Vol 14, No 4 (2018)
- Year: 2018
- Articles: 7
- URL: https://vestnikugrasu.org/byusu/issue/view/653
Articles
Change of electric properties of the border of the «metal-semiconductor» section under the effect of ion irradiation
Abstract
The paper first proposes a method of targeted direct transformation of the characteristics of a silicon bipolar high-power microwave transistor due to a change in the chemical composition at the «molybdenum - silicon» interface, the electrophysical properties of «molybdenum - silicon» contacts, and the electrophysical characteristics of transistor structure regions by irradiating «molybdenum - silicon» emitters with phosphorus ions transistor. The possibilities of this method are investigated and confirmed by experiments.
7-22
Controlled processes of the parameters transformation by ion beams in silicon bipolar microwave transistors
Abstract
The paper considers the formation of a transition layer of Mo - Si contacts, as well as the effect of Mo film deposition regimes and methods of heat treatment of contacts. It was found that when forming contacts of microwave transistors, by deposition of a Mo film on the surface of an epitaxial silicon layer, the structure of the latter depends on the dose of doping with phosphorus ions and on the temperature of post-implantation annealing. The results of experiments and two-dimensional physico-mathematical modeling to study the dependence of the parameters of test samples of the KT916A transistor depending on the dose of matching the emitters with phosphorus ions through a molybdenum film are presented. It is shown that with an increase in the doping dose, the surface and maximum concentration of phosphorus increases. At the same time, both energy and frequency characteristics of the transistor are improved, and the radiation resistance increases.
23-37
The sintering process limits grinding quartz powder in a planetary mill ago-2 with optimal energo tension
Abstract
The study of the agglomeration limit of quartz powder grinding at the AGO-2 planetary mill was carried out. For operation, several modes were selected, 3 basic modes with a coefficient of filling grinding media φ=0,5; 0,6; 07, as well as one additional mode with a filling factor φ=0,4 and a smaller proportion of quartz powder. The agglomeration limit for quartz during mechanical activation on AGO-2 is the average powder diameter of 1.5 µm, and the maximum value of the specific surface is 15,000 cm2/g. The paper proposes a method for calculating the energy intensity of the AGO-2 activator, by which it was possible to estimate the optimal mode of treatment of quartz to obtain ultrafine particles with a load factor φ=0,4 and a time of mechanical activation up to 60 seconds. Determination of the average size and specific surface area of the particles after mechanical activation was carried out by the method of gas permeability Of the pocket - Goat using the device PSH-11. Measuring the temperature of the mixture of grinding media and powder in the drum was made contact thermometer TK-5.09, equipped with a thermocouple 3V9-500.
41-48
Receiving radiation-resistant material by shs method
Abstract
All The first results of obtaining radiation-resistant material by the SHS method are presented in the article. Synthesis of material based on the system Fe2O3-Al-Cr2O3-MoO3-Ti. The resulting material was irradiated with an electron beam of 1.8 MeV. The synthesis process was filmed by an action video camera. Fourier image analysis revealed the instability of combustion regimes and predicted the quality of reaction products. A comparative analysis of the microstructure of the samples before and after irradiation with electrons confirmed the results of the FFT. Despite the relatively low quality of the synthesis products, the embrittlement occurred at the absorbed dose of 70 Mrad. In the future, it is planned to improve the methodology for identifying unstable synthesis modes and adjusting the percentage ratio of the charge components.
49-57
Visualization of the gas-dynamic structure of plasma flows of a pnk-50 plasma torchusing the shadow method
Abstract
The paper presents the study of the gas-dynamic structure of air plasma flows produced by the PNK-50 spray torch using the shadow (schlieren) method. The operation of the plasma torch was studied in three different configurations, differing, among other things, by the diameter of the output section of the channel: 6, 8, 10 mm. The subsonic and supersonic modes of operation of the plasma torch were investigated in the range of plasma-forming air flow 1.4-10.5 g / s and arc current range 140-230 A.In all typical modes of operation of the plasma torch, the flow has a developed turbulent structure with a full angle of jet opening between 23 and 27 degrees. An additional mode of operation of the plasma torch with an output nozzle diameter of 14 mm allowed the realization of a laminar flow regime. It is established that the laminar-turbulent transition is observed in the range of Reynolds numbers 400 - 900. The pattern of supersonic flow impinging a flat barrier - a substrate for placedat a distance of 85 mm from the plasma torch, is visualized.
61-68
Precision measurement of the velocity of propagation shs wave by the method of chrono-topographical analysis
Abstract
The paper describes a method for detecting reaction cells with a given depth of response on thermal images. A technique has been developed for the formation of chronographic and topographic maps of the process from the cells that make up the combustion front. It is shown that the integral chronographic map allows us to identify the ergodicity of the SHS process and reduce by 1-2 orders of magnitude the size of the confidence interval in the estimated propagation velocity of the combustion front. A method is proposed for measuring the propagation velocity of the SHS process, which takes into account the deviation in the orientation of the regular grid of the matrix sensor of the chamber from the normal to the combustion front. The method combines the analysis of chronographic and topographic maps and integrates two approaches to determining the direction of the normal: the analysis of spatial data of thermal images; control of the delay time of appearance of the reaction front in different normal sections. The estimation of the error of the method was performed in the course of experimental studies of the SHS phenomenon in the Ni-Al system. It is shown that for high-resolution thermal imaging data (5.8 μm and 2 ms) with a sensor size of 1 MP, the error is 0.05 %, and using higher-dimensional sensors or a tracking thermal control, you can achieve a value of 0.0005 %.
69-79
Development of software for registration and digital processing of spectrograms of heat radiation of heterogeneous particle flows in gas-thermal spraying process of coatings
Abstract
The article describes the functional blocks of the created software intended for registration and subsequent processing of spectrograms of thermal radiation of heterogeneous particle flows based on the BTC-110S spectrometer. Software in the form of a software package is planned for use in solving the problem of monitoring and measuring the temperature of a particle flow in the process of spraying functional coatings based on solving the “inverse” problem of restoring the temperature distribution of sprayed particles by of their “integral” thermal spectrum. The developed hardware-software complex for processing of spectrograms of thermal radiation of a particle flow can be used to optimize the regimes of gas-thermal spraying of coatings with effective performance characteristics.
83-89