In order to impart electrical conductivity to the magnesium alloy micro-arc oxidation(MAO)coating,the electroless copper plating was performed.Effects of plating temperature and complexing agent concentration on the p...In order to impart electrical conductivity to the magnesium alloy micro-arc oxidation(MAO)coating,the electroless copper plating was performed.Effects of plating temperature and complexing agent concentration on the properties of the electroless copper plating layers were studied by measuring their microstructure,corrosion resistance and electrical conductivity.It was found that the optimized plating temperature was 60°C,and the most suitable value of the complexing agent concentration was 30 g/L.Under this condition,a complete and dense plating layer could be obtained.The formation mechanism of the plating layer on magnesium alloy MAO coating was analyzed.A three-stage model of the plating process was proposed.The square resistance of the plated specimen was finally reduced to 0.03Ω/□after the third stage.Through electroless copper plating,the MAO coated sample obtained excellent electrical conductivity without significantly reducing its corrosion resistance.展开更多
In order to obtain substrates with good conductive foam for high porosity foam metal materials used in the metal electrodes,the technique of electroless copper plating on the microcellular polyurethane foam with pore ...In order to obtain substrates with good conductive foam for high porosity foam metal materials used in the metal electrodes,the technique of electroless copper plating on the microcellular polyurethane foam with pore size of 0.3 mm was investigated.The main factors affecting the deposition rate such as the solution composition,temperature,pH value and adding ultrasonic were explored.The results show that the optimum process conditions are CuSO4 16 g/L,HCHO 5 mL/L,NaKC4H4O6 30 g/L,Na2EDTA 20 g/L,K4Fe(CN)6 25 mg/L,pH value of 12.5-13.0 and temperature of 40-50℃.Under these technical conditions, the process has excellent bath stability.Adding ultrasonic on the process can elevate the deposition rate of copper by 20%-30%.The foam metal material with a porosity of 92.2%and a three-dimensional network structure,was fabricated by electro-deposition after the electroless copper plating.展开更多
The amount of Cu coating by chemical plating was investigated based on quadratic regression orthogonal experimental design being adapted to the variation law of temperature, pH value and Ni2+ concentration, and the re...The amount of Cu coating by chemical plating was investigated based on quadratic regression orthogonal experimental design being adapted to the variation law of temperature, pH value and Ni2+ concentration, and the relevant regression equation was expressed as y=2.1609+0.5295×10-3T2-0.0342P2-0.0265N2+0.0023TP+0.0020TH+0.0199PN-0.0959T+0.3814P-0.2073N. The results showed that the deposition rate augmented with the increasing in temperature, pH value and Ni2+ concentration. The experimental parameters of the optimal coating were temperature 75 °C, pH value 8.5 and Ni2+ concentration 1.2 g/L. The electrochemical tests indicated that the cycle stability increased from 60.66% to 75.58%, indicating that the treated alloy exhibited better corrosion resistance.展开更多
The electrochemical mechanism of anode oxidation of HCHO in electroless copper plating solution with N, N, N′, N′-tetrakis(2-hydroxypropyl)ethylenediamine (THPED) was investigated by measuring cyclic voltammetry cur...The electrochemical mechanism of anode oxidation of HCHO in electroless copper plating solution with N, N, N′, N′-tetrakis(2-hydroxypropyl)ethylenediamine (THPED) was investigated by measuring cyclic voltammetry curves and anodic polarization curves. Three different oxidation peaks occur at the potentials of -0.62 V (Peak 1), -0.40 V (Peak 2) and -0.17 V (Peak 3) in the anode oxidation process of THPED-containing solution. The reaction at Peak 1, a main oxidation reaction, is the irreversible reaction of adsorbed HCHO with hydrogen evolution. The reaction at Peak 2, a secondary oxidation reaction, is the quasi-reversible reaction of adsorbed HCHO without hydrogen evolution. The reaction at Peak 3 is the irreversible oxidation of anode copper. The current density of Peak 1 increases gradually, that of Peak 2 remains constant and that of Peak 3 decreases with the increase of HCHO concentration. The current density of Peak 3 increases with the increase of THPED concentration and the complexation of THPED promotes the dissolution of anode copper.展开更多
