Influence of deformation extent on the microstructure and mechanical properties of aluminum alloy forging with complex shape

Influence of deformation extent of preforming on the microstructure and mechanical properties of 7A09 aluminum alloy rib-web type forging with complex shape was investigated by methods of tensile test, metallographic observation, TEM and SEM observation in order to obtain the optimal forming process. Results show that the intensity and the hardness are increased with the incremental deformation extent of performing, while the plasticity and the stress corrosion resistance are decreased. With the increase of deformation extent of preforming, the storage deformation energy increases and refined grains are gained. Moreover, the increase of storage energy is in favor of the increase of solid solubility and the precipitation of strengthening phase, which can enhance the tensity and the hardness of forgings. The decreased electrical conductivity is mainly the result of grain boundary increase caused by the grain refinement. Therefore, deformation extent should be adjusted by above laws according to the application requirement of the parts when the forming process is designed.