Crystallographic Texture Investigation of Thick Section Friction Stir Welded AA6082 and AA5083 Using EBSD

Abstract

In the present work, a FEI Sirion FEG-SEM equipped with a Nordlys CCD camera controlled by HKL Channel 5 software has been used to characterize the crystallographic texture of 20mm thick friction stir welded AA6082-T651 and AA5083-O. The crystallogaphic texture has been nvestigated near the top surface of the weld nugget at the shoulder affected region and near the base of the nugget in the probe affected region. The crystallographic texture in the shoulder affected region is complex in terms of determing the local reference frame of deformation and it requires complicated rotations to resemble the ideal simple shear texture. This implies the complex deformation histroy experinced in this region. However, the crystallographic texture in the probe-dominated region is simple shear texture. This implies that the deformation conditions across the whole weld nugget in this region are mianly dominated by the shear deformation generated by the probe rotation with the forward motion of the tool only playing a minor role in determining the local deformation gradient. Alternating bands between (+)and (C) was observed in the NG region of FSWed AA6082. The existence of A component is observed with an existence of strong C texture component which implies that when the C component is strong it can be associated with the A texture components.The crystallographic texture of AA5083 at both the shoulder and the probe dominated region is weak relative to that of the AA6082 .