Preparation of Diamond-like Carbon Films on the Surface of Ti Alloy by Electro-deposition

In this paper, diamond-like carbon (DLC) films were deposited on Ti alloy by electro-deposition. DLC films were brown andcomposed of the compact grains whose diameter was about 400 nm. Examined by XPS, the main composition of the filmswas carbon. In the Raman spectrum, there were a broad peak at 1350 cm^(-1) and a broad peak at 1600 cm^(-1), which indicatedthat the films were DLC films.

Cathodic micro-arc electro-deposition of ZrO_2 coatings in an aqueous solution containing colloidal particles

By a novel technique-cathodic micro-arc electro-deposition (CMED), ZrO_2coatings were deposited on an FeCrAl alloy. Experimental results show that the necessary conditionsfor obtaining ZrO_2 coatings are to apply a pulse peak voltage over a critical value and addmoderate amounts of ZrO_2 colloidal particles and Zr(NO_3)_4 in the aqueous solution. Theas-deposited coatings are porous because hydrogen, water, and other vapors are generated andreleased from the coatings to the solution during the spark reaction. The coatings containmonoclinic and tetragonal crystalline ZrO_2 with certain degree of amorphous structure. Theprocessing parameters and mechanism of CMED were discussed.

Mechanical Characterization of Close Cell Aluminum Foams Reinforced by High Voltages Electro-deposition

The parameters for the electro-deposition of Cu were optimized in order to increase the compressive properties of close cell aluminum. Different values of deposition voltages and times were considered to vary the amount of deposited Cu. The surface morphology of the coating was observed by SEM and the compressive properties were evaluated by MTS. The results show that the coating is more homogeneous and compact with increasing voltage in a certain range, and beyond which, the coating quality decreases apparently. The reason is dedicated to the discharge rate of Cu2+ and nucleus formed in unit time. The compression results show three experienced stages: elastic deformation stage, collapse deformation stage and densification stage. After the electro-deposition of Cu, the elasticity modulus is increased obviously and the platform stress is also increased. Under the same strain, the stress of the aluminum foam with coating is reinforced comparing with the aluminum foam without coating. Furthermore, the platform area is widened apparently. In addition, Cu-SiC nanocomposite coatings are electrodeposited in alumium foams for further improving the mechanical characterization.

Electro-Deposition of Ni-La Film in Urea-NaBr Melt and Its Hydrogen Evolution Properties

The Ni-La alloy was electro-deposited in urea-NaBr melt. The codeposition behavior and effect of the cathodic current density on the coating composition were examined. As a result, lanthanum codeposited with nickel to form Ni-La alloy under the inducement effect of nickel. With the increase of the cathodic current density, the content of lanthanum of the deposit rose at first, then decreased, and reached the maximal value (10.3%(atom fraction)) at the current density 15 mA·cm-2. The crystallization behavior of Ni89.7La10.3 coating was investigated by means of differential scanning calorimetry and X-ray diffraction. The structure of Ni89.7La10.3 as-plated coating was amorphous phase. The amorphous phase was converted into center cubic close packed Ni-La (Fm3m) solid solution at 469.8 ℃. The electro-catalytic activity of hydrogen evolution of Ni89.7La10.3 coating was studied using electrochemical experiments, the results showed that the electro-catalytic activity of hydrogen evolution of Ni89.7La10.3 coating was better than that of nickel.

Electro-deposition tangsten coating on low activation steel substrates from Na_2WO_4-ZnO-WO_3 melt salt

Tungsten coating is considered as a promising alternative material for plasma facing materials(PFC) in future fusion devices.The electro-deposition of tungsten in Na_2WO_4-ZnO-WO_3 melt at 1173 K on low activation steel substrates was studied in this work.Adherent and smooth tungsten films were deposited under various pulsed current conditions.The crystal structure and microstructure of tungsten deposits were characterized by XRD,SEM and EDX techniques.The results show that pulsed current density and duty cycle have a significant influence on tungsten nucleation and electro-crystallization phenomena.Uniform and smooth tungsten coating with high purity and high adherence is obtained on low active steel substrates as cathodic current density ranges from 35 to 25 mA·cm_(-2).

Structure and Magnetic Properties of Ni Nanowires Array Fabricated by Direct Current Electro-deposition in Anodic Alumina Membrane

Ordered nanostructure arrays of Ni-Al 2O 3 were synthesized by direct current electro-deposition in anodic alumina membranes (AAM). The investigation with a n electron microscope,an X-ray diffractmeter and a vibration sample magnetomete r indicates that the Ni nanowires, growing in the pores of AAM with about 45nm i n diameter, are monocrystalline and have a definite preferred crystallizing orie ntation. The magnetic behavior of the arrays and their mechanism were discussed.

