挤压镁合金腐蚀与防护研究进展

Progress in Corrosion and Protection of Extruded Magnesium Alloys

随着挤压镁合金的广泛应用,如何改善其较差的耐蚀性自然成为无可回避的重要研究课题。通过综合分析国内外挤压镁合金腐蚀研究领域的相关研究成果,从腐蚀行为与防护技术两个方面进行了讨论。挤压镁合金易于受到多种腐蚀形式的破坏,其腐蚀行为、性能和机理受到材料特性和腐蚀环境等多种因素的影响,表现出多样性和复杂性,特别是应力和腐蚀协同所用下的挤压镁合金失效行为,尚需开展深入研究。通过优化制备工艺参数、合金化和热处理等技术进行组织和成分优化,基于应力条件、不同的腐蚀环境,开发新型耐腐蚀挤压镁合金,对于提高挤压镁合金抗腐蚀性能,扩大其应用领域具有实用价值。电化学镀、化学转化膜、自修复涂层等涂层技术在合金表面形成钝化膜、陶瓷膜以及释放缓蚀剂,对挤压镁合金提供了有效防护。其中,自修复涂层能够有效解决涂层破损产生的局部腐蚀问题,极大地改善了膜层的防护性能,拥有良好的应用前景,是涂层研发的新方向。

With the wide application of extruded magnesium alloys, how to improve its poor corrosion resistance has naturally become an important research topic inevitably. Through comprehensive analysis on relevant research results in the field of corrosion research of extruded magnesium alloys at home and abroad, the corrosion behavior and protection technology have been discussed. Extrusion magnesium alloy is easy to be damaged by many kinds of corrosion forms, and its corrosion behavior, performance and mechanism are affected by many factors such as material characteristics and corrosion environment, showing diversity and complexity. In particular, the failure behavior of extruded magnesium alloy under the synergistic effect of stress and corrosion needs to be further studied. The microstructure and composition were optimized by optimizing the preparation parameters, alloying and heat treatment. Based on the stress condition and different corrosion environment, the development of a new type of corrosion-resistant extruded magnesium alloy is of practical value for improving the corrosion resistance of extruded magnesium alloy and expanding its application field. Electrochemistry plating, chemical conversion coating, self-healing coating and other coating technologies provide effective protection against extruded magnesium alloy by forming passivation film, ceramic film and releasing corrosion inhibitor on the surface of the alloy. Among them, the self-healing coating can effectively solve the local corrosion problem caused by the damage of the coating, greatly improve the protective performance of the film layer and is a new direction of coating research and development due to good application prospect.