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Information × Registration Number 0211U006684, 0110U005702 , R & D reports Title Formation of high-strength nanophase composites in amorphous Al-based alloys under the temperature and deformation actions popup.stage_title Head Tkatch Viktor Ivanovich, Registration Date 09-03-2011 Organization A.A. Galkin Physics and Engineering Institute of National Academy of Science of the Ukraine popup.description2 The mechanisms and kinetics of structural changes occurring under linear heating and isothermal annealing of amorphous Al-(Ni,Co,Fe)-(Gd,Y) alloys in connection with the changes of their ductility and hardness were studied by X-ray diffraction both at small and large angles, resistometry, bend testing and microhardness measurements. The effect of chemical composition on the embrittlement mechanisms and thermal stability of the high strength nanophase composites which formed in the investigated alloys at first crystallization step was established. The main goal of this work is to find the correlations between chemical composition, structural parameters of nanophase composites and their thermal stability, strength characteristics and plasticity. It has been established that under continuous heating the amorphous ribbons exhibit abrupt ductile-brittle transitions which in the amorphous alloys containing only Ni as TM are caused by enrichment of amorphous matrix during nanocrystallization whereas in the glasses containing additions of Co or Fe the loss of ductility is resulted from the structural relaxation processes (formation of Gd or Y-enriched nanoclusters and loss of the excess free volume). It has been found that ductile-brittle transitions take place when the increasing microhardness reaches the level which corresponds to the yield strength limit nearly 1 GPa. It has been demonstrated that full crystallization of the amorphous Al87Ni8Gd5 ribbon results in partial recovery of ductility. The existence of three different mechanisms of the nanophase composite structure decay has been found. It has been shown that the highest level of thermal stability of nanocomposite structures takes place in the alloys in which formation of the intermetallic compounds in the residual amorphous phase occurs by the mechanism of nucleation and growth. The recommendations concerning the chemical compositions of the Al-TM-RE alloys which are promising candidates both for the bulk nanostructured samples fabrication and for using as reinforcement phases in the metal-matrix composites will be done. The areas of application are engineering and aerospace industry. Product Description popup.authors Костиря Сергій Олексійович Крисов Віктор Іванович Максимов Віктор Володомирович Моісеєва Тетяна Миколаївна Попов Вячеслав Васильович Рассолов Сергій Геннадійович popup.nrat_date 2020-04-02 Close