The recent development of electron sensitive and pixelated detectors has attracted the use four-dimensional scanning transmission microscopy (4D-STEM). Here, we present a precession diffraction assisted 4D-STEM technique for automated orientation mapping using spot patterns directly captured by an in-column scintillator based complementary metal-oxide-semiconductor (CMOS) detector. We compare r...

Nanotwinned metals have the potential for use as structural materials by virtue of having a combination of high strength as well as reasonable ductility and damage tolerance. In the current study, the tribological response of nanotwinned copper has been characterized under conditions of repeated frictional sliding contact with a conical tip diamond indenter. Pure ultrafine-grained copper specim...

The strength-ductility trade-off has been a long-standing dilemma in materials science. This has limited the potential of many structural materials, steels in particular. Here we report a way of enhancing the strength of twinning-induced plasticity steel at no ductility trade-off. After applying torsion to cylindrical twinning-induced plasticity steel samples to generate a gradient nanotwinned ...

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. ...

This paper reports the sliding wear properties and mechanisms of Hadfield high-Mn austenitic steel in a dry-sliding reciprocal tribotest against WC counterpart. The associated were studied through extensive characterisation obtained worn surface using analytical SEM, TEM, XRD micro-hardness test. revealed coefficient scale 10?14 m3·N?1·m?1 friction 0.5–0.6. encountered severe plastic deformatio...

Aging and quenching at critical temperatures were applied to a hot-rolled (HR) Fe-24.86Ni-5.8Al-0.38C (mass%) dual-phase alloy obtain B2 precipitates with various volume fractions sizes. Higher yield strength stronger strain hardening achieved in the aged samples compared these for HR sample, corresponding deformation mechanisms carefully revealed. The show hetero-deformation induced that sampl...

We present a unified mechanistic model to rationalize size-dependent flow stress, activation volume and strain-rate sensitivity for metals with either nanocrystalline grains or nanoscale twins. The non-uniform partial dislocation model for flow stress [Asaro and Suresh, Acta Mater, Vol. 53, pp. 3369–3382, 2005; Gu et al., Scripta Mater, Vol. 62, pp. 361–364, 2010] is generalized here to conside...

Odd electron diffraction patterns (EDPs) have been obtained by transmission electron microscopy (TEM) on silicon nanowires grown via the vapour-liquid-solid method and on silicon thin films deposited by electron beam evaporation. Many explanations have been given in the past, without consensus among the scientific community: size artifacts, twinning artifacts or, more widely accepted, the exist...

• Hcp nano-lamellae were induced by cryogenic dynamic deformation in a CoCrNi MEA. Size effect of hcp the MEA was studied MD for first time. Sample with small-spaced lamellae is even stronger than pure hard phase. Strength increases increasing/decreasing width/spacing nano-lamellae. More interfaces provide resistance dislocation slip and transmission. Deformation-induced various widths interspa...