Cu-P-silicon carbide （SiC） composite coatings were deposited by means of electroless plating.The effects of pH values,temperature,and different concentrations of sodium hypophosphite （NaH2PO2·H2O）,nickel sulf...Cu-P-silicon carbide （SiC） composite coatings were deposited by means of electroless plating.The effects of pH values,temperature,and different concentrations of sodium hypophosphite （NaH2PO2·H2O）,nickel sulfate （NiSO4·6H2O）,sodium citrate （C6H5Na3O7·2H2O） and SiC on the deposition rate and coating compositions were evaluated,and the bath formulation for Cu-P-SiC composite coatings was optimised.The coating compositions were determined using energy-dispersive X-ray analysis （EDX）.The corresponding optimal operating parameters for depositing Cu-P-SiC are as follows：pH 9;temperature,90oC;NaH2PO2·H2O concentration,125 g/L;NiSO4·6H2O concentration,3.125 g/L;SiC concentration,5 g/L;and C6H5Na3O7·2H2O concentration,50 g/L.The surface morphology of the coatings analysed by scanning electron microscopy （SEM） shows that Cu particles are uniformly distributed.The hardness and wear resistance of Cu-P composite coatings are improved with the addition of SiC particles and increase with the increase of SiC content.展开更多
By means of electroless copper deposition method a complex image has been fabricated in a mixture of cupric sulphate and formaldehyde, the surface and subsurface properties of which has been studied in detail by X-ray...By means of electroless copper deposition method a complex image has been fabricated in a mixture of cupric sulphate and formaldehyde, the surface and subsurface properties of which has been studied in detail by X-ray photoelectron spectroscopy (XPS) combined with sputter depth profiling technique analyzing distribution and chemical state of copper and silver. Depth profiling by XPS in conjunction with Ar+ sputtering shows that the catalytic activity of silver persists, catalyzing reduction of copper. The integral areas of spectra Ag3d after electroless copper deposition for 5 min at different sputtering times demonstrate that the amount of silver at the surface is greater than that in the interior. And then, the quite likely reasonable explanations are provided for the result. Additionally, the chemical shift of Ag3d XPS and deconvolution of Ag3d XPS spectrum have been also analyzed respectively at length.展开更多
A new method is described for the electroless deposition of copper onto glass. Commercially available glass slide was modified with γ-aminopropyltrimethoxysilane to form self-assembled monolayer (SAM) on it. Then it ...A new method is described for the electroless deposition of copper onto glass. Commercially available glass slide was modified with γ-aminopropyltrimethoxysilane to form self-assembled monolayer (SAM) on it. Then it was dipped directly into PdCl_2 solution instead of the conventional SnCl_2 sensitization followed by PdCl_2 activation. Experimental results showed that the Pd 2+ ions from PdCl_2 solution were coordinated to the amino groups on the glass surface resulting in the formation of N-Pd complex. In an electroless copper bath containing a formaldehyde reducing agent, the N-Pd complexes were reduced to Pd 0 atoms, which then acted as catalysts and initiated the deposition of copper metal. Although the copper deposition rate on SAM-modified glass was slow at the beginning, it reached to that of conventional method in about 5 min.展开更多
Electroless copper plating was studied using dimethylamine borane （DMAB） as reductant and 1,5,8,12- tetraazadodecane as additive and triethanolamine （TEA） as buffer. The effects of pH, temperature and concentratio...Electroless copper plating was studied using dimethylamine borane （DMAB） as reductant and 1,5,8,12- tetraazadodecane as additive and triethanolamine （TEA） as buffer. The effects of pH, temperature and concentrations of reactants and additives on the anodic oxidation of DMAB and the cathodic reduction of copper ion were investigated. Experimental results indicate that high pH values （10-12.5） promote the oxidation of DMAB, and suppress the reduction of the copper ion, while high bath temperatures （55-70℃） accelerate both anodic oxidation and cathodic reduction. Increase of the Cu2＋and DMAB concentrations can improve the deposition rate of copper plating. Results for a dual-chelating-agent system indicate that 1,5,8,12-tetraazadodecane plays an important role in chelation, while the main effect of TEA is adsorption on copper surfaces to inhibit DMAB oxidation and to promote deposition.展开更多
