from the conferences organized by TANGER Ltd.
It is shown from the point of view of the quasicrystalline model of metallic melts that during the liquid phase treatment by nanosecond electromagnetic pulses it may be possible the occurrence of energy fluctuations in the melt, change of short-range order structure in the atoms arrangement, reducing the cluster size and shortening their lifespan, decreasing the disordering temperature. These processes change the physical properties of the melt, crystallization parameters, physical-mechanical and operational properties of the obtained alloys. It is theoretically justified that irradiation of the melt with nanosecond electromagnetic pulses, by reducing the surface energy of an interphase boundary "crystal-melt" and contributing to increase in degree of the melt undercooling, increases the formation rate of nucleation centers in a unit volume of the melt and provides the refinement of microstructure of resulting castings. In addition, increasing the wettability of solid particles by the melt and reducing the surface tension at the interphase boundaries leads to substantial dispersion of nonmetallic inclusions and intermetallic phases, which causes the formation of additional crystallization centers. It is assumed that when the nanosecond electromagnetic pulses are applied to the liquid phase, the bond energy curve shifts toward a lower value of the interatomic distance, while the absolute value of the bond energy decreases. For this reason, the melt irradiation provides the possibility of an energetically and kinetically easier moving of atoms from one stable state to another, which accelerates diffusion processes and deactivates clusters.
Keywords: Electromagnetic pulses, aluminum alloys, crystallization, bond energy, quasicrystalline model© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.