A new method of low-temperature cementation of stainless steel by decomposition of C2H2 in low-energy electron beam generated plasma

The method of low-temperature (400-500?C) cementation of AISI430 stainless steel by decomposition of acetylene in a wide (100 cm2) low-energy (200-300 eV) electron beam generated plasma in an Ar+C2H2 gas mixture was investigated. The composition of a beam Ar+C2H2-plasma is investigated and it is shown that the degree of decomposition of acetylene varies with the current and energy of the electron beam. It is shown that the magnitude of the flow of acetylene significantly affects the formation rate and hardness of the hardened layer. From the obtained results it can be seen that at fixed values of argon pressure ( ∼ 0.8 mTorr), beam current (3.5 A), bias voltage (-120 V), sample temperature (500?C) and exposure time (3 h) increase in QC2H2 from 1 to 4-5 cm3•min-1 leads to an increase in the thickness and microhardness of the hardened layer. With a further increase in QC2H2, an abrupt decrease in the rate of formation of the hard layer occurs. © 2019 IOP Publishing Ltd. All rights reserved.Russian Foundation for Basic Research, RFBR: 18-38-00561_mol_аThe authors thanks to A.I. Medvedev for X-ray phase analysis of samples and Yu.S. Surkov for the optical emission spectroscopy researches. The work was financially supported in part by the RFBR (grant No. 18-38-00561_mol_а)

LOW-TEMPERATURE CEMENTATION OF STAINLESS STEEL IN A LOW-ENERGY ELECTRON BEAM GENERATED PLASMA

The method of low-temperature (350–500 °C) carburizing of 12Х18Н10Т stainless steel in a plasma of a wide (100 cm 2) low-energy (200–300 eV) electron beam in Ar + C2H2 gas mixture was studied. The optimal processing parameters were determined, which ensure the formation of a strengthened diffuse layer. Hardened surface layers with a hardness of up to 11 GPa in thickness up to 60 μm for 6 hours are obtained.Исследован способ низкотемпературной (350–500 оС) цементации нержавеющей стали марки 12Х18Н10Т в плазме широкого (100 см 2) низкоэнергетичного (200–300 эВ) электронного пучка в Ar + C2H2 газовой смеси. Определены оптимальные параметры обработки, обеспечивающие формирование упрочненного диффузного слоя. Получены модифицированные поверхностные слои твердостью до 11 ГПа толщиной до 60 мкм за 6 ч.Работа выполнена при поддержке гранта РФФИ, № 18-38-00561_мол_а

Investigation of the conditions for the formation of SiCN-based coatings in arc discharge with self-heated hollow cathode

Method for low-temperature (<200°C) deposition of SiCN-based coatings in a large volume chamber (0.3 m 3 ) by decomposition of organosilicon precursor in nitrogen-argon plasma of discharge with self-heated hollow cathode and remote anode (40 cm) at pressure of ∼1 mTorr was investigated. The analysis of the composition of coatings by IR spectroscopy and the analysis of plasma composition are carried out by optical emission spectroscopy. The influence of discharge current (10-40 A) and the flow of gas mixture (5-15 sccm hexamethyldisilazane and 60 sccm Ar-N 2 mixture) on plasma composition and elemental composition of coatings was investigated. It is shown that the degree of decomposition of precursor molecules is increased with growth of the current and with increase of Ar content in the gas mixture. © 2018 Web Portal IOP. All rights reserved.The study was financially supported by the Russian Science Fund, grant No. 18-79-00233

Obtaining of TiSiCN Coatings by Anodic Evaporation of Titanium and Decomposition of Hexamethyldisilazane in a Low-Pressure Arc Discharge

The method of TiSiCN-coatings deposition by anodic evaporation of Ti and decomposition of an organosilicon precursor (hexamethyldisilazane) in a low-pressure (∼1 mTorr) nitrogen-argon arc discharge with a self-heated hollow cathode is investigated. The plasma composition was analyzed by optical emission spectroscopy. TiSiCN coatings with a thickness of up to 10 microns and a hardness of up to 30 GPa were obtained in 1.5 hours at a temperature of 400 C. © Published under licence by IOP Publishing Ltd.The work was supported by the Russian Science Foundation (grant no. 20-79-10059)

