The processes of surface nanostructuring of titanium carbide by Nd radiation: YAG-laser with the wavelength of 1.06 microns is investigated. The laser pulse length is 40 ns, the travel rate is 10 mm / s. The radiation energy density on the surface of titanium carbide at the oscillation frequency of 2000 Hz is 2.06 ÷ 6.36 J / cm2. The re-sults of ab initio study of the atomic, electronic structure, and the elastic characteristics of TiC and TiC1-хOх (x = 0,25; 0,5; 0,75) are presented. The band structure of TiC calculated with the use of the density functional theory corresponds to a metal type. It is shown that the calculated elastic properties of titanium carbide are in good agreement with the known theoretical and experimental estimates. The study of the microstructures topog-raphy on the of titanium carbide surface using the atomic force microscopy (AFM) shows that in the area of the direct laser action, the roughness is 0.254 µm. Mechanical properties in the direct laser impingement spots, and in the temperature exposure regions are investigated by the nanoindentation. The effect of nanostructuring is determined: the titanium carbide surface hardness goes up to 47.2 hPa after the laser action
titanium carbide, structure modeling, atomic structure, electronic structure, laser action, effect of nanostructuring, hardness, elastic properties
Введение. Улучшение свойств материалов — одна из важнейших научных задач. Новый эффективный метод, позволяющий добиться этой цели, — наноструктурирование поверхности материалов лазерным излучением. В работах О. Н. Крохина и Ю. В. Афанасьева [1, 2] заложены основы наноструктурирования поверхности твердых тел наносекундными лазерными импульсами. Технологии лазерного нано/микроструктурирования поверхности материалов базируются на физических процессах образования структурных объектов микро- и нанометровых размеров при воздействии лазерных импульсов различной интенсивности и длительности [3]. Нано/микроструктуры на поверхности материалов образуются в процессе прямого поверхностного наноструктурирования на основе наносекундных лазеров [4–6]. Другой способ — осаждение продуктов абляции на поверхности подложки, удаленной от мишени [3, 5].
1. Afanas’ev, Y. V., Krokchin, О. N. Vaporization of Matter Exposed to Laser Emission. Journal of Ex-perimental and Theoretical Physics, 1967, vol. 25, no. 4, pp. 639-645.
2. Afanasyev, Y. V., Krokhin, O. N. Gazodinamicheskaya teoriya vozdeystviya lazera na kondensiro-vannye veshchestva. [Gasdynamic theory of laser impact on condensed substance.] Trudy FIAN, 1970, vol. 53, 118 p. (in Russian).
3. Zavestovskaya, I. N. Lazernoe nanostrukturirovanie poverkhnosti materialov. [Laser nanostructuring of materials surfaces.] Quantum Electronics, 2010, vol. 40, no. 11, pp. 942-954 (in Russian).
4. Tokarev, V. N., Khomich, V. Y., Shmakov, V. A. Formirovanie nanostruktur pri lazernom plavlenii poverkhnosti tverdykh tel. [Formation of nanostructures under laser melting of solid surface.] Doklady Akade-mii Nauk, 2008, vol. 419, no. 6, pp. 754-758 (in Russian).
5. Mikolutskiy, S. I., et al. Zarozhdenie i rost nanostruktur na poverkhnosti tverdogo tela, oplavlennogo lazernym impul´som. [Formation and growth of nanostructures on the surface of solids melted by laser pulses.] Nanotechnologies in Russia, 2011, vol. 6, no. 11-12, pp. 65-69 (in Russian).
6. Lapshin, K. E., et al. Formirovanie nanostruktur na poverkhnosti nitrida kremniya pod vozdeystviem izlucheniya F2-lazera. [Formation of nanostructures on the surface of silicon nitride under F2-laser irradiation.] Fizika i khimiya obrabotki materialov, 2008, no. 1, pp. 43-49 (in Russian).
7. Agya, A., Carter, E.-A. Structure, bonding, and adhesion at the TiC (100)/Fe (110) interface from first principles. Journal of Chemical Physics, vol. 118, no. 19, pp. 8982-8996.
