Effect of microstructural evolution on mechanical properties of friction stir welded AA2009/SiCp composite

Microstructure and texture evolution during accumulative roll bonding of aluminium alloy AA5086

“…Strength improvement after ARB can primarily be attributed to grain refinement, although significant contribution is expected from large redundant deformation in this material. Eizadjou et al [12] have confirmed that strain hardening and sub-grain formation are mainly responsible for strength improvement up to the 4th pass and grain refinement dominates afterwards. The presence of a hard surface layer due to wire brushing may also lead to strength improvement to some extent [38].…”

“…6b inset. Such interface debonding has been frequently observed during tensile testing of ARB processed materials with interfaces being originally parallel to the loading direction [12,39]. Strain hardening due to redundant deformation does not contribute much in ductility reduction because of the positive effect from submicron grains in the microstructure [39].…”

“…DuringARB, deformation bands lead to the formation of shear bands under severe straining. This process eventually gives rise to a layered microstructure separated by high angle boundaries [12]. The equiaxed grains that are bounded by high angle boundaries at the inter-layer interfaces possibly result from continuous dynamic recrystallization.…”

“…During the next ARB pass, these surfaces appear in the middle of the sheet. Thereafter, rotation of shear component due to interfacial shear during further deformation leads to Dillamore component [12]. This component is closely located to copper component in the orientation space (please refer to Table 3 for exact location of these components), which sometimes makes them difficult to distinguish.…”

“…Different variations of SPD processes, e.g. equal channel angular pressing (ECAP), high pressure torsion (HPT), multi-axial forging (MAF), etc., have been successfully applied to fabricate UFG materials [4][5][6][7][8][9][10][11][12][13][14][15]. Accumulative roll-bonding (ARB) is one such SPD process which has great potential for industrial scaling up since it does not need forming facilities with large load capacity [16].…”