Showing papers on "Electroless nickel plating published in 2006"
TL;DR: In this article, the effect of the substrate microstructure and roughness on the deposition rate, nucleation, and mechanical properties of Ni-plating on Mg alloy AZ91 has been investigated.
Abstract: Electroless Ni-plating on Mg alloy AZ91 has been studied to understand the effect of the substrate microstructure and roughness on the deposition rate, nucleation, coating microstructure, and mechanical property of the coatings. Experimental results indicate that the growth of Ni deposit in the early stage was influenced by the substrate microstructure and roughness. The electroless Ni-plating on the abrasive blasted AZ91 (rough) substrate showed a higher deposition rate than that on the finely polished one, indicating that the mechanical roughening enhances the nucleation and coalescence of Ni crystallites. Scratching tests showed that higher coating adhesion is achieved on the roughened AZ91 substrate. Wear tests, however, showed that the Ni plating on the rough substrate has a higher friction coefficient than that on the polished surface. The hardness and adhesion property of Ni coatings before and after heat treatment were also characterised.
167 citations
TL;DR: In this paper, the electroless plating of Ni on Mg alloys was investigated and the critical load (a measure of adhesion strength) reached 13.1 N. The plating process was strongly influenced by the substrate microstructure at the early stage.
Abstract: Magnesium (Mg) and its alloys are being used as structural components in industry because of their high strength-to-weight ratio and relatively high stiffness. A shortcoming of Mg based alloys is their high electrochemical activity and poor corrosion resistance. Therefore, coatings or surface treatment are needed for protection purpose. This paper reports our work on electroless plating of Ni on Mg alloys. Pure Mg, AZ31 and AZ91 Mg alloys were used as the substrates to investigate the deposition rate, nucleation process, chemical composition and microstructure of the electroless Ni coatings. It was found that the deposition processes are strongly affected by the alloy substrates. Ni plating on AZ31 alloy has higher deposition rates and lower surface roughness than that of other substrates. SEM investigations showed that nodular morphology of Ni coatings formed on the substrates. Chemical pre-treatment before plating increases the substrate surface roughness significantly. The plating process was strongly influenced by the substrate microstructure at the early stage. Deposition was initiated on the phase and grain boundaries due to the inter-grain galvanic coupling. Fine substrate microstructure such as that of AZ31 alloy provided a large amount of nucleation sites, benefiting the nucleation and growth processes of the electroless nickel plating. The adhesion strengths of the coatings on AZ31 and AZ91 alloys are higher than that on pure Mg. The critical load (a measure of adhesion strength) of AZ31 reached 13.1 N.
101 citations
TL;DR: In this paper, surface modification of the silicon carbide nanoparticles (SiCP) by electroless nickel plating was performed, and the results showed that a nanoscale agglomerative nickel layer was coated on the SiCP.
85 citations
TL;DR: In this paper, the porosity of the plating coating was evaluated by the combination of corrodkote and filter paper, and the effects of plating solution on porosity were investigated through scanning electron microscopy (SEM) and electrochemical potentiodynamic polarization.
69 citations
TL;DR: In this article, a new process with zinc transition layer obtained by combining immersing zinc in an improved zinc bath containing FeCl3 and electroplating zinc, is used to plate Magnesium alloy AZ91D.
Abstract: A new process, which is characterized with zinc transition layer obtained by combining immersing zinc in an improved zinc bath containing FeCl3 and electroplating zinc, is used to plate Magnesium alloy AZ91D. Corrosion testing and SEM images indicate that the immersion zinc layers obtained in zinc immersion baths with FeCl3 are more compact. Peel testing shows that there is good adhesion to the subsequent electrodepositing layer. The electroplating zinc can further promote the coverage of zinc transition layer on the magnesium alloy substrate before electroless nickel plating and reduce the galvanic corrosion effect between Mg alloy and Ni–P alloy. The good zinc deposit can be obtained by electroplating zinc in pH 9∼10 zinc pyrophosphate bath at 40 °C under the current density of 2∼3 A/dm2. The developed new process of electroless nickel plating greatly improves the adhesion and coverage of Ni–P coating. The zinc transition layer obtained by the developed process can supersede copper transition layer obtained by cyanide plating process in electroless nickel plating on magnesium alloy.
54 citations
TL;DR: In this article, a new electroless nickel (EN) plating technique is described, which eliminates the conventional use of palladium catalyst, and the optimal pretreatment conditions are obtained to deposit nickel on the surface of the SiCp/Al composites reinforced with 70 vol.% fine particulate silicon carbide.
