电镀镍磷合金技术

镀液稳定可保持长期使用，大大提高了电镀原材料的利用率。与化学镀镍磷合金(常称化学镀镍)相比较，此项工艺的原材料成本仅为前者的1/4，生产成本不到前者的1／2。镀层沉积速度快，最高可达50μm/h，较化学镀镍快数倍。可稳定地获得高磷(10～11％)高耐蚀镍磷合金，也可获得中磷或低磷镍磷合金。镀层外观光亮．     

化学镀镍磷合金沉积速度的研究

较系统地研究了镀液温度、ｐＨ值、缓冲剂及稳定剂等因素对化学镀Ｎｉ－Ｐ合金沉积速度的影响规律,并给出了满意的实验结果。     

电刷镀镍磷合金研究现状及展望

指出了镍镍合金电刷镀是电刷镀技术的发展和提高,其镀层性能优异,硬度高,并具有良好耐磨减率及防腐耐蚀性能,研究开发了低磷、中磷及高磷镍合金工艺,并对国内该项技术现状及发展方向进行了概述。     

磷含量及热处理对化学镀镍磷合金耐蚀性能的影响

研究了磷含量及热处理对化学镀镍磷合金腐蚀行为的影响,结果表明:磷含量对镀层耐蚀性影响很大,磷含量增加,镀层钝化膜形成速率加快,耐蚀性能提高;当磷含量超过8.5％,镀层为非晶态结构,耐蚀性能优异。热处理直接影响了镀层的耐蚀性能,200℃热处理1h,可改善镀层耐蚀性能,温度超过300℃,镀层组织结构发生改变,耐蚀性能降低。     

影响化学镀镍磷合金沉积速度的几个问题

化学镀镍磷合金是近年来兴起的一种表面处理技术 ,由于其良好的物理性能和耐腐蚀性能 ,越来越受到人们的重视 ,在石油和化工方面的应用越来越广泛。由于其对反应条件要求较为苛刻 ,故在组织现场施镀时 ,其沉积速度往往达不到所希望的结果。我们根据多年来从事这方面的研究及实际生产应用中所掌握的数据 ,总结出在酸性条件下影响化学镀镍磷合金沉积速度的几个问题。1　工件的前处理对沉积速度的影响化学镀镍磷合金对工件表面的处理情况要求较高 ,工件上所带的油污 ,必须彻底清除 ,否则在施镀时 ,会严重影响沉积速度 ,同时 ,在处理完油污后 ,…     

黄铜化学镀镍磷合金的工艺与性能

研究了黄铜化学镀镍磷合金的工艺。对镀层的成分、结构、结合力和耐腐蚀性进行了分析研究。实验表明:采用酸性镀液施镀,可得到结合力强,磷含量大于12％,非晶态结构的Ni-P合金镀层;并具有优异的耐蚀性。     

高磷高速化学镀Ni—P合金工艺的研究

通过试验确定高速（１８－３０μｍ／ｈ）、高磷质量分数（１０－１３．５％）化学镀Ｎｉ－Ｐ镀液配方及工艺条件,镀液稳定、镀层性能优良。     

ZL104合金表面化学镀镍磷合金层的研究

在ＺＬ１０４合金表面上进行Ｎｉ－Ｐ与Ｎｉ－Ｃｕ－Ｐ化学镀,以提高ＺＬ１０４合金材料的耐蚀性与耐磨性。结果表明：化学镀可以显著提高ＺＬ１０４合金表面的硬度,并改善其在５％ＮａＣｌ溶液中的耐蚀性;在２００～５２０℃温度下热处理后,镀层的硬度显著提高,但耐蚀性略有降低,这可能与镀层中的析出物Ｎｉ３Ｐ析出有关。     

氧化铝含量对Ni-P化学复合镀层摩擦学性能的影响

采用化学镀技术制备了不同氧化铝含量的Ni-P复合镀层,并用球盘式磨损试验机测试了镀层的摩擦磨损性能。利用扫描电镜、光学显微镜和X射线衍射仪对镀层和对偶球的表面形貌、成分及微观结构进行了表征,分析了镀层的磨损机理。结果表明：镀层中氧化铝质量分数最高可达34.7%,但镀层磷含量显著降低,Ni-P合金基体为无定形结构;镀层的摩擦因数(约为0.49～0.58)高于Ni-P合金,且随着氧化铝含量的增加先降低后增加,镀层的维氏硬度从502上升至764,磨损率从1.2×10_-14 m₃/(Nm)单调下降至3.2×10_-15 m₃/(Nm),镀层的主要磨损机理由粘着磨损逐步转变为磨粒磨损。     

A new method for electroless Ni-P plating on AZ31 magnesium alloy

Coating Ni-P films on AZ31 magnesium alloys via electroless plating and organic coatings (organsilicon heat-resisting varnish), was studied. An organic coating was proposed as the interlayer between Ni-P coating and AZ31magnesium alloy substrate, to replace the traditional chromium oxide plus HF pretreatment. The Ni-P deposited on the interlayer was also characterized by its structure, morphology and corrosion-resistance. The interlayer on the substrate not only reduces the corrosion of magnesium during Ni-P plating process, but also reduces the potential difference between the matrix and the second phase. The result of the cross-cut test indicates the adhesion between the substrate and the interlayer is good enough. A Ni-P film with fine and dense structure was obtained on the AZ31 magnesium alloy. The electrochemical measurements show that the sample with Ni-P film exhibits lower corrosion current density and more positive corrosion potential than the substrate. Furthermore, the Ni-P coating on the AZ31 magnesium alloy exhibits high corrosion resistance in the rapid corrosion test illustrated in this paper. The method proposed in this work is environmentally friendly: no fluoride or hexacalent chromium compounds are used. In addition, it provides a new concept for plating the metals, which are considered difficult to plate due to high reactivity.     

