668.045.18

molybdenum, tungsten, plasticity, heat treatment.

The recommended ways of improving the technological and physico-mechanical properties of refractory metals (molybdenum and tungsten) after diffusion annealing in several stages are described. In order to significantly increase the technological characteristics and transition to stricter conditions of operation of products made of refractory metals, it is necessary to improve the already existing methods of metal processing and make significant changes in the development of new ones. Different directions of processing of refractory metals have been studied and analyzed, which involve the process of heating and cooling of metals, while their near-surface layers receive certain complex technological processes of redistribution of chemical components. A certain part begins to migrate to the surface of the metal-vacuum distribution, another part moves into the depth, and still another part remains without movements. The behavior of carbon, oxygen and nitrogen penetration elements was studied when molybdenum and tungsten were heated to a temperature of 800 ^oC and then cooled to room temperature. To evaluate changes in the mechanical properties of molybdenum and tungsten after diffusion annealing, appropriate tests were conducted. In order to study the changes in the technological and physico-mechanical properties of refractory metals after the process of diffusion annealing in an active powder environment, bending and buckling tests were conducted. Conducted studies on the content of oxygen in refractory metals during the second heating showed that its concentration in tungsten decreases by almost two times, and in molybdenum by five times. The technological process of purification refractory metals can be significantly accelerated if molybdenum and tungsten are heated in pulse mode, which involves heating and cooling, as is known, this method of thermal treatment of metals stimulates the processes of transfer of impurities penetrating from the depth of the volume of metals to their surface. The conducted studies established that after the first diffusion annealing, the plasticity coefficient of molybdenum increased by 3–4 times, and that of tungsten by 2–3 times, compared to untreated samples of refractory metals. Based on the analysis of literature data and conducted research, a set of measures aimed at improving the technological and physico-mechanical properties of refractory metals (molybdenum and tungsten) after diffusion annealing in an active powder environment is proposed.

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3. Buketov A., Stukhlyak P., Maruschak P., Panin S., Menou A. Regularities of impact failure of epoxy composites with Al₂O₃ microfiller and their analysis on the basis of external surface layer concept. Key Engineering Materials, 712, 2016, pp. 149–154.
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7. Leonid G. Kozlov, Leonid K. Polishchuk, Oleh V. Piontkevych, Roman. M. Horbatiuk, Mykola P. Korinenko, Paweł Komada, Sandugash Orazalieva, Olga Ussatova. Experimental research characteristics of counterbalance valve for hydraulic drive control system of mobile machine. Przegląd elektrotechniczny. ISSN 0033-2097, R. 95, Vol. 2019. No. 4. pp. 104–109.
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11. Bochar I., Horbatyuk R. Increasing the plasticity of molybdenum and tungsten. Bulletin of the Ternopil State Technical University, 2000, vol. 5, no. 1, рр. 16–20. [In Ukrainian].
12. Bochar I. Y., Dzyadykevich Y. V., Horbatyuk R. M. The composition of the mixture for boronizing products from silicon carbide and molybdenum disilicide (patent), no. 30237 A dated November 15, 2000 Bull, no. 6–11. [In Ukrainian].
13. Bochar I. Y., Dzyadykevich Yu. V., Horbatyuk R. M. The composition of the mixture for silicification of silicon carbide and molybdenum disilicide products (patent), no. 30239 А dated November 15, 2000 Bull, no. 6–11. [In Ukrainian].
14. Bochar I., Horbatyuk R. Properties of the protective composition applied to the surface of ceramic materials. Scientific Notes Series: Engineering Mechanics. Lutsk: LNTU, no. 24, 2009, рр. 21–28. [In Ukrainian]
15. Bochar I., Horbatyuk R. Influence of activators on the process of diffusion saturation of SiC and MoSi₂ with silicon and boron. Bulletin of the Ternopil State Technical University, 2002, vol. 7, no. 1, рр. 19–26. [In Ukrainian].

