Preparation of electromagnetic shielding wood-metal composite by electroless nickel plating

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 （XRI）） 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℃. 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.

Copper-Ti_3SiC_2 composite powder prepared by electroless plating under ultrasonic environment

In this article, a new type of Cu-Ti3SiC2 composite powder prepared using the electroless plating technique was introduced. The initial Ti3SiC2 particles are 11 μm in diameter on an average. The Cu plating was carried out at middle temperature （62-65℃） with the application of ultrasonic agitation. The copper deposition rate was determined by measuring the weight gain of the powder after plating. It has been found that the pretreatment of Ti3SiC2 powder is very important to obtain copper nanoparticles on the surface of Ti3SiC2 The optimum procedure before plating aimed to add activated sites and the adjustment of the traditional composition of the electroless copper plating bath could decelerate the copper deposition rate to 0.8 gm/h. X-ray diffraction （XRD） indicates that the chemical composition of the plating layer is copper. SEM images show that the surface of the Ti3SiC2 particles is successfully coated with continuous copper layer. The wetting property between the copper matrix and Ti3SiC2 can be improved so as to increase the interfacial strength.

PROCESS AND PROPERTIES OF ELECTROLESS PLATING RE-Ni-B-SiC COMPOSITE COATINGS

Technology and properties of electroless composite RE-Ni-B-SiC coatings have been investigated.Results show that stabilizer plys a decisive role in electroless composite Ni-B-SiC,the addition of appropriate quantity of RE(rare earth) into the Ni-B-SiC bath not only increases SiC content in composite coatings,their hardness and wear resistance but also improves crystalline fineness,Wear resistance increases with the increase of SiC.Hardness and wear resistance of composite coatings reach peak values a fter heat treatment at 4OO and 500℃ for 1h respectively.

Study of Electroless Ni-P-CNTs Composite Plating

无电的 Ni-P-carbon nanotubes 合成 plating 在铜底层上被学习。冶金显微镜，扫描电子显微镜， X 光检查衍射计和微坚硬测试者被用来学习无电的 Ni-P-carbon nanotubes 的结构，体质和表演合成沉积物。而为合成沉积物的谷物和坚硬的密度增加，经验的结果证明与在无电的 plating 答案的碳 nanotubes 内容的增长，样品表面上的谷物尺寸减少。而且，增加的碳 nanotubes 不仅为合成存款改进结晶化的度而且从非结晶的状态帮助他们的转变到 nanocrystal 状态。

Preparation and thermal treatment of Pd/Ag composite membrane on a porousα-alumina tube by sequential electroless plating technique for H_2 separation

Pd/Ag/α-Al2O3 composite membranes were prepared by sequential electroless plating technique. The prepared membranes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy techniques （ICP-AES）. Effects of annealing time, Ag content, and air treatment on the hydrogen permeation flux and morphology of the alloys were investigated. The results of the investigation showed that the prepared type of tube had a good potential as substrate for membrane preparation. In addition, a uniform defect-free alloy was prepared by annealing at 550 ℃ in H2 atmosphere. The permeation results showed an increase in H2 permeation flux by increasing the Ag content and the annealing time. In addition, the air treatment of the prepared membranes at 400 ℃ for 1 h changed the morphology of the alloy and substantially enhanced the hydrogen flux.

Electroless plating Ni-P matrix composite coating reinforced by carbon nanotubes

Ni-P matrix composite coating reinforced by carbon nanotubes (CNTs) was deposit ed by electroless plating. The most important factors that influence the content of carbon nanotubes in deposits,such as agitation,surfactant and carbon nanot ubes concentration in the plating bath were investigated. The surface morphology,structure and properties of the Ni-P-CNTs coating were examined. It is found that the maximum content of carbon nanotubes in the deposits is independent of carbon nanotubes concentration in the plating bath when it is up to 5 mg/L. The test results show that the carbon nanotubes co-deposited do not change the str ucture of the Ni-P matrix of the composite coating,but greatly increase the ha rdness and wear resistance and decrease the friction coefficient of the Ni-P-C NTs composite coating with increasing content of carbon nanotubes in deposits.