The molybdenum powders with average particle size of 3 μm were coated with copper by electroless plating. The influence of pretreatment, solution composition and plating conditions on electroless copper plating was s...The molybdenum powders with average particle size of 3 μm were coated with copper by electroless plating. The influence of pretreatment, solution composition and plating conditions on electroless copper plating was studied. The copper-coated molybdenum powders were examined by SEM and XRD. Results indicate that a series of optimization methods is used to add activated sites before electroless copper plating. Taking TEA and EDTA as chief and assistant complex agents respectively, 2,2＇-bipyridyl and PEG as double stabilizers, the Mo powders are coated with copper successfully with little Cu20 contained, at the same time, Mo-Cu composite powders with copper content of 15 - 85 wt% can be obtained. The optimal values of pH, temperature and HCHO concentration are 12 -13, 60 -65 ℃ and 22 -26 mL/L, respectively.展开更多
The use of more and more electron products requires interior wood products to have the performance of electromagnetic shielding. One of the ways to realize it is to introduce the chemical plating which has already bee...The use of more and more electron products requires interior wood products to have the performance of electromagnetic shielding. One of the ways to realize it is to introduce the chemical plating which has already been developed in electron industry into wood processing. The paper clarifies the mechanism of electroless copper and gold plating and its application to wood. It emphasizes the development and technology of electroless copper and gold plating on wood. Meanwhile, it points out that it is highly feasible to take this technology into effect.展开更多
Molybdenum powders with a diameter of approximately 3 μn were coated with copper using the electroless plating technique in the pH 12.5-13 and temperature range of 55-75℃. The optimization of the electroless copper ...Molybdenum powders with a diameter of approximately 3 μn were coated with copper using the electroless plating technique in the pH 12.5-13 and temperature range of 55-75℃. The optimization of the electroless copper bath was evaluated through the combination of process parameters like pH and temperature. The optimized values ofpH and temperature were found to be 12.5 and 60℃, respectively, which attributes to the bright maroon color of the coating with an increase in weight of 46%. The uncoated and coated powders were subjected to microstructural studies using scanning electron microscope （SEM） and the phases were analyzed using X-my diffrction （XRD）. An attempt was made to understand the growth mechanism of the coating. The diffusion-shrinkage autocatalytic model was suggested for copper growth on the molybdenum surface.展开更多
Mo powders with average particle size of 3 μm were attempted to coat with copper by electroless plating technique. The effect of the solution composition and plating conditions on the electroless copper plating was s...Mo powders with average particle size of 3 μm were attempted to coat with copper by electroless plating technique. The effect of the solution composition and plating conditions on the electroless copper plating was studied. The uncoated and coated powders were subjected to the microstructural studies by SEM and the phases were analyzed by XRD. The results indicate that the Mo powders are coated with copper,at the same time,Mo-Cu composite powders with Cu content ranging from 15% to 85%(mass fraction) can be obtained. The optimal values of pH,HCHO concentration and temperature are in the ranges of 12-13,22-26 ml/L and 60-65 ℃,respectively. The diffusion-shrinkage autocatalytic model is suggested for the growth mechanism of electroless coating over the surface.展开更多
