SBIR PHASE I: Application of Advanced Molybdate Conversion Coatings to Aluminum Alloys and Anodized Aluminum

这个小企业创新研究第一阶段项目将展示使用一种新方法将钼酸盐（六价钼）转化涂层应用于铝合金和飞机用阳极氧化铝的可行性。化学转化涂料，特别是铬酸盐转化涂料，已经发现了广泛的商业和军事应用。特别令人感兴趣的是在飞机铝合金上使用化学转化涂层，因为它们具有优异的耐腐蚀性和作为油漆有效基础的能力。用于开发该涂层的传统镀液含有铬酸盐（六价铬），并且涂层中残留的铬酸盐是观察到的高度缓蚀的主要原因。然而，铬酸盐是剧毒的，它们在废水中的存在受到严格限制。因此，开发一种使用无毒化学物质的铝合金和阳极氧化铝涂层是非常可取的，这种化学物质可以作为传统铬酸盐涂层工艺的替代品。该项目的关键是使用“高级氧化工艺（AOPs）”，在后处理阶段促进低价钼氧化为六价钼，从而增强铝合金保护氧化膜的形成。拟议的程序简单，环保，可以通过刷或喷涂应用。这个项目应该产生一个可行的替代污染的传统铬酸盐转化过程用于众多的商业和军事终端项目。钼酸盐（六价钼）工艺最终可以取代传统的铬酸盐转化涂层用于商业应用。发达的技术对环境和人类健康也将是有益的。

This Small Business Innovation Research Phase I project will demonstrate the feasibility of using a new approach to apply molybdate (hexavalent molybdenum) conversion coatings to aluminum alloys and anodized aluminum for aircraft applications. Chemical conversion coatings, particularly chromate conversion coatings, have found widespread commercial and military applications. Of particular interest is the use of chemical conversion coatings on aircraft aluminum alloys, because of their excellent corrosion resistance and their ability to serve as an effective base for paint. Conventional baths used to develop this coating contain chromates (hexavalent chromium), and it is the residual chromates in the coating that are largely responsible for the high degree of corrosion inhibition observed. However, chromates are highly toxic and their presence in wastewater effluents is severely restricted. Thus, it is highly desirable to develop a coating for aluminum alloys and anodized aluminum utilizing non-toxic chemicals that could serve as an alternative to the conventional chromate coating process. The key to the proposed project is the use of `Advanced Oxidation Processes (AOPs)` to promote the oxidation of low valence molybdenum to hexavalent molybdenum in a post-treatment stage and, hence, enhance the formation of protective oxide films on aluminum alloys. The proposed procedure is simple, environmentally benign, and can be applied by brushing or spraying. This project should produce a viable alternative to the polluting conventional chromate conversion process used for a multitude of commercial and military end items. The molybdate (hexavalent molybdenum) process could eventually replace conventional chromate conversion coatings for commercial applications. Developed technology will also be beneficial with respect to the environment and human health.