Obrabotka Metallov 2019 Vol. 21 No. 3

OBRABOTKAMETALLOV Vol. 21 No. 3 2019 138 MATERIAL SCIENCE References 1. Hou W.-M., Thalmann R. Thermal expansion measurement of gauge blocks. Proceedings SPIE , 1998, vol. 3477. Recent Developments in Optical Gauge Block Metrology , pp. 272–278. DOI: 10.1117/12.323116. 2. Li Z., Jia H., Ma H., Guo W., Liu X., Huang G., Li R., Jia X. FEM analysis on the effect of cobalt content on thermal residual stress in polycrystalline diamond compact (PDC). Science China Physics, Mechanics and Astronomy , 2012, vol. 55, pp. 639–643. DOI: 10.1007/s11433-012-4654-4. Thermal Coefficient of Linear Expansion of Tungsten-Cobalt Cemented Carbide Igor Efimovich a, * , Ivan Zolotukhin b , Evgenii Zav’yalov c Tyumen Industrial University, 38 Volodarskogo, Tyumen, 625000, Russian Federation a https://orcid.org/0000-0002-9060-4988, egor_kosin@mail.ru, b https://orcid.org/0000-0002-1517-9117 , ivan.zolotukhin@mail.ru , c http://orcid.org/0000-0002-1704-4734, zavjaloves@tyuiu.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2019 vol. 21 no. 3 pp. 129–140 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2019-21.3-129-140 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 10 June 2019 Revised: 09 July 2019 Accepted: 15 August 2019 Available online: 15 September 2019 Keywords : Thermal properties of materials Thermal coefficient of linear expansion, TCLE CTE Thermal deformation Thermal strain Thermal expansion of solids Dilatometry Thermomechanical analysis Tungsten-cobalt cemented carbide WC based cemented carbides WC-Co Sintered hard alloys ABSTRACT Introduction . Products containing cemented carbides (WC-Co), operating at high temperatures, experience large temperature deformations. The calculation accuracy of these deformations depends on the accuracy of the thermal coefficient of linear expansion (TCLE). In the literature, the data on the TCLE values for tungsten-cobalt cemented carbides vary significantly; TCLE type, experimental conditions are often not specified, and the correlation of TCLE and temperature is often neglected. The purpose of the work . The focus of this research is TCLE of tungsten-cobalt cemented carbide with different cobalt content in the range of 3-20 wt. %. The objective of the research is obtaining correlation between the linear thermal deformation and the temperature for tungsten-cobalt cemented carbide with different cobalt content and updating the TCLE values in view of its change as related to the temperature. The methods of investigation . The study used push-rod dilatometer Netzsch 402 PC to obtain experimental data in air. To eliminate low temperature distortions of the push-rod dilatometer due to the design features of this device a special method of experimental data processing is applied. This method includes calculation of true TCLE based on the deformations of the samples obtained from dilatometer; approximation the estimated TCLE by a linear function with its further integration by temperature for obtaining the correlation between the relative thermal deformation and temperature. Results and Discussion . The study obtained experimental values of linear thermal expansion in the range from 20 to 650  С and calculated true TCLE. It is found that a relationship of the true TCLE on the temperature is linear and calculated the coefficients of the corresponding approximating functions for different cobalt content. Also the study derived dependences of the relative thermal deformations of tungsten-cobalt cemented carbide for different cobalt content from the temperature, and provided the corresponding polynomial approximant coefficients. Moreover it is found, that with increasing the cobalt content, the value of TCLE and the rate of its change with temperature enlarge linearly. As the result study provides generalized formulas enabling to calculate for cemented tungsten carbide the relative thermal deformation, the true and mean TCLE based on the known temperature and cobalt content by weight. The results may help to calculate thermal deformation and stresses in a consisted cemented tungsten carbide products. ______ * Corresponding author Efimovich Igor A. , Ph.D. (Engineering), Assistant Professor Tyumen Industrial University 38 Volodarskogo, 625000, Tyumen, Russian Federation Tel.: +7 (3452) 50-49-15, e-mail: egor_kosin@mail.ru cient of linear expansion of tungsten-cobalt cemented carbide. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2019, vol. 21, no. 3, pp. 129–140. DOI: 10.17212/1994-6309-2019-21.3-129-140. (In Russian). For citation: Efimovich I.A., Zolotukhin I.S., Zav’yalov E.S. Thermal coeffi