Abstract: A new electroless nickel (EN) plating technique is described, which eliminates the conventional use of palladium catalyst. The paper has studied systematically the nickel activation technology and its effect on the deposition rate, as well as theoretical description of the activation and deposition processes for electroless Ni–P alloys. It has been found that the deposition rates increase and approach a maximum value with the increase in the immersion time, the temperature and time of the heat treatment during activation process. The optimal pretreatment conditions are obtained to deposit nickel on the surface of the SiCp/Al composites reinforced with 70 vol.% fine particulate silicon carbide. The nickel activation and electroless nickel plating are investigated using SEM, EDAX and XPS. Also, microhardness, adhesion and porosity measurements are carried out to characterize the coatings. Electroless nickel layer adheres better to nickel-activated SiCp/Al composites because nickel-substrate bonding takes place during activation and plating. The values of microhardness are enhanced after coating with nickel. A model is purposely introduced to describe the growth of catalytic centers in the active film and its effect on the deposited layer.
49 citations
TL;DR: In this paper, the effects of the buffer agent and plating parameters on the properties and structures of the plating coatings on magnesium alloy were investigated by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Xray diffraction (XRD).
Abstract: In this paper, the electroless nickel-plating on magnesium alloy was studied, using NiSO4·6H2O as the main salt in the electroless plating alkaline solutions. The effects of the buffer agent and plating parameters on the properties and structures of the plating coatings on magnesium alloy were investigated by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). In addition, the weight loss/gain of the specimens immersed in the test solution and plating bath was measured by using the electro-balance, to evaluate the erosion of the alloy in the plating solutions. The adhesion between the electroless plating coatings and the substrates was also evaluated. The compositions of the non-fluoride and environmentally friendly plating bath were optimized through Latin orthogonal experiment. The buffer agent (Na2CO3) added to the plating bath was found to be useful in increasing the growth rate of the plating coating, adjusting the adhesion between the electroless plating coatings and the substrates, and maintaining the pH value within the range of 8.5–11.5, which is required for the successful electroless nickel-plating on magnesium alloy with NiSO4·6H2O as the main salt. Trisodium citrate dihydrate was found to be an essential component of the plating bath to plate magnesium alloy, with an optimum concentration of 30 g L−1. The obtained plating coatings are crystalline with preferential orientation of (111), having advantages such as low-phosphorus content, high density, low-porosity, good corrosion resistance and strengthened adhesion.
46 citations
TL;DR: In this paper, stable, low-resistance contacts on porous silicon have been realized by electroless nickel deposition from a very weakly alkaline solution followed by copper thickening.
Abstract: In this paper stable, low-resistance contacts on porous silicon have been realized by electroless nickel deposition from a very weakly alkaline solution followed by copper thickening. The porous silicon layer after nickel deposition has been analysed by x-ray diffraction, which shows that a porous silicon nickel structure is successfully achieved from the bath. FESEM studies have been performed which show that the surface morphology of the porous silicon layer remains intact after nickel–copper plating. The mean roughness of the porous silicon surface has been found to improve after nickel plating from the AFM studies. Electrical characterization shows that the J–V characteristics of the nickel–copper-plated porous silicon lateral structure contact is fairly linear up to a certain value of applied voltage. Specific contact resistance of the nickel on porous silicon has been measured for the first time and has been found to be of an order of magnitude lower than that of other metals. No significant ageing is visible in this electroless nickel contact contrary to the vacuum-evaporated nickel contact.
45 citations
TL;DR: In this article, a second-order response surface model with central composite design (CCD) has been used to take into account the effect of curvature in the predicted response.
43 citations
TL;DR: In this paper, the effect of cupric (Cu2+) ion as an additive in the acidic electroless nickel plating bath on the characteristics of the resulting nickel−phosphorus (Ni−P) alloys was investigated mainly with X-ray diffraction, scanning electron microscopy, and energy-dispersive X -ray (EDX) spectrometry.
Abstract: The effect of cupric (Cu2+) ion as an additive in the acidic electroless nickel plating (ENP) bath on the characteristics of the resulting nickel−phosphorus (Ni−P) alloys was investigated mainly with X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray (EDX) spectrometry. Cupric ions in the acidic ENP bath using hypophosphite anions as reductants have been reported ambiguously as stabilizers or codeposit constituents. In this work, the critical concentration of added copper salts, CuSO4·5H2O, that starts to inhibit the ENP process was determined to be ca. 536 mg/L. In general, the deposition rate, surface morphology, and pit formation on the surface of as-deposits are significantly improved with Cu2+ addition at concentrations less than the critical value. The electroless nickel alloys were shown as a mixture of an amorphous deposit and a crystalline copper metal rather than as amorphous alloys alone.1,2 During the initial stage of the electroless plating process, the copper conten...
