Search academic texts

Information × Registration Number 0215U007278, 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 20-02-2015 Organization A.A. Galkin Physics and Engineering Institute of National Academy of Science of the Ukraine popup.description2 The object is the mechanisms of formation and decomposition processes of the high-strength nanocomposite states in amorphous Al-based alloys. The results of the studies of structure, thermal stability, crystallization mechanisms and mechanical properties for wide range of the Al-(Ni,Co,Fe)-(Gd,Y,Nd) alloys in amorphous and nanocomposite states were generalized using the X-ray diffraction, electron microscopy, differential scanning calorimetry, electrical resistance, microhardness and the relative deformation of fracture measurements. For the first time, the mechanisms of nanocomposite structures crystallization were determined and it was established that the temperature ranges of their existence and activation energies of their decomposition correlated between each other and were higher in the alloys where the second crystallization stages occurred via nucleation and growth mechanisms. It was shown that the nucleation rate of Al nanocrystals decrease in amorphous Al87Ni8Y5 alloy might be quantitatively described by the classical model of homogeneous nucleation by taking into account changes in the thermodynamic driving force. It was established that the ductile-brittle transition temperature of amorphous Al86-88(Ni,Fe,Со)8-6(Gd,Y,Nd)5-6 alloys was inversely proportional to the ratio of averaged values of the shear modulus to bulk volume modulus calculated from the chemical compositions of alloys and the alloys with enhanced resistance to the thermal induced embrittlement were developed. It was found that the preliminary heating of the amorphous Al87Ni8Y5 alloy samples up to the temperatures corresponding to that of the nucleation rate maximum resulted in enhancement of the volume density number of Al nanocrystal and to enlargement (about 10%) in the microhardness of nanocomposite structure. Field of application: mechanical engineering and aerospace industry. Product Description popup.authors Васильєв С. Костиря С. Максимов В. Моісеєва Т.М. Рассолов С. Свиридова К. popup.nrat_date 2020-04-02 Close