The full annealing AA6061 aluminum alloy was subjected to severe plastic deformationvia the combination of equal channel angular pressing (ECAP) and cold rolling (CR) in order torefine its microstructure and to improve its mechanical properties. According to the results of hotand cold tensile tests, the combination of ECAP and CR significantly affected the final strengthand ductility of studied...

A microscopic phase field (MPF) model is formulated to describe quantitatively the core structure and energy of dislocations using ab initio data as input. Based on phase field microelasticity theory implemented in the slip plane using Green’s function to describe the longrange elastic interaction, the MPF model is a three-dimensional generalization of the Peierls model. Using the same generali...

A crack-free Ti-43Al-9V-0.2Y alloy sheet was successfully fabricated via hot-pack rolling at 1200 °C. After hot-rolling, the β/γ lamellar microstructure of the as-forged TiAl alloy was completely converted into a homogeneous duplex microstructure with an average γ grain size of 10.5 μm. The dynamic recrystallization (DRX) of the γ phase was systematically investigated. A recrystallization fract...

A nano/ultra-fine grain Al-0.2wt% Zr alloy was produced by accumulated roll bonding (ARB) processafter 10 cycles. The fraction of high angle grain boundaries increased from 8% to 65.4% during 10passes during ARB process. This alloy was subjected to tensile test at different temperatures (523,573and 623 K) and strain rates (0.1 and 0.01 s-1). The optimum condition of temperature and strain rate ...

There are typographical errors in the section entitled ‘‘Grain boundaries’’ in the PDF version of this Article, where ‘‘c’’ was omitted. The sentence ‘‘The formation energy of grain boundaries, , as function of the angle h is shown in Fig. 6c, as calculated by the CFF and DFTmethods.’’ should read ‘‘The formation energy of grain boundaries, c, as function of the angle h is shown in Fig. 6c, as ...

The unique nonuniform deformation characteristic of high-pressure torsion was used to produce nanostructures with systematically varying grain sizes in a copper disk, which allows us to study the grain-size effect on the deformation mechanisms in nanostructured copper using a single sample. The as-processed copper disk has 100–200 nm grains near its center and 10–20 nm grains at its periphery. ...

A crack trapping model is developed for the fracture resistance of high-angle grain boundaries in free-standing brittle thin films, based on which a new size effect is predicted. In addition to the crystallographic misorientations, the grain boundary toughness is also dependent on the film thickness, primarily due to the geometrically necessary crack front branching. 2007 Elsevier Ltd. All righ...

In this paper we consider a free boundary problem which describes contact angle dynamics on inhomogeneous surface. We obtain an estimate on convergence rate of the free boundaries to the homogenization limit in periodic media. The method presented here also applies to more general class of free boundary problems with oscillating boundary velocities.

Formation of crystalline defects due to cyclic martensitic transformations (CMT) in the iron-manganese Fe-18 wt.% Mn-2 wt.% Si alloy was investigated using X-ray diffractometry. Conditions for accumulation of fragment sub-boundaries with low-angle misorientations and chaotic stacking faults in crystal lattice of austenite and ε-martensite were analyzed.

In this paper we consider a free boundary problem which describes contact angle dynamics on inhomogeneous surface. We obtain an estimate on convergence rate of the free boundaries to the homogenization limit in periodic media. The method presented here also applies to more general class of free boundary problems with oscillating boundary velocities.