Deformation Characterization, Twinning Behavior and Mechanical Properties of Dissimilar Friction-Stir-Welded AM60/AZ31 Alloys Joint During the Three-Point Bending

Abstract

The AZ31 and AM60 alloys were used for dissimilar friction stir welding (FSW) in this study. The microstructure characteristics of the joint and its three-point bending performance were investigated. The electron backscattered diffraction results showed that the grains in the nugget zone (NZ) were more uniform and refined to a certain extent after FSW, but the grain size of AM60 in the NZ was larger than that of AZ31. The texture was strong locally in the NZ and presented a symmetric distribution characteristic from the advancing side to the retreating side. There were special texture features in the joint, resulting in the occurrence of severe strain localization during the bending process compared with the base materials, which can be well explained by the calculated Schmid factor in terms of the assumed stress state for bending. The bending tests revealed that the joint presented good bending properties compared with AZ31 BM. The bending fracture morphologies suggested that the fracture tended to the NZ interface on the AZ31 side, which was mainly due to the higher SF for basal slip and dislocation concentration degree in the region, and the relatively lower bending strength of AZ31 metal.

Heterogeneous Deformation Behaviors of an Inertia Friction Welded Ti2AlNb Joint: an In-situ Study

“…10d, e, microcracks generate from the B2/O boundaries owing to the stress concentration and expand along the B2 grain boundary under ~ 9% strain. Firstly, the slip incompatibility between B2 and O phases could lead to excessive stress at the B2/O boundaries, which causes the nucleation of microcracks [17,33]. Secondly, the B2 grain boundary is weak and brittle, attributed to the slow absorption of dislocations of HAGBs compared to the LAGBs [16].…”

Unusual Spreading of Strain Neutral Layer in AZ31 Magnesium Alloy Sheet during Bending

“…Therefore, bendability is an essential indicator that represents the formability of Mg alloy sheets. The evaluation and improvement of the bendability of Mg alloy sheets has attained adequate attention [15][16][17][18][19][20][21].…”