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Information × Registration Number 0211U000952, 0107U000163 , R & D reports Title Investigation of the physical nature of long-term strength and fracture mechanisms of light metal alloys with a close-packed (hcp - and fcc) structure popup.stage_title Head Tkachenko Vladimir Grigorjevich, Registration Date 11-03-2011 Organization Frantzevich Insitute for Materials Science Problems of the Ukranian National Academy of Sciences popup.description2 A new physical model of the dislocation microyielding (below the macroscopic yield point) is developed, which takes into account the physical kinetics of defects including the dislocation dragging by Cottrell impurity atmospheres. The structural - energy efficiency concept of useful long-term strength is formulated with its main provisions and a physical interpretation of the observed results. Another model describing the durability of heterogeneous materials under the dislocation creep at above brittleness temperatures allows for the physical nature of microplasticity deformation and features of its localization. The method for calculating the components of the parameters of kinetic equations is proposed. The method of precision introduction of refractory alloying element (Ti,Fe,Sr,Gd) is suggested (in atomic - segregation level). For the first time in world practice refractory titanium having the largest (with respect to hcp Mg) value of H = 16-30 kJ/mol) is introduced in the bulk low-melting matrix of cast magnesium alloy. New Ukrainian magnesium alloy systems Mg-Al-Ca-Ti, Mg-Al-Ca-Sr and Mg-Al-Ca-Gd have improved (30%) castability, low-temperature ductility (4-5% elongation at 20 C), excellent performance of high-temperature strength and long-term strength. Their increased (by 150 - 200 C) heat resistance as well as more high creep resistance (at 70 MPa/150 with over 200 hours) favorably compare with the automotive industry alloys AZ91D, AS21, as well as the European alloy AE42 (Mg-4% Al-2.5% REM), containing large additions of the RE. The electronic structure of nanoclusters Al30Ba2, Al31Ba2 with fcc structure and the structure Al18Ba9 Al4Ba are calculated using methods DFT and FLAPW (with full approximation for the cluster potential). Product Description popup.authors Бекенев Володимир Львович Вовчок Олександр Сергійович Гайдуков Олександр Іванович Кондрашев Олександр Іванович Лашук Микола Костянтинович Лисенко Анатолій Олександрович Максимчук Ігор Миколайович Малка Олександр Миколайович Медалович Ніна Прокопівна Оранська Олена Іванівна Осокін Георгій Анатолійович Фрізель Віктор Вадимович Хрипливий Анатолій Олександрович Щерецький Олександр Анатолійович popup.nrat_date 2020-04-02 Close