As a kind of cost-efficient hydrogen storage materials with high hydrogen capacity and light weight, Mg-based alloys have attracted much attention. This review introduces an effective technique in producing bulk ultrafine-grained (UFG) Mg alloys and promoting its hydrogen storage property, namely, equal-channel angular pressing (ECAP). This paper briefly describes the technical principle of ECA...

Tubular channel angular pressing (TCAP) process was proposed recently as a novel severe plastic deformation technique for producing ultrafine grain and nanostructured tubular components. In this paper, an upper-bound approach was used to analyze the TCAP process. Deformation of the material during TCAP process is analyzed using upper-bound analysis to determine maximum required load. The effect...

A study was carried out on the aging behaviour of a solution treated 6082 aluminium alloy deformed by equal channel angular pressing up to six passes. Aging of the so obtained ultrafine alloy was studied by DSC and TEM analyses as well as by isothermal treatments at 130, 160 and 180 C. The results showed that the formation of metastable 00 and 0 precipitates were markedly anticipated and that t...

Article history: Received 25 October 2015 Received in revised form 2 December 2015 Accepted 3 December 2015 Available online 17 December 2015 We investigated the strain rate sensitivity (SRS) of freestanding ultrafine-grained aluminum films with similar thickness (~240 nm) and mean grain size (~275 nm) but highly dissimilar texture. For (110) textured bicrystalline films, flow stress increased ...

Mechanism of fatigue crack initiation was investigated in ultrafine-grained (UFG) magnesium alloy AZ91 processed by equal channel angular pressing (ECAP). Fatigue behaviour of UFG material was compared to the behaviour of material in an initial as-cast state. Focused ion beam technique (FIB) was applied to reveal the surface relief and early fatigue cracks. Two substantially different mechanism...

A method is presented for recognition of nanograins in high-resolution transmission electron microscope (HRTEM) images of nanocrystalline materials. We suggest a numerical procedure, which is similar to the experimental dynamic hollow cone darkfield method in transmission electron microscopy and the annular dark-field method in scanning transmission electron microscopy. The numerical routine is...

In this paper, an extended accumulative roll bonding (ARB) technique, called the 'Four-Layer Accumulative Roll Bonding (FL-ARB)' technique, is presented for the first time. This technique has been employed to produce ultrafine-grained commercial pure aluminum sheets with success. After three FL-ARB passes, the grain size of pure aluminum was seen to reduce to 380 nm. The bonding strength of the...

The paper presents the evaluation of the mechanical and fatigue properties of an ultrafine-grained (UFG) Al 6061 alloy processed by high-pressure torsion (HPT) at room temperature (RT). A comparison is made between the UFG state and the coarse-grained (CG) one subjected to the conventional aging treatment Т6. It is shown that HPT processing leads to the formation of the UFG microstructure with ...