The deformation microstructure of face-centered cubic cobalt subjected to surface mechanical attrition treatment was studied as a function of strain levels. Strain-induced c ! e transformation and twinning deformation were evidenced by transmission electron microscopy and were found to progress continuously in ultrafine and nanocrystalline grains as the strain increased. 2004 Acta Materialia In...

Abstract Metals with a bimodal grain size distribution have been found to both high strength and good ductility. However, the coordinated deformation mechanisms underneath ultrafine-grains (UFGs) coarse grains (CGs) still remain undiscovered yet. In present work, Cu 80% volume fraction of recrystallized micro-grains was prepared by annealing equal-channel angular pressing (ECAP) processed ultra...

In this paper, cyclic flaring and sinking (CFS) as a new severe plastic deformation (SPD) method was employed to produce the ultrafine grain (UFG) copper tubes. The extra friction has eliminated in the CFS method that provided the possibility for production of longer UFG tubes compared to the other SPD methods. This process was done periodically to apply more strain and consequently finer grain...

An ultrafine/nano grained AZ31 magnesium alloy was produced through four-pass ECAP processing. TEM microscopy indicated that recrystallized regions included nano grains of 75 nm. Pole figures showed that a fiber basal texture with two-pole peaks was developed after four passes, where a basal pole peak lies parallel to the extrusion direction (ED) and the other ~20° away from the transverse dire...

Austenitic stainless steels are extensively used in various applications requiring good corrosion resistance and formability. In the current study, the formation of nano/ ultrafine grained austenitic microstructure in a microalloyed AISI 304L stainless steel was investigated by the advanced thermomechanical process of reversion of strain-induced martensite. For this purpose, samples were subjec...

Al–Mg alloy powder was cryomilled to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic forging. The consolidation resulted in a bulk material with ultrafine grains of about 250 nm, and the material exhibited enhanced strength compared to conventionally processed Al–Mg alloy. The hardness of as-cry...

austenitic stainless steels are extensively used in various applications requiring good corrosion resistance and formability. in the current study, the formation of nano/ ultrafine grained austenitic microstructure in a microalloyed aisi 304l stainless steel was investigated by the advanced thermomechanical process of reversion of strain-induced martensite. for this purpose, samples were subjec...

This paper presents an overview of fundamentals and potential applications ultrafine-grained Al-based conductors developed with the help severe plastic deformation (SPD) techniques. Based on deliberate formation nanoscale features (such as nanoprecipitates, segregation solutes along crystallographic defects so on) within ultrafine grains, it is possible to optimise their mechanical functional p...

the effect of pre-existing nano sized precipitates on the mechanisms and rate of grain refinement has been investigated during the severe plastic deformation. a binary al–0.2sc alloy, containing coherent al3sc particles, of 3.62 nm in diameter has been deformed by accumulative roll bonding up to 10 cycles. the resulting deformed structures were quantitatively analyzed using electron backscatter...