Crack behavior in Mg/Al alloy thin sheet during hot compound extrusion

A novel and effective method to co-extrude metallic alloys is described which named Direct Extrusion and Bending-Shear Deformation. The compound extrusion plates have cracked at 290 °C and 3 mm/s. According to this phenomenon, a model was built to investigate the crack generation and development between the 6061 Al and AZ31 Mg alloy during the compound extrusion process by DEFORM-3D. The cracking behavior of the Mg/Al composite rod with a soft Mg AZ31 core and a hard Al 6061 sleeve were systematically studied to disclose the influence of microstructure on crack in the different regions. The simulation results show that the distribution of strain and velocity has significant differences due to the influence of dies structure and material properties at different locations in the same region. The experimental results show that in the same conditions, there are differences in recrystallization and texture weakening of AZ31 Mg alloys and 6061 Al alloy, which are important factors for the formation of crack. Both the Mg layer and the Al layer have a homogeneous microstructure in the region d. Keywords: AZ31 Mg alloy, 6061 Al alloy, Compound extrusion, Crack, EBSD