The effect of galvanically induced potentials on the friction and wear behavior of a 1 RK91 stainless steel regarding to tribocorrosion was investigated using an oscillating ball-on-disk tribometer equipped with an el...The effect of galvanically induced potentials on the friction and wear behavior of a 1 RK91 stainless steel regarding to tribocorrosion was investigated using an oscillating ball-on-disk tribometer equipped with an electrochemical cell. The aim of this investigation is to develop a water-based lubricant. Therefore 1 molar sodium chloride(NaCl) and 1% 1-ethyl-3-methylimidazolium chloride [C_2 mim][Cl] water solutions were used. Tribological performance at two galvanically induced potentials was compared with the non-polarized state: cathodic potential-coupling with pure aluminum- and anodic potential-coupling with pure copper. Frictional and electrochemical response was recorded during the tests. In addition, wear morphology and chemical composition of the steel were analyzed using scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS), respectively. The galvanically induced cathodic polarization of the stainless steel surface results in electrochemical corrosion protection and the formation of a tribolayer. Cations from the electrolyte(sodium Na^+ and 1-ethyl- 3-methylimidazolium [C_2 mim]^+) interact and adhere on the surface. These chemical interactions lead to considerably reduced wear using 1 NaC l(86%) and 1% 1-ethyl-3-methylimidazolium chloride [C_2 mim][Cl](74%) compared to the nonpolarized system. In addition, mechanical and corrosive part of wear was identified using this electrochemical technique. Therefore this method describes a promising method to develop water-based lubricants for technical applications.展开更多
研究植入式人体通信方式中通信信号的衰减与不同耦合方式之间的关系。涉及的耦合方式包括电容耦合、电流耦合、正向容阻耦合和反向容阻耦合4种。通过建立等效电路模型进行仿真计算,以及在模拟体内环境的水模型中实验测量的方式,对20 MH...研究植入式人体通信方式中通信信号的衰减与不同耦合方式之间的关系。涉及的耦合方式包括电容耦合、电流耦合、正向容阻耦合和反向容阻耦合4种。通过建立等效电路模型进行仿真计算,以及在模拟体内环境的水模型中实验测量的方式,对20 MHz通信频率下不同耦合方式的通信衰减进行对比。仿真和实验的结果均表明,正向容阻耦合方式下通信的衰减最小,分别为26 d B(计算值)和28 d B(测量值),而电容耦合、电流耦合和反向容阻耦合方式的通信衰减依次增大。这一结果反映出不同耦合方式之间的机制区别,同时意味着若将人体通信方式应用于植入式医疗设备中,正向容阻耦合方式将是最好的选择。展开更多
基金the he MFW-BW(Ministeriumfür Wirtschaft,Arbeit und Wohnungsbau Baden-Württemberg,Project:BioSis)for funding this project
文摘The effect of galvanically induced potentials on the friction and wear behavior of a 1 RK91 stainless steel regarding to tribocorrosion was investigated using an oscillating ball-on-disk tribometer equipped with an electrochemical cell. The aim of this investigation is to develop a water-based lubricant. Therefore 1 molar sodium chloride(NaCl) and 1% 1-ethyl-3-methylimidazolium chloride [C_2 mim][Cl] water solutions were used. Tribological performance at two galvanically induced potentials was compared with the non-polarized state: cathodic potential-coupling with pure aluminum- and anodic potential-coupling with pure copper. Frictional and electrochemical response was recorded during the tests. In addition, wear morphology and chemical composition of the steel were analyzed using scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS), respectively. The galvanically induced cathodic polarization of the stainless steel surface results in electrochemical corrosion protection and the formation of a tribolayer. Cations from the electrolyte(sodium Na^+ and 1-ethyl- 3-methylimidazolium [C_2 mim]^+) interact and adhere on the surface. These chemical interactions lead to considerably reduced wear using 1 NaC l(86%) and 1% 1-ethyl-3-methylimidazolium chloride [C_2 mim][Cl](74%) compared to the nonpolarized system. In addition, mechanical and corrosive part of wear was identified using this electrochemical technique. Therefore this method describes a promising method to develop water-based lubricants for technical applications.
文摘研究植入式人体通信方式中通信信号的衰减与不同耦合方式之间的关系。涉及的耦合方式包括电容耦合、电流耦合、正向容阻耦合和反向容阻耦合4种。通过建立等效电路模型进行仿真计算,以及在模拟体内环境的水模型中实验测量的方式,对20 MHz通信频率下不同耦合方式的通信衰减进行对比。仿真和实验的结果均表明,正向容阻耦合方式下通信的衰减最小,分别为26 d B(计算值)和28 d B(测量值),而电容耦合、电流耦合和反向容阻耦合方式的通信衰减依次增大。这一结果反映出不同耦合方式之间的机制区别,同时意味着若将人体通信方式应用于植入式医疗设备中,正向容阻耦合方式将是最好的选择。
