高性能轻合金表面三价铬转化膜工艺的研究进展

Research progress of trivalent chromium conversion coatings applied on high-quality light alloys

高性能铝、镁合金是典型高比刚度和比强度的轻质结构材料,而铝镁自身化学活性高,其结构件在腐蚀环境中易点蚀失效,严重影响轻质装备的长周期安全服役。因此,简单经济且高效耐蚀的表面转化膜处理技术备受青睐。本文从转化膜基本概念和分类出发,详细介绍了三价铬转化膜成膜机理和影响因素,重点评述了三价铬转化膜耐蚀性能和铬酸盐价态的影响因素,并总结了三价铬转化膜工艺发展的重要成果和存在问题,展望了其未来的发展趋势和研究热点。

High-quality aluminium and magnesium alloys are the typical light-weight materials with high values of specific strength and stiffness.However,the active chemistry of aluminium and magnesium leads to the high sensitiveness to the pitting corrosion and failure in the corrosive environments,threatening the long-term and safe operation and service of such equipment.In this sense,the economic and effective corrosion-protection conversion treatment technology is welcome in the industries.The present paper introduced the basic concept of conversion coating and its types simply,and then the formation mechanism and influencing factors of trivalent chromium conversion coatings in detail.The corrosion protection performance,chromium valence change and influencing factors were commentated specifically.The outstanding output and present questions of the TCP development were summarized.Finally,the future development and research hotspots were expected.