Evaluation of microstructure and tensile behavior of fine-grained AZ61 alloy tube processed by severe plastic deformation

The aim of this study is to find the effect of the Parallel Tubular Channel Angular Pressing (PTCAP) technic as a Severe Plastic Deformation (SPD) method on microstructure and mechanical properties of as-extruded AZ61 magnesium alloy. The main reason to accomplish this research is to achieve certainty while this process could enhance the mechanical characteristics of magnesium alloy. To this end, the initial material was processed for one, two and three passes at 350 °C. Afterward, the microstructure was studied by optical microscope (OM) and scanning electron microscope (SEM). Next, to verify the mechanical properties alterations, tensile tests were performed for each specimen. Then, in order to investigate stress and strain status during the process, process simulations were fulfilled by employing the software Abaqus. Microstructure investigations revealed the fact that after just one pass, great grain refinement occurred within the material. Al4Mn as a secondary phase was noted for 1-pass, 2-pass and 3-pass processed specimens via scanning electron microscopy images and Energy Dispersive X-ray Spectroscopy (EDS) patterns. Finite elements method results illustrated the highest value of stress for the second half-cycle of the third pass. The maximum amount of strain tolerated by material belonged to the second half-cycles of the second and third pass. Finally, it could be reasoned that the best properties achieved for the 2-pass processed specimen possessed the best strength and deformability values.