材料工程2025，Vol.53Issue(10)：115-123,9.DOI:10.11868/j.issn.1001-4381.2023.000077
镁合金表面单宁酸转化膜的制备及性能
Preparation and properties of tannic acid conversion coating on magnesium alloy
摘要
Abstract
An environmentally friendly conversion coating is prepared on AZ91D magnesium alloy surface by chemical conversion method using tannic acid as the coating forming agent to improve corrosion resistance.The acid regulating the pH value of the conversion solution is selected by contrast experiment.The pH value,reaction temperature,and conversion time are optimized by the Box-Behnken test,and the optimum process conditions are obtained.The effect of pH value on the corrosion resistance of the conversion coating is also discussed.CuSO4 pitting time and electrochemical experiments are used to judge the corrosion resistance,SEM and EDS are used to characterize the coating surface morphology and element composition of AZ91D magnesium alloy.The results show that the optimum process of tannic acid conversion coating is as follows:tannic acid content 10 g/L,pH value 2.7(hydrochloric acid regulation),reaction temperature 41℃,conversion time 15 min.The conversion coating has good corrosion resistance,uniform density,and the covering is complete.The coating is mainly composed of tannic acid hydrolysate and Mg2+chelate.Box-Behnken test result shows that the pH value has a great influence on the corrosion resistance of the conversion coating.When the pH value is too low,the coating is rough and poorly compacted;while when the pH value is too high,the coating is thin and lacks continuity,which cannot completely cover the surface of the magnesium alloy.关键词
镁合金/单宁酸/转化膜/工艺条件/响应面法Key words
magnesium alloy/tannic acid/conversion coating/process condition/Box-Behnken分类
矿业与冶金引用本文复制引用
张书弟,许宇恒,何欢欢,刘琳坤,雷全达..镁合金表面单宁酸转化膜的制备及性能[J].材料工程,2025,53(10):115-123,9.基金项目
国家自然科学基金项目(51771050) （51771050）