8. Ilyasov, V. V., et al. Ul´tratonkie uglerodnye plenki na sapfire, vyrashchennye metodom lazernoy ablyatsii: sintez i ASM-issledovanie. [Ultrathin carbon films on sapphire grown by laser ablation: synthesis and AFM-study.] Vestnik of DSTU, 2012, vol. 62, iss. 1, pp. 31-35 (in Russian).
9. Belikov, А. V., Skripnik, A. V., Zulina, N. A. Grafitovye nanostruktury, formiruemye v pole izlucheni-ya glass: Yb-, Er-lazera na poverkhnosti raznykh podlozhek. [Graphite nanostructures formed in the radiation field glass: Yb-, Er-laser on the surface of various substrates.] Izvestiya vuzov. Fizika, 2012, no. 1, pp. 1-2 (in Russian).
10. Kuramochi, H., et al. Surface reconstruction of TiC (001) and its chemical activity for oxygen. Ap-plied Physics Letters, 1999, vol. 75, no. 24, pp. 3784-3786.
11. Giannozzi, P., et al. Quantum espresso: a modular and open-source software project for quantum simulations of materials. Journal of Physics: Condensed Matter, 2009, vol. 21, no. 39, p. 395502.
12. Golesorkhtabar, R., et al. ElaStic: A tool for calculating second-order elastic constants from first principles. Computer Physics Communications, 2013, vol. 184, no. 8, pp. 1861-1873.
13. Hill, R. The Elastic Behavior of a Crystalline Aggregate. Proceedings of the Physical Society. Sec-tion A. 1952, vol. 65, p. 349.
14. Hill, R. Elastic properties of reinforced solids: Some theoretical principles. Journal of the Mechanics and Physics of Solids, 1963, vol. 11, no. 5, pp. 357-372.
15. Marques, L.-S., et al. Influence of oxygen addition on the structural and elastic properties of TiC thin films. Plasma Processes and Polymers, 2007, vol. 4, pp. 195-199.
16. Dridi, Z., et al. First-principles calculations of vacancy effects on structural and electronic properties of TiCx and TiNx. Journal of Physics: Condensed Matter, 2002, vol. 14, no. 43, p. 10237.
17. Holliday, J. E. Soft-X-ray valance state effects in conductors. Advance in X-ray Analysis,1970, vol. 13, p. 136.
18. Jiang, B., et al. Structural studies of TiC1−xOx solid solution by Rietveld refinement and first-principles calculations. Journal of Solid State Chemistry, 2013, vol. 204, pp. 1-8.
19. Ilyasov, V. V., Pham, D. K., Kholodova, O. M. Izuchenie atomnoy, elektronnoy struktury i uprugikh kharakteristik karbida titana iz pervykh printsipov. [Study on atomic and electronic structure, and elastic char-acteristics of titanium carbide from first principles.] Uporyadochenie v mineralakh i splavakh (OMA-17) : sb. trudov 17-go mezhdunar. simp. [Ordering in minerals and alloys (OMA-17): Proc. 17th Int. Symp.] Rostov-on-Don; t. Yuzhny, 2014, iss. 17, vol. 1, pp. 131-134 (in Russian).
20. Li, Y., et al. Elastic and thermodynamic properties of TiC from first-principles calculations. Science China Physics, Mechanics and Astronomy, 2011, vol. 54, no. 12, pp. 2196-2201.
21. Yang, Y., et al. First-principles calculations of mechanical properties of TiC and TiN. Journal of Al-loys and Compounds, 2009, vol. 485, no. 1, pp. 542-547.
22. Francisco, E., Blanco, M., Sanjurjo, G. Atomistic simulation of Sr F 2 polymorphs. Physical Review B., 2001, vol. 63, no. 9, p. 094107.
23. Gilman, J., Roberts, B. Elastic constants of TiC and TiB2. Journal of Applied Physics, 1961, vol. 32, no. 7, pp. 1405-1405.
24. Pugh, S.-F. XCII. Relations between the elastic moduli and the plastic properties of polycrystalline pure metals. Philosophical Magazine. Series 7, 1954, vol. 45, pp. 823-843.
