Severe plastic deformation of rheoforged aluminum alloy A356

In this research, the electromagnetic stirring (EMS) process was used to produce semi-solid slurry with globular structure from cast A356 aluminum alloy. Then the slurry was forged in a die, which named rheoforging process. Utilizing multidirectional forging (MDF), the effect of severe plastic deformation on microstructure and mechanical properties of this alloy in dendritic and globular states was investigated. Shear punch, micro- and macro-hardness tests were used to study the mechanical properties of these samples. For metallographic examinations, the optical microscope equipped with the Clemex® image analyzer software was used. Optimum globular structure of rheoforged specimens was achieved to deform those in three successful passes of MDF. The results show that more severe strain can be imposed on globular structure with respect to dendritic one. Also, MDF process can effectively improve the strength of the samples with no noticeable change in globules morphology of the rheoforged samples.