ECAP and Rolling: The influence of deformation path on strain distribution at severe plastic deformation

A.M. KLIAUGA; V. L SORDI; N. S. DE VINCENTIS; R.E. BOLMARO; N. SCHELL; R.E. BOLMARO

Cancún

Congreso; XXV International Materials Research Congress; 2016

MRS

It is well known that severe plastic deformation (SPD) is an effective processing tool for introducing exceptional grain refinement, and thereby producing a significant increase in the mechanical strength of metals and alloys. Grain fragmentation and dislocation accumulation, among other defects, proceed at different paces depending fundamentally on grain orientations, strain paths and active deformation mechanisms. On the current work we compare the strain distribution induced by equal channel angular pressing (ECAP) and the conventional rolling processes on some fcc alloys: aluminium, copper, and austenitic stainless steel. The accumulated strain was measured by Vickers hardness test and the tensile behaviour after deformation was evaluated by Tension tests. Williamson-Hall and Convolutional Multiple Whole Profile (CMWP) techniques were applied to peak broadening analysis on experimental results stemming from laboratory Cu Kα X-rays, and synchrotron radiation from LNLS (LaboratórioNacional de Luz Síncrotron, Campinas, Brazil) and Petra III line (HEMS station, at DESY, Hamburg, Germany). With increasing strain the average dislocation density increased while the individual crystalline size became smaller. These two quantities obeyed the Taylor relationship. When rolling is compared to ECAE, the rolling process produces small diffraction domains, almost as much or smaller than ECAE processing, but with the particularity of still allowing a highly preferred orientation of the crystals, i.e. strong texture and a more heterogeneous distribution of dislocations within the texture components.