W.H. El-Garaihy
Abstract
Nowadays, Equal Channel Angular Processing (ECAP) is one of the most appealing and potentially efficient Severe Plastic Deformation techniques (SPD) for fabricating Ultrafine Grained (UFG) and Nanostructured materials (NS) with sufficiently improved mechanical properties which has enabled this technique ...
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Nowadays, Equal Channel Angular Processing (ECAP) is one of the most appealing and potentially efficient Severe Plastic Deformation techniques (SPD) for fabricating Ultrafine Grained (UFG) and Nanostructured materials (NS) with sufficiently improved mechanical properties which has enabled this technique to be used in industrial applications. In this study, commercially pure aluminum was processed by ECAP through route A for up to 4 passes. A Finite Element (FE) analysis was carried out and compared to the experimental findings in order to investigate the effects of the geometric and the process’ parameters on the plastic deformation behavior of the work-piece during the ECAP process. The number of passes was selected as an input factor, while hardness values and compressive properties were modeled as the response. The total imposed stresses and strain as a function of the number of passes were examined. The FE analysis were carried out, yielding favorable results, concurring perfectly with the experimental findings and the microstructural evolution.
Waleed H. El-Garaihy; Ayman M. Alaskari; Eisa A. Ameshaiei; Samy E. Oraby
Abstract
A loading combination of hot compaction (HC) together with high-pressure torsion (HTP) was used to consolidate discs of AA6061 considering rotations up to 4 revolutions and loading pressure values of 1 and 3 GPa. Mathematical models were established to grasp the true functional interrelationships and ...
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A loading combination of hot compaction (HC) together with high-pressure torsion (HTP) was used to consolidate discs of AA6061 considering rotations up to 4 revolutions and loading pressure values of 1 and 3 GPa. Mathematical models were established to grasp the true functional interrelationships and variations in the resulting relative densities, mechanical properties, and micro-structural evolutions as affected by the HPT processing pressure and the imposed strain. Sequential iterative nonlinear regression procedures were employed to get the most suitable mathematical relationships that express the relationship between the variables under study. The developed models were examined for its adequacy and significance by using ANOVA analysis as well as many other statistical criteria. Response surface and contour graphs were established for a better understanding of the true functional dependence and, for a quantitative assessment of the intended relationships. It was observed that uniformity of hardness distribution increased with increasing each of the equivalent strain (εef) and the imposed pressure. A remarkable increase in the compressive strength of deformed discs has been observed. HPT processing produced a tri-model structure with micron scale grains and subgrains, and nano-scale substructure.
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