Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), sc...Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), scanning electron microscopy(SEM), and electron backscatter diffraction(EBSD).The coating bonding strength is assessed by pull-out tests and scribing in accordance with GB/T 9286-1998.The results show that the Cu coating with a thickness of 30 μm deposited on GF/PEEK by magnetron sputtering has lower roughness, finer grain size, higher crystallinity, as well as better macroscopic compressive stress,bonding strength, and electrical conductivity than the Cu coating deposited by electroplating.展开更多
Pollution in recent times has become prevalent due to industrial expansion,hence,releasing pollutants into the environ-ment.Thus,this study aimed at investigating the effects of effluents from electroplating companies...Pollution in recent times has become prevalent due to industrial expansion,hence,releasing pollutants into the environ-ment.Thus,this study aimed at investigating the effects of effluents from electroplating companies on growth,heavy metals accumulation and concentrations in Amaranthus viridis.Seeds of A.viridis were obtained from the National Institute of Hor-ticulture,Ibadan.Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun,Lagos.Seeds were sown,nursed,and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A(5 and 10%conc.)and Effluent B(5 and 10%conc.)and control respec-tively.Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer.Data collected were subjected to a one-way analysis of variance.Results revealed that Effluents A and B are highly acidic and above discharge limits.Also,the result revealed that 5%conc.of Effluents A and B had more effects on growth(p<0.05)of A.viridis across the harvests than 10%conc.in relation to control.This result showed that the effluent samples affect the growth rhythms of plants.Results further revealed vigorous–1–1 accumulation of the heavy metals:Zn(241.66µg kg±0.10 at third harvest in Effluent A:10%),Cu(68.25µg kg±0.23 at–1–1 first harvest in Effluent B:5%),Cr(500µg kg±0.90 in harvests at all concentrations.)and Ni(500µg kg±0.90 at third harvest in Effluent B:5%)and all these metals are far above the control and permissible limits of WHO/FAO recommenda-tions.From this study,it could be concluded that electroplating effluents had adverse effects on growth and increased metals’bioaccumulation in A.viridis.Therefore,the treatment of effluents to enhance an eco-friendly environment should be done.展开更多
A coordinative disposal process for treatment of electroplating sludge and stainless steel pickle waste liquid containing Cu, Ni, Zn, Cr and Fe etc., has been developed to recover valuable metals and to eliminate poll...A coordinative disposal process for treatment of electroplating sludge and stainless steel pickle waste liquid containing Cu, Ni, Zn, Cr and Fe etc., has been developed to recover valuable metals and to eliminate pollution. The recovery of Cu, Ni, Zn and Cr is 94%, 91%, 90% and 95%, respectively. The ammonia was recycled by the simplified process of CaO caustic distillation. The precipitated product of Cu, Ni and Zn obtained from caustic distillation of ammonia was separated by extraction or high\|pressure hydrogen reduction in an autoclave. The qualified metal salt products were obtained through extraction. The rich chromium residue from coordinative disposal was subjected to recover Cr by hydrothermal oxidation in NaOH medium and Fe\-3O\-4 was synthesized by wet methods from the residue produced by extracting Cr. Cr was a stable chemical fixed in Fe\-3O\-4 and harmless. The recovery process has been used in a pilot plant with sludge production capacity of 2000 t/a.展开更多
Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coate...Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated layers were observed under a metallographic microscope.The effects of pretreatment sequence,pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed.Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer.Sensitivity of the metal-coated FBG(MFBG)sensor was almost two times that of normal bare FBG sensor.The measuring temperature of the MFBG sensor could be up to 280℃,which was much better than that of conventional FBG sensor.展开更多
The present paper aims to investigate the influence of the current density in the electroplating process on the microstructure, crystal texture transformations, and corrosion behavior of Ni/Co pumice multilayer nanoco...The present paper aims to investigate the influence of the current density in the electroplating process on the microstructure, crystal texture transformations, and corrosion behavior of Ni/Co pumice multilayer nanocomposite coatings. The Ni/Co pumice composite coatings were prepared by deposition of Ni, followed by the simultaneous deposition of pumice nanoparticles (NPs) in a Co matrix via an electroplating process at various current densities. Afterward, the morphology, size, topography, and crystal texture of the obtained samples were investigated. Furthermore, electrochemical methods were used to investigate the corrosion behavior of the produced coatings in a solution of 3.5wt% NaCl. The results indicated that increasing the plating current density changed the mechanism of coating growth from the cell state to the column state, in- creased the coating thickness, roughness, and texture coefficient (TC) of the Co (203) plane, and reduced the amount of pumice NPs incorporated into the Ni/Co pumice composite. The electrochemical results also indicated that increasing the current density enhanced the corrosion resistance of the Ni/Co pumice composite.展开更多
