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1.
超声波辅助化学镀可以改善镀层性能,而目前鲜见将超声波引入铝合金表面化学镀Ni-Cu-P的报道.采用二次浸锌工艺对6061铝合金进行前处理,再制备Ni-Cu-P化学镀层,对比了有无超声波辅助化学镀Ni-Cu-P层的结构与性能.结果表明:超声波改变了化学镀Ni-Cu-P的沉积速度和结晶过程,有助于形成均匀、致密、较厚的镀层,从而提高了镀层的耐磨性和耐腐蚀性.  相似文献   

2.
聚苯乙烯塑料表面化学镀铜的研究   总被引:4,自引:0,他引:4  
研究了聚苯乙烯表面化学镀铜的表面预处理以及化学镀铜工艺对化学镀铜的影响。结果表明,聚苯乙烯经过硫酸和重铬酸钾处理后.表面的极性官能团如羰基、羧基等大大增加。表面处理提高了塑料表面对金属镀层的附着力。对工艺因素的研究表明.化学镀铜的速度与温度、反应时间以及还原剂浓度等相关。  相似文献   

3.
采用化学镀技术,实现了芳纶纤维表面Ni-Cu-P的合金化处理,利用SEM、EDS和XRD分别对芳纶纤维原始样品、粗化后及施镀后的表面形貌、原始纤维及镀层的成分和物相组成进行了分析比较,并用冷热循环法对合金化后的芳纶纤维进行了结合力测试。结果表明:芳纶纤维表面化学镀Ni-Cu-P后呈灰色,镀层与基体结合力较好,镀层中Ni的质量含量为5.44%,Cu的为18.57%,P的为6.39%,且镀层以Cu、Ni3P、Cu3P为主。  相似文献   

4.
玄武岩纤维增强环氧树脂复合材料复合机制   总被引:5,自引:0,他引:5  
用三种硅烷偶联剂KH550、KH560和KH570分别处理玄武岩纤维(BF),以未经偶联剂处理的BF为对照组。X射线电子能谱(XPS)分析三种偶联剂对BF的改性,发现BF表面的Si元素与偶联剂中的Si元素形成了Si—O—Si键,其含量顺序为KH550〉KH570〉KH560。测定了不同方法处理后的BF增强环氧树脂(BF...  相似文献   

5.
黄亮  高岩  郑志军  李浩 《功能材料》2007,38(4):683-687
采用直接镀工艺,在铝基体上获得了化学镀N-P、Ni-Cu-P各种结构镀层.用X射线衍射分析了镀层结构;用SEM观察了各种结构镀层的表面形貌;测定了各种结构镀层的镀速和结合力;利用线性极化和阳极极化曲线分析了各种结构镀层的耐蚀性能.结果表明,利用直接化学镀工艺可以在铝基上获得结合力良好的镀层;通过控制络合剂的用量可以得到不同结构和不同铜含量的Ni-Cu-P镀层;当镀层达到一定厚度后,Cu元素可以显著提高镀层的耐蚀性能.  相似文献   

6.
稀土可有效改善化学镀Ni-Cu-P层的硬度、耐蚀性能,目前,对此研究还不够深入。在Ni-Cu-P化学镀液中引入不同含量的Ce4+,采用金相显微镜和电子能谱分析了所得Ni-Cu-P镀层的表面形貌和成分,利用极化曲线和交流阻抗谱考察了Ce4+对Ni-Cu-P镀层在室温海水中的耐蚀性能的影响。结果表明,加入Ce4+能减少Ni-Cu-P镀层的缺陷,使晶粒细化,镀层表面平整;镀层中不含Ce,Ce4+促进了镀层的非晶态化程度,从而提高了其耐蚀性;镀层的自腐蚀电位比紫铜基材的低,自腐蚀电流密度远小于紫铜基材,添加Ce4+能提高Ni-Cu-P镀层的耐蚀性,其自腐蚀电流密度低于未加稀土所得的镀层。  相似文献   

7.
不锈钢化学镀Ni-P/Ni-W-P合金镀层的研究   总被引:4,自引:1,他引:4  
讨论了316L不锈钢上化学镀Ni-P/Ni-W-P合金镀层的工艺,重点是直接影响镀层与基体间结合力的关键过程--不锈钢基体的前处理工艺.试验发现,在前处理工艺中侵蚀活化液和预镀镍液的配方是最重要的.对2种镀层成分和结构的分析、结合力及硬度的测试表明,用本方法前处理工艺对316L不锈钢基体处理后进行化学镀能获得性能可靠的Ni-P/Ni-W-P合金镀层.  相似文献   

8.
梁平  史艳华 《材料保护》2012,45(3):8-10,3
为了进一步提高Ni-P镀层的耐蚀性能,在Ni-P化学镀液中加入硫酸铜制备了Ni-Cu-P三元合金化学镀层,测试了镀层的沉积速度,采用扫描电镜(SEM)观察了镀层的表面形貌,测试了镀层在5.0%H2SO4,5.0%NaOH及3.5%NaCl溶液中的动电位极化曲线,并与Ni-P化学镀层进行了比较。结果表明:Ni-Cu-P镀层表面的胞状物比Ni-P镀层的更加细小,镀层致密性更好;Ni-Cu-P镀层在3种介质中均表现出更好的耐均匀腐蚀性和抗点蚀性能,主要是因为Ni-Cu-P镀层的非晶态结构减少了镀层缺陷数量,从而减少了腐蚀发生的敏感位置和腐蚀微电池的数量,同时更加细小的晶粒也使Ni-Cu-P镀层比Ni-P镀层更容易钝化和维持钝态,另外Ni-Cu-P镀层更为致密也减少了腐蚀介质渗入基体的通道。  相似文献   

9.
Ni-Cu-P化学镀层的制备及其耐烟气冷凝液的腐蚀性能   总被引:2,自引:2,他引:0  
为了解决冷凝式燃气利用设备的腐蚀问题,采用化学镀工艺在紫铜基体上沉积Ni-Cu-P层.利用扫描电镜(SEM)、电子能谱(EDX)、电子探针(EPMA)分析镀层的形貌和成分,利用极化曲线和交流阻抗谱考察了紫铜基材及其Ni-Cu-P镀层在15℃和60℃煤气烟气冷凝液中的耐腐蚀性能.结果表明:Ni-Cu-P化学镀层表面均匀平...  相似文献   

10.
粘结NdFeB永磁体化学镀Ni-Cu-P防护层及阻氢性能研究   总被引:2,自引:0,他引:2  
对粘结NdFeB永磁体化学镀Ni-Cu-P合金防护层的工艺过程及镀层的阻氢性能进行了研究。磁体经碱性去油、缓蚀酸洗、镀前均匀隔离与活化处理后再进行化学镀Ni-Cu-P合金,可获得了质量良好的耐蚀性镀层,该镀层对磁体磁性能无不良影响,且有良好的阻氢性能,在25℃、10MPa高压H2环境中,阻氢时间为19min。  相似文献   

11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.  相似文献   

12.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.  相似文献   

13.
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.  相似文献   

14.
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.  相似文献   

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16.
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.  相似文献   

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19.
水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。  相似文献   

20.
可燃气体检测报警器测量结果的不确定度评定   总被引:1,自引:0,他引:1  
本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。  相似文献   

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