Showing papers on "Electroless nickel plating published in 2019"

A low temperature electroless nickel plating chemistry

Abstract: An acidic electroless nickel bath was formulated to plate high phosphorus nickel alloy at a low temperature from 45 to 50 °C. The low temperature EN bath, containing nickel ions, reducing agent, complexing agent, stabilizer, and accelerator, was optimized in composition to deposit high phosphorus nickel alloy (>11 wt% P) at temperature

Effects of electroless nickel plating method for low temperature joining ZnS ceramics

Abstract: ZnS has been widely used as a material for windows in optical systems. This is because it has a good transmittance in both mid-infrared and far-infrared bands, a stable chemical performance, a moderate linear thermal expansion coefficient and an adequate mechanical strength. ZnS windows need the so-called splice technology implementation to satisfy the integrity of large size applications or special surface structures. Traditional ZnS light windows are mechanically assembled with metal frames. However, the strength of the large-size ZnS formed by mechanical assembly is low. Consequently, an adequate joining technology is needed to overcome the low splice strength and improve the mechanical strength of the assembly. In this paper, we proposed a pre-metallization method by using an electroless plating of Ni on ZnS surface. Subsequently, a low temperature joining by using a Sn63Pb37 solder was completed. By a study of the process and the corresponding mechanism of the electroless nickel plating, a Ni–P layer with a controllable P content and thickness has been formed, and a smooth surface and a good combination with ZnS has been obtained. The microstructure of the Sn63Pb37 and Ni–P/ZnS was analyzed, and the phase composition and element distribution within the joint were determined. The influences of process parameters on the microstructures of the joints have been explored, including the brazing temperature, the time of thermal energy preservation and the thickness of the coating. Finally, the shear strengths of joints under different imposed parameters were optimized leading to the peak soldering temperature of 250 °C and the dwell at the peak of 1 min. The fractures were along Ni–P/ZnS ceramic interface, therefore, a successfully low temperature joining process on ZnS ceramics using Ni–P plating and Sn63Pb37 solder had been performed.

Influence of zinc-dipping on electroless nickel coating on magnesium alloy

Abstract: In this paper, the effect of zinc dipping pretreatment on corrosion resistance of electroless nickel plating on magnesium alloy was studied. The results showed that the corrosion resistance...

Optimisation of process parameters for electroless nickel plating on SS316L for refrigeration systems

Abstract: Nowadays, refrigeration systems are important for industrial and domestic applications. The coefficient of performance of a vapour compression refrigeration system can be improved if a redu...

Preparation method of porous nano flaky nickel phosphide material loaded by multiple substrates

Abstract: The invention discloses a preparation method of a porous nano flaky nickel phosphide material loaded by multiple substrates. The preparation method comprises the following steps: firstly, carrying outultrasonic cleaning on a substrate, putting the substrate into a catalyst solution to carry out loading of an electroless nickel plating catalyst, putting the substrate loaded with the catalyst intoan electroless nickel plating solution to carry out electroless nickel plating, and finally placing phosphorus at the bottom of a crucible, placing the nickel-plated substrate above the phosphorus, covering the crucible with a cover, and putting the crucible in a tubular furnace for phosphating so as to obtain the porous nano flaky nickel phosphide material loaded by the substrate. The method is simple in process, low in cost and short in period. The prepared nickel phosphide/conductive substrate material has high electrocatalytic hydrogen evolution activity in an acidic electrolyte, has verylow overvoltage potential and Tafel slope, has high stability, is good in mechanical property, can be directly used as a hydrogen evolution electrode to assemble an acidic electrolytic cell, and has avery high application value.

Enhanced thermoelectric properties of Bi2S3 polycrystals through an electroless nickel plating process

Abstract: Bi2S3 is an eco-friendly alternative compound for thermoelectric devices. However, the low electrical conductivity of the pristine Bi2S3 hinders the improvement of its ZT value, which further restricts its application in the field of thermoelectricity. In this work, we report the first attempt to optimize the thermoelectric properties of Bi2S3 by electroless nickel plating. A nickel plated Bi2S3 powder sample was synthesized by electroless nickel plating on the precursor Bi2S3 powder prepared by mechanical alloying. Then, the powder was sintered to a bulk material by spark plasma sintering. The relationships between the composition, microstructure and thermoelectric properties of the bulk samples were investigated. The XRD results showed a AgBi3S5 second phase which was formed by the reaction of Ag residues with the Bi2S3 substrate during the sintering process. The nickel element and AgBi3S5 second phase introduced in the nickel plating process directly affect the electronic conductivity and Seebeck coefficient of the nickel plating sample, resulting in the relatively high power factor of 244 μW m−1 K−2 at 628 K. What's more, the thermal conductivity of the sample was also reduced moderately, obtaining a low value of 0.40 μW m−1 K−1 at 628 K. Therefore, a maximum ZT value of 0.38 was obtained at 628 K for the nickel plated sample, which is three times higher than that (0.12 at 628 K) of pristine Bi2S3 materials.