This research aims to use several kind of rare earth oxides, such as Nd2O3, Yb2O3, Ce2O3 and La2O3, to improve the electroless plating and electroplating processes for surface metallization of quartz optical fiber (si...This research aims to use several kind of rare earth oxides, such as Nd2O3, Yb2O3, Ce2O3 and La2O3, to improve the electroless plating and electroplating processes for surface metallization of quartz optical fiber (silicon fiber) for its practical uses. The effects of the rare earth oxides on the deposition rate of Ni-P-B, the stability of the plating solution and the surface property of the film were investigated and the comparisons of their behaviours were made. The effects of rare earth oxide of La2O3 on the hardness and surface property of the Ni film prepared by electroplating process were studied. The surface morphonogies, compositions and hardness of the Ni-P-B and Ni films were characterized and analyzed by SEM, MSM, ICP and DIMHM, respectively. The experimental results showed that Ce2O3 with the concentration of 4 mg·L-1 was the best one among the four rare earth oxides with suitable concentrations in increasing the deposition rate, enhancing the stability of the electroless plating solution and improving the surface property of the Ni-P-B film. The improvements of the hardness and surface property of the Ni film prepared by electroplating with adding La2O3 were discovered. No obvious influences of Ce2O3 and La2O3 on the compositions of Ni-P-B and Ce free in the Ni-P-B film were found because of its much more nagative deposition potential than those of the used reducing agents in this experiment. The total diameter of the quartz optical fiber with deposited Ni-P-B film and Ni film was about 1.7 mm, which could be satisfactorily for the practical uses of quartz optical fiber in many fields.展开更多
A novel process of electroplating amorphous Fe Cr Ni alloy in chloride aqueous solution with Fe(Ⅱ), Ni(Ⅱ) and Cr(Ⅲ) was reported. Couple plasma atomic emission spectrometry (ICP AES), X ray diffractometry(XRD), sca...A novel process of electroplating amorphous Fe Cr Ni alloy in chloride aqueous solution with Fe(Ⅱ), Ni(Ⅱ) and Cr(Ⅲ) was reported. Couple plasma atomic emission spectrometry (ICP AES), X ray diffractometry(XRD), scanning electronic microscopy(SEM), microhardness test and rapid heating cooling method were adopted to detect the properties of the amorphous Fe Ni Cr deposit, such as composition, crystalline structure, micrograph, hardness, and adherence between deposit and substrate. The effects of the operating parameters on the electrodeposit of the amorphous Fe Ni Cr alloy were discussed in detail. The results show that a 8.7?μm thick mirror like amorphous Fe Ni Cr alloy deposit, with Vicker’s hardness of 530 and composition of 45%~55% Fe, 33%~37% Ni, 9%~23% Cr was obtained by electroplating for 20?min at room temperature(10~30?℃), cathode current 10~16?A/dm 2, pH=1.0~3.0. The XRD patterns show that there only appears a broad hump around 2 θ of 41?°~47?°for the amorphous Fe Ni Cr alloy deposit, while the SEM micrographs show that the deposit contains only a few fine cracks but no pinholes.展开更多
In electroplating lines,many conductor rolls are installed in electroplating bath.Typical electroplatings are tin plating(ETL) and zinc plating(EGL),and from required product qualities,a vertical cell for the former a...In electroplating lines,many conductor rolls are installed in electroplating bath.Typical electroplatings are tin plating(ETL) and zinc plating(EGL),and from required product qualities,a vertical cell for the former and a horizontal cell for the latter is often used.Generally,chrome plating or WC cermet thermal spray coating is applied to stainless steel conductor roll in ETL for prolonging service life by improvement of wear resistance and corrosion resistance.On the other hand,Hastelloy type alloy substrate is used for conductor rolls in EGL due to severe corrosion environment of electro plating solution.Thermal spray coating is effective for reducing wear,but there are many cases where the coating cannot complete expected service life when corrosion becomes an issue.In this study,thermal spray coating for ETL conductor roll and development of the coating for EGL conductor roll to meet expected service life are described.展开更多