Effect of Pulse Parameters on Deposition in Concrete Crack using Pulse Current Electro-deposition

To evaluate the effect of pulse parameters on the formation of electrodeposits in concrete cracks, five different types of pulse current were set up, and ZnSO_4 and MgSO_4 solutions were used as the electrolytes. The rate of weight gain, rate of surface coating, rate of crack closure and crack filling depth were measured. Scanning electron microscopy was used to assess the morphology of the electrodeposits, and energy dispersive spectroscopy was used to analyze the mineral composition of the electrodeposits in the cracks. The experimental results demonstrate that, among five different pulse parameters, when T_（on）/T_（off）=0.8 ms/0.8 ms, the healing effect of electro-deposition is the best. The pulse mode hardly affects the mineral composition of the electrodeposits but changes the micromorphology. In addition, for both ZnSO_4 and MgSO_4 solutions, when T_（on）/T_（off）=0.8 ms/0.8 ms, the crystal structure of the electrodeposits is the most uniform and the densest.

Electro-Deposition of Cu on Open Cell Aluminum Foams

This manuscript deals with the electro-deposition of Cu on aluminum foams. Metallic foams are highly porous materials which present complex structure of three-dimensional open cells. This aspect causes strong limitations in mass transport due to electro-deposition technology. Experimental tests were performed to study the influence of the operational parameters on the overall performance of the coated aluminum foams. The experimental findings revealed that the manufactured metal foams were characterized by a high thermal conductivity and low process costs, making these materials very promising in many technological fields. On the basis of the experimental results, analytical models are proposed to predict the quantity and the quality characteristics of the coating.

Effect of mechanical attrition on microstructure and properties of electro-deposition coatings on NdFeB

Surface mechanical attrition treatment （SMAT） was developed to synthesize nanostructure coatings on alloy surface. The SMAT action was applied in the process of Ni and Cu electroplating coatings on NdFeB substrates in this paper. The role of mechanical attrition during barrel plating on the microstructure, mechanical and corrosion resistant properties of the coatings was exam- ined. The scanning electron microscopy （SEM） observation showed that the mechanical attrition could refine grain size, markedly smooth the coating surface and obviously decrease the number of pore in the coatings. The continuous collisions of glass balls onto the NdFeB samples could induce more beneficial nucleation defects on the coating, which was helpful for increasing nucleation sites and the nucleation rate. The mechanical attrition could also restrain the heterogeneous growth of the coating grain tips due to the abra- sive action of stainless steel balls. The Tafel polarization curve experimental results indicated that SMAT process could enhance the corrosion resistance of coatings on NdFeB. The scratching test revealed that the binding force between coating and NdFeB substrate could be improved dramatically with SMAT process.

In-situ electro-deposition synthesis of MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces

A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnO_(x)-NiCo_(2)O_(4)-2:2 sample,oxidizing about 90% of benzene(T_(90)) at 198℃ under 12000 h^(-1) gaseous hourly space velocity.This work shed new light on the design of excellent monolithic catalysts,which might pave the way for the industrialization of benzene combustion.

Corrosion Resistance of Steel in Cracked Reinforced Concrete after Electro-depositon Treatment

An electro-deposition method has been recently proposed to repair cracked reinforced concrete. To evaluate the corrosion resistance of the reinforcing steel in cracked concrete, three different parameters including type of auxiliary electrode, electrode distance, and current density were studied. Tafel polarization curve was used to evaluate the corrosion resistance of the steel. Self-corrosion potential and corrosion current of the steel were tested. The results indicate that the corrosion resistance improvement of the reinforcing steel is optimal as prism titanium mesh is applied as auxiliary electrode, followed by the flaky titanium mesh and the column titanium bar. When the electrode distance is 60 mm, the corrosion resistance improvement of the reinforcing steel is optimal, and with 80 mm electrode distance, the corrosion resistance improvement is the poorest. The property falls in between them when 40 mm electrode distance is used. Moreover, the corrosion resistance improvement of the reinforcing steel increases as the current density goes up.

