Influence of multi-microstructural alterations on tensile property inhomogeneity of 7055 aluminum alloy medium thick plate

The microstructure of an aged 7055 aluminum alloy medium thick plate at the center and edge was characterized and its influence on tensile property inhomogeneity through the thickness was investigated. The content of coarse second phases is higher and the size is larger at the center than the edge. The precipitates in grains have smaller sizes and a higher number density at the edge than the center due to macro-segregation in the ingot. A higher fraction of low angle grain boundaries (LAGBs) and a stronger β fiber rolling texture retain at the center owing to prevailed recovery, while more fine recrystallized grains exist and the fractions of Brass and Copper texture components obviously decrease at the edge due to higher degrees of recrystallization. The strength is higher at the center than the edge when loaded along RD and TD, while the strength difference between the edge and the center decreases when loaded along the direction of 45°. Moreover, the strength differences in RD, TD and 45° are higher at the center than the edge. The anisotropy of strength and inhomogeneity through the thickness can be mainly attributed to a stronger β fiber rolling texture at the center.