Surface Metallization of Glass Fiber(GF)/Polyetheretherketone(PEEK) Composite with Cu Coatings Deposited by Magnetron Sputtering and Electroplating

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.

Bidirectional rotating direct-current triboelectric nanogenerator with self-adaptive mechanical switching for harvesting reciprocating motion

Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.

Analyses of nonequilibrium transport in atmospheric-pressure direct-current argon discharge under different modes

The key plasma parameters under different discharge modes, such as heavy-particle and electron temperatures, electron number density, and nonequilibrium volume of plasmas, play important roles in various applications of gas discharge plasmas. In this study, a self-consistent two-dimensional nonequilibrium fluid model coupled with an external circuit model is established to reveal the mechanisms related to the discharge modes, including the normal glow, abnormal glow,arc, and glow-to-arc transition modes, with an atmospheric-pressure direct-current(DC) argon discharge as a model plasma system. The modeling results show that, under different discharge modes, the most significant difference between the preceding four discharge modes lies in the current and energy transfer processes on the cathode side. On one hand, the current to the cathode surface is mainly delivered by the ions coming from the plasma column under the glow discharge mode due to the low temperature of the solid cathode, whereas the thermionic and secondary electrons emitted from the hot cathode surface play a very important role under the arc mode with a higher cathode surface temperature and higher ion flux toward the cathode. On the other hand, the energy transfer channel on the cathode side changes from mainly heating the solid cathode under the glow mode to simultaneously heating both the solid cathode and plasma column under the arc mode with an increase in the discharge current. Consequently, the power density in the cathode sheath(P_c) was used as a key parameter for judging different discharge modes, and the range of(0.28–1.2) × 10^(12) W m^(-3) was determined as a critical window of P_c corresponding to the glow-to-arc-mode transition for the atmospheric-pressure DC argon discharge, which was also verified by comparison with the experimental results in this study and the data in the previous literature.

Effects of Electroplating Effluents on Growth, Heavy Metals Accumulation and Concentrations in Amaranthus viridis Lin.

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.

Cyanide-free silver electroplating process in thiosulfate bath and microstructure analysis of Ag coatings

Cyanide-free silver electroplating was conducted in thiosulfate baths containing AgNO3 and AgBr major salts, respectively. The effects of major salt content and current density on surface quality, deposition rate and microhardness of Ag coatings were investigated. The optimized electroplating parameters were established. The adhesion strength of Ag coating on Cu substrate was evaluated and the grain size of Ag coating was measured under optimized electroplating parameters. The optimized AgNO3 content is 40 g/L with current density of 0.25 A/dm2. The deposited bright, smooth, and well adhered Ag coating had nanocrystalline grains with mean size of 35 nm. The optimized AgBr content was 30 g/L with current density of 0.20 A/dm2. The resultant Ag coating had nanocrystalline grains with mean size of 55 nm. Compared with the bath containing AgBr main salt, the bath containing AgNO3 main salt had a wider current density range, and corresponding Ag coating had a higher microhardness and a smaller grain size.

Surface pretreatment of Mg alloys prior to Al electroplating in TMPAC-AlCl_3 ionic liquids

It is difficult to directly electroplate Al on Mg alloys. The effects of pretreatment parameters on the corrosion resistance of films obtained on AZ31 Mg alloy surface were studied by using potentiodynamic polarization curves, to produce a compact interfacial layer as zinc-immersion deposition. After the substrate was pretreated under optimized conditions, aluminum was electrodeposited on AZ31 from TMPAC-AlCl3 room temperature ionic liquids. The depositions were characterized by scanning electron microscope equipped with energy dispersion X-ray. The results show that the traditional pretreatment of Mg alloys was successfully used for the Al-electroplating process from TMPAC-AlCl3 ionic liquids. The entire procedure includes alkaline cleaning, chemical pickling, surface activation （400 mL/L HF acid, 10 min）, zinc-immersion （20 min） and anhydrous treatment. A relatively compact zinc-immersion film was prepared on the substrate surface. A silvery-colored satin aluminum deposition was obtained on AZ31 from TMPAC-AlCl3 using direct current plating.

Recovery of heavy metals from electroplating sludge and stainless steel pickle waste liquid by ammonia leaching method

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.

Electroless Nickel Plating and Electroplating on FBG Temperature Sensor

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.