41 citations
TL;DR: In this article, nano ZnO particles were synthesized by using an electrochemical technique and incorporated the particles into Ni-P plates, which resulted in improvement of metallurgical and corrosion resistance characteristics of the plates.
TL;DR: In this paper, it was shown that the diameters, lengths and growth densities of SiNWs could be controlled by the Ni content of the electroless plating layer on the silicon substrate.
TL;DR: In this paper, the effects of solution amount, plating time and plating temperature on surface resistivity and electromagnetic shielding effectiveness were investigated by using electroless nickel plating, and P content, microstructure and surface feature of layers obtained at different temperatures were analyzed by energy dispersion spectrometer (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Abstract: Electrical and electromagnetic shielding wood-metal composite was prepared by using electroless nickel plating. The effects of solution amount, plating time and plating temperature on surface resistivity and electromagnetic shielding effectiveness were investigated. And P content, microstructure and surface feature of layers obtained at different temperatures were analyzed by energy dispersion spectrometer (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that layers with higher electro-conductivity and electromagnetic shielding effectiveness were obtained under the optimum conditions that plating solution was 500 mL, plating time was 30 min and plating temperature was 62°C. The results showed by EDS analysis that P content increased gradually in a small extent with plating temperature increased. It was showed by XRD and SEM analysis that layers plated at different temperatures were all microcrystalline structure and uniform and successive, which had noticeable metal luster. Those indicated that plating temperature had little influence on microstructure and surface feature under pH value invariable.
TL;DR: In this article, reinforcement of electroless Ni-P plate with ZrO2 has been proposed and shown to have high stability and excellent electrocatalytic activity in hydrogen evolution reaction.
TL;DR: In this paper, an electroless plating of Ni-P on Mg alloys was reported, and the maximum friction coefficient was found to be 0.3 on the electroless nickel coating of pure Mg substrate and the critical load of AZ31 reached 13.1 N.
Abstract: Magnesium (Mg) and its alloys are being used as structural components in industry because of their high strength-to-weight ratio and relatively high stiffness. A shortcoming of Mg based alloys is their poor corrosion and wear resistance. Therefore, coatings or surface treatment are needed for protection purpose. This paper reports our work on electroless plating of Ni-P on Mg alloys. Pure Mg, AZ31 and AZ91 Mg alloys were used as the substrates to investigate friction and adhesion properties of the electroless Ni-P coatings. The maximum friction coefficient (~0.3) was found on the electroless nickel coating of pure Mg substrate. The adhesion strengths of the coatings on AZ31 and AZ91 Mg alloys are higher than that on pure Mg. The critical load (a measure of adhesion strength) of AZ31 reached 13.1 N.
01 Jan 2006
TL;DR: In this paper, the authors discuss plating in terms of 30 min and 62 ° C, and show that plating can be done in 30 min, and 60 ° C.
Abstract: 电；电磁的防护木头金属合成被使用无电的镍 plating 准备。答案的效果总计， plating 时间；表面抵抗力上的 plating 温度；电磁的防护有效性被调查。并且 P 满足，微观结构；在不同温度获得的层的表面特征被精力分散分光计(版本) 分析， X 光检查衍射(XRD ) ；扫描电子显微镜学(SEM ) 。结果出现了那有更高的电镀物品传导性的层；电磁的防护有效性在 plating 答案是 500 mL 的最适条件下面被获得， plating 时间是 30 min；plating 温度是 62 ° C。P 内容与 plating 温度在小程度逐渐地增加了的版本分析显示出的结果增加了。它被 XRD 显示出；在不同温度的层 plated 都是微晶质的结构的 SEM 分析；制服；连续，它有显著金属光泽。那些显示 plating 温度几乎没在微观结构上有小影响；在 pH 下面的表面特征不变。
17 Nov 2006
TL;DR: Ozonated water treatment was studied as a replacement for conventional chromic acid etching of plating on ASA Resin in this paper, which achieved favorable adhesion without roughening the plastic's surface.
Abstract: In view of environmental concerns, ozonated water treatment was studied as a replacement for conventional chromic acid etching of plating on ASA Resin. Ozonated water treatment achieves favorable adhesion without roughening the plastic's surface. Chemical analysis and cross-sectional observations show the formation of polar groups on the surface of the treated resin. Catalytic palladium particles are dispersed and adsorbed into the treated resin surface layer after the catalyzing step. Nickel ions penetrate and scatter into the treated resin layer during electroless nickel plating. These observations prove that favorable adhesion can be attributed to the formation of a nanoscale reformed layer, which is completely different from the conventional anchor effect produced using chromic acid etching.