The Studies of Composite Electroless Plating Process on Sintering Ndfeb Permanent Magnet

A reasonable pre-treatment and an ultrasonic pre-plating Cu film were applied for sintering NdFeB permanent magnet. The samples were then plated in neutral bath (PH=7) for 40min and in acidic bath (PH=4.8～5.1) for 2h. A composite electroless plating with different phosphor content was obtained. The results show that the composite plating coatings are dense and have a strong bond with the substrate, which contribute to the excellent corrosion resistance of the plating coating.

ELECTROLESS PLATING COMPOSITE COATINGS OF Ni-Ti-Re ON THE SURFACE OF DIAMOND

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Fabrication of W@Cu Composite Powders by Direct Electroless Plating Using a Dripping Method

A direct electroless copper （Cu） coating on tungsten powders method requiring no surface treatment or stabilizing agent and using glyoxylic acid （C2H203） as a reducing agent was reported. The effects of copper sulfate concentration and the pH of the plating solution on the properties of the prepared W@Cu composite powders were assessed. The content of Cu in the composite powders was controlled by adjusting the concentration of copper sulfate in the electroless plating solution. A uniform, dense, and consistent Cu coating was obtained under the established optimum conditions （flow rate of C2H203 = 5.01 mL/min, solution pH = 12.25 and reaction temperature 45.35℃） by using central composite design method. In addition, the crystalline Cu coating was evenly dispersed within the W@Cu composite powders and Cu element in the coating existed as Cu~. The formation mechanism for the W@Cu composite powders by electroless plating in the absence of surface treatment and stabilizing agent was also proposed.

Electroless nickel plated graphite fibers and surface behavior in G_(r(Ni))/6061Al composite

The electroless nickel plated graphite fibers reinforced aluminum matrix composites (Gr(Ni))/Al) were produced by squeeze casting, and the microstructure of Gr(Ni)/Al composite and surface behavior of Ni-P coating were studied. The optimum process of electroless Ni-P plating included: burning to get rid of glue→degreasing→neutralization→acidulating→sensitizing→activation→electroless plating. The surface analysis results show that the electroless nickel plating can diffuse into the graphite fiber surface during the squeeze casting, and the Ni-P coating and aluminum alloys can produce brittle phase NiAl3 or NiAl. The X-ray diffraction(XRD) results indicate that Al4C3 is so little that no Al4C3 peaks are found, and the harmful Al4C3 can be decreased by the electroless plating Ni-P coating. The coating improves the interfacial bonding of continuous graphite fibers reinforced aluminum matrix composites.

Preparation and Tribological Properties of Ni-P Electroless Composite Coating Containing Potassium Titanate Whisker

镍磷(捏)合成涂层包含 potassiumtitanate (K_2Ti_6O_( 13 ))络腮胡子( PTW )被涂层的无电的 plating.The 表面形态学 andcomponent 准备被扫描电子显微镜学( SEM )和精力dispersiveX光线光谱学( EDX )调查，分别地在前后用 pin-on-disk 穿 test.The tribological 表演 wasevaluated 在干燥 conditions.It 下面穿测试者被发现 Ni-P-PTWscomposite

Magnetic Properties Hard-Soft SmCo₅-FeNi and SmCo₅-FeCo Composites Prepared by Electroless Coating Technique

Composites of SmCo5-FeNi and SmCo5-FeCo, hard-soft magnetic materials, have been synthesized via electroless plating of magnetically hard SmCo5 powder particles with magnetically soft FeNi and FeCo, respectively. The influence of coating thickness of soft magnetic layers on the structure and magnetic properties of the composite has been studied. Overall FeNi coating was found to be less dense compared to FeCo for the same plating duration. Structurally the coat ing was found to be nodular in morphology. These coating have dramatic effect on the overall magnetic property of the composite. As compared to FeNi coated SmCo5 composite, two-fold increase in the saturation magnetization has been observed upon coating SmCo5 (Ms^28 emu/g) with FeCo to a value 56 emu/g. The coercivity of composite powder was found to decrease with increasing the coating layer thickness. The absence of exchange spring behavior in the hard-soft composite is attributed to magnetically soft layer thickness exceeding the theoretical length limit for exchange-spring coupling.

