共查询到19条相似文献,搜索用时 171 毫秒
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钯镀层具有优良的耐腐蚀性、耐磨性、耐光性和电器性能。广泛应用于电器连接点、连接器IC引导线架和印制板(PCB)等电子电器零件中和装饰品工业。同时钯镀层比金镀层廉价,使用过程中不涉及氰化物等剧毒化学品,生产过程安全便捷,因而可用钯镀层替代传统使用的金镀层。本文研制了一种制备高纯二氯四氨合钯[Pd(NH_3)_4cl_2]的生产工艺,该生产工艺简单稳定安全,生产设备条件要求低,通过加入脱水剂能大大提高产品产量,经电镀实验验证得到的钯镀层各项性能指标优良,媲美硬金镀层。 相似文献
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针对9Cr18不锈钢的耐磨需求,选用硬铬镀层、Ni-P化学镀层、Ni-c BN/h BN复合镀层等3种镀层,通过扫描电镜、划痕法、球盘磨损试验等研究了其在微观结构、结合力、常温及高温耐磨性等方面的差异。结果表明,3种镀层的硬度均可达800 HV以上,但Ni-c BN/h BN复合镀层的硬度略高;经过预镀镍处理后Ni-c BN/h BN复合镀层与基体之间的结合强度高达68 MPa,但硬铬镀层与基体的结合力较差;Ni-P化学镀层和Ni-c BN/h BN复合镀层在常温下的耐磨性相当,但Ni-c BN/h BN复合镀层在200℃下的耐磨性略优;硬铬镀层在摩擦应力作用下涂层出现明显剥落、黏着磨损严重,耐磨性较差。Ni-c BN/h BN复合镀层更宜选作9Cr18不锈钢表面的耐磨镀层。 相似文献
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在机械泵旋片用45Mn钢板表面制备了化学镀Ni-P/PTFE复合镀层,并研究了PTFE的质量浓度对化学镀Ni-P/PTFE复合镀层的沉积速率、耐磨性、耐蚀性及表面形貌的影响。结果表明:适当增加PTFE的质量浓度,有利于加快沉积速率,提高化学镀Ni-P/PTFE复合镀层的耐磨性和耐蚀性。化学镀Ni-P/PTFE复合镀层表面呈胞状形貌,PTFE均匀分布在表面。当PTFE的质量浓度为8 g/L时,化学镀Ni-P/PTFE复合镀层具有最佳的耐磨性和耐蚀性。 相似文献
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采用钯盐对SiCp/Al复合材料表面进行活化,化学镀后在复合材料表面获得Ni-P镀层。利用扫描电镜(SEM)、能谱成分分析仪(EDS)、极化曲线、X射线衍射仪(XRD)以及热震测试等手段对镀层的性能进行了研究,并观察了镀覆过程中镀层表面形貌的变化。结果表明:钯盐的活化作用较好,钯原子优先在复合材料的基体晶界、SiCp/Al界面及SiCp表面粗糙处形成催化活化中心;铝合金基体与SiCp增强相表面均被镀覆,且镀层光亮、致密、连续,耐蚀性好,结合力高,属于中磷镀层。 相似文献
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在TC4合金表面分别制备了Cu/micro-WC复合镀层和Cu/nano-WC复合镀层。比较了两种复合镀层的表面形貌、化学成分和显微硬度,同时分析了两种复合镀层的摩擦特性。结果表明:两种复合镀层都由Cu、W、C元素组成,显微硬度都明显低于TC4合金的显微硬度;摩擦试验前后,两种复合镀层表面轮廓曲线的形态都存在明显的不同;与Cu/micro-WC复合镀层相比,Cu/nano-WC复合镀层的表面形貌较好,W元素的质量分数较高,耐磨性较强。 相似文献
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介绍了Palluna(R)ACF-100钯镍合金电镀工艺,其流程主要包括:碱性除油或电解除油,酸洗,光亮或半光亮镀镍,镍活化,镀钯镍合金,镀硬金或金钴合金.镀钯镍合金的最佳工艺条件为:Pd 15 g/L,Ni 16g/L,温度60℃,pH 5.5,阴极电流密度60 A/dm2.所得合金含钯80%(质量分数),镀速可达14μm/min.镀层结合力好、延展性高,耐磨、焊接性能优良,混合流动气体腐蚀测试结果令人满意.该工艺无氨无氯,操作容易,镀液使用寿命长. 相似文献
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在45#钢基体上制备了n-Al2O3/Ni和n-SiC–Al2O3/Ni复合刷镀层,采用能谱仪(EDS)、X射线衍射仪(XRD)、扫描电镜(SEM)和T-11球盘式磨损试验机等设备对比研究了2种复合刷镀层的组织及性能。EDS分析结果表明,n–Al2O3/Ni复合刷镀层中纳米颗粒特征元素Al的质量分数为5.65%,n-SiC–Al2O3/Ni复合刷镀层中纳米颗粒特征元素Al的质量分数为5.63%,Si元素的质量分数为4.86%。SEM分析结果表明,与n-Al2O3/Ni复合刷镀层相比,n-SiC–Al2O3/Ni复合刷镀层的表面更加平整,组织更加细化。n-SiC–Al2O3/Ni和n-Al2O3/Ni复合刷镀层的显微硬度分别为587HV和555HV,n-SiC–Al2O3/Ni复合刷镀层的耐磨性是n-Al2O3/Ni复合刷镀层的1.7倍。 相似文献
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在三价铬Cr–C镀液中添加1~5 g/L的h-BN自润滑微粒,运用直流电沉积技术在Q235碳素结构钢基体上制备了Cr–C/h-BN复合镀层。利用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计、摩擦磨损试验机等设备分析了h-BN微粒添加量、电流密度等工艺参数对镀层组织和性能的影响。结果表明:在电流密度20 A/dm2,h-BN添加量3 g/L的条件下,可获得h-BN微粒体积分数为6.15%的复合镀层。h-BN微粒的添加改善了Cr–C合金镀层的耐磨性,Cr–C/h-BN复合镀层在室温干摩擦条件下的磨损率减少了22%,平均摩擦因数由原先的0.49降低至0.31。 相似文献
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Weiwei Chen 《Electrochimica acta》2010,55(22):6865-9102
Novel sol-enhanced Ni-TiO2 nano-composite coatings were electroplated by adding a transparent TiO2 sol into the traditional electroplating Ni solution. It was found that the structure, mechanical properties and corrosion resistance of the nano-composite coatings were largely determined by the sol concentration. The higher sol concentration in the plating electrolyte led to a higher content of TiO2 nano-particles in the coating matrix. The coating prepared at the sol concentration of 12.5 mL/L had the best microhardness, wear resistance and corrosion resistance. Adding excessive sol to the electrolyte changed the surface microstructure, caused cracking on the coating surface and deteriorated the properties. It was demonstrated that the corrosion resistance of the composite coatings is determined by two factors: surface microstructure and incorporation of TiO2 nano-particles. 相似文献
