Effect of grain orientation on microstructures during hot deformation of AA 3104 aluminium alloy by plane strain compression

AA 3104 aluminium alloy was deformed at a temperature of 510°C and at a strain rate of 5 s−1 to strains of 0.14, 0.53, 1.52, and 2.49 by plane strain compression. The effect of grain orientation on microstructures has been investigated using transmission electron microscopy (TEM). The results show that the grain orientation has a strong effect on the microstructures at low strains.

The microstructures can be classified into three types according to the process of grain subdivision and the characteristics of dislocation boundaries. Every type of microstructure is concentrated in a positive district in orientation distribution figure. The microstructures in grains near the brass and S orientations correspond to the Type AI microstructure.

The grains near the copper orientation appear as a Type AII microstructure. The Type B microstructure is found in the region near the rotated Goss orientation. The Type C microstructure is concentrated in the cube orientation. At large strains approximately equiaxed subgrains are observed.