Synthesis of Nanocomposite TiSiCN Coatings by Titanium Evaporation and Organosilicon Compound Activation in Hollow Cathode Arc Discharge

TiSiCN coatings have been obtained by anode evaporation of titanium and the decomposi-tion of hexamethyldisilazane in an arc discharge, using a self-heated hollow cathode, at the pressure rate of 1 mTorr of the Ar+N2 gas mixture. The proposed method makes it possible to independently and widely change the amount of metal and precursor vapor flows, the pressure and composition of the vapor-gas mixture and the degree of ionic interaction on the surface of the growing coating within a single discharge system. The paper presents the method and the results of the effect of a current discharge (10–50 A), and the flux of precursor vapours (0–1 g/h), on deposition rates, compositions, and properties of TiSiCN coatings deposited by an advanced combined PVD+PECVD method. Dense homogeneous TiSiCN coatings up to 6 µm thick and up to 27.5 GPa in hardness were obtained at 7.5 µm/h. The composition of the obtained coatings has been studied by X-ray diffraction and X-ray photoelectron spectroscopy, and it has been shown that the presented methods can form nanocomposite coatings with nanocrystallites TiC, TiN, and TiCxN1−x 3–10 nm in the amorphous matrix based on SiCN. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 20-79-10059Funding: This research was funded by Russian Science Fund, grant number 20-79-10059

Investigation of the Plasma Composition of a Discharge with a Self-Heating Hollow Cathode and an Active Anode in a Gas Mixture with Titanium and Hexamethyldisilazane Vapors

The analysis of composition of low-pressure (~0.1-1 mTorr) hollow cathode arc plasma in Ar+N2 gas mixture with Ti+hexamethyldisilazane vapors was carried out by optical emission spectroscopy. The influence of HMDS flow rate (1-10 g/h), discharge current (10-50 A) and Ti-vapors flow on hexamethyldisilazane decomposition degree and plasma composition and was investigated. The proposed plasma activation method provides both an intense flow and a high activation degree of metal vapors, and a sufficient decomposition degree of precursor vapors for the formation of solid TiSiCN coatings at a high deposition rate. Test coatings with a thickness of 6 microns and a hardness of 31 GPa were obtained in 1 hour at 400ºС. © 2021 Institute of Physics Publishing. All rights reserved.The work was supported by the Russian Science Foundation (grant no. 20-79-10059)

Effect of the Reactive Gas Activation Method on the Degree of Dissociation and Plasma Parameters of an ARC Discharge with a Hollow Cathode and Anode

The paper studies the influence of arc discharge parameters on the activation conditions of N2. The plasma spectrum and voltampere characteristics of a cylindrical probe are investigated. The degree of dissociation of N2 and the density of the ion current near the substrate are determined.Работа поддержана проектом РНФ № 20-79-10059

INFLUENCE OF THE COMPOSITION OF THE VAPOR-GAS MEDIUM ON THE HARDNESS AND DEPOSITION RATE OF TiN COATINGS DEPOSITED BY THE METHOD OF ANODIC EVAPORATION

Titanium nitride films were obtained by anodic evaporation of Ti in an arc discharge plasma at temperatures above 1700°C in Ar-N2 gas medium. The effect of nitrogen flow (1-20 ml/min), ion energy (0-250 eV), and titanium vapor flow on the deposition rate of TiN coatings and their hardness is studied.Работа выполнена при поддержке РНФ (грант № 20-79-10059)

Voice user identification in access control systems

На данный момент основным средством контроля доступа являются пропускные пункты, оборудованные различными средствами контроля доступа. Но большинство из средств контроля доступа имеют высокую цену. Причем большая часть расходов приходиться на выделение персонального средства идентификации каждому пользователю. Решением данной проблемы может стать голосовая идентификация. Использование биометрии позволяет отказаться от чипов и карт доступа, исключить потерю средства идентификации и его кражу. А использование голоса позволит отказаться от дорогостоящего оборудования для считывания данных.At the moment, the primary means of access control checkpoints are equipped with a variety of means of access control. But most of the access controls are expensive. And most of the costs fall on the allocation of personal identification means for each user. The solution to this problem is to voice recognition. The use of biometrics eliminates the chips and access cards, identification means to eliminate loss and theft. And the use of the voice will eliminate the expensive equipment to read the data