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Alternative process to hexavalent chromium plating, substitute materials and new designs are urgently needed owing to the requirement of “clean” manufacture. This comparative study was conducted to systematically investigate the tribological and electrochemical behavior of the Cr-C alloy coatings electrodeposited from a trivalent chromium bath and the hard Cr coatings electrodeposited from conventional hexavalent chromium bath, using reciprocating ball-on-disc tribometer and electrochemical analyzer. The electroplated Cr-C alloy coatings with thickness of 50 μm and acceptable quality that can be used for wear resistance as well as corrosion resistance purposes were produced successfully. The results show that the as-deposited Cr-C alloy coatings exhibited crack-free surface and amorphous/microcrystalline structure. The following heat treatment resulted in the cracked surface and the increase in hardness for the electroplated Cr-C alloy coatings. In contrast, the conventional Cr coatings exhibited cracked surface and their hardness decreased with the increase in annealing temperature. The electroplated Cr-C alloy coatings after heat treatment at 200 °C for 1 h exhibited better wear resistance than the conventional Cr coatings. In regard to the electrochemical behavior, the as-deposited Cr-C alloy coatings exhibited better corrosion resistance than the conventional Cr coatings. Therefore, the electroplated Cr-C alloy coatings are environmentally acceptable candidates to replace the conventional Cr coatings. 相似文献
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Jiayi He Xuexia Lan Zhongwu Liu Dongling Jiao Xichun Zhong Yitian Cheng Chunmei Tang Wanqi Qiu 《Ceramics International》2021,47(17):23888-23894
A CrN ceramic coating is a promising substitution for electroplated Cr (Ⅵ) hard coatings; however, it has not yet replaced a decorative Cr (Ⅵ) layer owing to its low reflectivity of visible light and relatively poor corrosion resistance. A Cr/CrN composite structure can address these shortcomings. Our recent work demonstrated that an addition of Fe can facilitate the densification of hot-pressed Cr sputtering targets and enhance the mechanical properties of Cr/CrN composite coatings. In this work, we focus on reporting optical properties and corrosion resistance of the Fe-modified Cr/CrN layers for decorative applications, and clarifying the effect of Fe on these performances. The results show that Fe can increase the amount of metallic phase in the Cr/CrN composite structure and helps enhance its reflectance in the visible region. The composite coating deposited by Cr90Fe10 (at.%) target/alloy exhibits a greater reflectivity of visible light and a better corrosion resistance than those of a single-phase CrN coating. This is attributed to its fine microstructure, which is beneficial for a dense and smooth surface. The color of the coating can be controlled by both the partial pressure ratio of N2 during deposition and the Fe content in the Cr-Fe sputtering target. The present results show that the addition of Fe can lead to the reduction in the processing cost of Cr targets, enhance the mechanical properties of the composite coatings, and broaden the deposition window. Such cost-effective Fe-modified Cr/CrN composite coatings are expected to be used in various decorative applications. 相似文献