The effectiveness of copper and nickel uptake by microalgae grown in the mixture of electroplating effluent and sewage was studied. The results showed that a high percentage of copper removal (68.1%-88.2%) was achieve...The effectiveness of copper and nickel uptake by microalgae grown in the mixture of electroplating effluent and sewage was studied. The results showed that a high percentage of copper removal (68.1%-88.2%) was achieved by Chlorellapyrenoidosa (strain No. 26) reared in the mixture of 90% electroplating effluent and 10% raw sewage during the first 3 days despite the fact that cell growth was inhibited. Similar results were also obtained by using Chlorella HKBC-C3, another species collected from one of the heavy metal polluted sites in Hong Kong, isolated and cultured in the Biology Department. There was no significant difference (P>0.05) in the removal of copper and nickel from the effluent between these 2 algal species. However, it was noted that removal of nickel from the mixture by the two species were comparatively lower (<20%) than the removal of copper (>68%).展开更多
Time-resolved measurement of atomic emission enhancement is performed by using a 500-fs KrF laser pulse incident upon a high density supersonic O2 gas jet, synchronized with an orthogonal ns frequency-doubled Nd:YAG ...Time-resolved measurement of atomic emission enhancement is performed by using a 500-fs KrF laser pulse incident upon a high density supersonic O2 gas jet, synchronized with an orthogonal ns frequency-doubled Nd:YAG laser pulse. The ultra-short pulse serves as an igniter of the gas jet, and the subsequent ns-laser pulse significantly enhances the atomic emission. Analysis shows that the contributions to the enhancement effect are made mainly by the bremsstrahlung radiation and cascade ionization.展开更多
The TiB2 coatings deposited over nickel substrate by electroplating was investigated, which is in molten salt of a fluoride mixture involving KF, NaF, K2 TiF6 and KBF4. Effects of temperature, cathodic current density...The TiB2 coatings deposited over nickel substrate by electroplating was investigated, which is in molten salt of a fluoride mixture involving KF, NaF, K2 TiF6 and KBF4. Effects of temperature, cathodic current density (Jc) and duration on the coating's formation were examined. The composition, morphology and structure of the coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray detector (EDS) and X-ray diffraction (XRD). The results show that the coatings, with black, smooth and uniform appearance, are composed of predominating TiB2 and small amounts of nickel titanium oxide (Ni0.75 Ti0.125 O). The coatings show a nodular morphology and the grain size is dependent on the Jc and ranges about 1 - 10 μm. There is a linear relationship between the coating's thickness and the time of electrolysis within certain duration range. The reduction of the potassium can take place simultaneously with the electrochemical synthesis of TiB2 as the Jc is in excess of certain level. The hardness of the TiB2 coatings is likely to be deteriorated due to the presence of potassium and Ni0.75Ti0.125 O in the coatings.展开更多
Lithium(Li)metal batteries have long been deemed as the representative high-energy-density energy storage systems due to the ultrahigh theoretical capacity and lowest electrochemical potential of Li metal anode.Unfort...Lithium(Li)metal batteries have long been deemed as the representative high-energy-density energy storage systems due to the ultrahigh theoretical capacity and lowest electrochemical potential of Li metal anode.Unfortunately,the intractable dendritic Li deposition during cycling greatly restrains the large-scale applications of Li metal anodes.Recent advances have been explored to address this issue,among which a specific class of electrolyte additives for electroplating is deeply impressive,as they are economic and pragmatic.Different from the conventional additives that construct solid electrolyte interphase(SEI)layer on anodes,they make dendrite-free Li metal anodes feasible through altering Li plating behavior.In this research news article,the interlinked principles between industrial electroplating and Li deposition are firstly illustrated.The featured effects of electroplating additives on regulating Li plating morphology are also summarized and mainly divided into three categories:co-deposition with Li cation,coordination with Li cation,and leveling effect of Li films.Furthermore,the mechanism exploration or derivative use of electroplating additive for dendrite suppression and potential research directions are proposed,with emphasizing that industrial electroplating might enable Li metal anode to scalable battery techniques and spread to metal battery systems beyond Li.展开更多
