不锈钢基体上电沉积钯-镍合金镀层的工艺参数优化

以钯的质量分数很高为目标,兼顾镀液性能及镀层质量,采用单因素试验对不锈钢基体上电沉积钯-镍合金镀层的工艺参数进行了优化。将工艺参数设置为:pH值8.0、温度35℃、电流密度1.2 A/dm~2、中速搅拌、电沉积时间100 min。在不锈钢基体上制备出钯的质量分数达到70.26%的钯-镍合金镀层。该镀层表面均匀、平整,孔隙率为1.05个/cm~2。     

脉冲电沉积工艺参数对Ni-W-P合金镀层性能的影响

针对传统镀硬铬沉积速率低、污染环境等问题,采用脉冲电沉积方法在碳钢表面制备Ni-W-P代铬镀层。采用显微硬度计、扫描电子显微镜、X射线衍射仪和电化学工作站研究了脉冲频率、平均电流密度和占空比对镀层性能的影响。结果表明:随着脉冲频率、平均电流密度和占空比的增加,镀层的硬度和耐蚀性均呈现出先增大后减小的变化规律;当脉冲频率为250Hz,平均电流密度为4.0A/dm2,占空比为30%时,镀层为非晶态结构,表面光滑、平整,结构致密,硬度可达5 140MPa,耐蚀性较好。     

316L不锈钢表面脉冲电镀钯的性能

以316L不锈钢为基体,分别采用脉冲电镀和直流电镀法制备了钯膜层。对比研究了脉冲电镀钯和直流电镀钯的微观结构、显微硬度、孔隙率、耐蚀性等性能。与直流电镀钯膜层相比,脉冲电镀钯膜层更为均匀、致密,晶粒尺寸更小,孔隙率更低,显微硬度更高,附着力更强。另外,脉冲电镀钯膜层在80°C的20%H2SO4和20%H2SO4+0.001 mol/L Cl-中的耐腐蚀性均优于直流电镀钯膜层。     

脉冲频率对纳米晶镍镀层结构及性能的影响

采用脉冲电沉积方法在黄铜基体上制备纳米晶镍镀层。研究了脉冲频率对镀镍层的微观结构、硬度及耐蚀性的影响。结果表明:直流电沉积制备的镀镍层表现为(111)晶面和(200)晶面的双择优取向,而脉冲电沉积制备的镀镍层仅在(111)晶面表现出择优取向;脉冲电沉积制备的镀镍层的硬度和耐蚀性均高于直流电沉积制备的镀镍层的;不同脉冲频率下制备的镀镍层的硬度没有显著差别,约为5 500 MPa;但不同脉冲频率下制备的镀镍层的耐蚀性存在差别,脉冲频率为0.1kHz时制备的镀镍层在3.5%的NaCl溶液中的耐蚀性最好。     

脉冲电沉积Co-W磁性薄膜

采用脉冲电沉积法制备Co-W 磁性薄膜.研究脉冲周期和占空比对沉积速率,Co-W薄膜的形貌、结构以及磁性能的影响.结果表明:脉冲周期与占空比对薄膜的沉积速率、形貌、结构和磁性能都有较大的影响.随着脉冲周期和占空比的不断增加,沉积速率呈现先增大后减小的趋势;而Co-W薄膜的矫顽力呈现减小的趋势.这主要是由于晶粒尺寸增大的缘故.AFM研究表明:随着占空比增大,薄膜颗粒增大,表面平整度下降,空隙率增加;脉冲周期影响薄膜表面聚集颗粒团;增大脉冲周期,该聚集团会增大.     

脉冲喷射电沉积镍工艺的研究

由于直流电沉积镍使用极限电流密度下,沉积速度低。本文介绍脉冲喷射电沉积的方法制备镍镀层。研究了脉冲频率、占空比、电流密度及糖精对镀层晶粒尺寸的影响。结果表明：镀层晶粒尺寸随脉冲频率、平均电流密度的增大而减小;随空比的增大而增大。少量糖精的加入能有效降低镀层晶粒尺寸。     

占空比对纳米晶镍镀层结构及性能的影响

采用电沉积方法在黄铜基体上制备出纳米晶镍镀层,并研究了占空比对镀镍层微观结构、硬度及耐蚀性的影响。结果表明:低占空比下镀镍层的择优取向面为(111)晶面,高占空比下呈现出(111)和(200)的双择优取向;随着占空比的增大,镀镍层的晶粒尺寸逐渐增大;占空比为70%时所得镀镍层的硬度最高;占空比为20%时所得镀镍层在3.5%的NaCl溶液中的耐蚀性最好。     