Mssbauer study of the field induced uniaxial anisotropy in electro-deposited FeCo alloy films

Thin ferromagnetic films with in-plane magnetic anisotropy are promising materials for obtaining high microwave permeability. The paper reports a MSssbauer study of the field induced in-plane uniaxial anisotropy in electro-deposited FeCo alloy films. The FeCo alloy films were prepared by the electro-deposition method with and without an external magnetic field applied parallel to the film plane during deposition. Vibrating sample magnetometry and MSssbauer spectroscopy measurements at room temperature indicate that the film deposited in external field shows an in-plane uniaxial anisotropy with an easy direction coinciding with the external field direction and a hard direction perpendicular to the field direction, whereas the film deposited without external field does not show any in-plane anisotropy. MSssbauer spectra taken in three geometric arrangements show that the magnetic moments are almost constrained in the film plane for the film deposited with applied magnetic field. Also, the magnetic moments tend to align in the direction of the applied external magnetic field during deposition, indicating that the observed anisotropy should be attributed to directional ordering of atomic pairs.

Electrochemical behaviors of Mg^(2+) and B^(3+) deposition in fluoride molten salts

By using cyclic and linear sweep voltammetry,the electrochemical deposition behaviors of Mg^2＋ and B^3＋ in fluorides molten salts of KF-MgF2 and KF-KBF4 at 880℃ were investigated,respectively.The results show that the electrochemical reduction of Mg^2＋ is a one-step reaction as Mg^2＋＋2e-→Mg in KF-1%MgF2 molten salt,and the electrochemical reduction of B^3＋ is also a one-step reaction as B^3＋＋3e-→B in KF-KBF4 （1%,2% KBF4） molten salts.Both the cathodic reduction reactions of Mg^2＋ and B^3＋ are controlled by diffusion process.The diffusion coefficients of Mg^2＋ in KF-MgF2 molten salts and B^3＋ in KF-KBF4 molten salts are 6.8×10^-7 cm^2/s and 7.85×10^-7 cm^2/s,respectively.Moreover,the electrochemical synthesis of MgB2 by co-deposition of Mg and B was carried out in the KF-MgF2-KBF4 （molar ratio of 6：1：2） molten salt at 750℃.The X-ray diffraction analysis indicates that MgB2 can be deposited on graphite cathode in the KF-MgF2-KBF4 molten salt at 750℃.

Hydroxyapatite Coatings on Titanium Prepared by Electrodeposition in a Modified Simulated Body Fluid

Hydroxyapatite coatings were directly prepared on anodized titanium by electro-deposition method in a modified simulated body fluid.The configuration,structure and bioactivity of the coating were investigated with scanning electron microscopy(SEM),X-ray diffraction analyzer(XRD)and Fourier transform infrared spectros-copy(FTIR)techniques.The results demonstrated that pure and homogeneous hydroxyapatite coating can be obtained without any post-treatment.The prepared coating showed good bioactivity in simulated body fluid(SBF).The time required for a fully covered dense hydroxyapatite coatings was 4 days immersion in SBF.

Preparation and Electrochemical Properties of the Pd-modified Cu Electrode for Nitrate Reduction in Water

The Pd-modified Cu （Pd/Cu） electrodes for nitrate reduction were prepared using electro-deposition method at different potentials, Compared with other different electrodes so far studied in our work （Cu, Sn/Cu and Pd/Ti electrode） using cyclic voltammetry method, Pd/Cu electrode showed the highest electrocatalytic capacity of nitrate reduction. It was found that at more negative electrode potential the smaller Pd particles formed on the Cu electrode, which was beneficial to the nitrate reduction. With increasing deposition amount of Pd, the capacity of nitrate reduction increased. Too rich Pd, however, has a negative influence on the capacity of nitrate reduction. In our study, the maximum nitrate reduction current was 2.07 mA/cm^2, when electrodeposition potential of Pd was -0.3 V and deposition amount was 0.9 C.

Preparation of dendritic bismuth film electrodes and their application for detection of trace Pb(Ⅱ)and Cd(Ⅱ)

In this paper,dendritic Bi film electrodes with porous structure had successfully been prepared on glassy carbon electrode using a constant current electrolysis method based on hydrogen bubble dynamic templates.The electrode prepared using a large applied current density showed an increased internal electroactive area and a significantly improved electrochemical performance.The analytical utility of the prepared dendritic Bi film electrodes for the determination of Pb(Ⅱ)and Cd(Ⅱ)in the range of 5–50 μg·L^(-1)were presented in combination with square wave stripping voltammetry in model solution.Compared with non-porous Bi film electrode,the dendritic Bi film electrode exhibited higher sensitivity and lower detection limit.The prepared Bi film electrode with dendritic structure was also successfully applied to real water sample analysis.

