Ni-P-纳米金刚石粉复合电刷镀层的耐磨性研究

研究了纳米金刚石粉对复合电刷镀镀层形成速率、显微硬度和耐磨性的影响;测试了在不同的热处理温度、载荷及金刚石粉含量下复合刷镀层的耐磨性能;分析了复合镀层的磨损机理.结果表明:镀层的磨损体积损失均随热处理温度的升高而下降,并在400℃时达到最小值;载荷增大,磨损体积损失增大;当纳米金刚石加入量为20～30g/L时,镀层的耐磨性最好.复合镀层提高耐磨性的原因在于复合粒子在基体金属表面形成突起,起到了支撑载荷、避免粘着磨损及减小摩擦系数的作用.     

Ni-P/纳米金刚石复合镀层组织和性能的研究

采用化学镀技术在钢基体材料上制备了Ni-P/纳米金刚石复合镀层,研究了纳米金刚石浓度、搅拌速度等工艺参数时复合镀层的微观组织和摩擦系数的影响.结果表明,在镀液中纳米金刚石浓度相同的条件下,不同的搅拌速度对镀层的表面形貌和性能均有较大影响,镀层的摩擦系数当转速达到200 r/min时为最小,再提高搅拌速度摩擦系数反而会升高.在一定的搅拌速度下,镀层的摩擦系数随镀液中纳米金刚石浓度的提高先降低后上升,浓度为10 g/L.时摩擦系数达到最小.     

电镀镍-纳米金刚石复合镀层研究

本文采用电镀的方法获得了镍-纳米金刚石复合镀层，用间接法分析了镀层中纳米金刚石的含量，用TEM对纳米金刚石在镀层中的形态、分布情况及镀层结构进行了分析，并通过优化施镀温度、时间、电流密度及金刚石悬浮量等工艺参数，使镀层的性能获得改变。试验结果表明：镀液温度为60℃，电流密度为2A／dm^2的共沉积条件下，镀层的硬度、耐磨性高，镀层中纳米金刚石的沉积量也较高，纳米金刚石能够均匀分布在镀层中，特别是复合镀层耐磨性的改变具有重要的实际意义。     

铝基Ni-P/纳米金刚石复合镀层组织和性能的研究

在合理选择化学镀Ni-P合金和工艺条件的前提下,采用对比试验研究了搅拌速度和纳米金刚石浓度对镀层微观组织的影响,并检测了镀层的耐磨损性能。结果表明,镀液中纳米金刚石浓度相同条件下,搅拌速度为300 r/min时镀层表面形貌最好;在相同搅拌速度下,纳米金刚石加入量为6 g/L时,镀层微观组织均匀、致密,摩擦系数低并且稳定。     

纳米金刚石/镍电刷镀复合镀层机械性能研究

本文对普通快速镍镀层和纳米金刚石/镍复合镀层的显微硬度和耐磨性进行了研究,分析了纳米颗粒含量、镀层厚度、加热温度等参数对纳米复合镀层显微硬度及摩擦性能的影响。结果表明:由于纳米金刚石的弥散强化作用,使得复合镀层的硬度和耐磨性大幅提高,摩擦系数明显降低。镀液中纳米金刚石含量约30g/L时,镀层硬度最高为650HV,经过300℃处理,硬度仍能保持在480HV之上。     

Ni-Co/纳米金刚石复合镀层抗磨损性能的研究

采用电沉积法在45#钢样品表面制备了含有纳米金刚石的镍-钴合金基复合镀层。对复合镀层的显微硬度和微观结构进行了测试。并考察了阴极电流密度、镀液pH值等主要工艺参数对纳米复合镀层耐磨性的影响。结果表明：纳米金刚石的弥散强化作用，可以有效地提高镀层的硬度。在干摩擦条件下，纳米复合镀层的耐磨性是镍-钴合金镀层的3倍；     

Ni-P-金刚石化学复合镀层耐磨性能研究

在镍磷化学镀的基础上,研究了微米、纳米金刚石化学复合镀工艺。采用正交试验方法,研究化学镀液、金刚石种类与浓度、表面活性剂种类与含量以及热处理温度对镀层耐磨性能的影响。通过超声搅拌,实验成功制备出具有优异耐磨性能的Ni-P-金刚石复合镀层。结果表明：对镀层耐磨性影响明显的因素依次为表面活性剂的种类和含量,金刚石颗粒的含量和种类,而镀液的种类和热处理温度对镀层耐磨性的影响较小。并且,最佳工艺为：添加阴离子表面活性剂,含量为1：15,复合颗粒为金刚石微粉,浓度为10g/L,镀层热处理温度为400℃。     

化学镀纳米金刚石/Ni复合镀层制备及其摩擦学性能

研究了金刚石含量、表面活性剂及热处理温度等工艺因素对Ni-P-纳米金刚石灰粉复合镀层的摩擦磨损性能的影响,并对复合镀层的表面形貌及组织结构进行了分析.结果表明:添加爆轰纳米金刚石灰粉能提高复合镀层的耐磨性能.热处理温度与表面活性剂种类对金刚石灰粉复合镀层耐磨性能的影响最大,复合镀层耐磨性能最佳时的工艺参数为:金刚石灰粉含量为4 g/L,热处理温度为400℃,表面活性剂采用SHP,其含量为1:20.     