1. Bochar I. Y., Loskutov V. F., Khizhnyak V. G., Pogrebova I. S., Horbatyuk R. M. Carbide coatings on steels and hard alloys: monograph. Ternopil: Lileya, 1998. 144 p. [In Ukrainian]
2. Kovbashyn V., Bochar I. Investigation of the change in technological properties of refractory metals after diffusion saturation. Scientific Journal of the Ternopil National Technical University: TNTU, no. 1 (109), 2023, pp. 121–129
3. Buketov A., Stukhlyak P., Maruschak P., Panin S., Menou A. Regularities of impact failure of epoxy composites with Al₂O₃ microfiller and their analysis on the basis of external surface layer concept. Key Engineering Materials, 712, 2016, pp. 149–154.
4. Fedoreiko V. S., Lutsyk I. B., Iskerskyi I. S., Zagorodnii R.I . Increase of energy efficiency of heat generator through batching components of burning. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 2014, (4), pp. 27–32.
5. Horbatyuk R. M. Surface hardening of molybdenum and tungsten. Mechanical engineering. Lviv, no. 1, 2000, рр. 14–18. [In Ukrainian]
6. Bochar I. Y., Dziadykevich Yu. V., Smiyan O. D., Horbatyuk R. M. Method of processing molybdenum and tungsten and their alloys (patent), no. 30238 A dated November 15, 2000 Bull, no. 6–11. [In Ukrainian]
7. Leonid G. Kozlov, Leonid K. Polishchuk, Oleh V. Piontkevych, Roman. M. Horbatiuk, Mykola P. Korinenko, Paweł Komada, Sandugash Orazalieva, Olga Ussatova. Experimental research characteristics of counterbalance valve for hydraulic drive control system of mobile machine. Przegląd elektrotechniczny. ISSN 0033-2097, R. 95, Vol. 2019. No. 4. pp. 104–109.
8. Kovbashyn V., Bochar I. Method of reaction-sintered products processing based on silicon carbide and molybdenum disilicide. Scientific Journal of the Ternopil National Technical University. Ternopil: TNTU, no. 2 (94), 2019, рр. 75–79.
9. Sosnovsky P. A., Epik A. P. The use of activators in the process of diffusion contact saturation of metals in powders. Protective high-temperature coatings. Lviv, Nauka, 1972, рр. 22–23. [In Ukrainian]
10. Kovbashyn V., Bochar I. The study of technological peculiarities for improvement of chemical and physico-mechanical properties of reaction-sintered ceramic materials based on molybdenum disilicide. Scientific Journal of the Ternopil National Technical University. Ternopil: TNTU, no. 2 (106), 2022, рр. 39–46.
11. Bochar I., Horbatyuk R. Increasing the plasticity of molybdenum and tungsten. Bulletin of the Ternopil State Technical University, 2000, vol. 5, no. 1, рр. 16–20. [In Ukrainian].
12. Bochar I. Y., Dzyadykevich Y. V., Horbatyuk R. M. The composition of the mixture for boronizing products from silicon carbide and molybdenum disilicide (patent), no. 30237 A dated November 15, 2000 Bull, no. 6–11. [In Ukrainian].
13. Bochar I. Y., Dzyadykevich Yu. V., Horbatyuk R. M. The composition of the mixture for silicification of silicon carbide and molybdenum disilicide products (patent), no. 30239 А dated November 15, 2000 Bull, no. 6–11. [In Ukrainian].
14. Bochar I., Horbatyuk R. Properties of the protective composition applied to the surface of ceramic materials. Scientific Notes Series: Engineering Mechanics. Lutsk: LNTU, no. 24, 2009, рр. 21–28. [In Ukrainian]
15. Bochar I., Horbatyuk R. Influence of activators on the process of diffusion saturation of SiC and MoSi₂ with silicon and boron. Bulletin of the Ternopil State Technical University, 2002, vol. 7, no. 1, рр. 19–26. [In Ukrainian].