Large-scale production of high purity (99.999%), nano-twinned, and ultrafine-grained copper foils (22 m thick) was successfully implemented by the use of nanoscale multilayer technology. The process allows the production of up to fourteen 10 cm diameter foils during a single deposition run with high levels of reproducibility. Mechanical tests demonstrate that the strength of the Cu foils (σy ∼ ...

Accumulative roll-bonding (ARB) is a severe plastic deformation process that is using rolling to produce ultrafine grains in coarse grained metallic materials. In this study, ARB has been applied on 70/30 brass up to 6 cycles at ambient temperature and non-lubricated conditions to apply a true strain up to 4.8 Von Mises strain. Microstructures of ARBed brass samples were characterized by scanni...

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...

in this study, the effects of nitrogen addition on the production of ultrafine/nano grained aisi 201l stainlesssteel by advanced thermo-mechanical process were investigated. cast samples were first homogenized at 1200 °c for 4 h, hot-rolled at 1100 °c and finally, solution-annealed at 1150 °c for 2.5 h. unidirectional and cross multipass cold rolling at 25 °c was carried out to 90% reduction in...

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...

For the first time, tribological behaviour of 316 L stainless steel (316 SS) additively manufactured via laser powder bed fusion (L-PBF) with ultrafine- and nano-grains obtained from high-pressure torsion (HPT) processing has been investigated. The pin-on-disk dry sliding wear test results demonstrate enhancement performance after HPT processing, as indicated by consistently lower coefficient f...

Al 5083 alloy powder was mechanically milled in liquid nitrogen to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic (QI) forging. The consolidation resulted in ultrafine grains (UFG) of about 250 nm, and the bulk material exhibited enhanced strength compared to conventionally processed Al 5083. T...

Ambient and cryogenic surface mechanical attrition treatments (SMAT) are applied to bcc iron plate. Both processes result in significant surface grain refinement down to the ultrafine-grained regime; the cryogenic treatment results in a 45% greater grain size reduction. However, the refined region is shallower in the cryogenic SMAT process. The tensile ductility of the grain size gradient remai...

We have investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Tra...