Ni-P金刚石化学复合镀层制备及摩擦磨损性能分析

目的研究不同粒径微米金刚石对Ni-P金刚石化学复合镀层摩擦磨损性能的影响。方法选择出一组优良的Ni-P化学镀工艺参数,在镀液中分别加入不同粒径的金刚石微粒,制备含不同粒径微米级金刚石颗粒的化学复合镀层。用SEM和XRD,观察并分析了不同粒径金刚石对热处理前后Ni-P金刚石化学复合镀层微观形貌和组织结构的影响;通过硬度和摩擦磨损实验,研究了不同粒径金刚石颗粒对复合镀层硬度及摩擦磨损性能的影响。结果制备的复合镀层厚度为30μm左右,金刚石质量分数达到21%~25%,且金刚石均匀分散在Ni-P镀层中。热处理前镀层为非晶结构,经过400℃×2 h的热处理后,镀层晶化为硬度更高的Ni3P。金刚石能提高镀层硬度,其中粒径为9μm的复合镀层硬度最高,达到1261HV。Ni-P金刚石复合镀层的摩擦系数为0.4~0.52,随着金刚石粒径的增大,摩擦系数不断减小。金刚石使镀层的磨损机制发生了变化,随着金刚石粒径的增大,硬质合金球的磨损加剧。结论随着金刚石粒径的增大,镀层硬度增加,摩擦系数减小,耐磨性增大。     

纳米金刚石的加入对镁合金Ni-P镀层组织和性能的影响

目的提高镁合金化学镀层的力学性能。方法选择出一组优良镁合金化学镀Ni-P工艺参数,在Ni-P镀液中加入不同的纳米金刚石浓度。通过观察所得镀层的微观组织形貌,对比镀层形貌组织;通过对复合镀层进行热处理,分析镀层组织结构的变化;通过测定金刚石加入前后镀层的摩擦系数,检测了复合镀层的耐磨损性能;通过查看镀层腐蚀斑点数目,检测复合镀层的耐腐蚀性能。结果随着纳米金刚石浓度的增加,复合镀层的形貌越好,当纳米金刚石加入量达到6 g/L时,所得复合镀层的微观形貌均匀、致密。热处理使镀层结构由非晶态变为结晶态,显微硬度明显提高。金刚石的加入致使镀层的摩擦系数降低且稳定,相比化学镀Ni-P镀层,加入金刚石后的复合镀层的腐蚀斑点数较少。结论纳米金刚石的加入大大提高了镀层的力学性能。     

SiC颗粒尺寸对镍基复合镀层耐磨性和耐蚀性的影响

在正交实验基础上,对比研究微米SiC(平均粒径1.5 μm)和纳米SiC(平均粒径20 nm)增强复合镍基镀层的摩擦磨损行为和耐腐蚀性能.通过TEM、SEM、EDX和XRD等手段研究颗粒分散状态以及复合镀层的表面和截面形貌、成分及相结构.采用球-盘滑动摩擦磨损试验机研究复合镀层的耐磨性.电化学阻抗谱测量在3.5%的NaCl水溶液中进行.结果表明:微米级颗粒增强复合镀层可以获得更高的表面硬度,两种增强复合镀层具有相似的摩擦磨损行为.电化学阻抗谱分析表明:SiC颗粒的加入可以提高镀层的耐腐蚀性,且纳米颗粒复合镀层具有更好的耐蚀性.     

镍磷非晶纳米晶复合镀层的制备及其耐蚀性

对电沉积12．3％P（质量分数）镍磷合金进行热处理，部分晶化获得非晶纳米晶复合镀层。利用X射线衍射仪、透射电镜和高分辨透射电镜分析镀层的结构。结果表明，镀态时镀层呈典型的非晶态结构，控制热处理工艺可得到非晶纳米晶的复合镀层。通过动电位极化曲线（3．5％NaCI溶液）测定，得知部分晶化的镀层耐蚀性得到改善。由于具有少量纳米晶相镶嵌于连续非晶相上，非晶纳米晶复合结构的镍磷合金镀层耐蚀性优于非晶态镍磷合金镀层。     

Effects of TiO2 particles size and heat treatment on friction coefficient and corrosion performance of electroless Ni-P/TiO2 composite coatings

The effects of the titanium dioxide (TiO₂) particles size on the friction coefficient and corrosion performance of the Ni-P/TiO₂ composite coatings before and after heat treatment at 400°C for 1h have been investigated. Pin-on-disc analysis results have revealed that the highest and the lowest friction coefficients belonged, respectively, to the simple Ni-P coating and the Ni-P/TiO₂ composite coating containing TiO₂ particles of the average size of 0.1 μm (μ ～ 0.62 against 0.52). Eventually, a relative reduction in the corrosion resistance and the friction coefficient (as low as μ ～ 0.38) have been observed after heat treatment of Ni-P and Ni-P/TiO₂ composite coatings.     