Ni-P-PTFE复合镀层工艺及摩擦学行为研究

在化学沉积N i-P镀层的工艺基础上,制备N i-P-PTFE复合镀层,利用SEM和XRD分析镀层的表面形貌和组织结构,探讨镀液中活性剂和PTFE含量对复合镀层结合力、硬度、摩擦因数、磨损率以及复合镀层PTFE粒子含量的影响,采用MRH-3摩擦磨损试验机研究复合镀层摩擦学行为,分析复合镀层的磨损机制,确定最佳工艺条件。结果表明在最佳工艺条件下制备的N i-P-PTFE复合镀层具有良好的摩擦学性能,其磨损机制为黏着和轻微磨粒磨损。

化学复合镀Ni-P-PTFE工艺的试验研究

针对泵、阀等部件在高温、高速、高磨蚀条件下对耐磨性和耐腐蚀性的要求,以化学镀Ni-P工艺为基础,对化学复合镀Ni-P-PTFE工艺进行了试验研究,确定了PTFE加入量、表面活性剂类型及其用量与镀层中PTFE质量分数和镀速的关系,以及温度、pH和搅拌方式对复合镀层质量的影响。提出的化学复合镀Ni-P-PTFE的工艺为:十六烷基三甲基溴化铵60 mg/L、壬基酚聚氧乙烯醚5 mL/L、镀液中PTFE粒子质量浓度5 g/L、镀液pH4.8、施镀温度90℃、间歇搅拌。试验结果表明:镀液性能稳定,镀层外观光滑平整,镀层内PTFE粒子分布均匀,镀层中PTFE质量分数为20%,镀层厚度20μm。

化学镀 Ni-P-PTFE 复合镀层沉积工艺研究

对化学镀Ｎｉ－Ｐ－ＰＴＦＥ复合镀层工艺进行了较全面的研究。详细测定和评述了表面活性剂浓度，ＰＴＦＥ浓度与镀层中ＰＴＦＥ粒子含量及镀速的关系，以及基础镀液性质和操作条件对复合镀的影响。提出了一种具有实用价值的化学镀Ｎｉ－Ｐ－ＰＴＦＥ复合镀层工艺技术。镀液稳定，镀层质量优良，镀层中ＰＴＦＥ含量达２５～３０ｖｏｌ％。

Ni-P-PTFE复合化学镀层的摩擦磨损与耐蚀性研究

测量了Ni一P－PTFE复合化学镀层的摩擦系数和磨损性能，并结合扫描电镜观察的方法研究了硬化热处理对镀层摩擦磨损性能的影响。室内外暴露试验、中性盐雾试验以及浸泡腐蚀试验证明该镀层具有优良的耐蚀性。

Ni-P-PTFE化学复合镀的工艺研究

用化学镀的方法制备了Ni-P-PTFE复合镀层。为了确定合适的工艺,研究了Ni-P-PTFE化学复合镀的工艺中温度、pH值、表面活性剂等参数对镀速、镀层中PTFE含量和硬度的影响。试验表明：温度和pH值升高,镀速增大,PTFE含量先升高再降低,硬度下降;FC4表面活性剂的加入量增大,镀速下降、PTFE含量先升高再降低,硬度下降。在此基础上确定了工艺参数,温度85℃,pH值4.4-4.6,PTFE含量8mL/L,FC4表面活性剂的加入量为0.4g/L。

Ni-P-PTFE化学复合镀层的耐磨性能研究

制备了Ni-P-PTFE化学复合镀层,在MM-200型磨损试验机上研究了PTFE加入量、热处理温度和载荷对复合镀层摩擦因数和磨损量的影响。结果表明:镀层摩擦因数在PTFE加入量为8mL/L时最小,同时镀层磨损量在此时也最小;在不同热处理温度下,Ni-P-PTFE复合镀层表现出较好的耐磨性和较小的摩擦因数;当载荷超过98N后,镀层的摩擦因数增大;随着载荷的增大,镀层的磨损量增大。

化学镀梯度Ni-P-PTFE镀层修复磨损液压阀芯工艺

通过化学镀梯度Ni-P-PTFE镀层,修复磨损液压阀阀芯,介绍了修复工艺的流程、条件和配方。通过采用间歇搅拌和梯度镀层,提高了修复层的性能,结果表明修复效果良好,修复件寿命接近新件。