The compact Cu coating with smooth surface and refined grain was prepared at high current density by mechanical attrition enhanced electroplating(MAEE) process.The mechanical attrition(MA) action was supplied by the v...The compact Cu coating with smooth surface and refined grain was prepared at high current density by mechanical attrition enhanced electroplating(MAEE) process.The mechanical attrition(MA) action was supplied by the vertical movement of glass balls on the sample surface with a special vibrating frequency.The plating bath was CuSO4 and H2SO4.It is demonstrated from field emission scanning electron microscopy(FESEM) results that the new coating shows smooth and refined surface morphology in high speed MAEE process.The further studies show that the spherical grain or pillar-shape grain can be obtained by traditional electroplating process at the current density of 200-600 mA/cm2.And the coatings are loosen,porous and easy to brush off.The pyramid-shape grain with diameter of less than 1 μm was obtained by MAEE process under the same condition.And the coatings are compact and pore-free.The rapid electroplating process can be obtained by MA action.展开更多
A metal electrode is a significant component of a zinc–air battery(ZAB),but the metal material is usually not elastic,which severely restricts the application of flexible and stretchable ZABs in the field of wearable...A metal electrode is a significant component of a zinc–air battery(ZAB),but the metal material is usually not elastic,which severely restricts the application of flexible and stretchable ZABs in the field of wearable electronic devices.Herein,we report a flexible and stretchable metal-coated textile prepared by a dynamic stretching–electroplating based on a wavy spandex textile substrate.Benefiting from the unique woven and wavy structure,the metal-coated textile shows a high stretchability of 100%and stable conductivity.In situ scanning electron microscope observation during stretching showed that the tensile strain of the metal-coated textile is mainly attributed to the deformation of the microfiber network at the bottom position of the wave structure.In addition,a sodium carboxymethyl cellulose–polyacrylic acid–potassium hydroxide composite hydrogel has been used as the electrolyte.This hydrogel shows excellent ionic conductivity,mechanical properties,and water retention properties,which makes it suitable for the semi-open system of ZAB.Furthermore,a flexible and stretchable sandwich-structure ZAB,assembled using the above-mentioned electrodes and electrolyte,operates stably even under rapid stretching/releasing cycle deformation.Because of its facile preparation and low cost,this flexible and stretchable ZAB is suitable for fabrication of large-area batteries to obtain higher output current and power to drive wearable electronic devices.展开更多
It is demonstrated that the nickel can be deposited directly on the surface of carbon nanotubes without pre-sensitization by Sn 2+ and Pd 2+ in a watt bath containing suspended nanotubes by electroplating. The nickel ...It is demonstrated that the nickel can be deposited directly on the surface of carbon nanotubes without pre-sensitization by Sn 2+ and Pd 2+ in a watt bath containing suspended nanotubes by electroplating. The nickel is deposited as spherical nanoparticle on the nanotubes. By increasing reaction time, the carbon nanotube is fully coated with nickel. A probable model, which represents the formation process of carbon nanotube-nickel composites by electroplating, is presented. The results show that this method is efficient and simple for preparing carbon nanotube-metal composite.展开更多
The electrodeposition of Zr-Ti alloy has been studied in molten fluoride system consisting of fluorides of both zirconium and titanium dissolved in FLINAK (KF:NaF:LiF = 42.0:11.5:46.5 mol). A coherent dense deposit of...The electrodeposition of Zr-Ti alloy has been studied in molten fluoride system consisting of fluorides of both zirconium and titanium dissolved in FLINAK (KF:NaF:LiF = 42.0:11.5:46.5 mol). A coherent dense deposit of the alloy with a smooth surface is obtained on different material substrates. X-ray diffraction has demonstrated that the alloy deposit is a Ti-Zr solid solution with Ti mainly and its preferred orientation is strongly along Ti[110] direction. The properties of the deposit are better than those of a pure zirconium coating. The optimum operating parameters are a temperature of about 800°C, a current density less than 40mA/cm2, a solution about 15wt% ZrF4 and 15wt% K2TiF6 in FLINAK as well as pure zirconium as anode material.展开更多
The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electroche...The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.展开更多
