Effect of crystal orientations and precipitates on the corrosion behavior of the Al-Cu alloy using single crystals

•Single crystals with different orientations were prepared to investigate the corrosion behavior of the Al-Cu alloy.•The corrosion rates of the Al-Cu alloy varied in different crystal orientations.•The corrosion pits of the as-quenched alloy show the geometric shapes corresponding to the crystal orientations.•The corrosion of the aged alloy was propagated in the form of corroded bands that parallel to the {001}Al plane.•The precipitation of θ' phase significantly deteriorated the corrosion resistance of the Al-Cu alloy.