Patent•
04 Jan 2006
TL;DR: In this article, the authors propose a manufacturing method of a conductive fine particle that is simple and efficient, and can adjust the size of the projection of the conductive particle easily.
Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive fine particle that is simple and efficient, and can adjust the size of the projection of the conductive fine particle easily. SOLUTION: The manufacturing method of a conductive fine particle comprises a step of catalyst carrying process for carrying a catalyst onto the surface of a particle to be plated; and an electroless nickel plating process for performing plating treatment to the particle to be plated by one initial make-up of plating bath without adding any nickel salt or reducing agents at 25-75°C, in an acid plating liquid containing a nickel salt of 0.017-2.56 mol and an equivalent weight of 0.34-3.4 mol of the reducing agent per 1 litter plating liquid to an area to be plated of 2.5-30 m 2 /L of the particle to be plated. COPYRIGHT: (C)2007,JPO&INPIT
Journal Article•
TL;DR: In this article, an electroless plating of Ni-P alloy on poplar veneer was analyzed with SEM, EDS and XRD, and it was shown that the plating layer had micro-crystalline structure in which the content of P was very low and the main element was nickel by EDS analysis.
Abstract: Electromagnetic shielding wood-metal composite was prepared by electroless plating of Ni-P alloy on poplar veneer.The structure of nickel plating layer and the content of P in it were analyzed with SEM,EDS and XRD.The electromagnetic shielding and electric properties of electroless nickel plated poplar veneer were investigated.SEM photographs showed that the surface of the veneer was covered with a layer of continuous and uniform Ni-P alloy entirely,which made the poplar veneer more like metal.It was shown by XRD analysis that the plating layer had microcrystalline structure in which the content of P was very low and the main element was nickel by EDS analysis.The surface resistance of electroless plated poplar veneer was very low.However,the electromagnetic shielding effectiveness was high and close to 60 dB at frequencies from 9 KHz to 1.5 GHz.
Patent•
26 Sep 2006
TL;DR: In this article, an electroless nickel plating solution by which an under barrier metal for a metal bump or a solder bump can be formed by electroless Nickel plating with an uniform thickness on a silicon wafer composed of a multitude of IC chips is presented.
Abstract: Provided is an electroless nickel plating solution by which an under barrier metal for a metal bump or a solder bump can be formed by electroless nickel plating with an uniform thickness on a silicon wafer composed of a multitude of IC chips The electroless nickel plating solution containing an aqueous nickel salt, a reducing agent, a complexing agent and a pH buffering agent includes lead ions of 001-1ppm, cobalt ions of 001-1ppm and a sulfur compound of 001-1ppm
TL;DR: In this article, a decrease in nickel plating rate and an increase in P amount incorporated into the coatings have been found to be proportional to the increase in stability of Ni2+ ions complexes with organic acids ions.
Abstract: Electroless nickel plating in solutions containing acetate, lactate, citrate and glycine as ligand has been studied at pH 4·5. A decrease in nickel plating rate and an increase in P amount incorporated into the coatings have been found to be proportional to the increase in stability of Ni2+ ions complexes with organic acids ions. 0·2 mM CuSO4 sufficiently stabilises all the studied electroless plating solutions and increases the nickel plating rate. The presence of dicarboxylic acid (malonic, succinic or adipic) along with Cu2+ in the plating solution increases the NiP plating rate, hypophosphite utilisation efficiency and decreases coatings roughness, they become brighter and smoother. These effects are more pronounced if dicarboxylic acid of higher molecular weight is used as an additive.
TL;DR: A polystyrene seed with a narrow size distribution was synthesized by the dispersion polymerization method first, then uniformly swollen up and crosslinked with divinylbenzene (DVB) utilizing the dynamic swelling polymerization technique as discussed by the authors.
Abstract: A polystyrene seed with a narrow size distribution was synthesized by the dispersion polymerization method first, then uniformly “swollen up” and cross-linked with divinylbenzene (DVB) utilizing the dynamic swelling polymerization technique. The surface of hollow poly(styrene-co-DVB) particles was coated with nickel by the electroless plating method. The density of the synthesized “core–shell”-type conductive particle was 3.06 g/cm3, significantly lower than the density of pure metallurgical nickel of 8.91 g/cm3. Hence, the sedimentation problem, which often occurs in the blend of high-density metal fillers with a relatively low density polymer matrix, could be overcome as the metal fillers were replaced by the synthesized core–shell-type conductive particles.
