基于二值图像的铝合金加速腐蚀损伤演化规律研究

Research on Evolution Process of Accelerated Corrosion Damage of Aluminum Alloy Based on Binary Image

将LY12CZ铝合金在EXCO溶液中加速腐蚀试验后,运用二值图像技术分析试样表面加速腐蚀损伤的演化过程,计算出不同加速腐蚀时间的孔蚀率和蚀坑数目.结果表明,LY12CZ铝合金在EXCO溶液中呈现先点蚀再晶间腐蚀最后剥蚀的腐蚀规律.腐蚀初期孔蚀率增加缓慢而蚀坑数目增加明显;腐蚀后期腐蚀速率加快,蚀坑逐渐连成一片,腐蚀加重,腐蚀形貌趋于复杂.

The corrosion behavior of LY12CZ aluminum alloy in exfoliation corrosion （EXCO） solution is studied with the accelerated corrosion test. Binary image technology is applied to the corrosion image processing. The corrosion area and the number of corrosion pits are calculated by image processing technique. Test results quantitatively show that the corrosion process of LY12CZ aluminum alloy corrosion in EXCO is pitting corrosion at first then intergranular corrosion and exfoliation corrosion at last. In the early stage of evolution of corrosion process, pitting corrosion rate increased slowly, and the number of corrosion pits increased significantly. As time increases, the small pits were connected each other to form big pits, pitting corrosion area became larger, corrosion became more serious and corrosion morphology became complicated.