Physicochemical Conditions of Boron–Siliconizing of Molybdenum-Based Alloys in Chlorine and Fluorine Medium
Tetiana Loskutova,
Michael Scheffler,
Vitalii Ivanov,
Inna Pohrebova,
Yaroslav Kononenko,
Maryna Bobina,
Nadiia Kharchenko,
Marian Bartoszuk,
Ivan Pavlenko
Affiliations
Tetiana Loskutova
Department of Physical Materials Science and Heat Treatment, Y.O. Paton Institute of Materials Science and Welding, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 37, Beresteiskyi Ave., 03056 Kyiv, Ukraine
Michael Scheffler
Faculty of Mechanical Engineering, Institute for Materials and Joining Technology, Otto-von-Guericke University Magdeburg, 2, Universitätsplatz, 39106 Magdeburg, Germany
Vitalii Ivanov
Department of Manufacturing Engineering, Machines and Tools, Faculty of Technical Systems and Energy Efficient Technologies, Sumy State University, 116, Kharkivska St., 40007 Sumy, Ukraine
Inna Pohrebova
Department of Electrochemical Production Technology, Faculty of Chemical Technology, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 37, Beresteiskyi Ave., 03056 Kyiv, Ukraine
Yaroslav Kononenko
Department of Physical Materials Science and Heat Treatment, Y.O. Paton Institute of Materials Science and Welding, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 37, Beresteiskyi Ave., 03056 Kyiv, Ukraine
Maryna Bobina
Department of Physical Materials Science and Heat Treatment, Y.O. Paton Institute of Materials Science and Welding, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 37, Beresteiskyi Ave., 03056 Kyiv, Ukraine
Nadiia Kharchenko
Department of Applied Materials Science and Technology of Structural Materials, Faculty of Technical Systems and Energy Efficient Technologies, Sumy State University, 116, Kharkivska St., 40007 Sumy, Ukraine
Marian Bartoszuk
Department of Machine Technology and Materials Science, Faculty of Mechanical Engineering, Opole University of Technology, 5, Mikołajczyka St., 45-271 Opole, Poland
Ivan Pavlenko
Department of Computational Mechanics Named after V. Martsynkovskyy, Faculty of Technical Systems and Energy Efficient Technologies, Sumy State University, 116, Kharkivska St., 40007 Sumy, Ukraine
The physicochemical conditions of the siliconizing and boron–siliconizing processes of molybdenum-based alloys in a closed reaction space in an environment of chlorine and fluorine at reduced pressure were studied. Theoretical calculations of the equilibrium composition of systems with the participation of silicon, boron, molybdenum, nitrogen, oxygen, chlorine, and fluorine were carried out, which made it possible to determine the influence of process parameters (temperature, composition of the reaction medium) on the probable phase composition of the obtained coatings. Based on thermodynamic calculations, the composition and rational consumption of the initial powders and the temperature intervals of the chemical heat treatment (CHT) during the complex saturation of molybdenum-based alloys with silicon and boron were modeled. It was established that it is advisable to use chlorine as an activator, which leads to the formation of molybdenum chlorides MoCl4 and MoCl3 in the composition of the gas phase and can indicate the flow of exchange reactions between chlorides and the matrix of the processed material in the reaction space. The rational saturation temperature of alloys based on molybdenum with silicon and boron is determined—1100–1250 °C. The possibility of the existence of condensed phases MoSi2, MoB2.15, B6Si, MoB1.65, and MoB is shown.