In a hard chromium electroplating process, a heat exchanger is employed to remove the heat produced from the high current intensity in an electroplating bath.Normally, a conventional U shape heat exchanger is installe...In a hard chromium electroplating process, a heat exchanger is employed to remove the heat produced from the high current intensity in an electroplating bath.Normally, a conventional U shape heat exchanger is installed in the bath, but it provides low heat removal.Thus, this study designs a novel W serpentine shape heat exchanger with identical heat transfer area to the conventional one for increasing heat removal performance.The performance of the heat exchange is tested with various flow velocities in a cross-section in range of 1.6 to 2.4 m·s^(-1).Mathematical models of this process have been formulated in order to simulate and evaluate the heat exchanger performance.The results show that the developed models give a good prediction of the plating solution and cooling water temperature, and the novel heat exchanger provides better results at any flow velocity.In addition, the W serpentine shape heat exchanger has been implemented in a real hard chromium electroplating plant.Actual data collected have shown that the new design gives higher heat removal performance compared with the U shape heat exchanger with identical heat transfer area; it removes more heat out of the process than the conventional one of about 23%.展开更多
基金Funded by Shenzhen-Hong Kong Innovative Collaborative Research and Development Program (Nos.SGLH20181109 110802117, CityU 9240014)Innovation Project of Southwestern Institute of Physics (Nos.202001XWCXYD002, 202301XWCX003)CNNC Young Talent Program (No.2023JZYF-01)。
文摘Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), scanning electron microscopy(SEM), and electron backscatter diffraction(EBSD).The coating bonding strength is assessed by pull-out tests and scribing in accordance with GB/T 9286-1998.The results show that the Cu coating with a thickness of 30 μm deposited on GF/PEEK by magnetron sputtering has lower roughness, finer grain size, higher crystallinity, as well as better macroscopic compressive stress,bonding strength, and electrical conductivity than the Cu coating deposited by electroplating.
文摘Pollution in recent times has become prevalent due to industrial expansion,hence,releasing pollutants into the environ-ment.Thus,this study aimed at investigating the effects of effluents from electroplating companies on growth,heavy metals accumulation and concentrations in Amaranthus viridis.Seeds of A.viridis were obtained from the National Institute of Hor-ticulture,Ibadan.Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun,Lagos.Seeds were sown,nursed,and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A(5 and 10%conc.)and Effluent B(5 and 10%conc.)and control respec-tively.Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer.Data collected were subjected to a one-way analysis of variance.Results revealed that Effluents A and B are highly acidic and above discharge limits.Also,the result revealed that 5%conc.of Effluents A and B had more effects on growth(p<0.05)of A.viridis across the harvests than 10%conc.in relation to control.This result showed that the effluent samples affect the growth rhythms of plants.Results further revealed vigorous–1–1 accumulation of the heavy metals:Zn(241.66µg kg±0.10 at third harvest in Effluent A:10%),Cu(68.25µg kg±0.23 at–1–1 first harvest in Effluent B:5%),Cr(500µg kg±0.90 in harvests at all concentrations.)and Ni(500µg kg±0.90 at third harvest in Effluent B:5%)and all these metals are far above the control and permissible limits of WHO/FAO recommenda-tions.From this study,it could be concluded that electroplating effluents had adverse effects on growth and increased metals’bioaccumulation in A.viridis.Therefore,the treatment of effluents to enhance an eco-friendly environment should be done.
文摘A coordinative disposal process for treatment of electroplating sludge and stainless steel pickle waste liquid containing Cu, Ni, Zn, Cr and Fe etc., has been developed to recover valuable metals and to eliminate pollution. The recovery of Cu, Ni, Zn and Cr is 94%, 91%, 90% and 95%, respectively. The ammonia was recycled by the simplified process of CaO caustic distillation. The precipitated product of Cu, Ni and Zn obtained from caustic distillation of ammonia was separated by extraction or high\|pressure hydrogen reduction in an autoclave. The qualified metal salt products were obtained through extraction. The rich chromium residue from coordinative disposal was subjected to recover Cr by hydrothermal oxidation in NaOH medium and Fe\-3O\-4 was synthesized by wet methods from the residue produced by extracting Cr. Cr was a stable chemical fixed in Fe\-3O\-4 and harmless. The recovery process has been used in a pilot plant with sludge production capacity of 2000 t/a.
基金the National Natural Science Foundation of China(No.60777038).
文摘Metal-coated fiber Bragg grating(FBG)temperature sensors were prepared via electroless nickel(EN)plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated layers were observed under a metallographic microscope.The effects of pretreatment sequence,pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed.Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer.Sensitivity of the metal-coated FBG(MFBG)sensor was almost two times that of normal bare FBG sensor.The measuring temperature of the MFBG sensor could be up to 280℃,which was much better than that of conventional FBG sensor.