This paper showed simple and effective synthesis of copper nanoparticles within controlled diameter using direct electroless deposition on glass substrates, following the sensitization and activation steps. Electroles...This paper showed simple and effective synthesis of copper nanoparticles within controlled diameter using direct electroless deposition on glass substrates, following the sensitization and activation steps. Electroless-deposited metals, such as Cu, Co, Ni, and Ag, and their alloys had many advantages in micro- and nanotechnologies. The structural, morphological, and optical properties of copper deposits were characterized using X-ray diffraction （XRD）, atomic force microscopy （AFM）, and UV-Vis spectroscopy. The structural data was further analyzed using the Rietveld refinement program. Structural studies reveal that the deposited copper prefers a （111） orientation. AFM studies suggest the deposited materials form compact, uniform, and nanocrystalline phases with a high tendency to self-organize. The data show that the particle size can be controlled by controlling the activator concentration. The absorption spectra of the as-deposited copper nanoparticles reveal that the plasmonic peak broadens and exhibits a blue shift with decreasing particle size.展开更多
Nanocrystalline copper films were prepared on the glass by electroless plating technique. The surface characterization of copper films with different deposition time was studied by field emission scanning electron mic...Nanocrystalline copper films were prepared on the glass by electroless plating technique. The surface characterization of copper films with different deposition time was studied by field emission scanning electron microscopy(FESEM) and atomic force microscopy(AFM). The results indicate that the copper films have a(111) texture. A continuous and smooth film forms on the glass substrate at deposition times of 5 min. The surface roughness of as-deposited copper films becomes rougher with large nodules as the deposition time increases. According to Fuchs-Sondheimer(F-S),Mayadas-Shatzkes(M-S) theory and a combined model,the grain boundary reflection coefficient(R) is calculated in the range of 0.40-0.75. The theoretical analysis based on the experimental results show that the grain boundaries contribute mainly to the increase of electrical resistivity of nanocrystalline copper film compared with the film surfaces.展开更多
In this work, an electroless method of coating copper on the basalt short fibers using copper sulphate solution is described. In order to avoid any interfacial reactions in the basalt fiber reinforced metal matrix com...In this work, an electroless method of coating copper on the basalt short fibers using copper sulphate solution is described. In order to avoid any interfacial reactions in the basalt fiber reinforced metal matrix composites, the basalt fibers were coated with copper. The effects of the time of sensitization, activation, metallization, PdCl2 concentration, pH and temperature bath on the extent of copper coating on basalt fiber are reported. The conditions used for electroless coating were optimized to obtain a uniform and continuous layer of copper. Using this method, it is possible to deposit up to about 25 wt% copper on the basalt fiber. The resultant composite fiber was characterized by scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) during and after the coating process. The effects of the thickness of copper coating on surface condition and also the tensile strength of the basalt fibers have been investigated. The study of surface condition of the coated basalt fibers by SEM showed that the copper coating at the thickness of about 0.2 μm had the best continuity on the basalt fibers. The results of tensile tests of basalt fibers coated with different thickness of copper showed that increasing the thickness of coating layer decreased the overall strength of fibers.展开更多
Copper serpentines used in gas heaters are currently coated with lead-tin alloy using hot-dip technology where copper is immersed in molten lead (98%)-Tin at about 400°C. The major drawback of this technique i...Copper serpentines used in gas heaters are currently coated with lead-tin alloy using hot-dip technology where copper is immersed in molten lead (98%)-Tin at about 400°C. The major drawback of this technique is the pollution resulted from lead vapors which cause much harm to the labors in the unit. The present work investigates an eco-friendly plating technique to replace the currently used technology. Electroless plating of copper samples with lead or Lead (98%)-Tin alloy is carried out from a plating bath contained lead salt, tin salt, reducing agent and stabilizing agent. The parameters affecting the coating quality such as the plating time, temperature and bath composition were optimized. The chemical analysis and coating morphology of the formed coatings are examined by XRD, SEM and EDS to reach the best bath composition as well as the best conditions to coat copper with lead or lead-tin electrolessly. The electrochemical properties of copper and copper coated samples are also examined using electrochemical impedance spectroscopy.展开更多
