排序方式: 共有44条查询结果,搜索用时 15 毫秒
1.
2.
3.
张圣麟 《中国稀土学报(英文版)》2009,27(3):469-473
Zinc phosphate coatings formed on 6061-Al alloy, after dipping in phosphating solutions containing different amounts of Y2O3(yttrium oxide), were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical measurements. Significant variations in the morphology and corrosion resistance afforded by zinc phosphate coating were especially observed as Y2O3 in phosphating solution varied from 0 to 40 mg/L. The addition of Y2O3 changed the initial potential of the interface between aluminum alloy substrate and phosphating solution and increased the number of nucleation sites. The phosphate coating thereby was less porous structure and covered the surface of aluminum alloy completely within short phosphating time. Phosphate coating was mainly composed of Zn3(PO4)2-4H2O (hopeite) and AIPO4(aluminum phosphate). Y2O3, as an additive of phosphatization, accelerated precipitation and refined the gain size of phosphate coating. The corrosion resistance of zinc phosphate coating in 3% NaCl solution was improved as shown by po-larization measurement. In the present research, the optimal amount of Y2O3 was 10-20 mg/L, and the optimal phosphating time was 600 s. 相似文献
4.
5.
常温快速磷化剂的研究 总被引:8,自引:2,他引:6
研制了一种锌系常温快速磷化液,考察了复合促进剂所含物质对磷化液磷化效果的影响,同时讨论了如何提高磷化成膜速度和磷化膜的耐蚀性等问题,并指出了工艺上的改进. 相似文献
6.
7.
8.
铝合金稀土硝酸盐磷化的电化学行为 总被引:4,自引:0,他引:4
采用电化学测试和扫描电镜等方法研究了硝酸铈对6061铝合金磷化过程及磷化膜形貌的影响.结果表明,硝酸铈的加入改变了铝合金基体与磷化液之间液固界面间的初始电位;硝酸铈吸附在铝合金表面上形成凝胶,成为磷酸盐晶体形成的良好晶核,磷化晶粒细化,生成较为致密的磷化膜,膜的耐蚀性得到提高.硝酸铈使铝合金达到最高电位的时间缩短,阴极极化电流密度增大,磷化速度加快.硝酸铈在整个铝合金磷化过程中起到了成核和促进的作用.在本实验条件下,最佳硝酸盐含量为20 mg/L~40 mg/L. 相似文献
9.
采用扫描电镜(SEM)、X射线衍射(XRD)及能谱(EDX)和电化学测试的方法,研究了稀土硝酸盐(REN)对6061铝合金锌系磷化成膜过程的影响,结果表明,少量的稀土硝酸盐添加到磷化液中可以提高磷化成膜速度和细化晶粒,改变磷化膜的组成,但稀土硝酸盐本身并不构成磷化膜的组成成分,它实质上是具有良好载氧能力的促进剂,具有良好的成核促进作用和阴极去极化作用.与在不含稀土硝酸盐的磷化液中所形成的磷化膜相比,铝合金在含有稀土硝酸盐的磷化液中所形成的磷化膜具有较低的化学活性,其耐蚀性得到提高,在所研究的工艺条件下,最佳硝酸盐含量为20~40 mg/L. 相似文献
10.