Related papers: Rough diamond anvils: Steady microstructure, yield…
Rough diamond anvils (rough-DA) are introduced to intensify all occurring processes during an in-situ study of heterogeneous compression of strongly pre-deformed Zr in diamond anvil cell (DAC). Crystallite size and dislocation density of Zr…
Severe plastic deformations under high pressure are used to produce nanostructured materials but were studied ex-situ. We introduce rough diamond anvils to reach maximum friction equal to yield strength in shear and perform the first…
The first in situ quantitative synchrotron X-ray diffraction (XRD) study of plastic strain-induced phase transformation (PT) has been performed on $\alpha-\omega$ PT in ultra-pure, strongly plastically predeformed Zr as an example, under…
Various phenomena (phase transformations, chemical reactions, and friction) under high pressures in diamond anvil cell are strongly affected by fields of all components of stress and plastic strain tensors. However, they could not be…
Plastic strain-induced phase transformations (PTs) and chemical reactions under high pressure are broadly spread in modern technologies, friction and wear, geophysics, and astrogeology. However, because of very heterogeneous fields of…
The first experiments in dynamic rotational diamond anvil cell (dRDAC) on severe plastic deformation (SPD) and BCC<->HCP phase transformation (PT) at pressure up to 27.6 GPa, rotation rates up to 1,500 RPM, and strain rates up to 2,094 /s…
The first study of the effect of the initial microstructure on its evolution under hydrostatic compression before, during, and after the irreversible $\alpha\rightarrow\omega$ phase transformation and during pressure release in Zr using in…
Deep-focus earthquakes that occur at 350-660 km are theorized to be caused by strain-induced olivine-spinel phase transformation (PT). We introduce and apply dynamic rotational diamond anvil cell with rough diamond anvils to deform San…
The transformation pathways of carbon at high pressures are of broad interest for synthesis of novel materials and for revealing the Earth's geological history. We have applied large plastic shear on graphite in rotational anvils to form…
Processes involving severe plastic deformations (SPD) and phase transformations and chemical reactions (PTs/CRs) under high pressures are widespread for obtaining new nanostructured phases and their processing, mechanochemical synthesis,…
Zirconium (Zr) is an important engineering material with numerous practical applications. It undergoes martensitic $\alpha$ to $\omega$ phase transformation (PT) at pressures that vary from 0.67 GPa to 17 GPa under different loading…
The microstructure and mechanical properties of materials saturate to steady states after severe plastic deformation (SPD). Despite the well-known effect of temperature on the steady-state microstructure, there is no general agreement on…
We have studied the surface of pure and oxidized Pt$_3$Zr(0001) by scanning tunneling microscopy (STM), Auger electron microscopy, and density functional theory (DFT). The well-annealed alloy surface shows perfect long-range chemical order.…
Surfaces of natural diamonds etched in high-pressure experiments in H2O, CO2 and H2O-NaCl fluids were investigated using Atomic Force Microscopy. Partial dissolution of the crystals produced several types of surface features including the…
Extreme pressures and temperatures create conditions that allow even hard and brittle materials to deform plastically. Despite extensive research, the upper limits of flow strength, the resistance to plastic flow, remain uncertain, and the…
Shear stresses are the driving forces for the creation of both point and extended defects in crystals subjected to high pressures and temperatures. Recently, we observed anomalous elastic materials response in shock-compressed silicon and…
We study the structural evolution of Sr$_3$Ir$_2$O$_7$ as a function of pressure using x-ray diffraction. At a pressure of 54 GPa at room temperature, we observe a first-order structural phase transition, associated with a change from…
The structural evolution of two selected compositions of Yttria-Stabilized Zirconia (YSZ), with 3mol% (3YSZ) and 8mol% (8YSZ) of Y2O3, have been investigated under pressure using in-situ synchrotron X-ray diffraction (XRD) and Raman…
In situ studies under severe plastic deformation at high pressures, employing rotational/shear diamond anvil cells (RDAC), have recently gained much interest in the high-pressure community owing to their potential applications in material…
Under high pressure conditions, Zr undergoes a phase transformation from its ambient equilibrium hexagonal close packed $\alpha$ phase to hexagonal $\omega$ phase. Upon returning to ambient conditions, the material displays hysteretic…