Effect of loading orientations on the microstructure and property of AlCu single crystal during stress aging

The precipitation behavior and property of AlCu alloy during stress aging under various loading orientations were investigated using single crystals. The resulting microstructures and the strength property were examined by transmission electron microscope (TEM) and compression test, respectively, and the effect of the distribution of θ′-plates on strength property were discussed. The results show that the precipitation distribution of θ′ was significantly affected by the loading orientation during stress aging of AlCu single crystals. Loading along close to 〈011〉Al directions provided more uniform precipitation distribution of θ′ as compared to loading along close to 〈001〉Al directions, and therefore provided higher strengthening stress of the θ′-plates for the stress aging sample. The results suggested that regulating the distribution of θ′ and therefore improving strength property are possible via controlling the loading orientation during stress aging.