ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY OF TWO DIFFERENT AGED STATUS OF A NEW TYPE Al-Cu-Li ALLOY TREATED BY DIFFERENT AGING PROCESSES

Electrochemical impedance spectroscopy (EIS) and the corrosion behavior of a new type Al-Cu-Li alloy in T6 aged and T8 aged status during corrosion process were studied.The corrosion resistance of T8-treated samples was better than that of T6-treated ones because of the deformation before aging.The difference of the two type samples in corrosion behavior was analyzed by microstructure observation,including grain boundary and sub-boundary,precipitates in matrix of samples before corrosion.Due to the deformation,precipitate T1 phase in T8-treated samples was smaller than that in T6-treated ones,which leaded to smaller stress caused by corrosion products in T8-treated samples.Thus,corrosion resistance of T8-treated samples was better than that of T6-treated ones.