Electroless copper plating on diamond particles precoated with 1%Cr was carried out to evaluate the effects of various experimental parameters on coating quality and deposition rate to obtain the optimized reaction pa...Electroless copper plating on diamond particles precoated with 1%Cr was carried out to evaluate the effects of various experimental parameters on coating quality and deposition rate to obtain the optimized reaction parameters. The formulated samples under optimized parameters were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectra and optical microscopy. The best parameters, where uniform and maximum coating thickness was achieved, are etching with 20%NaOH for 30 min, sensitization and activation with SnCl2 and PdCl2 for 5 and 20 min, respectively. The composition of the copper solution bath was 16 g/L CuSO4＆#183;5H2O, 35 mL/L formaldehyde （HCHO）, 23 g/L KNaC4H4O6 at 60 ℃, pH=13 and stirring at （350±15） r/min under ultrasonication.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301105)the National Natural Science Foundation of China(No.51804190)+4 种基金the Shandong Provincial Natural Science Foundation,China(No.ZR2021ME240)the Youth Science Funds of Shandong Academy of Sciences,China(No.2020QN0022)the Shandong Province Key Research and Development Plan,China(Nos.2019GHZ019 and 2019JZZY020329)the Jinan Science&Technology Bureau,China(No.2019GXRC030)the Innovation Pilot Project for Fusion of Science,Education and Industry(International Cooperation)from Qilu University of Technology(Shandong Academy of Sciences),China(No.2020KJC-GH03)。
文摘In order to impart electrical conductivity to the magnesium alloy micro-arc oxidation(MAO)coating,the electroless copper plating was performed.Effects of plating temperature and complexing agent concentration on the properties of the electroless copper plating layers were studied by measuring their microstructure,corrosion resistance and electrical conductivity.It was found that the optimized plating temperature was 60°C,and the most suitable value of the complexing agent concentration was 30 g/L.Under this condition,a complete and dense plating layer could be obtained.The formation mechanism of the plating layer on magnesium alloy MAO coating was analyzed.A three-stage model of the plating process was proposed.The square resistance of the plated specimen was finally reduced to 0.03Ω/□after the third stage.Through electroless copper plating,the MAO coated sample obtained excellent electrical conductivity without significantly reducing its corrosion resistance.
文摘In order to obtain substrates with good conductive foam for high porosity foam metal materials used in the metal electrodes,the technique of electroless copper plating on the microcellular polyurethane foam with pore size of 0.3 mm was investigated.The main factors affecting the deposition rate such as the solution composition,temperature,pH value and adding ultrasonic were explored.The results show that the optimum process conditions are CuSO4 16 g/L,HCHO 5 mL/L,NaKC4H4O6 30 g/L,Na2EDTA 20 g/L,K4Fe(CN)6 25 mg/L,pH value of 12.5-13.0 and temperature of 40-50℃.Under these technical conditions, the process has excellent bath stability.Adding ultrasonic on the process can elevate the deposition rate of copper by 20%-30%.The foam metal material with a porosity of 92.2%and a three-dimensional network structure,was fabricated by electro-deposition after the electroless copper plating.
基金Project supported by the National Natural Science Foundation of China (50974042)Scientific Research Special Foundation of Doctor Subject of Chinese Universities (20090042120015)the Fundamental Research Funds for the Central Universities (N090302007)
文摘The amount of Cu coating by chemical plating was investigated based on quadratic regression orthogonal experimental design being adapted to the variation law of temperature, pH value and Ni2+ concentration, and the relevant regression equation was expressed as y=2.1609+0.5295×10-3T2-0.0342P2-0.0265N2+0.0023TP+0.0020TH+0.0199PN-0.0959T+0.3814P-0.2073N. The results showed that the deposition rate augmented with the increasing in temperature, pH value and Ni2+ concentration. The experimental parameters of the optimal coating were temperature 75 °C, pH value 8.5 and Ni2+ concentration 1.2 g/L. The electrochemical tests indicated that the cycle stability increased from 60.66% to 75.58%, indicating that the treated alloy exhibited better corrosion resistance.
