In this research, variant selection of martensite transformed from ultrafine-grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process and subsequent annealing was investigated with respect tomorphology of parentaustenitic phase. The results show that the original shape of austenite grain is very effective factor in determiningthe preferred variants of martensite transformed...

Micro-forming with ultrafine-grained (UFG) materials is a promising direction for the fabrication of micro-electro-mechanical systems (MEMS) components due to the improved formability, good surface quality, and excellent mechanical properties it provides. In this paper, micro-compression tests were performed using UFG pure aluminum processed by equal-channel angular pressing (ECAP) with subsequ...

the study of nucleation mechanism of new grains during severe plastic deformation of magnesium alloys is of great importance to control the characteristics of final microstructures.  to investigate the role of discontinuous recrystallization, a wrought az31 magnesium alloy was deformed by accumulative back extrusion process at 330 °c.  the obtained microstructures were studied using optical and...

A Ti–46Al(at.%) polysynthetically twinned alloy, which contained a characteristic lamellar spacing of k 1⁄4 1:3 lm, was converted to a polycrystalline fully-lamellar microstructure with k 1⁄4 19:9 nm using an a-phase solution treatment followed by a2 þ c aging. Tensile experiments, performed on microsamples extracted from within single grains of the polycrystalline material, illustrated that ul...

The study of nucleation mechanism of new grains during severe plastic deformation of magnesium alloys is of great importance to control the characteristics of final microstructures.  To investigate the role of discontinuous recrystallization, a wrought AZ31 magnesium alloy was deformed by accumulative back extrusion process at 330 °C.  The obtained microstructures were studied using optical and...

Data about an effect of cyclic γ-α-γ martensitic transformations on the structure state of reverted austenite Fe-31.7 wt.% Ni-0.06 wt.% C alloy are presented. The effect of multiple direct γ-α and reverse α-γ martensitic transformations on fragmentation of austenitic grains has been investigated by electron microscopy and X-ray diffraction methods. An ultrafine structure has been formed by nano...

Dynamic recrystallization (DRX) is an important grain refinement mechanism to fabricate steels with high strength and high ductility (toughness). The conventional DRX mechanism has reached the limitation of refining grains to several microns even though employing high-strain deformation. Here we show a DRX phenomenon occurring in the dynamically transformed (DT) ferrite, by which the required s...

High-resolution electron backscatter diffraction (EBSD) was used to examine the grain structure in long rods of ultrafine-grain (UFG) commercial-purity titanium produced for medical implants. The UFG material was obtained by equal channel angular pressing (ECAP) using a Conform scheme followed by rod drawing. The microstructure was found to be bimodal consisting of relatively coarse elongated g...

in this article, commercially pure copper samples were severely deformed by equal channel angular pressing (ecap) up to eight passes at room temperature. the effects of severe plastic deformation on the microstructure, mechanical properties, and electrical conductivity of the copper were investigated. the microstructure evolution was followed by optical microscope and field emission scanning el...

The accumulation of defects, and in particular He bubbles, can have significant implications for the performance of materials exposed to the plasma in magnetic-confinement nuclear fusion reactors. Some of the most promising candidates for deployment into such environments are nanocrystalline materials as the engineering of grain boundary density offers the possibility of tailoring their radiati...