Document Type: Research Paper
Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran
Circular simple shear extrusion process was introduced as a new geometry for simple shear extrusion technique to fabricate ultrafine-grained materials. Similar to the simple shear extrusion method, this process is also based on direct extrusion, and the samples deform in a simple shear manner. In this investigation, the simulations were carried out using the commercial finite element code ABAQUS/Explicit and the process was performed experimentally on commercially pure aluminum (AA1050) samples. Besides, the optimized length of the deformation channel was measured, 26 mm using the commercial simulation package DEFORM 3D. The effects of back-pressure and processing routes on deformation behavior and hardness homogeneity were studied in the simulation and experiment. Uniaxial compression test, X-ray diffraction, and Vickers microhardness test were performed on the samples to determine the mechanical and microstructural properties. The experimental results were in good agreement with the ones obtained by simulation. It was found that in the practical approach with the absence of back-pressure, route D had the most homogeneous distribution of strain in the cross-section and throughout the length of the samples. The results of compression and microhardness tests showed that the mechanical properties of the samples were improved compared to the annealing state. Also, a significant reduction in crystallite size can be seen in the XRD results leading to an average crystallite size of 103 nm after 10 passes.