Formation and Structure of Al–Si Layer on Contact Surface of Aluminium–Reactive Flux of KF–AlF$_3$–K$_2$SiF$_6$ System
O. M. Sabadash, S. V. Maksymova
E. O. Paton Electric Welding Institute, NAS of Ukraine, 11 Kazymyr Malevych Str., UA-03150 Kyiv, Ukraine
Received: 02.08.2019; final version - 07.05.2020. Download: PDF
When heating the reactive flux of the KF–AlF$_3$–K$_2$SiF$_6$ system on an aluminium substrate, two processes occur; reduction of silicon from potassium hexafluorosilicate; contact-reactive melting of silicon with aluminium. As a result, an Al–Si alloy layer is formed on the reaction surface, the composition of which is close to hypereutectic, which is confirmed by the results of X-ray microanalysis. The microstructure of the crystallized Al–Si metal layer contains aluminium-based solid solution grains and a hypereutectic component with a silicon concentration (% wt.): 17.18 in intercrystalline areas, as well as individual discrete inclusions of the lamellar phase, which is close in stoichiometric composition to the compound FeSiAl$_5$. Comparative experiments on a graphite substrate showed that the silicon content in the flux residues after heating corresponds to its content in the initial flux composition.
Key words: reactive flux of the KF–AlF$_3$–K$_2$SiF$_6$ system, contact melting, silicon, aluminium, Al–Si metal layer.
PACS: 61.20.Qg, 61.25.Mv, 61.66.Fn, 81.15.Lm, 82.45.Mp
Citation: O. M. Sabadash and S. V. Maksymova, Formation and Structure of Al–Si Layer on Contact Surface of Aluminium–Reactive Flux of KF–AlF$_3$–K$_2$SiF$_6$ System, Metallofiz. Noveishie Tekhnol., 42, No. 8: 1079—1092 (2020) (in Ukrainian)