Obrabotka Metallov 2014 No. 1

ОБРАБОТКА МЕТАЛЛОВ № 1 (62) 2014 22 МАТЕРИАЛОВЕДЕНИЕ OBRABOTKAMETALLOV (METAL WORKING • MATERIAL SCIENCE) N 1(62), January – March 2014, Pages 14–23 Application of the method of laser-plasma surface modification of metals to improve tribological characteristics of combustion engines Bagayev S.N. 1 , D.Sc. (Physics and Mathematics), Academician, Russian Academy of Sciences, Director Grachev G.N. 1 , Ph.D. (Physics and Mathematics), Head of Laboratory, e-mail: grachev@laser.nsc.ru Smirnov А.L. 1 , Chief Designer Khomyakov M.N. 1 , Engineer Tokarev A.O. 2 , D.Sc. (Engineering), Associate Professor Smirnov P.Yu. 3 , General Director 1 Institute of Laser Physics Siberian Branch of Russian Academy of Sciences, 13/3 Ac. Lavrentyev’s pr., Novosibirsk, 630090, Russian Federation 2 Novosibirsk State Academy of Water Transport, 33 Shhetinkina st., Novosibirsk, 630099, Russian Federation 3 Optogard Nanotech Limited, 100 Novaja st., Moscow region, Odintsovo, Skolkovo, 143025, Russian Federation Received 19 December 2013 Revised 30 January 2014 Accepted 5 February 2014 Abstract The results of the development of laser-plasma method for surface hardening of metals in two areas: high- performance surface modification of iron and synthesis of superhard (20 - 30 GPa ) nanocomposite coatings are presented. Laser- plasma method is based on pulsed optical plasma discharge. Repetitive discharge is ignited with a high repetition frequency (tens of kHz) by laser pulses at the focus of the CO2 laser beam. For the formation of the plasma in the processing head, high flow of gas: argon , nitrogen and oxygen is generated. Plasma gas flow in the plasma-chemical chamber has a speed of 500 m / s and pressure up to 0.5 MPa. For the synthesis of coatings a two- channel plasma chemical chamber additionally provides delivery of thealloying gas in the focus area of the laser. To improve the wear resistance of gray cast iron in friction couples by laser processing, a structure with high- hardness (12-20 GPa ) nanostructured surface layer and having thickness of 1 micron, which is adjacent to a layer with a thickness of about 100 microns with a locally hardened regions surrounding the graphite areas . The resulting structure of the surface reduces the coefficient of friction by 30% and twentyfold increase in wear resistance under conditions of hydrodynamic friction. This is due to the creation of micro-relief wear pairs , including capillary channels accumulating grease by location of graphite and solid constituents - ledeburite and martensite surrounding these microgroves. Keywords: laser plasma, technologies of gray cast iron-surface hardening, synthesis of superhard coatings. References 1. Bagaev S.N. , Grachev G.N. , PonomarenkoA.G. , SmirnovA.L. , DeminV.N. , OkotrubA.V., BaklanovA.M., Onishhuk A.A. Lazernyj plazmohimicheskij sintez nanomaterialov v skorostnyh potokah gazov, pervye rezul’taty i perspektivy razvitija metoda [Laser plasma chemical synthesis of nanomaterials in high-speed gas flows, the first results and prospects of development of the method]. Nauka i nanotehnologii: materialy nauchnoj sessii Prezidiuma Sibirskogo otdelenija RAN [Science and nanotechnology: materials science session of the Siberian Branch of the Russian Academy of Sciences, December 22, 2006], Novosibirsk, SB RAS Publ., 2007, pp. 123–135. 2. Bagaev S.N., Grachev G.N., Demin V.N., Smirnov A.L., Smirnov P.Ju., Smirnova T.P., Homjakov M.N. O vozmozhnosti ispol’zovanija tehnologii uprochnenija poverhnosti metallov s primeneniem lazerno-plazmennoj ustanovki dlja nanomodifikacii poverhnostej metallov i sinteza sverhtverdyh pokrytij [The possibility of using