Dilatometric analysis of aluminium alloy with submicrometre grained structure

Microstructure evolution during FSW/FSP of high strength aluminum alloys

“…4b, in this orientation an inclined grain boundary image contains only one central light band and two darker, broad bands. This pattern type is a typical feature of: (1) non-equilibrium GBs with high energy and (2) long range stresses caused by an absorption of a large number of lattice dislocations [17,18]. Dislocations were clearly detected in the larger grains, as can be seen in Fig.…”

“…4a). Specific "diffusive" diffraction contrast [17,18] of inclined grain boundaries (GBs) was also observed. As shown in Fig.…”

Producing bulk ultrafine-grained materials by severe plastic deformation

“…The term "severe plastic deformation" was fi rst introduced in a short paper describing the deformation of an Al-4% Cu-0.5% Zr alloy using high-pressure torsion, 7 but the term became widely recognized in the fi eld when it was subsequently used in an overview describing the structure and properties of UFG metals processed through SPD. 8 This latter paper also received very extensive attention and is now listed with more than 400 citations.…”

Grain refinement of aluminum alloys by friction stir processing

“…Similarly, the high boundary misorientations suggest that the very small grains formed in specimen A are not subgrain, but are grains separated grain boundary image contains only one central light band and two dark broadened bands. This pattern type is a typical feature of; (1) non-equilibrium GBs with high energy, and (2) long range stresses caused by the absorption of a large number of lattice dislocations [29,30]. These microstructure features clearly indicate that the nanocrystalline grains were created by discontinuous dynamic recrystallization (DRX) at elevated temperature during FSP, wherein some grain boundaries evolved by absorption of numerous dislocations provided by the surrounding structure.…”