A study on the electroless Ni-P deposition on WE43 magnesium alloy

In this paper an attempt has been made to understand the mechanism of the deposition process of an electroless Ni-P (EN) coating on WE43 magnesium alloy. Also a number of properties concerning the deposited coatings have been reviewed. The results show that the starting microstructure of the alloy consists of a primary α phase together with some eutectic β phase at triple points and along with some grain boundaries. Microstructural studies reveal an uneven distribution of alloying elements in the phases and they are predominantly segregated to the eutectic β phase. This phenomenon can result in galvanic coupling between eutectic β and primary α phases. Detailed studies prove that the replacement reaction takes place at the early stages of coating, and is followed by the autocatalytic reaction at the next stages of deposition.The X-ray diffraction patterns of primitive coatings show a broad peak around 2θ of 45°, which is an indication of an amorphous or an extremely fine crystalline structure. Annealing at 400 °C for an hour led the nature of deposits to be changed to crystalline phases of Ni, Ni₃P, and NiP₃. Microhardness values of coatings are considerably higher than those of the bare substrate. These further increase when they are annealed at 400 °C for 1 h. Electrochemical polarization curves and calculated corrosion values reveal higher corrosion potential (E_corr) for the coating than for the bare substrate. This decreases again when the coating is annealed at 400 °C for 1 h.     

Direct electroless Ni-P plating on AZ91D magnesium alloy

An electroless Ni-P plating treatment was applied on AZ91D magnesium alloy to improve its corrosion resistance. Optimum pretreatment conditions and optimum bath of electroless nickel plating for magnesium alloy were found through many experiments. In order to avoid bother of pre-plating medium layer, a set of procedure of direct electroless Ni-P under the acid condition was investigated. The properties of the coating with 10% phosphorus were investigated. The results show that a coating with high hardness, low porosity and good adhesive strength is obtained. X-ray diffraction patterns show that the structure of the coating is an amorphous phase. After annealing at 400 ℃, the amorphous phase of Ni-P is transformed to crystalline phases, and some intermetallics as Ni3P and Ni5P2 are deposited from Ni -P solid solution along with an enhancing hardness from Hv 450 to Hv 910.     

Improved microhardness and wear resistance of the as-deposited electroless Ni-P coating

The coatings with different phosphorus contents were obtained by varying the ratio of lactic acid to acetic acid in the electroless plating bath. With the increase of phosphorus content, the structure of the electroless Ni-P coating transformed from nanocrystalline to a mixture of nanocrystalline and amorphous phases, then to amorphous phase. A record high hardness value of 910 HV_0.1 of as-deposited Ni-P coating was obtained at 7.97 at.% phosphorus content, and high wear resistance was accordingly achieved. The refined nanocrystalline grains with an average size of ~ 4 nm were found to be responsible for the record high hardness and improved wear resistance of the as-deposited Ni-P coating.     

镍磷合金镀层防变色性能初探

采用正交试验和条件试验，筛选出了一种以植酸、苯甲酸钠、钼酸钠和EDTA为基本组成的镍磷合金抗蚀防变色剂。通过孔隙率测定、18％～20％盐酸点滴实验、10％氯化钠浸泡实验和阳极极化曲线测试等实验，对镍磷合金层的抗腐蚀性能进行了研究。     

镁合金表面化学镀Ni-P合金研究

镁是一种极活泼的金属,其合金具有优异的性能,是得到广泛应用的重要原因.然而,镁合金在各介质中的不耐蚀,其应用受到了制约.据文献报道,已有多种方法被应用到镁合金上,但效果都不很理想;而化学镀镍技术是近年来发展较快的一种表面处理方法.进一步探讨了在AZ91D表面上进行化学镀镍的研究过程:通过多次试验确定了镁合金的前处理方案,研究了在酸性条件下镁合金表面直接化学镀镍的一套工艺路线,配置简单,操作方便,避免了预镀中间层的麻烦.并且测定了镀层的厚度、显微硬度,观察了镀态的金相组织;热震实验和划痕实验的结果表明镀层与衬底具有良好的结合力.     

硅烷膜在化学镀镍磷合金镀层上的封闭性能研究

化学镀镍磷合金镀层在形成过程中不可避免地存在着微孔,由于以碳钢为基体的化学镀镍磷合金镀层在大多数腐蚀介质中都属阴极性镀层,微孔的存在将会导致基体的孔蚀.采用表面硅烷化方法对镍磷合金镀层进行了封闭处理,结果表明:镍磷合金镀层表面硅烷化后可以大幅提高镍磷合金镀层的抗腐蚀性能.