磷酸盐涂层研究进展及其应用

随着世界环保压力与节能压力的剧增,绿色涂层已经成为金属腐蚀防护的发展趋势.磷酸盐涂层是一种机械强度高、热稳定性好、耐腐蚀且无毒环保的无机涂层.相较于金属涂层和无机硅涂层,磷酸盐涂层因其制备方法简便以及特殊的性能优势,受到越来越多的关注,在建筑、汽车、航海、航空航天、医疗等领域已取得广泛运用.分别介绍了反应固化型磷酸盐涂层和磷酸盐转化膜.首先阐述了反应固化型磷酸盐涂料的组成,包括胶黏剂、固化剂、功能填料和其他添加剂,并分别介绍了胶黏剂的合成及配比研究、固化剂的固化机理和选择、功能填料的选择对性能的影响以及其他添加剂对涂料整体性能和实用方面的影响.然后对磷酸盐转化膜这类特殊的磷酸盐涂层的成膜机理以及常用磷化液组成进行了介绍.成膜机理主要包括基体的电化学溶解、磷酸盐的结晶和成长、磷酸盐转化膜溶解与形成之间的动态平衡三个步骤.磷化液包括锌系、铁系、钙系、锰系磷化液以及它们之间的组合.此外,总结了磷酸盐涂层在防腐蚀、耐高温和一些其他性能方面的应用现状.最后对磷酸盐涂层今后的发展趋势进行了展望,指出磷酸盐涂层在航空航天和石油化工等领域的研究重点.

Research Progress and Application of Phosphate Coatings

With the pressure for environmental protection and energy saving being more serious, green coatings have become the development trend of metal corrosion protection. Phosphate coating is a kind of inorganic coating with high mechanical strength, good thermal stability and high corrosion resistance, which is also non-toxic and environmental-friendly. Compared with metallic coatings and inorganic silicon coatings, phosphate coating has attracted more and more attention due to its simple preparation method and performance advantages and has been widely applied in construction, automobile, navigation, aerospace, medicine and other fields. The reaction cured phosphate coating and phosphate conversion coating were introduced. At first, the composition of the reaction cured phosphate coating, including adhesive, curing agent, functional filler and other additives was expounded and the studies on synthesis and proportion of adhesive, the curing mechanism and the selection of curing agents, the influence of functional fillers on the performance, and the influence of other additives on the overall performance and practical applications were introduced, respectively. Then, the film-forming mechanism of the phosphate conversion coating as the special phosphate coating and the common phosphating solution were introduced. The film-forming mechanism mainly included three steps which were the electrochemical dissolution of substrate, the crystallization and growth of phosphates, and the dynamic equilibrium between the dissolution and formation of phosphate conversion film. Typical phosphating solution includes zinc system, iron system, calcium system, manganese system, and their combinations. The application of phosphate coating in corrosion protection, high temperature resistance and some other functions was summarized. Finally, the development trend of phosphate coatings was prospected, and it was pointed out that the research would focus on the application of phosphate coatings in the fields of aerospace and petrochemical industry.