镁合金Ni-P镀技术研究

铜介绍了镁合金表面镀Ni-P的研究现状及发展趋势,镁合金表面采用Ni-P镀是一种很有应用前景的表面处理工艺。

涤纶织物纳米碳化锆复合镀Ni-P镀层

采用化学复合镀技术,实现了涤纶织物纳米碳化锆酸性、碱性复合镀Ni-P。借助扫描电镜、X射线能谱仪、X射线衍射仪和热重分析仪对镀层表面形貌、成分、结构以及织物热性能进行了研究,并测试了化学镀织物的电磁波屏蔽效能和耐磨性能。结果表明:酸性化学镀Ni-P为无定形态,加入吐温80后向结晶态转变,为典型的纳米晶结构,加入纳米碳化锆后无定形态有所增强;碱性化学镀Ni-P为纳米晶结构,加入吐温80后衍射峰强度明显减弱,加入纳米碳化锆后衍射峰强度又有所增强。涤纶织物经过酸性、碱性化学镀Ni-P和纳米碳化锆复合镀Ni-P后,热起始分解温度都有所降低。随着纳米碳化锆的质量浓度的增加,酸性和碱性复合镀Ni-P织物的电磁波屏蔽效能逐渐减小。较普通化学镀Ni-P织物,酸性纳米碳化锆复合镀Ni-P织物的耐磨性变差,而碱性纳米碳化锆复合镀Ni-P织物的耐磨性变好。

基于冷换设备的Ni-P化学镀应用研究

以冷换设备为基体,采用低温液相化学镀法制备了耐腐蚀N i-P合金镀层,处理后的镀层为典型的非晶态结构,具有良好的耐蚀性,能够满足碳钢材料冷换设备表面防腐的要求,并制定了制备冷换设备用镀层的工艺方法。

化学镀Ni-P合金镀液稳定剂研究

通过不同稳定剂对酸性化学镀液稳定性、镀速以及使用周期影响情况的试验考查,发现用量为4-5 mg/L的复合型稳定剂稳定效果优于单一稳定剂;在同样施镀条件下,添加复合稳定剂后使用周期由原来的4-5个周期提高到8-9个周期。

Ni-P/Ag纳米复合化学镀层的耐磨损性能

Ni-P/非金属纳米化学镀溶液中纳米粒子容易团聚,镀液难以保持稳定性。在化学镀Ni-P溶液中添加纳米银粒子,在钢铁基体上制备了Ni-P/Ag纳米复合镀层。用显微硬度计、金相显微镜等技术分析了镀层的厚度、硬度和表面形貌,用磨损试验机研究了镀层的耐磨损性能。结果表明:银纳米粒子在镀液中的含量为1.0×10-7mol/L,银纳米粒子加快了镀层的沉积速度,使纳米复合镀层厚度增加;在相同的施镀条件下,Ni-P/Ag纳米复合镀层比Ni-P镀层具有更高的硬度和更好的耐磨损性能。

Ni-P电刷镀在拉深不锈钢材料模具上的应用

针对拉深不锈钢材料时影响模具使用的主要问题——粘着磨损问题,利用扫描电镜、硬度计、磨损实验机、X-射线衍射仪、能谱仪、光学显微镜等设备,通过考察NiSO4.6H2O、NaH2PO2.H2O、EDTA-2Na、C6H8O7.H2O、C3H6O3加入量对施镀后的镀层含P量、厚度、硬度、耐磨性、结合力、物相、形貌、能谱等的影响,获得了一种电刷镀优化配方,用其施镀可获得P含量(质量分数)为2%左右Ni-P镀层,该镀层经400℃左右的热处理后,与模具基材Cr12MoV有着良好的结合力,自身亦具有较高的硬度和良好的耐磨性.使用该配方和方法获得的镀层经生产验证,可以有效地解决模具的粘着磨损问题.

Ni-P/Al_2O_3化学复合镀工艺研究

采用正交设计法对Ni P/Al2 O3 化学复合镀工艺进行了优化。研究了镀液成分、工艺参数对复合镀层厚度、显微硬度、耐蚀性、耐磨性的影响。结果表明 ,Ni P/Al2 O3 化学复合镀层的显微硬度、耐磨性优于Ni P化学镀层的 ,弥散分布的Al2 O3 颗粒能显著减缓复合镀层在较高温度下的软化趋势。

