Low energy mechanical treatment of non-stoichiometric titanium carbide powder

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 3 2021 Low energy mechanical treatment of non-stoichiometric titanium carbide powder Tatyana Sablina 1, a, * , Irina Sevostyanova 1, 2, b 1 Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 pr. Akademicheskii, Tomsk, 634055, Russian Federation 2 National Research Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russian Federation а https://orcid.org/0000-0002-5941-5732, sabtat@ispms.ru, b https://orcid.org/0000-0001-6706-6512, sevir@ispms.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 3 pp. 112–123 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.3-112-123 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 06 May 2021 Revised: 24 May 2021 Accepted: 30 July 2021 Available online: 15 September 2021 Keywords : Titanium carbide Non-stoichiometry Phase composition Crystal lattice Mechanical treatmen Funding The results were obtained in the framework of the Integrated Project “Establishment of import-substituting high-tech full-cycle production of complex-shaped indexable carbide cutting inserts for priority industries” (Agreement No. 075-11-2019-036 dated November 27, 2019) implemented by the ISPMS SB RAS at the financial support of the Ministry of Education and Science of the Russian Federation as part of Decree of the Government of the Russian Federation No. 218 dated April 09, 2010. Acknowledgements The authors of the paper express their ac- knowledgement to the researcher with Abdulmenova E. for help in mechanical treatment of the powder and Professor S.N. Kulkov for a constructive discussion of the results obtained. Research were conducted at core facility “Structure, mechanical and physical properties of materials”. ABSTRACT Introduction. The practical significance of non-stoichiometric titanium carbides TiC х in various fields of technology and in medicine is expanding. In this regard, it is important to investigate both methods of obtaining titanium carbide powder and its properties in a wide range of stoichiometry. One of the effective ways to influence the physical and mechanical properties of powder systems is its mechanical treatment. Under shock-shear action, which is realized during processing in a ball mill, mechanical energy is transferred to the powder system, as a result of which it is ground, centers with increased activity on newly formed surfaces are formed; phase transformations, crystal lattice deformation, amorphization, formation of defects, etc. are possible. The aim of this work is to study the effect of low-energy mechanical treatment in a ball mill on the structure, phase composition and parameters of the fine crystal structure of non-stoichiometric titanium carbide powder obtained by reduction of titanium oxide with carbon and calcium. Materials and methods. Powder of titanium carbide TiC, obtained by calcium carbonization of titanium oxide was investigated. The powder was treated in a drum type ball mill. The structure of the powders before and after treatment was studied using the Philips SEM 515 scanning electron microscope. The specific surface area was determined by the BET method. The phase composition and parameters of the fine crystal structure of powder materials were investigated by X-ray analyzes. Results and discussion. It was established that an increase of the time of mechanical treatment in a ball mill of a non-stoichiometric titanium carbide powder TiC 0.7 leads to an increase in the specific surface area of the powder from 0.6 to 3.4 m 2 / g, and the average particle size calculated from it decreases from 2 μm to 360 nm. It is shown that in the process of treatment of the non-stoichiometric titanium carbide TiC 0.7 powder, its structural phase state changes. Powder particles consist of two structural components with different atomic ratio of carbon to titanium: TiC 0.65 and TiC 0.48 . Mechanical treatment of titanium carbide powder leads to a decrease in the microstresses of the TiC x crystal lattice and the size of coherently diffracting domains (CDD) from 55 to 30 nm for the TiC 0.48 phase. For the TiC 0.65 phase, with an increase in the duration of mechanical treatment, as well as for TiC 0.48 , the size of CDD decreases, and the level of microdistortions of the crystal lattice increases. This indicates that in the process of mechanical treatment, not only the grinding of powder particles occurs, but also an increase in its defects. For citation: Sablina T.Yu., Sevostyanova I.N. Low energy mechanical treatment of non-stoichiometric titanium carbide powder. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 3, pp. 112–123. DOI: 10.17212/1994-6309-2021-23.3-112-123. (In Russian). ______ * Corresponding author Sablina Tatyana Yu. , Ph.D. (Engineering) Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 pr. Akademicheskii, 634055, Tomsk, Russian Federation Tel.: 8 (3822) 286-988, e-mail: sabtat@ispms.ru