Anomalous compressibility of quartz glass within the tensile stress domain and at elevated temperatures

To provide shock-wave experiments with the metrological characteristics of fused quartz applied as a window material, we measure the free surface velocity history and the particle velocity history under dynamic compression in different experimental arrangements. From these measurements, we obtain data on the material compressibility within the tensile stress domain and at elevated temperatures. We show that the anomalous compressibility of the fused quartz takes place not only under compression but also under tension. We measure the elastic compression adiabats within the temperature range from 20 to 340°C.     

Equation of state of polytetrafluoroethylene for calculating shock compression parameters at megabar pressures

Semi-empirical equations of state (thermal and caloric) are obtained to calculate not only the kinematic parameters (shock wave velocity, particle velocity, and reverberation of waves) but also the thermodynamic parameters (temperature, pressure, and compression) of monolithic and porous polytetrafluoroethylene at high shock pressures. The equations of state are used to model wave interaction in shock-wave experiments using the developed hydrocode. The equations are verified by comparison simulation results with published results of experiments and the data of our shock compression tests of solid and porous samples of PTFE in the range of 10–170 GPa.     

Ceramics based on partly stabilized zirconium dioxide: technology,structure, properties,and behavior under dynamic action

Technology is described for manufacturing dense ceramic from very fine powder based on zirconium dioxide partly stabilized with yttrium oxide. Some engineering properties of the manufactured ceramic are defined. Its microstructure and phase composition are studied. Ceramic properties with impact-wave loading are studied, and values of dynamic elastic limit and spalling strength are obtained.     

Method of measurement of the dynamic strength of concrete under explosive loading

Within the framework of the search for the method of determination of the strength properties of concrete under the action of an explosion or high-velocity impact, suitable for large scale concrete samples, the evolution of the compression pulse in plates or rods made of concrete with compressive strength of 30 MPa was investigated. It was found that wave configuration consisting of the ramped elastic precursor with insignificant stress jump at the front followed by a dispersed plastic shock wave is formed in the plates under uniaxial shock compression. In this experimental configuration, the compressive strength of the material is not identified. Experiments with concrete rods of various diameters have demonstrated the scalability of the wave process. It was established that the compressive fracture of the rods occurs at a distance of around twice their diameters and is accompanied by the fast decay of the load pulse after that weakly decaying elastic wave was propagated along the rods. The measurements of parameters of the compression pulse at the end of the fracture zone allowed us to determine the value of the dynamic compression strength of concrete equal to \(105\pm 20~\hbox {MPa}\), which turned out to be 3.5 times higher than the static strength.     

Synthesis,Thermal Expansion Behavior and Sintering of Sodium Zirconium Nickel and Calcium Zirconium Nickel Phosphates

Inorganic Materials - New NZP-type solid solutions, Na1+2xZr2–xNix(PO4)3 and Ca0.5+xZr2–xNix(PO4)3 with x = 0.10, 0.25, and 0.50, have been prepared by solid-state reactions. The...     

Synthesis, luminescence, and biocompatibility of calcium- and lanthanide-containing NaZr2(PO4)3-type compounds

Ca_0.5Zr₂(PO₄)₃:Er/Yb and Ca_0.75Zr₂(PO₄)_2.5(SiO₄)_0.5:Er/Yb compounds have been prepared and their luminescence properties and biocompatibility have been investigated. We found synthesis conditions that ensured phase homogeneity and formation of nanopowders. Their luminescence properties have been studied. Under IR excitation, emission was observed at ?? = 0.525 ??m. Cells (neutrophil granulocytes) were shown to retain viability in the presence of the compounds studied.     

The Spall Strength and Dynamic Yield Stress of Hafnium

Technical Physics Letters - The spall strength and dynamic yield stress of polycrystalline hafnium have been measured in a series of plane-wave shock loading experiments using flat...