文摘The present paper aims to investigate the influence of the current density in the electroplating process on the microstructure, crystal texture transformations, and corrosion behavior of Ni/Co pumice multilayer nanocomposite coatings. The Ni/Co pumice composite coatings were prepared by deposition of Ni, followed by the simultaneous deposition of pumice nanoparticles (NPs) in a Co matrix via an electroplating process at various current densities. Afterward, the morphology, size, topography, and crystal texture of the obtained samples were investigated. Furthermore, electrochemical methods were used to investigate the corrosion behavior of the produced coatings in a solution of 3.5wt% NaCl. The results indicated that increasing the plating current density changed the mechanism of coating growth from the cell state to the column state, in- creased the coating thickness, roughness, and texture coefficient (TC) of the Co (203) plane, and reduced the amount of pumice NPs incorporated into the Ni/Co pumice composite. The electrochemical results also indicated that increasing the current density enhanced the corrosion resistance of the Ni/Co pumice composite.
基金the State Special Programs for 973 Key Foundamental Pre-Research (2005cca04300)
文摘This research aims to use several kind of rare earth oxides, such as Nd2O3, Yb2O3, Ce2O3 and La2O3, to improve the electroless plating and electroplating processes for surface metallization of quartz optical fiber (silicon fiber) for its practical uses. The effects of the rare earth oxides on the deposition rate of Ni-P-B, the stability of the plating solution and the surface property of the film were investigated and the comparisons of their behaviours were made. The effects of rare earth oxide of La2O3 on the hardness and surface property of the Ni film prepared by electroplating process were studied. The surface morphonogies, compositions and hardness of the Ni-P-B and Ni films were characterized and analyzed by SEM, MSM, ICP and DIMHM, respectively. The experimental results showed that Ce2O3 with the concentration of 4 mg·L-1 was the best one among the four rare earth oxides with suitable concentrations in increasing the deposition rate, enhancing the stability of the electroless plating solution and improving the surface property of the Ni-P-B film. The improvements of the hardness and surface property of the Ni film prepared by electroplating with adding La2O3 were discovered. No obvious influences of Ce2O3 and La2O3 on the compositions of Ni-P-B and Ce free in the Ni-P-B film were found because of its much more nagative deposition potential than those of the used reducing agents in this experiment. The total diameter of the quartz optical fiber with deposited Ni-P-B film and Ni film was about 1.7 mm, which could be satisfactorily for the practical uses of quartz optical fiber in many fields.
文摘A novel process of electroplating amorphous Fe Cr Ni alloy in chloride aqueous solution with Fe(Ⅱ), Ni(Ⅱ) and Cr(Ⅲ) was reported. Couple plasma atomic emission spectrometry (ICP AES), X ray diffractometry(XRD), scanning electronic microscopy(SEM), microhardness test and rapid heating cooling method were adopted to detect the properties of the amorphous Fe Ni Cr deposit, such as composition, crystalline structure, micrograph, hardness, and adherence between deposit and substrate. The effects of the operating parameters on the electrodeposit of the amorphous Fe Ni Cr alloy were discussed in detail. The results show that a 8.7?μm thick mirror like amorphous Fe Ni Cr alloy deposit, with Vicker’s hardness of 530 and composition of 45%~55% Fe, 33%~37% Ni, 9%~23% Cr was obtained by electroplating for 20?min at room temperature(10~30?℃), cathode current 10~16?A/dm 2, pH=1.0~3.0. The XRD patterns show that there only appears a broad hump around 2 θ of 41?°~47?°for the amorphous Fe Ni Cr alloy deposit, while the SEM micrographs show that the deposit contains only a few fine cracks but no pinholes.
文摘In electroplating lines,many conductor rolls are installed in electroplating bath.Typical electroplatings are tin plating(ETL) and zinc plating(EGL),and from required product qualities,a vertical cell for the former and a horizontal cell for the latter is often used.Generally,chrome plating or WC cermet thermal spray coating is applied to stainless steel conductor roll in ETL for prolonging service life by improvement of wear resistance and corrosion resistance.On the other hand,Hastelloy type alloy substrate is used for conductor rolls in EGL due to severe corrosion environment of electro plating solution.Thermal spray coating is effective for reducing wear,but there are many cases where the coating cannot complete expected service life when corrosion becomes an issue.In this study,thermal spray coating for ETL conductor roll and development of the coating for EGL conductor roll to meet expected service life are described.
