相关论文: Rough diamond anvils: Steady microstructure, yield…
Ultra-wide bandgap and the absence of shallow dopants are the major challenges in realizing diamond based electronics. However, the surface functionalization offers an excellent alternative to tune electronic structure of diamonds. Herein,…
In this study, we use discrete dislocation dynamics (DDD) simulation to investigate the effect of heterogeneous dislocation density on the transition between quasi-elastic deformation and plastic flow in face-centered cubic single crystals.…
The rheology of rocks transitions from a localized brittle behaviour to distributed plastic behaviour with increasing pressure and temperature. This brittle-plastic is empirically observed to occur when the material strength becomes lower…
When stressed sufficiently, solid materials yield and deform plastically via reorganization of microscopic constituents. Indeed, it is possible to alter the micro-structure of materials by judicious application of stress, an empirical pro-…
The deformation behavior of nearly fully pearlitic, bainitic and martensitic steels during severe plastic deformation is summarized in this paper. Despite their significantly different yield stresses and their microstructures, their…
The shear-transformation-zone (STZ) theory of plastic deformation in glass-forming materials is reformulated in light of recent progress in understanding the roles played the effective disorder temperature and entropy flow in nonequilibrium…
Molecular dynamics (MD) is employed to investigate the plastic deformation mechanisms of single crystalline yttria-stabilized tetragonal zirconia (YSTZ) nanopillars under uniaxial compression. Simulation results show that the nanoscale…
The yielding transition, structural relaxation, and mechanical properties of metallic glasses subjected to repeated loading are examined using molecular dynamics simulations. We consider a poorly-annealed Cu-Zr amorphous alloy periodically…
We present a combined experimental and theoretical study on the quasi-one-dimensional organic conductor (TMTTF)$_2$PF$_6$, and elucidate the variation of its physical properties under pressure. We fully resolve the crystal structure by…
The accurate prediction of solid-solid structural phase transitions at finite temperature is a challenging task, since the dynamics is so slow that direct simulations of the phase transitions by first-principles (FP) methods are typically…
We investigated the effects of uniaxial stress on the pressure-induced alpha-to-omega transition in pure titanium (Ti) by means of angle dispersive x-ray diffraction in a diamond-anvil cell. Experiments under four different pressure…
Shear banding is widely observed in natural fault zones as well as in gouge layers in laboratory experiments. Understanding the dynamics of strain localization under different loading conditions is essential for quantifying strength…
Brittle-ductile transition (BDT) is an important characteristic of amorphous (and semicrystalline) polymers. For a given strain rate, at temperatures above BDT, the polymers exhibit strain softening followed by yield and strain hardening,…
We use Shear Transformation Zone (STZ) theory to develop a deformation map for amorphous solids as a function of the imposed shear rate and initial material preparation. The STZ formulation incorporates recent simulation results [Haxton and…
We report a high-pressure study of orthorhombic rare-earth manganites AMnO3 using Raman scattering (for A = Pr, Nd, Sm, Eu, Tb and Dy) and synchrotron X-ray diffraction (for A = Pr, Sm, Eu, and Dy). In all cases, a structural and…
We demonstrate in this paper that atomic force microscopy can be successfully used to gain further insights into the understanding of transformation toughening in ceria stabilized zirconia. Transformation was induced by stresses accumulated…
A crystal plasticity theory was developed for use in simulations of dynamic loading at high pressures and strain rates. At pressures of the order of the bulk modulus, compressions o(100%) may be induced. At strain rates o(10^9)/s or higher,…
We report microscale friction experiments for diamond/metal and diamond/silica contacts under gigapascal contact pressures. Using a new nanoprobe technique which has sufficient dynamic range of force and stiffness, we demonstrate the…
Naturally-occurring granular materials often consist of angular particles whose shape and frictional characteristics may have important implications on macroscopic flow rheology. In this paper, we provide a theoretical account for the…
The paper presents a new approach, based on controlled oxidation of nanoscale metallic multilayers, to produce strong and hard oxide/metal nanocomposite coatings with high strength and good thermal stability. The approach is demonstrated by…