基金Project(200501045) supported by Innovation Fund of Guangdong Province of China
文摘The electrochemical mechanism of anode oxidation of HCHO in electroless copper plating solution with N, N, N′, N′-tetrakis(2-hydroxypropyl)ethylenediamine (THPED) was investigated by measuring cyclic voltammetry curves and anodic polarization curves. Three different oxidation peaks occur at the potentials of -0.62 V (Peak 1), -0.40 V (Peak 2) and -0.17 V (Peak 3) in the anode oxidation process of THPED-containing solution. The reaction at Peak 1, a main oxidation reaction, is the irreversible reaction of adsorbed HCHO with hydrogen evolution. The reaction at Peak 2, a secondary oxidation reaction, is the quasi-reversible reaction of adsorbed HCHO without hydrogen evolution. The reaction at Peak 3 is the irreversible oxidation of anode copper. The current density of Peak 1 increases gradually, that of Peak 2 remains constant and that of Peak 3 decreases with the increase of HCHO concentration. The current density of Peak 3 increases with the increase of THPED concentration and the complexation of THPED promotes the dissolution of anode copper.
基金supported by Universiti Sains Malaysia under the Research University Grant (RU. Grant No.1001/PKIMIA/811006)
文摘Cu-P-silicon carbide （SiC） composite coatings were deposited by means of electroless plating.The effects of pH values,temperature,and different concentrations of sodium hypophosphite （NaH2PO2·H2O）,nickel sulfate （NiSO4·6H2O）,sodium citrate （C6H5Na3O7·2H2O） and SiC on the deposition rate and coating compositions were evaluated,and the bath formulation for Cu-P-SiC composite coatings was optimised.The coating compositions were determined using energy-dispersive X-ray analysis （EDX）.The corresponding optimal operating parameters for depositing Cu-P-SiC are as follows：pH 9;temperature,90oC;NaH2PO2·H2O concentration,125 g/L;NiSO4·6H2O concentration,3.125 g/L;SiC concentration,5 g/L;and C6H5Na3O7·2H2O concentration,50 g/L.The surface morphology of the coatings analysed by scanning electron microscopy （SEM） shows that Cu particles are uniformly distributed.The hardness and wear resistance of Cu-P composite coatings are improved with the addition of SiC particles and increase with the increase of SiC content.
文摘By means of electroless copper deposition method a complex image has been fabricated in a mixture of cupric sulphate and formaldehyde, the surface and subsurface properties of which has been studied in detail by X-ray photoelectron spectroscopy (XPS) combined with sputter depth profiling technique analyzing distribution and chemical state of copper and silver. Depth profiling by XPS in conjunction with Ar+ sputtering shows that the catalytic activity of silver persists, catalyzing reduction of copper. The integral areas of spectra Ag3d after electroless copper deposition for 5 min at different sputtering times demonstrate that the amount of silver at the surface is greater than that in the interior. And then, the quite likely reasonable explanations are provided for the result. Additionally, the chemical shift of Ag3d XPS and deconvolution of Ag3d XPS spectrum have been also analyzed respectively at length.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .60 0 710 0 1)
文摘A new method is described for the electroless deposition of copper onto glass. Commercially available glass slide was modified with γ-aminopropyltrimethoxysilane to form self-assembled monolayer (SAM) on it. Then it was dipped directly into PdCl_2 solution instead of the conventional SnCl_2 sensitization followed by PdCl_2 activation. Experimental results showed that the Pd 2+ ions from PdCl_2 solution were coordinated to the amino groups on the glass surface resulting in the formation of N-Pd complex. In an electroless copper bath containing a formaldehyde reducing agent, the N-Pd complexes were reduced to Pd 0 atoms, which then acted as catalysts and initiated the deposition of copper metal. Although the copper deposition rate on SAM-modified glass was slow at the beginning, it reached to that of conventional method in about 5 min.
