Electro-explosive alloying of VT6 alloy surface by boron carbide powder with the subsequent electron-beam treatment

The formation of electro-explosive alloying zone with the thickness up to 50 µm has been revealed. It has been shown that it has a gradient structure, characterized by the decrease of carbon and boron concentration with the increase of the distance up to the treatment surface. The subsequent electron-beam treatment of alloying zone leads to flattening of alloying surface relief and is accompanied by the formation of a multilevel structure at the depth up to 30 µm, characterized by the interchange of some layers with a different level of alloying, having structure of a submicro- and nanoscale level

Study of highly defective titanium dioxide prepared via pulsed laser ablation

TiO2 powder was synthesized in the following way. At first, a colloidal solution of Ti in distilled water was obtained by PLA using Nd:YAG laser (wavelength of 1064 nm, frequency of 20 Hz, pulse duration of 7 ns). Then the colloidal solution was dried at 60 °C. After that, the powder was annealed at different temperatures

Effect of laser treatment of TiO2 on optical and photocatalytic properties

Nanomaterials based on dark titanium dioxide are of considerable interest as promising photocatalysts. In this work, titanium dioxide initially obtained by pulsed laser ablation (Nd:YAG laser with 1064 nm, 7 ns, 20 Hz) was subjected to additional laser treatment. The thus obtained powder materials were annealed and study of the structure by X-ray diffraction, optical properties by diffuse reflection spectroscopy, and photocatalytic properties in the processes of decomposition of the Rhodamine B dye and evolution of hydrogen from an aqueous methanol solution are presente

The Effect of vapor subcooling on film condensation of metals

This work presents an analysis of the interfacial "vapor-condensate" temperature distribution, which includes the effect of subcooling (supersaturation) in the vapor. Experimental data from previous investigators for different metals were analyzed. It is shown that taking into account this subcooling effect permits the thermal interphase resistance to be described with assumption of [sigma] = Constant = 1.0 where[sigma] is the condensation (mass accommodation) coefficient.Sponsored by National Science Foundatio

Improving the Mechanical Properties of SiC-ceramics by means of Vacuum Electron-ion-plasma Alloying with Titanium

The investigation results of elemental and phase composition, state of defective substructure and microhardness of the surface layer of "film (Ti)/substrate (SiC-ceramics)" system (Ti film 0.5 [mu]m thick was deposited on the surface of SiC-ceramics) subjected to treatment with an intense pulsed low-energy electron beam (15 J/cm{2}, 200 [mu]s, 0.3 s{-1}, 20 pulses) are presented. It is shown that irradiation of the "film (Ti)/substrate (SiC-ceramics)" system with an electron beam is accompanied by the formation of multielement multiphase (SiC; TiC; Ti5Si[3]) surface layer having submicro- and nanocrystalline structure. Microhardness of the irradiated surface layer reaches a value of 74 GPa, that is twice the value of microhardness of SiC-ceramics (36 GPa)

Surface structure of commercially pure VT1-0 titanium irradiated by an intense pulsed electron beam

It is shown that pulsed electron beam irradiation of commercially pure titanium at a beam energy density of 10 J/cm{2}, pulse duration of 150 [mu]s, number of pulses of N=5 pulses, and pulse repetition frequency of 0.3 Hz with attendant polymorphic [alpha]->[beta]->[ alpha] transformations allows a more than five-fold decrease in the grain and subgrain sizes of the material structure

Improving the Mechanical Properties of SiC-ceramics by means of Vacuum Electron-ion-plasma Alloying with Titanium

The investigation results of elemental and phase composition, state of defective substructure and microhardness of the surface layer of "film (Ti)/substrate (SiC-ceramics)" system (Ti film 0.5 [mu]m thick was deposited on the surface of SiC-ceramics) subjected to treatment with an intense pulsed low-energy electron beam (15 J/cm{2}, 200 [mu]s, 0.3 s{-1}, 20 pulses) are presented. It is shown that irradiation of the "film (Ti)/substrate (SiC-ceramics)" system with an electron beam is accompanied by the formation of multielement multiphase (SiC; TiC; Ti5Si[3]) surface layer having submicro- and nanocrystalline structure. Microhardness of the irradiated surface layer reaches a value of 74 GPa, that is twice the value of microhardness of SiC-ceramics (36 GPa)

Effect of extra laser irradiation on the photocatalytic properties of TiO2 obtained by pulsed laser ablation

in this work we study the effect of extra laser irradiation during the preparation by pulsed laser ablation in water on the structure and physicochemical properties of titanium dioxide. Extra laser irradiation leads to a decrease in particle size, a change in structure, and as a result, a change in optical and photocatalytic properties