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

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.