Mechanisms of grain refinement in aluminum alloys in the process of severe plastic deformation

Shear banding phenomenon during severe plastic deformation of an AZ31 magnesium alloy

“…The latter may end up subdividing the bands by high angle grain boundaries and in turn grain refinement. The occurrence of recrystallization in shear bands has been also discussed by Kaibyshev et al in aluminium alloys [23]. The occurrence of dynamic recrystallization refers to a process of negative work hardening, i.e.…”

Mechanisms of Dynamic Recrystallization in Aluminum Alloys

“…Any decrease in the critical strain imposed into an aluminum alloy to produce sub-micrometer scale or nanoscale structure is extremely important. The rate of the dynamic grain refinement is controlled by CDRX mechanism that, in turn, is strongly affected by the phase composition of aluminum alloys and the deformation temperature [7,10,14]. The aim of the present work is to give an outlook of CDRX mechanisms operating in different aluminum alloys in a wide temperature range.…”

“…This process provides the transformation of GNBs to sub-boundaries (Fig.3c) and is a prerequisite condition for a high rate of the (iii) process of CDRX. The combination of extensive deformation banding, which provides initial grain subdivision and introduce high misorientation, high stability of 3D arrays of sub-boundaries due to a high Zener drag pressure and a low portion of the lattice dislocations annihilated, allows producing UFG after relatively moderate strain [7][8][9][10][11][12][13][14]. Therefore, intermediate temperatures are optimal for the production of UFG structure in aluminum alloys.…”

Effects of Heat Treatment on the Mechanical Properties of Al-4% Ti Alloy

“…In reality grain refinement of aluminium by titanium is due to the occurrence of a peritectic reaction at the aluminiumrich end of the aluminium-titanium phase diagram [5,6]. A combination of titanium addition to aluminum alloy and other processing is thought as possible means of further improving the mechanical properties of this alloy especially for high temperature usage.…”