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Jianhua Deng Jinqiu Zhang Yanbin Tu Peixia Yang Maozhong An Peng Wang 《Ceramics International》2018,44(14):16828-16836
Ni/diamond dicing blades is the main tool for scribe of silicon wafer at present. In order to decrease the width of dicing slot on the wafer, it is necessary to reduce the thickness of blades, and to increase the hardness, toughness and wear resistance of the Ni/diamond composite coatings in the process of electrodeposition. In this paper, 1,4-bis(2-hydroxyethoxy)-2-butyne (BEO) was used as an organic additive in the composite baths containing nickel amino-sulfonate, nickel chloride, boric acid, sodium dodecyl sulfate (SDS) and diamond particles in sizes of 3–5?µm, in order to improve the properties of Ni/diamond coatings and produce ultra-thin Ni/diamond dicing blades. The textures of Ni/diamond composite coatings were mainly Ni (200) and Diamond (111) since the addition of BEO in the baths inhibited the growth of Ni (111) and Ni (220). Quantum chemical calculations and molecular dynamics (MD) simulations showed that BEO could adsorb at the nickel surface strongly and inhibit the electrodeposition of nickel atoms. With the increase in concentration of BEO in the baths, the cathodic polarization potentials shifted to more negative direction and the thicknesses of the coatings decreased. Adding the appropriate amount of BEO (0.1–0.2?g/L) in the baths, the roughness of the coating decreased the number of individual diamond particles in the coating increased, and the hardness and the wear resistance of the coating was improved. When the thickness of Ni/diamond composite coating on aluminum alloy wheeled substrate was 15?µm, the width of its dicing slot was 22?µm. However, the addition of BEO in the bath cannot change the adhesive wear mechanism of the coating. 相似文献
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Rizwan Sarwar Bajwa Zulfiqar Khan Vasilios Bakolas Wolfgang Braun 《Journal of Adhesion Science and Technology》2016,30(6):653-665
The effect of electrolytic chemical concentration on wear-resistance, corrosion-resistance, adhesion and wettability properties of pure nickel and nickel–alumina composite coatings has been investigated in this paper. Coatings were electroplated over steel substrates under constant pulse conditions using pulse electrodeposition technique. Corrosion-resistance results show that the anti-corrosion properties are increasing with medium concentration (MC) both for pure nickel and nickel–alumina composite coating. For anti-wear properties, the MC showed increasing trend in case of pure nickel coatings but decreased in nickel–alumina composite coatings. In composite coating, the higher and low concentrations of electrolyte showed the higher wear resistance properties. Furthermore, the influence of electrolyte concentration on changing surface morphologies, mechanical, wettability and adhesion properties have been investigated and reported here. Surface morphologies of the synthesized coatings were studied with scanning electron microscopy (SEM) and energy-dispersive spectroscopy. Coatings surface mapping and wear analyses were examined by using 3D white light interferometry. 相似文献