基金the UK Engineering and Physical Sciences Research Council (EP/D04717X/1)
文摘Electroless copper plating was studied using dimethylamine borane （DMAB） as reductant and 1,5,8,12- tetraazadodecane as additive and triethanolamine （TEA） as buffer. The effects of pH, temperature and concentrations of reactants and additives on the anodic oxidation of DMAB and the cathodic reduction of copper ion were investigated. Experimental results indicate that high pH values （10-12.5） promote the oxidation of DMAB, and suppress the reduction of the copper ion, while high bath temperatures （55-70℃） accelerate both anodic oxidation and cathodic reduction. Increase of the Cu2＋and DMAB concentrations can improve the deposition rate of copper plating. Results for a dual-chelating-agent system indicate that 1,5,8,12-tetraazadodecane plays an important role in chelation, while the main effect of TEA is adsorption on copper surfaces to inhibit DMAB oxidation and to promote deposition.
基金Sponsored by the National Natural Science Founation of China(Grant No.50301017)
文摘The molybdenum powders with average particle size of 3 μm were coated with copper by electroless plating. The influence of pretreatment, solution composition and plating conditions on electroless copper plating was studied. The copper-coated molybdenum powders were examined by SEM and XRD. Results indicate that a series of optimization methods is used to add activated sites before electroless copper plating. Taking TEA and EDTA as chief and assistant complex agents respectively, 2,2＇-bipyridyl and PEG as double stabilizers, the Mo powders are coated with copper successfully with little Cu20 contained, at the same time, Mo-Cu composite powders with copper content of 15 - 85 wt% can be obtained. The optimal values of pH, temperature and HCHO concentration are 12 -13, 60 -65 ℃ and 22 -26 mL/L, respectively.
文摘The use of more and more electron products requires interior wood products to have the performance of electromagnetic shielding. One of the ways to realize it is to introduce the chemical plating which has already been developed in electron industry into wood processing. The paper clarifies the mechanism of electroless copper and gold plating and its application to wood. It emphasizes the development and technology of electroless copper and gold plating on wood. Meanwhile, it points out that it is highly feasible to take this technology into effect.
文摘Molybdenum powders with a diameter of approximately 3 μn were coated with copper using the electroless plating technique in the pH 12.5-13 and temperature range of 55-75℃. The optimization of the electroless copper bath was evaluated through the combination of process parameters like pH and temperature. The optimized values ofpH and temperature were found to be 12.5 and 60℃, respectively, which attributes to the bright maroon color of the coating with an increase in weight of 46%. The uncoated and coated powders were subjected to microstructural studies using scanning electron microscope （SEM） and the phases were analyzed using X-my diffrction （XRD）. An attempt was made to understand the growth mechanism of the coating. The diffusion-shrinkage autocatalytic model was suggested for copper growth on the molybdenum surface.
基金Project (50301017) supported by the National Natural Science Foundation of China
文摘Mo powders with average particle size of 3 μm were attempted to coat with copper by electroless plating technique. The effect of the solution composition and plating conditions on the electroless copper plating was studied. The uncoated and coated powders were subjected to the microstructural studies by SEM and the phases were analyzed by XRD. The results indicate that the Mo powders are coated with copper,at the same time,Mo-Cu composite powders with Cu content ranging from 15% to 85%(mass fraction) can be obtained. The optimal values of pH,HCHO concentration and temperature are in the ranges of 12-13,22-26 ml/L and 60-65 ℃,respectively. The diffusion-shrinkage autocatalytic model is suggested for the growth mechanism of electroless coating over the surface.
文摘This paper showed simple and effective synthesis of copper nanoparticles within controlled diameter using direct electroless deposition on glass substrates, following the sensitization and activation steps. Electroless-deposited metals, such as Cu, Co, Ni, and Ag, and their alloys had many advantages in micro- and nanotechnologies. The structural, morphological, and optical properties of copper deposits were characterized using X-ray diffraction （XRD）, atomic force microscopy （AFM）, and UV-Vis spectroscopy. The structural data was further analyzed using the Rietveld refinement program. Structural studies reveal that the deposited copper prefers a （111） orientation. AFM studies suggest the deposited materials form compact, uniform, and nanocrystalline phases with a high tendency to self-organize. The data show that the particle size can be controlled by controlling the activator concentration. The absorption spectra of the as-deposited copper nanoparticles reveal that the plasmonic peak broadens and exhibits a blue shift with decreasing particle size.