Corrosion and wear-corrosion resistance properties of electroless Ni-P coatings on GFRP composite in wind turbine blades

Electroless nickel (EN) coatings with phosphorus are preferred in many industries such as the oil, chemical, plastic, mechanical, and electronic industries because of their excellent corrosion and wear resistance. This work evaluates the corrosion and wear-corrosion resistance of electroless nickel-phosphorus (ENP) coatings on glass fiber-reinforced plastic (GFRP) composites that are frequently used in wind turbine blades. The results demonstrated that the micro-porosity, phosphorus content, thickness and corrosion and wear-corrosion properties of ENP coatings on the GFRP substrate were all strongly related to the grinding pre-treatment condition, meaning the corresponding surface roughness state of the substrate. A higher P content (P > 7 wt.%), lower micro-porosity, greater thickness and greater hardness of the ENP coatings on GFRP substrate were obtained as the surface roughness of the substrate increased over 0.3 µm (as it did upon grinding with emery paper of lower than 800-grade), improving corrosion and wear-corrosion resistance properties.     

化学沉积Ni-P/Ni-W-P合金的热处理晶化及磨损行为

用XRD定量法分析了W的共沉积对Ni-P基合金镀层热处理晶化程度、晶粒尺寸的影响,通过镀层硬度测试、干摩擦条件下的磨损实验以及SEM形貌观察研究了镀层的磨损行为.结果表明:W的共沉积提高了镀态和热处理的Ni-W-P镀层的晶化程度,加速Ni相的晶化过程,提高了Ni3P相的晶化反应温度,并使Ni-W-P镀层硬度大于Ni-P镀层的硬度.非晶态Ni-9.27%P镀层晶化前后的磨损行为主要表现为粘着磨损;当P含量与其相同(相近)时,W的加入不改变Ni-5.13%W-9.32%P合金在镀态及低温热处理时的粘着磨损行为,但对高温(600 ℃以上)热处理镀层起主导作用的磨损形式为微切削磨损机制.     

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.     

Effect of SiC size dimensions on the corrosion wear resistance of the electrodeposited composite coating

Advances in materials' performance often require the development of composite systems, of which coated materials are one form. The abrasion and corrosion resistance of components can be greatly increased by protective coatings and this is a growing industry of considerable economic importance. This paper aims with a comparative wear corrosion study of pure nickel and Ni‐SiC nano structured composite coating. All the experiments concerning the effects of the rotation speed and the applied load on the corrosion behaviour and friction coefficient were carried out using the 0.5 M Na₂SO₄ neutral solution. The E_corr values measured at different disc rotation speeds and different friction loads show some differences between the two types of coatings. For wear corrosion tests an apparatus constructed in the Electrochemistry Laboratory, Dept. of Materials Engineering of Trento University was used. A PMMA cell contained the test solution and a transmission shaft with the tested sample, in the shape of a disc (diameter 40 mm and height 18 mm), connected to an electrical motor. A moving rod held an alumina parallelepiped counterface and the imposing load system thus obtaining a sliding type wear system.     

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。     

Deposition and corrosion resistance of electroless Ni-PCTFE-P nanocomposite coatings

The present work deals with the process of electroless deposition and electrochemical corrosion behavior of nickel-polychlorotrifluoroethylene-phosphorous (Ni-PCTFE-P) nanocomposite coatings. The process of autocatalytic-catalytic reduction of Ni in nickel sulfate and sodium hypophosphate solution with PCTFE suspended particles has been employed for the formation of the electroless Ni-PCTFE-P composite coatings. Surface morphology and composition of the composite coatings are characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) measurements and X-ray diffraction (XRD) analysis. Corrosion behavior of coatings is evaluated using open-circuit potential (E_OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization techniques in 3.5 wt.% NaCl solution. The study reveals significant shift in corrosion potential towards the noble direction, decrease in corrosion current density, increase in charge transfer resistance and decrease in double‐layer capacitance values with the incorporation of PCTFE particles in the Ni-P matrix. The significant improvement in corrosion resistance observed for Ni-PCTFE-P nanocomposite coatings (25.3 kΩ cm²) compared to Ni-P (16 kΩ cm²) could have resulted from the microstructural differences of pure Ni-P with Ni-PCTFE-P nanocomposite coatings.     

Abrasive wear resistance of electroless Ni-P coated aluminium after post treatment

Electroless nickel (EN) coatings are recognised for their hardness and wear resistance in automotive and aerospace industries. In this work, electroless Ni-P coatings were deposited on aluminium alloy substrate LM24 (Al-9 wt.% Si alloy) and the effect of post treatment on the wear resistance was studied. The post treatments included heat treatment and lapping with two different surface textures. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and micro-abrasion tester were used to analyse morphology, structure and abrasive wear resistance of the coatings. Post heat treatment significantly improved the coating density and structure, giving rise to enhanced hardness and wear resistance. Microhardness of electroless Ni-P coatings with thickness of about 15 μm increased due to the formation of Ni₃P after heat treatment.