Degradation of Phenol by Hydroxyl Radicals on Different Coating Lead Dioxide Electrodes

Lead dioxide electrodes on Ti substrates were prepared by thermal-deposition or electro-deposition. The amount of hydroxyl radicals generated at the electrodes prepared by the above-mentioned two methods was compared with that at the electrodes mingled with Bi or La prepared by electro-deposition. The experimental results indicate that the highest concentration of hydroxyl radicals generated by thermal-deposition, electro-deposition mingled with nothing, electro-deposition mingled with Bi or La was 0.781, 1.048, 1.838 or 2.044 μmol/L, respectively. When phenol was electrolyzed on the four electrodes at a current density of 30 mA/cm2, the removal efficiency of phenol after electrolysis for 1.5 h was 87.30%, 93.55%, 97.95% or 98.70%, TOC removal efficiency after electrolysis for 5 h was 86.76%, 94.26%, 98.53% or 99.60%, respectively. Through the degradation experiments of phenol, the amount of hydroxyl radicals was responsible for the removal efficiency of phenol. The electro-catalytic characteristics were investigated by SEM, the generation amount of hydroxyl radicals, the degradation degree of phenol and the stability and conductivity of the electrodes were also investigated. The experimental results indicate that the four electrodes all show good electro-catalytic characteristics; the electro-catalytic characteristics of the electrode mingled with La were superior to those of the other three ones, and the electrochemical degradation of phenol followed one-step reaction dynamics.

Stability of electrodeposited amorphous Ni-Fe-P alloys

The stability of the electrodeposited amorphous Ni-Fe-P alloys was studied by DTA,DSC,XRD and improved four-ball wear tester in order to clear its applied scope.The results show that the element content has influence on the stability of amorphous Ni-Fe-P alloy,in which the crystallization temperature increases with Fe content,and the increase of P content delays the appearance of stable crystallization phases and recrystallization.There exist 6 exothermal reactions during heating the amorphous Ni69Fe8P23 alloy continuously.The activation energies of exothermal reactions at 248,303,322,350,376 and 442 ℃ are 131.5,111.6,237.8,253.6 and 238.5 kJ/mol,respectively.The amorphous Ni60Fe22P18 alloy crystallizes when the heating temperature is beyond 250 ℃.The stable crystallization phases consist of Ni(Fe)and Ni3P-type compounds Ni3P,Fe3P,(Fe,Ni)3P.The pressure and fraction have influence on the stability of amorphous alloy.Rubbing above the critical pressure crystallization will take place on the fractional surface.The crystallization phases due to pressure and fraction are different from those due to heating.It is the crystallization that increases the wear resistance of Ni-Fe-P coating under higher pressure.

Ordered cone-structured tin directly grown on carbon paper as efficient electrocatalyst for CO_(2) electrochemical reduction to formate

The conversion of carbon dioxide to chemicals by the electrochemical reactions(ERC)is an efficient solution to the current energy crisis and excess CO_(2) emissions.It is still a great challenge and of significance to synthesize a highly selective,efficient,and non-noble metal electrocatalyst that facilitates the ERC reaction.A novel triton X-100(C_(14)H_(22)O(C_(2)H_(4)O)n)assisted electrodeposition method was developed to synthesize the ordered cone-structured tin(OCSn)electrocatalysts with controllable morphology and structure.The results suggest that Triton X-100 plays an important role in directing the structure of the Sn electrocatalysts during the electrodeposition process.The OCSn synthesized at 60 m A cm^(-2) achieves the best performances.It selectively catalyzes the ERC on the onset potential about 110 m V lower than Sn synthesized without Triton X-100.In 0.5 M Na HCO_(3),high faradaic efficiency(92%)for formate product on OCSn has been achieved.More prominently,the catalyst presents excellent stability,showing no performance deterioration during 30 h electrolysis.This work provides an efficient,green,and scalable synthesis method of the electrocatalyst for CO_(2) reduction to formate.

Influence of Mineral Admixtures on the Electrodeposition Healing Effect of Concrete Cracks

Two types of solutions（Zn SO4, Mg SO4） were selected to study the influence of mineral admixtures on the electro-deposition healing effect of concrete cracks. Four parameters（i e, rates of weight gain, surface coating, crack closure and crack filling depth） were measured. The mineral composition of electro-deposits in the cracks was analyzed. The study shows that the healing effect of mortar specimens with 10% fly ash is the worst, while the healing effect of mortar specimens with 20% fly ash is better than that of the specimens without fly ash. The rates of weight gain, surface coating, crack closure and crack filling depth decrease with increasing content of the ground granulated blast-furnace slag（GGBS）. The mineral admixtures have no influence on the composition of deposits.