Fractographic Analysis of 5052 Al-Mg Alloys Processed by Equal Channel Angular Pressing

Abstract

In this work, ECAP technique has been applied to 5052 Al-Mg alloys where the alloys find wide application in building and construction, automotive, cryogenic and marine applications. The alloy samples extruded by ECAP with four different deformation routes for 4 passes each were tensile tested and the observation of the fracture surfaces were carried out by using digital camera and Scanning Electron Microscope (SEM). The experimental results showed that the initial pre-annealed sample showed cup and cone shape of fracture, whereas the fractured ECAPed samples of all deformation routes exhibited shear feature in which the fracture surface made an angle with pressing direction of ECAP. The change of size and shape of dimples fracture from larger and irregular shape dimples in initial sample to much smaller and grains-look like dimples in ECAPed sample indicating the grain refinement occurred after ECAP. Among the ECAP deformation routes applied, route BC resulted in smallest dimples size, i.e. about below 2 mm in average. The post annealing subjected to ECAP samples recovered almost completely the fracture feature and fracture morphology to that of the initial one, which was achieved after annealing at 300°C.