文摘The effectiveness of copper and nickel uptake by microalgae grown in the mixture of electroplating effluent and sewage was studied. The results showed that a high percentage of copper removal (68.1%-88.2%) was achieved by Chlorellapyrenoidosa (strain No. 26) reared in the mixture of 90% electroplating effluent and 10% raw sewage during the first 3 days despite the fact that cell growth was inhibited. Similar results were also obtained by using Chlorella HKBC-C3, another species collected from one of the heavy metal polluted sites in Hong Kong, isolated and cultured in the Biology Department. There was no significant difference (P>0.05) in the removal of copper and nickel from the effluent between these 2 algal species. However, it was noted that removal of nickel from the mixture by the two species were comparatively lower (<20%) than the removal of copper (>68%).
基金Project supported by the National Natural Science Foundation of China (Grant No 10474081).
文摘Time-resolved measurement of atomic emission enhancement is performed by using a 500-fs KrF laser pulse incident upon a high density supersonic O2 gas jet, synchronized with an orthogonal ns frequency-doubled Nd:YAG laser pulse. The ultra-short pulse serves as an igniter of the gas jet, and the subsequent ns-laser pulse significantly enhances the atomic emission. Analysis shows that the contributions to the enhancement effect are made mainly by the bremsstrahlung radiation and cascade ionization.
文摘The TiB2 coatings deposited over nickel substrate by electroplating was investigated, which is in molten salt of a fluoride mixture involving KF, NaF, K2 TiF6 and KBF4. Effects of temperature, cathodic current density (Jc) and duration on the coating's formation were examined. The composition, morphology and structure of the coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray detector (EDS) and X-ray diffraction (XRD). The results show that the coatings, with black, smooth and uniform appearance, are composed of predominating TiB2 and small amounts of nickel titanium oxide (Ni0.75 Ti0.125 O). The coatings show a nodular morphology and the grain size is dependent on the Jc and ranges about 1 - 10 μm. There is a linear relationship between the coating's thickness and the time of electrolysis within certain duration range. The reduction of the potassium can take place simultaneously with the electrochemical synthesis of TiB2 as the Jc is in excess of certain level. The hardness of the TiB2 coatings is likely to be deteriorated due to the presence of potassium and Ni0.75Ti0.125 O in the coatings.
基金support from National Nature Science Foundation of China(Grant No.51872157)Shenzhen Technical Plan Project(Grant Nos.JCYJ20170412170911187 and JCYJ20170817161753629)+1 种基金Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(Grant No.2017BT01N111)Guangdong Technical Plan Project(Grant No.2017B090907005)
文摘Lithium(Li)metal batteries have long been deemed as the representative high-energy-density energy storage systems due to the ultrahigh theoretical capacity and lowest electrochemical potential of Li metal anode.Unfortunately,the intractable dendritic Li deposition during cycling greatly restrains the large-scale applications of Li metal anodes.Recent advances have been explored to address this issue,among which a specific class of electrolyte additives for electroplating is deeply impressive,as they are economic and pragmatic.Different from the conventional additives that construct solid electrolyte interphase(SEI)layer on anodes,they make dendrite-free Li metal anodes feasible through altering Li plating behavior.In this research news article,the interlinked principles between industrial electroplating and Li deposition are firstly illustrated.The featured effects of electroplating additives on regulating Li plating morphology are also summarized and mainly divided into three categories:co-deposition with Li cation,coordination with Li cation,and leveling effect of Li films.Furthermore,the mechanism exploration or derivative use of electroplating additive for dendrite suppression and potential research directions are proposed,with emphasizing that industrial electroplating might enable Li metal anode to scalable battery techniques and spread to metal battery systems beyond Li.
基金Project(50671006) supported by the National Natural Science Foundation of China
文摘The compact Cu coating with smooth surface and refined grain was prepared at high current density by mechanical attrition enhanced electroplating(MAEE) process.The mechanical attrition(MA) action was supplied by the vertical movement of glass balls on the sample surface with a special vibrating frequency.The plating bath was CuSO4 and H2SO4.It is demonstrated from field emission scanning electron microscopy(FESEM) results that the new coating shows smooth and refined surface morphology in high speed MAEE process.The further studies show that the spherical grain or pillar-shape grain can be obtained by traditional electroplating process at the current density of 200-600 mA/cm2.And the coatings are loosen,porous and easy to brush off.The pyramid-shape grain with diameter of less than 1 μm was obtained by MAEE process under the same condition.And the coatings are compact and pore-free.The rapid electroplating process can be obtained by MA action.
