Obrabotka Metallov 2019 Vol. 21 No. 1

OBRABOTKAMETALLOV Vol. 21 No. 1 2019 90 MATERIAL SCIENCE Study of the Laser Radiation Focusing Modes Effect on Geometrical and Mechanical Properties of Metal-Ceramic Tracks Alexander Golyshev 1, 2, a, * , Anatoly Orishich 1, 2, b 1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, 4/1 Institutskaya str., Novosibirsk, 630090, Russian Federation 2 Novosibirsk State University, 1 Pirogova street, Novosibirsk, 630090, Russian Federation a https://orcid.org/0000-0002-4243-0602, alexgol@itam.nsc.ru , b https://orcid.org/0000-0003-0551-0213, laser@itam.nsc.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2019 vol. 21 no. 1 pp. 82–92 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2019-21.1-82-92 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 23 November 2018 Revised: 18 January 2019 Accepted: 29 January 2019 Available online: 15 March 2019 Keywords : Laser cladding Optimization Metal ceramics Microhardness Scaling laws Tungsten carbide Funding A part of the work related to the adjustment of the cladding optimization technique, improvement of the technology of production of high-quality samples and searching for generalized parameters has been supported by the grant of the Russian Scientific Foundation “Investigation of multilayer laser formation of functional gradient cermet structures including B4C, TiC and TiB2, using pulsed-periodic laser radiation” № 18-79-00052. ABSTRACT Introduction. Additive technologies (АТ) present the method to produce particles by means of layered build-up of materials with any geometry. This technology plays important role in the manufacture of functional articles or in the recovery of worn parts with high strength capacity. Metal-ceramic structures including tungsten carbide and nickel alloy are widely used in tribological practices to protect the components under high-intensity wear, such as cutting tools, drilling and mechanical processing, in mining industry. The aim of the work is to optimize the laser cladding of metal-ceramic single tracks to obtain a monolithic weld structure with maximum hardness. The paper investigates the effect of the laser radiation on geometrical and mechanical characteristics of the formed tracks using a powder mixture based on nickel alloys (NiCrBSi) 60 % by weight and tungsten carbide (WC) 40 % by weight. Results and Discussion. It is established that the shape and mechanical characteristics are strongly influenced by the mode of laser radiation focusing (the mode of keyhole penetration or the mode of thermal conductivity) relative to the surface of the initial layer of the powder mixture. It is also found that when the parameter P V is used as an independent variable, every factors of the track width w and penetration depth Hm can be described with consistent dependencies for the keyhole mode. It is demonstrated that in the cladded track, in the thermal conductivity mode (the focusing mode f = ±20), one observes the uniform distribution of ceramic particles featuring the maximal value of microhardness. It is found that the cladded metal-ceramic structure has 4-5 times higher value of microhardness (850.4 HV0.1) than the substrate (178 HV0.1). For citation: Golyshev A.A., Orishich A.M. Study of the laser radiation focusing modes effect on geometrical and mechanical properties of metal-ceramic tracks. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2019, vol. 21, no. 1, pp. 82–92. doi: 10.17212/1994-6309-2019-21.1-82-92. (In Russian). ______ * Corresponding author Golyshev Alexander A. , Ph.D. (Physics and Mathematics), Researcher Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, 4/1 Institutskaya str., 630090, Novosibirsk, Russian Federation Tel.: 8 923-252-00-12 , e-mail: alexgol@itam.nsc.ru