基金Project (2004CB619301) supported by the National Basic Research and Development Program and Project 985-Automotive Engineering of Jilin University
文摘Nanocrystalline copper films were prepared on the glass by electroless plating technique. The surface characterization of copper films with different deposition time was studied by field emission scanning electron microscopy(FESEM) and atomic force microscopy(AFM). The results indicate that the copper films have a(111) texture. A continuous and smooth film forms on the glass substrate at deposition times of 5 min. The surface roughness of as-deposited copper films becomes rougher with large nodules as the deposition time increases. According to Fuchs-Sondheimer(F-S),Mayadas-Shatzkes(M-S) theory and a combined model,the grain boundary reflection coefficient(R) is calculated in the range of 0.40-0.75. The theoretical analysis based on the experimental results show that the grain boundaries contribute mainly to the increase of electrical resistivity of nanocrystalline copper film compared with the film surfaces.
文摘In this work, an electroless method of coating copper on the basalt short fibers using copper sulphate solution is described. In order to avoid any interfacial reactions in the basalt fiber reinforced metal matrix composites, the basalt fibers were coated with copper. The effects of the time of sensitization, activation, metallization, PdCl2 concentration, pH and temperature bath on the extent of copper coating on basalt fiber are reported. The conditions used for electroless coating were optimized to obtain a uniform and continuous layer of copper. Using this method, it is possible to deposit up to about 25 wt% copper on the basalt fiber. The resultant composite fiber was characterized by scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) during and after the coating process. The effects of the thickness of copper coating on surface condition and also the tensile strength of the basalt fibers have been investigated. The study of surface condition of the coated basalt fibers by SEM showed that the copper coating at the thickness of about 0.2 μm had the best continuity on the basalt fibers. The results of tensile tests of basalt fibers coated with different thickness of copper showed that increasing the thickness of coating layer decreased the overall strength of fibers.
文摘Copper serpentines used in gas heaters are currently coated with lead-tin alloy using hot-dip technology where copper is immersed in molten lead (98%)-Tin at about 400°C. The major drawback of this technique is the pollution resulted from lead vapors which cause much harm to the labors in the unit. The present work investigates an eco-friendly plating technique to replace the currently used technology. Electroless plating of copper samples with lead or Lead (98%)-Tin alloy is carried out from a plating bath contained lead salt, tin salt, reducing agent and stabilizing agent. The parameters affecting the coating quality such as the plating time, temperature and bath composition were optimized. The chemical analysis and coating morphology of the formed coatings are examined by XRD, SEM and EDS to reach the best bath composition as well as the best conditions to coat copper with lead or lead-tin electrolessly. The electrochemical properties of copper and copper coated samples are also examined using electrochemical impedance spectroscopy.
基金Project(9140A12060110BQ03)supported by the National Key Laboratory of Science and Technology on Materials under Shock and Impact,China
文摘Electroless copper plating on diamond particles precoated with 1%Cr was carried out to evaluate the effects of various experimental parameters on coating quality and deposition rate to obtain the optimized reaction parameters. The formulated samples under optimized parameters were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectra and optical microscopy. The best parameters, where uniform and maximum coating thickness was achieved, are etching with 20%NaOH for 30 min, sensitization and activation with SnCl2 and PdCl2 for 5 and 20 min, respectively. The composition of the copper solution bath was 16 g/L CuSO4＆#183;5H2O, 35 mL/L formaldehyde （HCHO）, 23 g/L KNaC4H4O6 at 60 ℃, pH=13 and stirring at （350±15） r/min under ultrasonication.
