碳化硅粒度及表面活性剂对Ni-SiC复合镀层中碳化硅含量及分布均匀性的影响

本文在电沉积镍的镀液中添加SiC颗粒于铜基体上制备Ni-SiC复合镀层,研究了表面活性剂种类和增强颗粒粒度对Ni-SiC复合镀层中碳化硅含量及分布均匀性的影响.SiC颗粒的粒度影响形核过电位,40 nm SiC颗粒比500 nm SiC颗粒提供更多成核活性点,且对于镍电结晶形核促进作用更明显.表面活性SDS对40 nm...     

Effects of Surfactants SDS and CTAB on Ni-SiC Deposition

The influences of surfactant type and concentration on the content and uniformity of SiC particles in Ni-SiC deposit were studied in this paper. The electrochemical behavior of preparing Ni-SiC composite coating was investigated using the cyclic voltammetry method. Then the impact of surfactants on the deposition potential of Ni-SiC coating was analyzed. Electrochemical studies showed that the cathode overvoltage increases gradually with increasing SDS (Sodium dodecyl sulfate) concentration. The CV curve showed the shift towards a lower current at a given potential with increasing SDS concentration. Ni-SiC composite coatings were prepared by electrodeposition. The experimental results show that the dispersion of 40nm SiC in Ni-SiC coating obtained in the electrolyte containing SDS is superior that containing CTAB (cetyltrimethyl ammonium bromide). CTAB increases the content of 40 nm SiC particles in the Ni-SiC coating, but the uniformity of 40 nm SiC particles in Ni-SiC composite coating is poor. SiC particles are still agglomerated. Compared with the anionic surfactant SDS and the cationic surfactant CTAB, surfactant SDS makes the particles better dispersed. But the contribution of surfactant SDS for co-deposition amount of SiC particles is negligible. The cationic surfactant CTAB can effectively improve the suspension performance of SiC particles and promote the co-deposition of SiC particles and metallic nickel. But there is still some reunion of SiC.     

冰晶石基铝电解质电导率的研究进展

综述冰晶石基铝电解质电导率的研究进展,分析各种因素对铝电解质电导率的影响,指出应该逐渐把目标转向低温电导率的研究,为实现低温铝电解提供可靠的实验数据和有益的参考资辩.     

采用共生矩阵的纹理特征提取方法

共生矩阵是一种常用的纹理特征提取方法,针对其易受噪声和图像中实体方向变化的影响等问题,提出一种新型共生矩阵纹理特征提取方法.该方法将傅里叶变换应用于原始图像,利用频域信息确定显著方向集合,把共生矩阵方法应用于显著方向集合以提取纹理特征.在进行图像匹配时,先在显著方向集合间进行相似度计算,后在纹理特征向量间进行相似度计算,显著方向集合中元素的显著性作为权重被引入纹理特征向量间的计算.实验结果表明,与传统共生矩阵方法相比,该方法针对有向纹理和无向纹理均具有较好的性能.     

Al2 O3基陶瓷材料的增韧研究进展

Al2 O3基陶瓷因其脆性限制了该项材料的使用范围。本文主要结合国内外陶瓷增韧技术研究现状,详细阐述了陶瓷脆性的由来和陶瓷增韧方法及相关机理。探讨了目前增韧方法的优缺点和未来发展方向。     

低温铝电解的研究

综述了低温铝电解的研究进展,分析了电解质组成对电解质物理化学性质的影响以及低温铝电解与节能的关系。指出氧化铝的溶解度小且溶解速度慢、电解质导电性差以及阴极结壳是实现低温铝电解所要解决的主要问题,提出了今后的研究方向。     

BN-AlN复合陶瓷的制备与性能研究现状

介绍了BN-Al N复合陶瓷的几种常见的制备方法,同时对BN-Al N复合陶瓷的性能研究现状进行了论述,最后对BN-Al N复合陶瓷的未来发展进行了展望。