201 stainless steels under the conditions of solid solution and mirror polishing were studied by artificial sweat soaking and electrochemical methods. The results show that the weekly nickel release rates in artificial sweat do not strictly correspond to the nickel contents, which present a descending order as 303 stainless steel of 2.06 μg/cm2 , 201 stainless steel of 1.51 μg/cm2 , 304 stainless steel of 0.08μg/cm2 and 316L stainless steel of 0.02 μg/cm2. Both the nickel release rates of type 303 and 201 stainless steels significantly exceed the threshold values regulated in EN1811 ： 2011 ; therefore, they should be avoided to be used as watch and jewelry materials owing to the risk of nickel sensitization. The nickel release rates of 316L and 304 stainless steels meet the requirements of the standard. Sulfide inclusions in stainless steel become the sources of pitting and exacerbate the damage of the passivation membrane, which is the significant cause to enhance the nickel release rates.展开更多
The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison ...The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison of nickel(Ni)release and cytocompatibility between pNiTi and dense NiTi(dNiTi)was made.The results showed that the pNiTi has good mechanical properties.Ni releases from pNiTi in vitro and in vivo are more serious than those form dNiTi.The proliferation and differentiation of cells cultured with the pNiTi extracting liquid are significantly worse,and the rate of early apoptosis is higher.In conclusion,pNiTi is mechanically similar to bone,but pNiTi releases more Ni and interferes with cell proliferation and differentiation.A significantly cautious approach should be adopted when using it as a medical implant.展开更多
基金financially supported by the foundation of Jewelry Engineering Technology Development Center of Guangdong Colleges and Universities(item No.131,Yue Edu.Sci)
文摘Nickel-containing stainless steels have been widely applied in watch and jewelry production, and their re- sponses to the Nickel Directive become a universal concern in the industry. The nickel release rates and corrosion be- haviors of types 316L, 304, 303 and 201 stainless steels under the conditions of solid solution and mirror polishing were studied by artificial sweat soaking and electrochemical methods. The results show that the weekly nickel release rates in artificial sweat do not strictly correspond to the nickel contents, which present a descending order as 303 stainless steel of 2.06 μg/cm2 , 201 stainless steel of 1.51 μg/cm2 , 304 stainless steel of 0.08μg/cm2 and 316L stainless steel of 0.02 μg/cm2. Both the nickel release rates of type 303 and 201 stainless steels significantly exceed the threshold values regulated in EN1811 ： 2011 ; therefore, they should be avoided to be used as watch and jewelry materials owing to the risk of nickel sensitization. The nickel release rates of 316L and 304 stainless steels meet the requirements of the standard. Sulfide inclusions in stainless steel become the sources of pitting and exacerbate the damage of the passivation membrane, which is the significant cause to enhance the nickel release rates.
文摘The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison of nickel(Ni)release and cytocompatibility between pNiTi and dense NiTi(dNiTi)was made.The results showed that the pNiTi has good mechanical properties.Ni releases from pNiTi in vitro and in vivo are more serious than those form dNiTi.The proliferation and differentiation of cells cultured with the pNiTi extracting liquid are significantly worse,and the rate of early apoptosis is higher.In conclusion,pNiTi is mechanically similar to bone,but pNiTi releases more Ni and interferes with cell proliferation and differentiation.A significantly cautious approach should be adopted when using it as a medical implant.
