镁合金自修复涂层研究进展

Self-healing Coatings Form Agnesium Alloys: A Review

镁合金的耐蚀性较差,使用过程常需要防护涂层。然而,涂层在使用过程中不可避免地遭到破坏,亟需开发自修复涂层以防止涂层破坏处的局部腐蚀。结合国内外在自修复涂层尤其是镁合金自修复涂层领域的研究成果,总结了自修复涂层的类型,包括化学转化膜型、掺杂型、填充型、微容器型、层层组装型和超分子本质修复型等。其中化学转化膜型承载的修复剂有限;掺杂型工艺简单,但可能降低涂层的稳定性;填充型可以减少修复剂对涂层稳定性的影响,但是可能降低层间结合力;微容器型可以阻隔涂层基体和修复剂,但需要满足多种条件;层层组装型能承载更多修复剂且修复过程更加智能;超分子本质修复型可以实现多次修复,但是修复过程常需要外部能量输入。通过比较各类涂层的特点,为研究者设计自修复涂层提供参考,并指出自修复涂层的设计需要根据实际情况,综合各类涂层的特点,完成修复剂的成功封装与释放,在保证涂层屏蔽性的基础上,赋予涂层自修复能力。

The corrosion resistance of magnesium alloys is poor, and coatings are required for actual applications. However, coatings are inevitably damaged during use. Thus, self-healing coatings shall be developed to avoid local corrosion of damaged spot on the coatings. By combining research achievements home and abroad in self-healing coating, especially for magnesium alloys, types of self-healing coatings including ichemical conversion coatings, mixed coatings, pore-filled coatings, micro-container coatings, layer-by-layer-assembled coatings and supramolecular intrinsic healing coatings were summarized. Chemical conversion coatings could only bear limited healing agents; mixed coating could be prepared by simple process but it might deteriorate stability of the coatings; pore-filled coatings could reduce the impact of healing agents on the coatings stability, but it may weaken the adhesion between porous coating and top coating; micro-container coatings could isloate healing agents from coating substrates, but it should meet many conditions; layer-by-layer-assembled coatings could bear more healing agents and its healing process was more intelligent; intrinsic supramolecular polymer could heal the same place for several times, but the healing process usually required external energy input. The characteristics of all self-healing coatings were compared to provide reference for researchers in designing self-healing coatings. In addition, the self-healing coatings should be designed based on the actual demands and self-healing agents should be sealed and released smoothly by allowing for characteristics of various coatings, so as to provide good self-healing capability for coatings while the shielding property was guaranteed.