Study On Deformation Microstructure Of AA 3104 Aluminum Alloy

The deformed microstructure of aluminum alloy is strongly related to the mechanical properties of aluminium alloy. In the present work we study the characterization of the microstructure and the effect of the grain boundary on the microstrcture of the deformed aluminum alloy, it is very useful to predict the deformed microstructure of the aluminum alloy.Some grains have the dislocation boundaries aligned with slip planes while others do not in deformed f.c.c. metals. Based on the Schmid analyze, the relationship of the type of the dislocation boundaries and grain orientation is determined. In plane strain compression, the Euler space of the f.c.c. metals can be divided into six regions, which are cube, r-cube, Goss, r-Goss, brass and copper orientation regions. The results show that the grains near the Goss, brass and S orientations have dislocation boundaries aligned with slip planes. The grains near the copper and rotated Goss orientation have dislocation boundaries far from the slip plan. Some grains with dislocation boundaries on slip plan and others not in the cube orientation region. The agreement between predicted and experimental data was excellent for both single crystals and polycrystals in f.c.c. metals.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 and 0.53 by plane strain compression. The microstructure and orientation gradient in the vicinity of grain boundaries were investigated using transmission electron microscopy. The results show that there is a significant difference in microstructures between the grain-boundary region and the grain interior, depending on the orientations of the neighbouring grains. The grain-boundary region usually displays smaller cells or subgrains and higher misorientation angles than the grain interior. A high orientation gradient is observed near the grain boundary, which corresponds to the difference in deformation microstructures. Based on the observations of the microstructure near grain boundary and crystal orientation, local dislocation density near a grain boundary was computed. The contour map of local dislocation content was presented that helps to visualize the heterogeneous deformation arising from the interaction between dislocations and grain boundaries. The contour map shows that the dislocation density exhibits a maximum at some distance from the grain boundary due to the relaxation of the pile-up stress generated in the neighboring grain.