recently, bulk nano-structured materials produced by severe plastic deformation (spd) have attracted scientists attention.  materials produced by spd are of great importance because of (1) non-porous structure, (2) great mechanical properties such as high strength and toughness and (3) proper dimension for mechanical and physical testing.  several methods have been introduced for imposing the s...

Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique. Quantitative analyses of the generated in situ Raman maps provide unique, new insight into the phase behavior of as-implanted a-Si. In particular, the ...

A special mechanism/mode of plastic deformation occurring through stress-driven rotations of low-angle grain boundaries (GBs) near crack tips in nanocrystalline and ultrafinegrained (UFG) materials is theoretically described. It is demonstrated that such rotations of GBs represent energetically favorable processes in wide ranges of parameters characterizing precracked specimens with nanocrystal...

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...

With regard to previous tensile deformation models simulating the tensile behavior of in-situ dendrite-reinforced metallic glass matrix composites (MGMCs) [Qiao et al., Acta Mater. 59 (2011) 4126; Sci. Rep. 3 (2013) 2816], some parameters, such as yielding strength of the dendrites and glass matrix, and the strain-hardening exponent of the dendrites, are estimated based on literatures. Here, Ti...

The incidence of failure of embedded pipelines has increased in Korea due to the increasing applied load and the improper compaction of bedding and backfill materials. To overcome these problems, a prefabricated lightweight plastic foundation using recycled plastic was developed for sewer pipelines. A small scale laboratory chamber test and two field tests were conducted to verify its construct...

Ultrafine-grained (UFG) metallic materials are at the cutting edge of modern materials science as they exhibit outstanding properties which make them very interesting for prospective structural or functional engineering applications. Due to the progress in severe plastic deformation techniques during the last decade, ultrafine-grained microstructures are no longer only restricted to easy to def...

Heterogeneous plastic deformation behavior of a coarse-grained Al-0.5%Mg multicrystal was investigated experimentally at the individual grain level. A flat uniaxial tensile specimen consisting of a single layer of millimeter-sized grains was deformed quasi-statically up to an axial strain of 15% at room temperature. The initial local crystallographic orientations of the grains and their evoluti...

We suggest a scalar model for deformation and flow of an amorphous material such as a foam or an emulsion. To describe elastic, plastic and viscous behaviours, we use three scalar variables: elastic deformation, plastic deformation rate and total deformation rate; and three material-specific parameters: shear modulus, yield deformation and viscosity. We obtain equations valid for different type...