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In order to accelerate the conversion coating formation on 6063 Al alloy in the Ce(NO3)3 solution, accelerants of chloride and ammonium salt were used. The coating morphology, composition and structure were analyzed with SEM/EDS, EPMA, XPS and XRD. The coating morphology is influenced by the composition, pH value and temperature of the treating solution. The coating composed of metal oxide, metal hydroxide and hydrate appears to be amorphous. The elements in the coating are Al, Ce, O, Mn and Mg, while the Ce element exists in the forms of Ce3+ and Ce4+. The accelerant of chloride can increase the compactness and Ce content of the coating, so the coating corrosion resistance is remarkably improved. A scheme for the electrochemical reaction in the coating formation was proposed, and the potential change in the coating formation was also studied. It is found that chloride can shorten the time period of the first and the second stages in coating formation. 相似文献
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棉针织物缝纫针洞的形成及解决途径探讨 总被引:1,自引:0,他引:1
棉针织物在缝纫过程中经常出现针洞现象,文章分析了缝纫针洞产生的主要原因,并从四个方面阐述了解决的途径:选用合适的机针针尖形状及针号;调整缝纫机零部件;提高面料的柔软性;控制坯布回潮率及车间温湿度。 相似文献
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AZ91D镁合金表面植酸转化膜的正交实验优化研究 总被引:4,自引:0,他引:4
通过正交实验对镁合金植酸处理工艺进行优化,并通过极化曲线、电位-时间曲线对镁合金植酸转化膜的耐腐蚀性能进行研究,采用金相显微镜对转化膜的微观形貌进行观察。结果表明,植酸转化膜耐腐蚀性能的工艺影响因素排序为:处理时间>温度>浓度>溶液pH值。AZ91D镁合金植酸转化膜具有良好的耐腐蚀性能,其自腐蚀电流密度小于铬酸盐转化膜,植酸表面处理技术有望代替对环境污染严重的铬酸盐处理技术。 相似文献