It is difficult to gain homogeneous coating when precision small holes are electroplated chrome, which affects the dimensional precision and the form precision of the product. 精密小孔在镀硬铬时,很难获得均匀的镀层,直接影响产品的尺寸精度和形位精度。
The result showed that the current density was 1.1-2. 7A/ dm2. The stable homogeneous golden plating coating could be obtained with the plating solution temperature and pH value being properly conditioned and through aftertreatment. 结果表明,电流密度为1.1~2.7A/dm~2,适当调节镀液温度和pH值,并经后处理工艺,可获得均一稳定的金色镀层。
And there is no crack in coating and substrate when content of rare earth goes up to 3% wt. The homogeneous and fine microstructure in coating is obtained, and the microhardness in coating is lower than that with no rare earth. 当稀土含量为3%Wt时,涂层及基体无裂纹出现,且涂层组织细小、均匀.涂层显微硬度值较未加稀土时低。
The chemical copper-coating treatment of the rare earth hydrogen-storage alloys powder was researched. The homogeneous copper coating surface can be obtained with surface pre-treated followed by copper coating in acid solution. 对稀土贮氢合金粉末进行了表面化学镀铜工艺的研究,经表面预处理后,再在酸性溶液中进行化学镀铜处理,可以得到厚度比较均匀的镀铜层。
The results show that it is a close and homogeneous coating, and the bonding between the coating and the matrix is mechanical and metallurgical. 结果表明,制备的非晶涂层组织致密,均匀,涂层与基材之间为冶金与机械相结合共同作用的成形特征;
Chemical elemental distribution is not homogeneous in every transitional coating. Zr and mg elemental distribution is similar, yet the distribution of Zr and Ni is supplementary. Cr and Al elements are placed as oxide inclusions in the boundary area between splats. 过渡层化学元素分布不均匀,其中Zr与Mg分布特征相同,Zr与Ni分布位置互补,Cr、Al主要以氧化物形式位于晶粒边界处。
The mullite/ mullite whisker grade composite coating is dense, homogeneous and no convex and there are no pores in coating and the interface between coating and based materials. 本实验制备出表面致密、均匀、无凹凸,与基体连接紧密且连接处无气孔的莫来石/莫来石晶须梯度复合涂层。
And the process is reliable in stable operating with homogeneous coating. 具有性能可靠、运行稳定、覆盖层均匀及可现场施工等优点;
Then composites of Bi_2O_3/ Cu-O-Cr with a homogeneous core/ shell structure were prepared by coating Cu-O-Cr on the surfaces of the as-synthesized spherical monodisperse Bi_2O_3 nano-particles using in-situ precipitation method. 通过共沉淀法制备球形单分散Bi2O3/Cu-O-Cr核壳结构复合纳米材料。
The results showed that the surfaces of the coatings are homogeneous, polished and with strong corrosion resistance which is superior to A3 steel specimen, nickel-phosphorus coating and phosphating film. 结果表明:在最佳施镀条件下,可得光亮、致密、耐腐蚀性强于A3钢、磷化膜及Ni-P镀层的纳米复合化学镀层。
Appropriate proportion rare earth elements make crystal grains thin and the structure homogeneous. Therefore, it reduced the corrosion rate in the electrolyte of coating, decreased coating in aqueous solution of current density, obviously improved coating corrosion resistance. 适量稀土元素使得微观晶粒明显变小,镀层变得均匀致密,从而降低镀层在电解质中的腐蚀速度,降低镀层在水溶液中的电流密度,明显提高镀层的耐腐蚀性能。
The results shows that the modifier PVA system makes the reaction system more homogeneous and the cross-linking of resorcinol is better to high polymerization of urea-formaldehyde prepolymer, as would achieve the better coating. 结果表明系统改性剂聚乙烯醇使得反应体系的乳化更为均一,更利于对芯材的包覆。间苯二酚交联剂的加入有利于脲醛预聚体的高聚反应,从而实现对芯材的更好包覆。
Secondly, we consider the case of a homogeneous coating and analyze the effects of the coating materials and thickness on the stability. 其次,考虑均匀涂层结构,分析了涂层材料和涂层厚度对稳定性的影响。