TL;DR: In this article, the electrochemical reaction mechanism is used to develop a mathematical model for an electroless nickel plating process of plated-through-hole board, which is calibrated against experimental data and the result is in good agreement with measured data.
Abstract: In this paper, the electrochemical reaction mechanism is used to develop a mathematical model for an electroless nickel plating process of plated-through-hole board. The model is calibrated against experimental data and the result, which is in good agreement with measured data, applied for state estimation of the unobservable processes. The electrical, chemical, and board parameters are estimated from measurements that are standard in the nickel plating industry.
Patent•
13 Apr 2006
TL;DR: In this article, the authors proposed a pretreatment liquid for electroless nickel plating consisting of a heterocyclic compound containing sulfur atoms in the molecule and an organic solvent, where the concentration is 0.0005 to 3 g/L.
Abstract: PROBLEM TO BE SOLVED: To provide a pretreatment liquid for electroless nickel plating where the generation of the abnormal precipitation of electroless nickel plating is reduced to a sufficient level. SOLUTION: The pretreatment liquid for electroless nickel plating comprises a heterocyclic compound containing sulfur atoms in the molecule and an organic solvent. In the heterocyclic compound, the concentration is 0.0005 to 3 g/L based on the total volume of the pretreatment liquid for electroless nickel plating, and, provided that the concentration of the heterocyclic compound is defined as M A (g/L), the concentration of the organic solvent is 5×M A to 5,000×M A mL/L based on the total volume of the pretreatment liquid for electroless nickel plating. COPYRIGHT: (C)2007,JPO&INPIT
TL;DR: In this article, the effects of electroless nickel plating of a hydrogen-absorbing alloy on the cycle characteristics of a nickel-metal hydride battery were investigated, and it was shown that the plating provided better electrochemical characteristics when its surface was partly and tightly covered by nickel particles under optimal electroless plating conditions.
Abstract: The effects of electroless nickel plating of a hydrogen-absorbing alloy on the cycle characteristics of a nickel-metal hydride battery were investigated. The cycle life was improved by employing an electroless nickel-plated hydrogen-absorbing alloy for the negative electrode, which retained the same high-rate level and low-temperature characteristics compared to a cell using a non-plated hydrogen-absorbing alloy. The electroless nickel-plated hydrogen-absorbing alloy provided better electrochemical characteristics when its surface was partly and tightly covered by nickel particles under optimal electroless plating conditions.
TL;DR: In this paper, the initial deposition mechanism of electroless nickel plating on AZ91D magnesium alloy was investigated by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX).
Patent•
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13 Mar 2006
TL;DR: In this paper, the authors proposed a plated base material which has a base material and a multi-layer film formed thereon, characterized in that the multi layer film comprises an electroless nickel plating film as an under layer, a substitution type of electroless palladium plating material having a thickness of not less than 0.2 nm and less than 10 nm or a weight of not more than 12.160 μg/cm2 as an intermediate film, and electroless gold plating films as an upper layer.
Abstract: Provide is a base material having an electroless plating film which is excellent in the corrosion resistance of a base metal and can improve the joinability by soldering, and further is advantageous over a conventional plating film from the view point of the production cost. A plated base material which has a base material and a multi-layer film formed thereon, characterized in that the multi-layer film comprises an electroless nickel plating film as an under layer, a substitution type of electroless palladium plating film having a thickness of not less than 0.2 nm and less than 10 nm or a weight of not less than 0.2432 μg/cm2 and less than 12.160 μg/cm2 as an intermediate film, and an electroless gold plating film as an upper layer.
TL;DR: In this article, the size-dependent electroless plating method was used to fabricate a new type of probe with a locally decreasing thickness of metal and a tiny tip size for a combined high-resolution shear-force and near-field optical microscope.
Abstract: This paper describes a size-dependent electroless plating method to fabricate a new type of probe with a locally decreasing thickness of metal and a tiny tip size for a combined high resolution shear-force and near-field optical microscope. In this method, the tip size and decreasing thickness profile, which affect the resolution capabilities of the microscopes, are controlled by adding a continuous ultrasonic wave with a frequency of 1 MHz to a nickel plating bath. The probe with a tip radius of curvature of 25 nm was successfully fabricated at an ultrasonic power density of 1.6 W cm−2, its metal thickness gradually decreased from 850 to 20 nm toward the distal tip.