Actual Problems in Machine Building 2024 Vol.11 N3-4

Actual Problems in Machine Building. Vol. 11. N 3-4. 2024 Materials Science in Machine Building ____________________________________________________________________ 82 14. Ткаченко Л.А., Репина А.В. Теория теплообмена: учебное пособие / под общ. ред. Н.Ф. Кашапова. – Казань: Изд-во КФУ, 2017. – 151 с. 15. Авиационные материалы. В 9 т.: справочник / под общ. ред. А.Т. Туманова. – М.: ОНТИ ВИАМ, 1973. – Т. 5 : Магниевые и титановые сплавы. – 585 с. 16. Взаимосвязь технологической пластичности со структурой титанового сплава ВТ16 / А.А. Ильин, С.В. Скворцова, Р. Хемпель, Н.В. Ручина // Сборник трудов международной конференции по титану «Ti–2006 в СНГ». – Киев: Наукова думка, 2006. – С. 291–295. INFLUENCE OF TEMPERATURE ON THE THERMAL DIFFUSIVITY OF TITANIUM (α + β)-ALLOYS Poltavets V.V.1, D.Sc. (Engineering), Associate Professor, e-mail: poltavetsvv@gmail.com Shapovalova N.N.2, Engineer, e-mail: shapovalova.nn80@mail.ru 1Donetsk National Technical University, 58 Artema str., Donetsk, 283001, Russian Federation 2Limited Liability Company «Energosbyt Donetsk», 87 Shchorsa str., Donetsk, 283048, Russian Federation Abstract When machining parts from high-strength titanium alloys, a set of technological difficulties arises that sharply reduce the efficiency of the cutting process. These difficulties necessitate the need for development of models of thermal processes when machining titanium alloys and for correction of values of the thermophysical constants of alloys. Due to the lack of relevant experimental information, the purpose of the paper is to study the influence of temperature on the thermal diffusivity of titanium two-phase (α + β)-alloys. Theoretical provisions for choosing the type of functional relationship of the thermal diffusivity coefficient with other physical characteristics of the substance during machining are the concepts of the theory of heat- and masstransfer. Based on the assumptions made, the thermal diffusivity coefficient is calculated using the Fourier-Ostrogradsky equation. Graphs of the dependence of the thermal diffusivity of titanium two-phase (α + β)-alloys on temperature in the range of 50–900ºC are plotted. Temperature dependences of the thermal diffusivity coefficient are close to linear in appearance at temperatures below the temperature of polymorphic transformation. Degree of variation of thermal diffusivity in said temperature range varies from 25 % for alloy VT22 to 90 % for alloy VT25. The obtained data on the influence of temperature on the thermal diffusivity of titanium (α + β)-alloys can be used for correction of mathematical models, which are suitable for calculation of instantaneous values of cutting forces in machining of titanium alloys. Keywords titanium alloys, machining, thermal physics, heat transfer, thermal conductivity, heat capacity, thermal diffusivity.

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