In this research,stainless steel bipolar plates for proton exchange membrane fuel cell(PEMFC)have been treated by an atmospheric plasma surface modification technology.The chemical composition and thickness of the oxi...In this research,stainless steel bipolar plates for proton exchange membrane fuel cell(PEMFC)have been treated by an atmospheric plasma surface modification technology.The chemical composition and thickness of the oxide film formed by plasma are conducted to verify by Auger electron spectroscopy(AES).Pitting resistance,potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS)are measured to evaluate the corrosion mechanism and electrochemical properties.The results show that the treated plates have a much thicker oxide film which leads to higher pitting potential,improved corrosion rate,less and smaller pitting holes than those without treatment.The stable chemical and electrochemical properties of the treated stainless steel bipolar plate indicate the stabilization of cell performance and longer service life.展开更多
Boron doped diamond(BDD)thin films have been deposited on Ti substrate with Ta interlayer by MP-CVD(microwave plasma chemical vapor deposition),and Ta interlayer was deposited by magnetron sputtering.The physical and ...Boron doped diamond(BDD)thin films have been deposited on Ti substrate with Ta interlayer by MP-CVD(microwave plasma chemical vapor deposition),and Ta interlayer was deposited by magnetron sputtering.The physical and electrochemical behaviors of the Ti/Ta/BDD electrode and its application in electrochemical oxidation of wastewater containing 2,4-dichlorophenol were studied.Raman spectroscopy and field emission scanning electron microscopy(FESEM)demonstrates that the films obtained exhibit well-defined diamond features.XRD spectroscopy shows no TiC in the BDD film with Ta interlayer.Electrochemical measurement shows the BDD electrode behaves low background current and wide working potential window up to 4 V.Further,the removal efficiency of chemical oxygen demand(COD)of the BDD electrodes were evaluated by the electrochemical oxidation of 2,4-dichlorophenol.展开更多
In this article,the absence of self-replenishing of cold spray is studied by examining the thick coating deposited around the pre-drilled microsize hole.Thick copper coating was deposited around the microsize holes(ab...In this article,the absence of self-replenishing of cold spray is studied by examining the thick coating deposited around the pre-drilled microsize hole.Thick copper coating was deposited around the microsize holes(about 200 and 500μm) using cold spraying methods on copper substrate,the cross-section of cavity around the hole were observed with SEM to investigate the characteristics of cavity.Computational methods were also used to investigate the original formation reason of the cavity.The results indicate:the original formation reason of cavity is that particles are too closed when impact onto the substrate.The repellant force between the particles perpendicular to the impaction direction will lead to porosity if the particles are too close.Much lower flatten ratio occurred for succeeding particle if the particles are too close at the same point because the momentum energy convert to the former particle's deformation.A high probability of above two phenomenon resulting from high powder feeding rate will form the original cavity.In relative wider cavity,coating can be deposited in the bottom,while in the relative narrow cavity,coating can not be deposited.The thickness of the coating in the cavity is much thinner than coating around the cavity.The cavity grow larger and larger on pre-drilled holes just as the regime effect of cold spray of fixed location deposition.展开更多
文摘In this research,stainless steel bipolar plates for proton exchange membrane fuel cell(PEMFC)have been treated by an atmospheric plasma surface modification technology.The chemical composition and thickness of the oxide film formed by plasma are conducted to verify by Auger electron spectroscopy(AES).Pitting resistance,potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS)are measured to evaluate the corrosion mechanism and electrochemical properties.The results show that the treated plates have a much thicker oxide film which leads to higher pitting potential,improved corrosion rate,less and smaller pitting holes than those without treatment.The stable chemical and electrochemical properties of the treated stainless steel bipolar plate indicate the stabilization of cell performance and longer service life.
文摘Boron doped diamond(BDD)thin films have been deposited on Ti substrate with Ta interlayer by MP-CVD(microwave plasma chemical vapor deposition),and Ta interlayer was deposited by magnetron sputtering.The physical and electrochemical behaviors of the Ti/Ta/BDD electrode and its application in electrochemical oxidation of wastewater containing 2,4-dichlorophenol were studied.Raman spectroscopy and field emission scanning electron microscopy(FESEM)demonstrates that the films obtained exhibit well-defined diamond features.XRD spectroscopy shows no TiC in the BDD film with Ta interlayer.Electrochemical measurement shows the BDD electrode behaves low background current and wide working potential window up to 4 V.Further,the removal efficiency of chemical oxygen demand(COD)of the BDD electrodes were evaluated by the electrochemical oxidation of 2,4-dichlorophenol.
基金Science and Technology Foundation of State Key Laboratory for Marine Corrosion and Protection(9140C2505030805)
文摘In this article,the absence of self-replenishing of cold spray is studied by examining the thick coating deposited around the pre-drilled microsize hole.Thick copper coating was deposited around the microsize holes(about 200 and 500μm) using cold spraying methods on copper substrate,the cross-section of cavity around the hole were observed with SEM to investigate the characteristics of cavity.Computational methods were also used to investigate the original formation reason of the cavity.The results indicate:the original formation reason of cavity is that particles are too closed when impact onto the substrate.The repellant force between the particles perpendicular to the impaction direction will lead to porosity if the particles are too close.Much lower flatten ratio occurred for succeeding particle if the particles are too close at the same point because the momentum energy convert to the former particle's deformation.A high probability of above two phenomenon resulting from high powder feeding rate will form the original cavity.In relative wider cavity,coating can be deposited in the bottom,while in the relative narrow cavity,coating can not be deposited.The thickness of the coating in the cavity is much thinner than coating around the cavity.The cavity grow larger and larger on pre-drilled holes just as the regime effect of cold spray of fixed location deposition.