工艺参数对Ni-ZrO_2纳米微粒复合镀层性能的影响

采用脉冲电源,在铜表面制备了复合镀层,研究了占空比、镀液中ZrO2纳米微粒添加量和脉冲频率对复合镀层的硬度、沉积速率和耐蚀性的影响。结果表明,随脉冲占空比的增加,镀层硬度、沉积速率和耐蚀性能均呈现先增大后减小的趋势;ZrO2纳米微粒的增加使镀层硬度增加,而沉积速率和耐蚀性能为先增大后减小;随脉冲频率的增加,镀层硬度、沉积速率及耐蚀性能均增加。最佳工艺参数应控制占空比为50%、ZrO2纳米微粒质量浓度9g/L、脉冲频率2000Hz。     

占空比对Ni-WC纳米复合镀层耐蚀性及硬度的影响

采用脉冲电沉积法在304不锈钢基体上制备出Ni-WC纳米复合镀层,并研究了占空比对Ni-WC纳米复合镀层耐蚀性及硬度的影响。结果表明:随着占空比的增大,Ni-WC纳米复合镀层的平均晶粒尺寸先减小后增大,硬度先增大后减小;当占空比为50%时,Ni-WC纳米复合镀层的平均晶粒尺寸最小,耐蚀性最好,硬度最大。     

脉冲电源对电沉积复合镀层的影响

随着脉冲电源开始取代直流电源应用到电沉积领域中,研究发现脉冲电源与复合电沉积的结合,使所制备的复合镀层组织结构得以改善,性能也明显提高。在脉冲复合电沉积中,脉冲占空比和脉冲峰值电流密度是两个重要的技术参数,对脉冲占空比和脉冲峰值电流密度对电沉积复合镀层的影响进行了分析和总结,为脉冲复合电沉积的研究和应用提供借鉴和参考。     

脉冲镀Ni-Co合金镀层内应力及钴含量的研究

研究了脉冲镀Ni-Co合金的工艺,讨论了脉冲电镀中占空比及频率对镀层内应力及钴含量的影响.实验结果表明:镀层内应力随占空比的增加而降低,随脉冲峰值电流密度增加而升高,随温度的升高而降低.镀层中Co的质量分数则随温度的升高而升高.     

Pulse current electrodeposition and corrosion properties of Ni–W alloy coatings

Ni–W alloy coatings were prepared on a mild steel substrate by means of pulse current (PC) and compared to the coatings electrodeposited by direct current (DC). In particular the study dealt with the influence of the frequency using pulse current on the surface morphology while maintaining a constant duty cycle. A constant charge for DC and PC electrodeposition of Ni–W alloy coatings was used. The morphology of the coatings was explored by scanning electron microscopy and the composition of the coatings was analysed by X-ray powder diffraction and energy dispersive X-ray analysis. Corrosion resistance of Ni–W alloy coatings was investigated by potentiodynamic polarization in a chloride medium. The corrosion products were analysed by Raman spectroscopy. It was found that the temperature of the electrolysis affects current efficiency of the DC and PC electrodeposition. The frequency of pulse electrodeposition alters the morphology of the Ni–W alloy coatings. There was evidence of the positive influence of increased tungstate concentration in the electrolyte on corrosion resistance of the Ni–W alloy coatings.     

Preparation and investigation of pulse co-deposited duplex nanoparticles reinforced Ni-Mo coatings under different electrodeposition parameters

In this work, Ni–Mo–SiC–TiN nanocomposite coatings were deposited on aluminium alloy by pulse electrodeposition with various electrodeposition parameters. The influences of the pulse frequency and duty cycle on the phase structure, morphology, mechanical and corrosion performance of the coatings were systematically investigated. The results showed that with increasing pulse frequency and decreasing duty cycle, the content of embedded duplex nanoparticles increased, and the grains refined gradually. The nanocomposite coating that was prepared at 20% duty cycle and 1000 Hz pulse frequency exhibited compact, uniform, and fine microstructures with the maximum incorporation of nanoparticles (6.81 wt% TiN and 1.72 wt% SiC). The wear rate and average friction coefficient then declined to 4.812 × 10^?4 mm³/N·m and 0.13, respectively, with a maximum microhardness of 519 HV. Simultaneously, the corrosion current density was reduced to 3.11 μA/cm², and a maximum impedance of 34888 Ω cm² was exhibited. The uniformly distributed duplex nanoparticles acted as a hindrance, which consequently supported the enhancement of corrosion and wear resistance. By investigating the variation of the pulse diffusion layer with electrical parameters, it was discovered that when the crystallite size is equivalent to or smaller than the diffusion layer thickness, it would be easier to cross the diffusion layer to incorporate in the coating. Additionally, the effects of various duty cycles and pulse frequencies on the nucleation process of the grains were discussed.     