Pulse electroplating of Ni-W-P coating and its anti-corrosion performance

Ni-W-P coatings were electrodeposited on copper substrates by pulse electroplating.Effects of electrolyte pH(1-3),temperature(40-80°C),average current density(1-7A/dm2)and pulse frequency(200-1000Hz)on deposition rate,structure and corrosion resistance performance of Ni-W-P coatings were studied by single factor method.Surface morphology,crystallographic structure and composition of Ni-W-P coatings were investigated by means of scanning electron microscopy,X-ray diffractometry and energy dispersive X-ray spectroscopy,respectively.Corrosion resistance performances of Ni-W-P coatings were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in3.5%NaCl solution(mass fraction)and soil-containing solution.It was found that the pulse electroplated Ni-W-P coatings have superior corrosion resistance performance and the electroplating parameters significantly affect the structure and corrosion resistance performance of Ni-W-P coatings.The optimized parameters of pulse electroplating Ni-W-P coatings were as follows:pH2.0,temperature60°C,average current density4A/dm2,and pulse frequency600Hz.The Ni-W-P coating prepared under the optimized parameters has superior corrosion resistance(276.8kΩ)and compact surface without any noticeable defect.

Removal of copper ions from electroplating rinse water using electrodeionization

An improved configuration of the membrane stack was adopted in the electrodeionization （EDI） cell to prevent precipitation of bivalent metal hydroxide during the running. The operational parameters that influenced the removal of copper ions from the dilute solution were optimized. The result showed that a moderate decrease in the inlet pH value and a moderate increase in the applied voltage could achieve a better removal effect. The steady process of electroplating wastewater treatment could be achieved with a removal efficiency of more than 99.5% and an enrichment factor of 5-14. The concentration of copper in purified water was less than 0.23 mg/L. This demonstrated the applicability of recovering heavy metal ions and purified water from electroplating effluent for industrial reuse.

Improvement of stability of trivalent chromium electroplating of Ti based IrO_2+Ta_2O_5 coating anodes

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.

Electroplating of Ni/Co–pumice multilayer nanocomposite coatings: Effect of current density on crystal texture transformations and corrosion behavior

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.

Progress of electroplating and electroless plating on magnesium alloy

The current research processes of electroplating and electroless Ni-P alloy plating on magnesium alloys were reviewed. Theoretically,the reason for difficulties in electroplating and electroless plating on magnesium alloys was given.The zinc immersion, copper immersion,direct electroless Ni-P alloy plating and electroplating and electroless plating on magnesium alloys prepared by chemical conversion coating were presented in detail.Especially,the research development of magnesium alloy AZ91 and AZ31 was discussed briefly.Based on the analysis,the existing problems and future research directions were then given.

Stimulation of Rare Earths in Quartz Optical Fiber Surface Metallization by Electroless Plating and Electroplating

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.

Electrochemical characteristics of electroplating and impregnation Ni-P/SiC/PTFE composite coating on 316L stainless steel

Ni-P/SiC/PTFE coating was obtained on the surface of 316L stainless steel by electrodeposition of Ni-P/SiC coating and immersion of PTFE(polytetrafluoroethylene).The surface morphology and composition were analyzed by scanning electron microscope and energy dispersive spectrometer.The corrosion resistance of the coating in 0.5 mol/L H2SO4+2×10−6 HF solution was studied by electrochemical method.Surface contact angle was used to test the hydrophobic properties of the coating.The results indicated that the Ni-P/SiC/PTFE coating prepared on the surface of stainless steel was uniform and compact,which significantly improved the self-corrosion potential of stainless steel.The self-corrosion current density decreased from 7.62 to 0.008μA/cm2.The durability performance of coating was tested under 0.6 V voltage and the stable corrosion current density value was 0.19μA/cm2,then wetting angle was tested after durability experiment and the value is 134.5°.

Electroplating process of amorphous Fe-Ni-Cr alloy

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.

Thermal spray coating on conductor rolls in electroplating line

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.

Influence of additives and concentration of WC nanoparticles on properties of WC−Cu composite prepared by electroplating

The effects of additives(polyethylene glycol(PEG),sodium dodecyl sulfate(SDS))and WC nano-powder on the microstructure,relative density,hardness and electrical conductivity of electroplated WC−Cu composite were investigated.The preparation mechanism was also studied.The microstructure of samples was analyzed by XRD,SEM,EDS,TEM and HRTEM.The synergistic effect of PEG and SDS made the WC−Cu composite more compact during the electroplating process.The hardness of WC−Cu composites increased with the increase in WC content,while the electrical conductivity decreased with the increase in WC content.The density of samples tended to increase initially and then decreased with increase in the additive content.When the electroplating solution contained 10 g/L WC nanopowder,0.2 g/L PEG and 0.1 g/L SDS,the WC−Cu composite exhibited hardness of HV 221 and electric conductivity of 53.7 MS/m.Therefore,the results suggest that WC−Cu composite with excellent properties can be obtained by optimizing the content of additives and WC particles.

Dynamic stretching–electroplating metal-coated textile for a flexible and stretchable zinc–air battery

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.

Microalgae as Bioabsorbents for Treating Mixture of Electroplating and Sewage Effluent

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%).