铝合金化学镀Ni-P合金的研究进展

本文分析了铝合金化学镀的特点,综述了铝合金化学镀Ni-P合金、Ni-W-P等三元合金、Ni-P/Ni-B双层复合镀及Ni-P-微粒化学复合镀的工艺流程及应用。

表面活性剂对复合镀(Ni-P)-MoS_2中MoS_2颗粒分散性的影响

选取阳离子表面活性剂十六烷基三甲基溴化铵、全氟辛基季铵碘化物、非离子表面活性剂聚乙二醇以及阴离子表面活性剂全氟辛酸磺酸钾。研究了不同类型的表面活性剂的复配对化学复合镀(Ni-P)-MoS2中MoS2分散性的影响。结果表明,阳离子与非离子表面活性剂之间的协同作用,有利于MoS2纳米颗粒的分散,可以提高(Ni-P)-MoS2复合镀层的质量。

(Ni-P)-纳米TiO_2化学复合镀配位剂的研究

以沉积速率、复合镀液稳定性、复合镀层的孔隙率、硬度和纳米TiO_2在镀液中的分散性为评价指标,研究了柠檬酸、乳酸及氨基乙酸三种配位剂对镀液和镀层性能的影响。结果表明,柠檬酸单独做配位剂时,复合镀液稳定性好、复合镀层孔隙率较低;乳酸单独做配位剂时,复合镀层硬度较高;在(Ni-P)-纳米TiO_2溶液中加入15 g/L柠檬酸和25 mL/L乳酸时,兼顾了柠檬酸和乳酸在溶液中单独做配位剂时镀层的耐蚀性和硬度,复合镀层硬度达到568.98 HV,孔隙率仅为0.52个/cm^2;而通过各项指标的考察,氨基乙酸不适合做配位剂。

联轴节端盖Ni-P化学镀镀层再制造工艺研究

端盖是高速动车组用联轴节的构成零件之一,每年因镀层磨损而大量失效,运用再制造技术对失效端盖进行修复很有意义。综合运用化学退镀、内圆面珩磨和Ni-P化学复合镀等工艺对端盖进行了再制造,并对端盖再制造Ni-P化学复合镀镀层进行扫描电子显微镜、能谱分析、显微维氏硬度、结合强度和耐磨性检测表征。结果表明:相对于端盖原件,端盖再制造Ni-P化学复合镀镀层的组织致密、厚度均匀,显微维氏硬度高,结合强度高,具有良好的耐磨性。运用该工艺成功对失效端盖进行了再制造,使其恢复了原有的性能,满足了使用要求。

Electroless Ni-P plating on Mg-Li alloy by two-step method

Pretreated Mg-Li alloy sheets were pre-plated in a NiCO3？2Ni（OH）2？4H2O solution to form a thin Ni-P alloy film and then plating in a NiSO4？6H2O solution was carried out to obtain a protective coating.The surface morphology,structure and corrosion resistance of the coating were studied.The results showed that a flat,bright and compact plating layer,which was integrated into the matrix metal,was obtained.The P content of the Ni-P coating reached 13.56%（mass fraction）.The hardness value of the Ni-P coating was about HV 549.The polarization curve showed that the corrosion potential of the Ni-P coating reached ？0.249 V（vs SCE）.A long passivation region was found on the polarization curve,and this phenomenon indicated that the coating has an excellent anti-corrosion property.

Preparation and tribological performances of Ni-P-multi-walled carbon nanotubes composite coatings

Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/（N.m）, respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process.

Effect of wear conditions on tribological properties of electrolessly-deposited Ni-P-Gr-SiC hybrid composite coating

The friction and wear properties of the electrolessly-deposited Ni-P-Gr-SiC composites were investigated. The effects of graphite content, load and rotation speed on the friction coefficient and wear resistance of the composite coatings were mainly investigated. The worn surface and cross section of the coatings were characterized by scanning electron microscopy and energy-dispersive X-ray analysis. The results show that the composite coatings reveal good antifriction and wear resistance due to the synergic effect of graphite and SiC particles. The formation of graphite-rich mechanically mixed layer （GRMML） on the surface of Ni-P-Gr-SiC coating contributes to the good tribological behavior of the wear counterparts and SiC particles play a load bearing role in protecting GRMML from shearing easily.

Effect of novel ternary ligand system on acidic electroless Ni-P plating on AZ91D magnesium alloy

The electroless Ni-P coatings on AZ91 D magnesium alloy substrate were prepared using the acidic hypophosphite-reduced electroless nickel bath containing the novel ternary ligand system. The results indicate that the deposition rate varies with the ternary ligand concentration in plating solution. The structural and morphological characteristics of the coatings were analyzed by XRD and SEM. The anticorrosion properties of the Ni-P coatings were evaluated in 3.5% NaCl solution by electrochemical impedance and potentiodynamic polarization methods. The amount of ternary ligands in electroless plating bath has an significant effect on the surface morphology and structure of Ni-P coatings. The decrease of crystallization temperature and increase of crystallization heat of all the deposits with an increase in ternary ligand concentration are found by DSC measurements. The coating obtained with 0.035 mol/L ternary ligand additive in plating bath can offer a better surface homogeneity and improve corrosion resistance.

