Plastic deformation behavior of Aluminum 5452 alloy under unconstrained high pressure torsion and effect of turns and applied pressures on their r*

High pressure torsion is an effective Severe Plastic Deformation method for producing nanostructured bulk materials. In this research, deformation behavior of Aluminum 5452 alloy disks obtained from unconstrained high pressure torsion has been studied. There is a region between adhesive zone and sliding zone defined as critical radius (r*) on vicinity of which, microhardness and effective applied strains (PEEQ) are more than those of other regions. Since Number of Turns and Applied Pressure are the most important parameters of HPT process, for studying their effects on r* of disks, in this research the process was simulated by applying conditions of previous experimental research. For this end, ABAQUS software was used and r* values were calculated and recorded. It was observed that by increasing N and applied P, r* values increase. For better studying the properties of disks obtained from unconstrained HPT process, the process was simulated under applied pressure of 2.7 GPa and 1, 2, 3 … and 10 turns. Eventually by using PEEQ distribution obtained from software, deformation behavior of disks in higher turns was analyzed, and specially the r* of unconstrained HPT that obtained from experimental tests and simulation, was examined.