Effect of Calcination Conditions on the Supercapacitive Performance of Activated Carbon/Nickel Oxide Nanocomposite Electrodes Prepared by Electroless Nickel Plating

Abstract: Electrochemical capacitors or supercapacitors or ultracapacitors have been identified as a promising technology that has a significant role to play in the electrical energy storage device revolution. Electrode material quality plays a crucial a role in defining the performance of the supercapacitor. This study fabricated nanocomposite electrodes from activated carbon and nickel oxide using electroless plating for supercapacitor applications. The electrochemical investigations reveal nanocomposite electrodes having prevalent capacitive performance in comparison to the activated carbon electrode. The specific capacitance, energy density and power density of the prepared composite samples were found to be 228.00–411.52 F g−1, 8.67–14.29 Wh kg−1 and 210.42–476.32 W kg−1, respectively, which signified an increase of 114.92–276.84 F g−1, 3.99–9.61 Wh kg−1 and 29.88–250.68 W kg−1, respectively, with regard to the carbon electrode. Furthermore, reduction in specific capacitance and energy density was observed when calcination temperature and time were increased from 300°C to 500°C and 1 h to 2 h, respectively, suggesting that calcination at an elevated temperature for a lengthy time is detrimental to the electrochemical performance of the nanocomposite electrodes. The nanocomposite electrode calcinated at 300°C for 1 h exhibited the highest improvement of 205% equally in specific capacitance and energy density, while the nanocomposite electrode calcinated at 500°C for 2 h offered the maximum power enhancement of 112%.

Effect of lead nitrate concentration on electroless nickel plating characteristics of gray cast iron

Abstract: In this paper, the effect of lead nitrate stabilizer concentration on the electroless nickel (EN) plating properties of gray cast iron was investigated in a sulfuric acid plating bath. The specific critical stabilizer concentration was found to vary the EN coating properties. At the critical stabilizer concentration or more, plating rate and the chemical composition of the EN coating were changed because the deposition of Ni and P was inhibited by excessive stabilizer concentration. The surface morphology of the EN coating was strongly influenced by the plating rate change with the stabilizer concentration and the galvanic coupling effect due to the microstructure of the substrate. The crystallinity of the EN coating tended to increase with increasing stabilizer concentration. As a result, the EN plating properties of gray cast iron were greatly affected by the stabilizer concentration in the plating bath and the microstructure of the substrate.

Effect of Na4P2O7·10H2O as complexing agent on deposition behavior and property of electroless Ni-P coating on ZK61M magnesium alloy

Abstract: The electroless Ni-P coating was prepared on ZK61M magnesium alloy by using Na4P2O710H2O as main complexing agent and NiSO46H2O as main salt in the electroless nickel plating solution. The effects of Na4P2O710H2O on deposition rate, growth progress and corrosion resistance of the Ni-P coating were investigated systematically in this study. The properties of the plating were characterized by the measurements including, scanning electronic microscope (SEM), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), electrochemical polarization and immersion tests in 5% NaCl solution. The results showed that the initial uniform deposition of the plating on the HF-activated substrate was achieved by using Na4P2O710H2O as the main complexing agent. The deposition rate showed an obvious upward trend with the increment on the concentration of Na4P2O710H2O. It was worth noting that the content of phosphorus reached more than 7 wt% in Ni-P coating while the concentration of Na4P2O710H2O was higher than 40 g L−1. Most importantly, the plating with an obvious microcrystal structure had excellent corrosion resistance. Moreover, no corrosion on the surface was observed while the sample was immersed into 5% NaCl solution for 12 h. The self-corrosion potential of the Ni-P coating exceeded −0.5 V. The self-corrosion current could be reduced about 2 orders of magnitude comparing to magnesium alloy substrate.

Fabrication of Nickel Coating on Polyethylene Terephthalate Substrate Modified with Primer: Effect of Surface Roughness on Structural Properties of Plated Coating

Abstract: Fabrication of nickel coating on polyethylene terephthalate substrate via primer modification combined with PdCl2 activation and electroless nickel plating is researched. The effect of surface roughness on structural properties of the plated coating was investigated. The modified substrate could adsorb Sn2+ and Pd2+, which can catalyze the electroless nickel plating. Increasing the SiO2 content in the primer could enhance surface roughness of primer coating, adsorbed capacity of Sn2+ and Pd2+, crystallinity and adhesive force of nickel-plated coating. The nickel-plated film was compact, as SiO2 particles were uniformly dispersed and well bonded with nickel coating. When the average roughness was about 18 μm, the plated coating presented thickness of 2 μm, a low resistivity of 6.6 × 10−5 Ω cm and good adhesive strength of 5B. In addition, selective and flexible nickel patterns could be obtained successfully after laser etching.

