Advanced Materials Research Vol. 1040

Abstract: The possible ways of shale destruction under electrophysical treatment were discussed. The products destruction were analyzed by GC-MS, DTA-TG and elemental analysis. The pyrolysis products formation was shown.

Abstract: The experimental results show that the relative permittivity in the threadlike silver azide crystals changes under the influence of the polarization field (10^-3 ÷ 10³ V/m). An amount of the formed intermediate product at a weak noncontact electric field decreases significantly that allows assuming that polarization influences primarily, at the stage of formation of the silver azide decomposition intermediate. The polarization in a constant noncontact electric field may be regarded as a control method of explosive sensitivity.

Abstract: The article reports on the aspects of reactive deposition ultra-thin TiO_x films (50 nm) by means of dual magnetron system with mirror and closed magnetic field (B field) configurations. The hysteresis effect of electrical discharge characteristics and oxygen partial pressure P(O₂) are presented. The dual magnetron with closed B field configuration has less hysteresis peculiarities and transits back to metallic deposition mode at higher O₂ flow rate (Q). The deposition rates don’t depend on B field configuration and correlate with changing of P(O₂) and discharge voltage. The refractive spectra and energy of band gap, which are measured by UV-visible spectrophotometry and ellipsometry (λ=632.8 nm) methods, have strong dependence on Q(O₂).

Abstract: In the article changes in the structure and mechanical properties of R6M5 steel surface layer after electrolytic-plasma nitriding are shown. The optimal mode of electrolytic-plasma nitriding of R6M5 high-speed steel in electrolyte based on carbamide, which allows saturation of the surface with nitrogen from low-temperature plasma and get the modified layer of high hardness and wear-resistance. It is established, that after electrolytic-plasma nitriding reduced R6M5 steel wear rate and increases its resistance to abrasive wear. Perspectivity of use an electrolytic-plasma nitriding method to improve performance cutting tools made from R6M5 steel is shown.

Abstract: A method of surface alloying of titanium substrates with tantalum in order to obtain corrosion-resistant layers is described. An electron beam injected into the atmosphere is used as a power source. A powder layer containing a composition of alloying components and a fluxing agent was placed on the surface of a Ti plate. The plate exposed to a scanning beam was moved at a speed of 1cm/sec. The scanning range was 5cm, the scanning frequency was 50 Hz and the beam power was 33.5 kW. To enhance the degree of alloying the coating procedure was repeated up to 4 times. Alloyed layers 2-3 mm thick containing up to 40 wt % Ta were obtained. The rate of corrosion in HNO₃ depends on the Ta concentration in the deposited material. It is tens and hundreds times lower than the rate of corrosion of unalloyed titanium for all coatings. Surface deposition by the proposed method can be used to protect internal surfaces of chemical reactors operating in media containing aggressive acids at increased temperatures up to the boiling temperature.

Abstract: Recently, the world's evolving experimental design and research work on the creation of technological methods and systems of layered laser synthesis products of machine parts. These systems allow to accelerate the introduction of new technology at all stages of product design to create its original layout in full size. There are currently variety of methods sintering of metal powders.This paper presents experimental data which show the effects of the strategy of forming a sintered layer in the synthesis of products by SLS.

Abstract: Metal powders are widely used in many modern technologies, as well as they have been applied in the form of various fillers composites. Recently, in some cases, the preliminary activation of metallic powders is made to improve the compatibility of the filler and the matrix. Undertook a study describe the influence of gamma radiation radioactive isotope Co⁶⁰ on copper powder. Gamma radiation also affects the character of laser sintering by layer-by-layer synthesis. Through this change was obtained in structure and the properties of the powder. On the whole it affects the process of layering laser sintering products.

Abstract: In this paper structure and mechanical properties of Ni₃Al intermetallic compound was studied. The materials was fabricated according to different schemes, which combined mechanical alloying of Ni and Al powders, self-propagating high temperature synthesis (SHS) and spark plasma sintering (SPS). Relative density of all sintered samples was ~ 97 %. Microhardness of the sintered materials ranged from 6100 to 6300 MPa. SPS of 86.71 % wt. Ni and 13.29 % wt. Ni powder at 1100 °C led to formation of material with the highest level of tensile strength equal to 400 MPa.

Abstract: The surface layer of steel was reinforced by electron-beam cladding at air atmosphere. Two types of powder mixtures were used to receive coatings: (1) titanium and graphite, (2) titanium and boron carbide. The formation of heterogeneous structure was observed in specimens after the electron-beam treatment by the methods of optical microscopy and scanning electron microscopy. The X-ray diffraction analysis was used to analyze the phase composition of the coatings. The wear resistance level of the coatings was estimated by friction test against loosely fixed abrasive particles. It was found that surface alloying of steel with carbon containing components led to the formation of material with an enhanced wear resistance level.

Abstract: The cladding of titanium and graphite powders on the cp-titanium workpieces using the electron beam injected to the atmosphere provided the formation of the surface layers with a high content of high-strength carbide particles. The main structural components in cladded layers are α-Ti (αʹ-Ti), titanium carbide and graphite. Electron beam current is the main technological parameter defining a thickness of the hardened layer. An increasing beam current ranged from 20 to 23 mA leads to the cladded layer growth up to 2.9 mm. However, in this case a significant decrease of the microhardness level and the wear resistance level of the cladded layer is not observed. An average microhardess value of the hardened layer is of 430 HV. Under the conditions of friction against fixed abrasive particles, a wear resistance level of the cladded layers is by 32-45 % larger than that of cp-titanium.