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Information × Registration Number 0221U102398, 0117U004352 , R & D reports Title Features of reactionary synthesis of heteromodular of ceramic composite popup.stage_title Head Popov Oleksiy Yu., Доктор фізико-математичних наук Registration Date 01-02-2021 Organization The scientific and Training Center "Physical and chemical Material Science"of National Academy of Sciences of Ukraine popup.description2  Object of the research: mechanisms of the new phase grain shape formation as well as the overall material structure evolution during the hot pressing of titanium and boron carbides powder mixture. Results: The interaction between the titanium and boron carbides begins at a temperature between 1000°C and 1200°C. 16-minute charge annealing at 1200°C results in the reaction degree of 50% which does not alter up to 1400°C. Further charge heating leads to the essential reaction speed increasing and the transformation completion after 16 minutes at 1600°C. During the reaction hot pressing the charge densifies in two stages, which starting temperatures correlate with those of the reaction initiation and acceleration. The in-situ reaction leads to formation of the following material structure features: (i) submicron faceted voids in boron carbide grains appears by means of boron vacancy unification; (ii) submicron inclusions of titanium diboride form inside the boron carbide grains because of titanium atoms via the boron vacancies diffusion; (iii) submicron plate-like graphite inclusions appear after carbon to boron displacement in titanium carbide grains improving the material physical and mechanical characteristics. As part of the thermodynamic description of the behavior of highly dispersed materials undergoing first order phase transformations during thermal annealing, a size-dependent solubility diagram of a two-component nanosized particle is calculated and constructed. The shift and change of the shape of the curves on the phase diagrams and such possible results as narrowing and complete disappearance of two-phase zones are obtained Product Description popup.authors Zagorodniy Vjacheslav V Kepich Tiberiy Yu. Krit Oleksiy M Popov Oleksii Yu. Rudenko Оlga V Shirinian Aram S. popup.nrat_date 2021-02-01 Close