Electroless Deposition on Three Substrates: Brass Washers, Cicada Exoskeletons, and Beetles

Abstract: This laboratory experiment showcases electroless deposition, an autocatalytic reduction process performed in aqueous solution containing a metal ion in the presence of a reducing agent yielding a coherent metal film. One set of experiments has been performed by second-semester general chemistry students in a 3 h lab session. After preparing an electroless nickel plating bath, they first plate a brass washer with nickel for 10 min at 85 °C. Using weight gain data for their brass washer along with its surface area, the thickness of the nickel coating is determined. The same electroless nickel plating bath is then used to plate a pretreated cicada exoskeleton with nickel. The three-step pretreatment procedure deposits Pd(s) nanoparticles on a nonconducting exoskeleton made of chitin, transforming it into a conducting substrate. A second set of experiments has been performed by upper-class chemistry majors. They (1) explore the reproducibility in weight gain when plating brass washers with nickel for 10, 20, 30, and 40 min time intervals, (2) plate beetles with nickel, and (3) plate cicada exoskeletons with copper using an electroless copper plating bath recipe they find in the literature. Weight gain data and photos of the plated cicada exoskeletons and beetles accompany this article. The nickel-plated brass washers and cicada exoskeletons were examined with XRF spectrometry. This analysis demonstrates that the nickel coating is not pure nickel but rather an alloy containing phosphorus.

Ionic palladium activation solution for electroless nickel plating on metallic copper surface and preparation method

Abstract: The embodiment of the invention discloses an ionic palladium activation solution for electroless nickel plating on a metallic copper surface and a preparation method thereof, and is used for solving the problems that in the prior art, diffusive plating and skip plating easily appear in a fine circuit and a process is complex. The embodiment of the invention provides the ionic palladium activationsolution for electroless nickel plating on the metallic copper surface. In terms of concentration, the activation solution comprises 8-15 ppm of palladium salt, 0.1-20 mL/L of inorganic acid, 0.01-1 g/L of a surfactant, 0.01-0.1 g/L of an accelerator, 0.1-10 g/L of a complexing agent and the balance of deionized water. Therefore, through improvement on a formula of the activation solution, the problems that in the prior art, diffusive plating and skip plating easily appear in the fine circuit and the process is complex are solved.

Method for preparing silicon-based anode material

Abstract: The invention relates to a method for preparing a silicon-based anode material. The method includes the following steps of (1) preparation and pretreatment of a silicon-based material; (2) roughening,sensitization and activation of the silicon-based material; (3) plating solution preparation: mixing a main salt solution and a complexing agent solution and then adding a stabilizer and a surfactantsequentially; (4) adding a product obtained in the step (2) to a plating solution prepared in the step (3), adjusting the pH value slowly and adding a reducing agent for electroless plating; (5) washing with deionized water and drying to obtain the anode material of a silicon-based lithium ion battery. The nano silicon and porous silicon surface electroless nickel plating mode is adopted to improve the conductivity of the material, solve the volume expansion problem in the silicon-based anode material cycling process and improve the electrochemical performance.

Aluminum alloy electroless nickel plating mixed metal activation method

Abstract: The invention provides an aluminum alloy electroless nickel plating mixed metal activation method. The method comprises the following steps that surface oil removal, deoxidizing film treatment and acid cleaning are performed on an aluminum base material in sequence, then the aluminum base material is placed in activation liquid for activation, the activation treatment temperature is 20-50 DEG C, and the activation time is 1-5 min. By means of the aluminum alloy electroless nickel plating mixed metal activation method provided by the invention, a prepared nickel plating layer has the characteristics of being uniform and compact, wear resistant, corrosion resistant, good in binding force and the like, the problems existing in the prior art of the tedious process, environmental pollution, slow beginning plating time, poor plating layer adhesion force and the like are solved, the production cost can further be reduced, and the aluminum alloy electroless nickel plating mixed metal activation method is suitable for large-scale industrial production.

/ Manufacturing method of conductive carbon papers/epoxy composites using electroless nickel-plating

Abstract: The present invention relates to a method to manufacture a carbon paper/epoxy electromagnetic shielding material, which comprises: (a) a step of immersing pitch-based carbon fiber in a metal plating solution to plate the carbon fiber; (b) a step of mixing an organic polymer compound with the plated carbon fiber via a wet method to make a carbon fiber web; (c) a step of immersing the made carbon fiber web in a thermosetting resin; and (d) a step of hardening the immersed carbon fiber web According to the present invention, nickel induces reflection and absorption of electromagnetic energy on the pitch-based carbon fiber formed through electroless plating to provide an excellent electromagnetic shield ratio, thereby providing effects of realizing high economic efficiency, a lightweight shape, and a small thickness compared to an existing epoxy composite material, while being applicable to various fields, such as an electronic device, a communication device, a precise device, a smart industry, and the like