脉冲电沉积镍-铜合金

采用脉冲电沉积技术在304不锈钢表面制备Ni-Cu合金镀层,镀液组成和工艺条件为:NiSO4ꞏ6H2O 200g/L,CuSO4ꞏ5H2O 10 g/L,十二烷基硫酸钠0.2 g/L,柠檬酸钠80 g/L,糖精0.2 g/L,pH 4.0,温度25°C,搅拌速率30 r/min,平均电流密度40~120 mA/cm2,脉冲频率0~100 Hz,占空比20%~90%,时间30 min。研究了平均电流密度、脉冲频率和占空比对Ni-Cu合金镀层的元素组成、表面形貌和显微硬度的影响,得到较优的工艺参数为:平均电流密度40 mA/cm2,脉冲频率50 Hz,占空比60%。该条件下所得Ni-Cu合金镀层由质量分数分别为56.53%和43.47%的Ni和Cu组成,呈“菜花”状形貌,结晶细致、均匀,显微硬度为614.4 HV。     

脉冲电镀镍及其性能的研究

采用瓦特镀镍液,研究了脉冲占空比、平均电流密度、温度对电沉积速率,镀层光亮度和镀层在w=3.5%的NaCl溶液中耐蚀性的影响.用扫描电镜研究了直流和脉冲镍镀层的表面形貌.结果表明:电沉积速率随脉冲占空比、平均电流密度及温度的增大而加快;镀层耐蚀性,光亮度随脉冲占空比增大而变差,随温度、平均电流密度的增大先变好后变差.较佳脉冲电镀条件为:平均电流密度0.75 A/dm~2,脉冲占空比5%,温度45～50 ℃,pH 2.5～3.0.X射线衍射分析结果表明,与直流镀镍相比,脉冲镍镀层在(111)晶面存在择优取向,镀层更致密,性能更好.     

脉冲参数对Tb-Fe-Co合金镀层的影响

以离子液体1-丁基-3-甲基咪唑四氟硼酸盐(BMIM-BF4)作为溶剂,加入自制的无水氟硼酸盐组成电解液,采用脉冲电沉积制备Tb-Fe-Co合金镀层,所得镀层均匀、致密、有金属光泽且镀层中铽的质量分数较高。考察了脉冲电压、脉冲占空比和脉冲频率对镀层表面形貌及镀层中铽的质量分数的影响,在最优工艺条件下,所制得的镀层中铽的质量分数可达50%。     

Effects of duty cycle and pulse frequency on microstructures and properties of electrodeposited Ni–Co–SiC nanocoatings

In this study, Ni–Co–SiC nanocoatings were fabricated using pulse current electrodeposition (PCE) method. Effects of duty cycle and pulse frequency on surface appearance, microstructure, phase structure, wear behavior, and corrosion resistance of as-deposited Ni–Co–SiC nanocoatings were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, nanoindentation, and both wear and corrosion tests. Results indicate that numerous small-sized grains formed on Ni–Co–SiC nanocoatings at 20% duty cycle to provide smooth, uniform, and fine microstructures. The content of SiC nanoparticles in Ni–Co–SiC nanocoatings decreased from 11.2 wt% to 7.4 wt% as duty cycle increased from 20% to 60%. However, the content of SiC nanoparticles in Ni–Co–SiC nanocoatings increased from 6.3 wt% to 9.7 wt% as pulse frequency increased from 100 Hz to 300 Hz. Ni–Co–SiC nanocoatings prepared at pulse frequency of 300 Hz and duty cycle of 20% exhibited average microhardness of 934.4 Hv and average thickness of 43.2 μm. Weight loss of Ni–Co–SiC nanocoatings at 300 Hz was only 17.2 mg, indicating significant wear resistance. In addition, Ni–Co–SiC nanocoatings produced at duty cycle of 20% and pulse frequency of 300 Hz exhibited the maximum impedance, indicating optimal corrosion resistance.     

双向脉冲电沉积纳米晶光亮镍镀层

采用双向脉冲电沉积法,以糖精和1,4-丁炔二醇作为光亮剂,在钢片上获得了光亮的纳米晶镍镀层.通过正交试验确定最佳的脉冲参教为:正向占空比50%,正向脉冲电流密度30A/dm2,正向周期10ms,反向占空比30%,反向脉冲电流密度8A/dm2.纳米晶光亮镍镀层晶粒细致均匀,孔隙率低,平整性好,无裂纹,具有良好的装饰效果.