基金National Natural Science Foundation of China and Guangdong Province,Grant/Award Number:U1601216National Natural Science Foundation for Excellent Young Scholar,Grant/Award Number:51722403+3 种基金National Youth Talent Support Program“131”First Level Innovative Talents Training Project in TianjinNational Natural Science Foundation for Distinguished Young Scholar,Grant/Award Number:52125404Tianjin Natural Science Foundation for Distinguished Young Scholar,Grant/Award Number:18JCJQJC46500。
文摘A metal electrode is a significant component of a zinc–air battery(ZAB),but the metal material is usually not elastic,which severely restricts the application of flexible and stretchable ZABs in the field of wearable electronic devices.Herein,we report a flexible and stretchable metal-coated textile prepared by a dynamic stretching–electroplating based on a wavy spandex textile substrate.Benefiting from the unique woven and wavy structure,the metal-coated textile shows a high stretchability of 100%and stable conductivity.In situ scanning electron microscope observation during stretching showed that the tensile strain of the metal-coated textile is mainly attributed to the deformation of the microfiber network at the bottom position of the wave structure.In addition,a sodium carboxymethyl cellulose–polyacrylic acid–potassium hydroxide composite hydrogel has been used as the electrolyte.This hydrogel shows excellent ionic conductivity,mechanical properties,and water retention properties,which makes it suitable for the semi-open system of ZAB.Furthermore,a flexible and stretchable sandwich-structure ZAB,assembled using the above-mentioned electrodes and electrolyte,operates stably even under rapid stretching/releasing cycle deformation.Because of its facile preparation and low cost,this flexible and stretchable ZAB is suitable for fabrication of large-area batteries to obtain higher output current and power to drive wearable electronic devices.
文摘It is demonstrated that the nickel can be deposited directly on the surface of carbon nanotubes without pre-sensitization by Sn 2+ and Pd 2+ in a watt bath containing suspended nanotubes by electroplating. The nickel is deposited as spherical nanoparticle on the nanotubes. By increasing reaction time, the carbon nanotube is fully coated with nickel. A probable model, which represents the formation process of carbon nanotube-nickel composites by electroplating, is presented. The results show that this method is efficient and simple for preparing carbon nanotube-metal composite.
基金The research is supported by National Science Foundation.
文摘The electrodeposition of Zr-Ti alloy has been studied in molten fluoride system consisting of fluorides of both zirconium and titanium dissolved in FLINAK (KF:NaF:LiF = 42.0:11.5:46.5 mol). A coherent dense deposit of the alloy with a smooth surface is obtained on different material substrates. X-ray diffraction has demonstrated that the alloy deposit is a Ti-Zr solid solution with Ti mainly and its preferred orientation is strongly along Ti[110] direction. The properties of the deposit are better than those of a pure zirconium coating. The optimum operating parameters are a temperature of about 800°C, a current density less than 40mA/cm2, a solution about 15wt% ZrF4 and 15wt% K2TiF6 in FLINAK as well as pure zirconium as anode material.
文摘The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.
基金Supported by Thailand Research Fund(TRF)under The Royal Golden Jubilee Ph.D.Program(PHD/0158/2550)Chulalongkorn University(Contract No.RES_57_411_21_076)Chulalongkorn Academic Advancement into its 2nd Century Project
文摘In a hard chromium electroplating process, a heat exchanger is employed to remove the heat produced from the high current intensity in an electroplating bath.Normally, a conventional U shape heat exchanger is installed in the bath, but it provides low heat removal.Thus, this study designs a novel W serpentine shape heat exchanger with identical heat transfer area to the conventional one for increasing heat removal performance.The performance of the heat exchange is tested with various flow velocities in a cross-section in range of 1.6 to 2.4 m·s^(-1).Mathematical models of this process have been formulated in order to simulate and evaluate the heat exchanger performance.The results show that the developed models give a good prediction of the plating solution and cooling water temperature, and the novel heat exchanger provides better results at any flow velocity.In addition, the W serpentine shape heat exchanger has been implemented in a real hard chromium electroplating plant.Actual data collected have shown that the new design gives higher heat removal performance compared with the U shape heat exchanger with identical heat transfer area; it removes more heat out of the process than the conventional one of about 23%.