An in situ measure method to study deposition mechanism of electroless Ni-P plating on AZ31 magnesium alloy

An in situ method was designed to measure a continuous open circuit potential （OCP） curve of AZ31 magnesium alloy and to observe the morphology variation of Ni-P coating during the process of the electroless plating. The deposition mechanism of the electroless Ni-P plating on AZ31 Mg alloy was studied by OCP curve, scanning electron microscopy （SEM）, and energy dispersion spectroscopy （EDS）. The process of electroless Ni-P plating contains the coating formation stage and the coating growth stage. The formation stage includes three procedures, i.e., the nucleation and growth of Ni crystallites, the extension of the coating in two-dimensional （2D） direction and the coalescence of the coating along three-dimensional （3D） direction. SEM investigations demonstrate that the spherical nodules of the Ni-P coating are not only formed during the coating growth stage, but also generated in the initial deposition stage of electroless Ni-P plating. The variation of the coating rates at different deposition stages corresponds to the deposition mechanism of their respective deposition stage.

Microstructure and depositional mechanism of Ni-P coatings with nano-ceria particles by pulse electrodeposition

Nano-CeO2 （RE） particles were co-deposited into Ni-P binary composite coatings by applying pulse current （PC） under ultrasonic （U） field. Morphology, chemical content and crystal microstructure were characterized by environmental scanning electron microscopy （E-SEM） with energy dispersive X-ray analysis （EDXA）, XRD diffractometry and transmission electron microscopy （TEM）. Experimental results show that Ni-P coating reinforced with 15g/L nano-CeO2, in amorphous state and with compact structure, can be improved in the microhardness from HV0.2580 to HV0.2780 by annealing at 600 °C for 2 h. The highest content of codeposited Ce and deposition rate can reach 2.3% and 68 μm/h, respectively. Furthermore, the effect of RE adsorption and pulse overpotential on depositional mechanism was investigated. n-CeO2 particles or Ce4＋ ions with strong adsorption capacity acted as the catalytic nucleus to improve densification effectively. During annealing at 600 °C for 2 h, n-CeO2 particles will uniformly adsorb on crystal grain to preferentially pad and heal up gaps of cracking Ni boundaries, promoting dispersion strengthening with refiner-grained structure.

Characteristics of microstructure and performance of laser-treated electroless Ni-P/Ni-W-P duplex coatings

Characteristics of microstructures of electroless Ni-P/Ni-W-P duplex coatings were investigated using SEM/EDX and XRD analysis techniques. Microhardness and wear behaviour of the coatings before and after laser crystallization were evaluated by measurements of hardnesses of coating surface and cross-section, and by unlubricated friction and wear experiments. The results indicate that it is possible to prepare electroless Ni-P/Ni-W-P duplex coatings by sequential immersion in two different plating baths. After laser crystallization, the microstructures of electroless Ni-P/Ni-W-P duplex coatings present the characteristics of higher degree of crystallization and larger grain size for outer layer Ni-W-P than inner Ni-P, but outer layer has a higher hardness. The wear resistance of laser-treated duplex coatings in a given process parameter conditions is superior to the as-plated ones. Laser treatment was performed directly in air without argon protection, which provides the possibility for application of industrialized production.

钕铁硼磁性材料表面耐蚀镀层

介绍了Ｎｄ－Ｆｅ－Ｂ磁性材料表面镀Ｎｉ－Ｐ（电镀和化学镀）、镀Ｎｉ－Ｆｅ（脉冲镀和电镀）、镀铬（六价铬和三价铬镀液电镀）的主要工艺条件和镀层的特点。

Electroless plating and growth kinetics of Ni-P alloy film on SiC_p/Al composite with high SiC volume fraction

After Sn/Pd activating, the SiCp/Al composite with 65% SiC (volume fraction) was coated by electroless Ni?P alloy plating. Surface morphology of the composite and its effect on the Ni?P alloy depositing process and bonding action of Ni and P atoms in the Ni?P alloy were studied. The results show that inhomogeneous distribution of the Sn/Pd activating points results in preferential deposition of the Ni?P alloy particles on the Al alloy and rough SiC particle surfaces and in the etched caves. The Ni?P alloy film has an amorphous structure where chemical bonding between Ni and P atoms exists. After a continuous Ni?P alloy film formed, electroless Ni?P alloy plating is not affected by surface morphology and characteristics of the SiCp/Al composite any longer, but by the electroless plating process itself. The Ni?P alloy film follows linear growth kinetics with an activation energy of 68.44 kJ/mol.