A Novel Severe Plastic Deformation Method for Manufacturing Al/Mg bimetallic Tube

A new severe plastic deformation for manufacturing Al/Mg bimetallic tube called TES (Tube Extrusion Shearing) process, which combines direct extrusion with two step shearing, is developed to Al/Mg bimetallic tube. To explore the deformation mechanism for Al/Mg bimetallic tube during TES process, both experiments and numerical simulations have been carried out. The stroke loads during TES process of Al/Mg bimetallic tubes have been simulated by establishing three-dimensional finite element model. Experiments show that by use of TES process the microstructures can be refined to 50% of the original grain size and with more uniform grain distribution. TES process could improve hardness obviously by comparing which fabricated by direct extrusion. Numerical results indicate TES increases the cumulative strains effectively by direct extrusion and additional shearing. The micro-structures and mechanical properties of the bonded layer were analyzed, The results showed that under the extrusion temperature of 420℃, the bonding layer of the sample obtained by extrusion shearing had no hole defects, and the thickness was about 22um, among which the stable layer was about 11um.The average hardness of the bonding layer is 221HV.