Microstructure evolution of commercial-purity titanium during cryorolling

Electron backscatter diffraction and transmission electron microscopy have been used to analyze the microstructural evolution of titanium during rolling at a cryogenic temperature (T = –196°C). It has been found that intensive twinning at the cryogenic deformation temperature accelerates the kinetics of micro structure refinement. The quantitative analysis of microstructure evolution in titanium upon cryorolling has shown that structure evolution is mainly related to mechanical twinning in the initial stages cryorolling is discusse

Ionospheric effects during first 2 hours after the Chelyabinsk meteorite impact

This paper presents the analysis of ionospheric effects in the region close to the Chelyabinsk meteorite explosion at 03:20UT 2013 February 15 from the Institute of Solar-Terrestrial Physics of Siberian Branch of Russian Academy of Sciences (ISTP SB RAS) EKB radar data, and from the Institute of Geophysics of Ural Branch of Russian Academy of Sciences (IG UB RAS) PARUS ionosonde data. Both instruments are located within the IG UB RAS Arti Observatory approximately 200 km northward from the estimated explosion site. According to the data obtained, the ionospheric disturbance caused by the meteorite flyby, explosion, and impact had high dynamics and amplitude. However, it obviously did not lead to a variation in the ionosphere mean parameters in the region above the disturbance center during the first 2 hours. Essential effects, however, were observed at more than 100-200 km from the explosion site and farther up to 1500 km.Comment: 30 pages, 15 figures, submitted to JAST

Microstructure evolution of a ti/tib metal-matrix composite during high-temperature deformation

A Ti/TiB metal-matrix composite (MMC) was produced by spark plasma sintering using a Ti-10wt.%TiB2 powder mixture at 850°C under a load of 40 MPa for 15 min. The microstructure evolution and mechanical behavior of the Ti/TiB composite during uniaxial compression at the temperature range 500 - 1050°С was studie

Effect of second phase particles on mechanical properties and grain growth in a CoCrFeMnNi high entropy alloy

Effect of annealing of a cold-worked CoCrFeMnNi alloy at temperatures of 500-900°C for 1-50 h on the structure and mechanical properties was studied in the present wor

Effect of plastic deformation on the structure and properties of the Ti/TiB composite produced by spark plasma sintering

A Ti/17 vol % TiB composite material is produced by spark plasma sintering of a mixture of titanium and 10 wt % TiB2 powders at a temperature of 1000°C. Multiaxial isothermal forging is performed at t = 850°C to enhance the mechanical properties of the composit

Grain-structure development in heavily cold-rolled alpha-titanium

High-resolution electron back-scatter diffraction (EBSD) analysis was employed to establish mircostructure evolution in heavily cold-rolled alpha-titanium. After thickness reductions of 75% to 96%, significant microstructure and texture changes were documented. The surface area of high-angle grain boundaries was almost tripled, thus giving rise to an ultra-fine microstructure with a mean grain size of 0.6 μm. Moreover, orientation spread around typical ‘split-basal’ rolling texture substantially increased. These effects were suggested to be related to the enhancement of pyramidal 〈c+a〉 slip. Grain-structure development in heavily cold-rolled alpha-titanium (PDF Download Available

Evolution of microstructure and mechanical properties of Tibased metal-matrix composites during high-pressure torsion

The microstructure and microhardness evolution of a Ti/TiB and Ti15(wt.%) Mo/TiB metal-matrix composites (MMC) during high-pressure torsion (HPT) at 400 °C was studie

Kinetics of recrystallization and grain growth in an ultra-fine grained CoCrFeNiMn-type high-entropy alloy

A novel high entropy alloy based on the CoCrFeMnNi system with substantial amounts of Al and C was studied. After cold rolling and annealing at 973-1273 K a duplex ultrafine grained structure composed of the recrystallized fcc grains and M23C6 and B2 particles was produced. Analysis of the coarsening behavior of grains and particles growth suggested that kinetics of both was controlled by volume diffusion. The apparent activation energy of structure coarsening during recrystallization was evaluate

Novel wearable VCSEL-based blood perfusion sensor

A wearable 850 nm VCSEL-based blood perfusion sensor operating on the principles of laser Doppler flowmetry (LDF) and Dynamic Light Scattering (DLS) has been developed and tested. The sensitivity of the sensor to changes in skin blood perfusion has been demonstrated