The binary mixture of Yb2O3-La2O3 was used as an additive to improve the traditional electroless plating for Pd-Ag co-deposition on the inside surface of a porous ceramic tube. The main attention were paid to investig...The binary mixture of Yb2O3-La2O3 was used as an additive to improve the traditional electroless plating for Pd-Ag co-deposition on the inside surface of a porous ceramic tube. The main attention were paid to investigating the effects of Yb2O3-La2O3 on Pd-Ag co-deposition rate, plating temperature, Ag content in film and Pd/Ag reduction potentials. The experimental results show that the co-deposition rate is increased by 63%, the plating temperature is decreased by 10～20 ℃ for obtaining the same co-deposition rate and the Ag content in film basically remains unchangeable when Yb2O3-La2O3 is added into the traditional electroless plating solution. The experiment also shows that Pd/Ag reduction potentials basically remain unchangeable with the binary rare earths based on the electrochemical mathematical models An inorganic composite membrane with alloy film of 76.8(mol)% Pd-23.2(mol)% Ag and the thickness of 7.7 μm on the porous ceramic tube was prepared and the permeation fluxes of hydrogen and nitrogen through the membrane are 8.65×10-3 and 1.92×10-6 m3·m-2·s-1 at 350 ℃ and 0.3 MPa respectively.展开更多
Ni-Mo-P coatings are obtained at the surface of ceramic substrate by electroless deposition using palladium as a surface catalyst.The influence of catalyst activation conditions on coatings’ properties was assessed b...Ni-Mo-P coatings are obtained at the surface of ceramic substrate by electroless deposition using palladium as a surface catalyst.The influence of catalyst activation conditions on coatings’ properties was assessed by structural,morphological,electrical,mechanical measurements and adhesion strength by using X-ray diffraction,field emission scanning electron microscopy,atomic force microscopy,Hall effect and nanoindentation techniques,respectively.The results indicated the formation of dense,continuous and uniform coatings consisting mainly of Ni.The coatings obtained at 300℃for 12 h exhibited the best electrical properties,namely resistivity of 9.32 μΩ cm,smaller roughness(Ra 0.090 μm) and average mechanical properties.The adhesion tests showed a firm adherence of the Ni-Mo-P coatings to the ceramic surface.The results of this study could offer an approach for obtaining conducting ceramic substrates in order to be employed in photovoltaic applications.The performance of demonstrative heterojunction solar cell obtained with such metallized ceramic is indicative of the high potential of the Ni-Mo-P electroless coatings for functional ceramics.展开更多
Recycling and reusing materials from waste have become a nexus in the development of sustainable materials,leading to more balanced technologies.In this study,we developed a composite coating by co-depositing recycled...Recycling and reusing materials from waste have become a nexus in the development of sustainable materials,leading to more balanced technologies.In this study,we developed a composite coating by co-depositing recycled ceramic particles,pulverised fly ash(PFA)and medical ceramics(MC),into a nickel–phosphorus matrix using a typical electroless plating process.Scanning electron microscopy(SEM)images indicated well-dispersed particles in the Ni–P matrix.However,compared with the MC particles,the PFA particles were distributed scantily with a lower content in the matrix,which could be due to the less impingement effect during the co-deposition.A modified microstructure with refined grains was obtained for the PFA-incorporated composite coating,as seen in the SEM micrograph.The X-ray diffraction result of the MC-incorporated composite coating showed the formation of Nix Siy phases in addition to the typical Ni3 P phases for the heattreated electroless Ni–P coatings.Upon heat treatment,the PFA-reinforced composite coating,due to a modified microstructure,exhibited a higher microhardness up to HK0.05818,which is comparable to that of the traditional SiC particle-embedded composite coating(HK0.05825).The findings can potentially open up a new strategy to further advance the green approach for industrial surface engineering.展开更多
基金Project supported by Science and Technology Committee of Jiangxi Province
文摘The binary mixture of Yb2O3-La2O3 was used as an additive to improve the traditional electroless plating for Pd-Ag co-deposition on the inside surface of a porous ceramic tube. The main attention were paid to investigating the effects of Yb2O3-La2O3 on Pd-Ag co-deposition rate, plating temperature, Ag content in film and Pd/Ag reduction potentials. The experimental results show that the co-deposition rate is increased by 63%, the plating temperature is decreased by 10～20 ℃ for obtaining the same co-deposition rate and the Ag content in film basically remains unchangeable when Yb2O3-La2O3 is added into the traditional electroless plating solution. The experiment also shows that Pd/Ag reduction potentials basically remain unchangeable with the binary rare earths based on the electrochemical mathematical models An inorganic composite membrane with alloy film of 76.8(mol)% Pd-23.2(mol)% Ag and the thickness of 7.7 μm on the porous ceramic tube was prepared and the permeation fluxes of hydrogen and nitrogen through the membrane are 8.65×10-3 and 1.92×10-6 m3·m-2·s-1 at 350 ℃ and 0.3 MPa respectively.
基金financially supported by the Escuela Politecnica Nacional(under Grant No.PIMI 15-09)the Secretaria de Educacion Superior,Ciencia,Tecnologia e Innovacion (SENESCYT) of Ecuador and Romanian National Authority for Scientific Research and Innovation CNCS-UEFISCDI(under Grant No. PN-III-P1-1.1-TE-2016-1544).
文摘Ni-Mo-P coatings are obtained at the surface of ceramic substrate by electroless deposition using palladium as a surface catalyst.The influence of catalyst activation conditions on coatings’ properties was assessed by structural,morphological,electrical,mechanical measurements and adhesion strength by using X-ray diffraction,field emission scanning electron microscopy,atomic force microscopy,Hall effect and nanoindentation techniques,respectively.The results indicated the formation of dense,continuous and uniform coatings consisting mainly of Ni.The coatings obtained at 300℃for 12 h exhibited the best electrical properties,namely resistivity of 9.32 μΩ cm,smaller roughness(Ra 0.090 μm) and average mechanical properties.The adhesion tests showed a firm adherence of the Ni-Mo-P coatings to the ceramic surface.The results of this study could offer an approach for obtaining conducting ceramic substrates in order to be employed in photovoltaic applications.The performance of demonstrative heterojunction solar cell obtained with such metallized ceramic is indicative of the high potential of the Ni-Mo-P electroless coatings for functional ceramics.
基金the financial support from Queen’s University Belfast,UK,in the form of a studentship。
文摘Recycling and reusing materials from waste have become a nexus in the development of sustainable materials,leading to more balanced technologies.In this study,we developed a composite coating by co-depositing recycled ceramic particles,pulverised fly ash(PFA)and medical ceramics(MC),into a nickel–phosphorus matrix using a typical electroless plating process.Scanning electron microscopy(SEM)images indicated well-dispersed particles in the Ni–P matrix.However,compared with the MC particles,the PFA particles were distributed scantily with a lower content in the matrix,which could be due to the less impingement effect during the co-deposition.A modified microstructure with refined grains was obtained for the PFA-incorporated composite coating,as seen in the SEM micrograph.The X-ray diffraction result of the MC-incorporated composite coating showed the formation of Nix Siy phases in addition to the typical Ni3 P phases for the heattreated electroless Ni–P coatings.Upon heat treatment,the PFA-reinforced composite coating,due to a modified microstructure,exhibited a higher microhardness up to HK0.05818,which is comparable to that of the traditional SiC particle-embedded composite coating(HK0.05825).The findings can potentially open up a new strategy to further advance the green approach for industrial surface engineering.
