ОСОБЛИВОСТІ ЗАСТОСУВАННЯ НАНОРОЗМІРНИХ ЧАСТИНОК ДЛЯ МОДИФІКУВАННЯ СТРУКТУРИ МЕТАЛЕВИХ СПЛАВІВ: Procesi littâ, 2024, Vol 4 (158), 14-24

• Дата: 2024
• Автор: Щерецький, В.О.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2024
• Теми: алюмінієві сплави; неметалічні частинки; кристалізація; зародки кристалізації; модифікування; електроконтактна взаємодія
• Онлайн доступ: https://plit-periodical.org.ua/index.php/plit/article/view/257
• Назва журналу: Casting Processes

The paper contains a retrospective review of the influence of various submicro- and nano-scale particles of different natures on melts, nucleation processes (nucleation of crystalline phases), and structure formation of castings during their cooling and crystallization. The review focuses on the distribution of micro- and nano-sized particles in melts, their wetting and modifying ability.The mechanisms of influence of micro- and nano-sized particles on the processes of formation of crystallization centers and subsequent growth of crystals during solidification of metal melts are considered. The contribution of surface forces and electrical contact interaction on the possibility of interphase interaction and the formation of substrates for heterogeneous crystallization wasevaluated. A number of non-metallic particles are considered, which are widely used as additives for the production of discretely reinforced composite materials based on aluminum alloys (among them are TiO2, SiO2, α-Al2O3, γ-Al2O3, SiC, etc.). The review shows that a significant role in the considered processes contributes such factors as the state of the surface of nanosized particles, their morphology, and electrical contact interaction which is related to the charge density on the surface of conductor particles, it makes a significant contribution to the reduction of interphase boundary surface energy. For dielectric substrates, the magnitude of the electrical contact interaction in common is relatively low, but this changes radically when the half-thickness (radius) of the particle is reduced to less than the Debye radius, this significantly increases the impact of the electrostatic component on the surface energy balance and leads to a decrease in the size of the critical nucleus. Thus, the influence of non-metallic particles on the nucleation and growth of crystallization nuclei in metal melts should be evaluated considering their parameters in complex, including the electrical contact interaction with the metallic melt.