Effect of Heat Treatment of Molten 6Bi2O3⋅SiO2 on the Phase Composition and Microstructure of Its Solidification Products

Inorganic Materials, vol. 58, pp. 1168–1178

Abstract

Abstract— We have studied the effect of heat treatment (isothermal holding in the temperature zone C, initial cooling temperature, and cooling rate) of a melt with the composition 85.7 mol % Bi2O3 + 14.3 mol % SiO2 (6 : 1) on the phase composition and microstructure of the forming crystals and found conditions for crystallization of a δ-Bi2O3-based metastable solid solution (δ*) at high melt cooling rates. The results demonstrate that low melt cooling rates lead to crystallization of the δ*-phase and an α-Bi2O3-based solid solution, followed by partial or complete eutectoid decomposition of dendritic δ*-phase crystals into a mixture of metastable phases, containing β*-Bi2O3 and η-Bi2SiO5 as well. Raising the melt cooling rate limits both the formation of secondary phases and eutectoid decomposition. The results we obtained make it possible to control the formation of polycrystalline Bi12SiO20 and δ-Bi2O3 upon 6Bi2O3⋅SiO2 melt solidification.

Authors 10

1. Timofey Vladimirovich Bermeshev corresponding

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

2. Vladimir P. Zhereb

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

3. М. П. Бундин

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

4. A. S. Yasinsky Aachen Institute for Process Metallurgy and Metal Recycling

   RWTH Aachen University · Siberian Federal University

   Affiliation as printed

   IME, Institute for Process Metallurgy and Metal Recycling, RWTH Aachen University, 52056, Aachen, Germany

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   IME, Institute for Process Metallurgy and Metal Recycling, RWTH Aachen University, Aachen, Germany

   Siberian Federal University, Krasnoyarsk, Russia

5. Денис Сергеевич Ворошилов

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

6. A. S. Samoilo

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

7. Elena Valentinovna Mazurova

   Russian Academy of Sciences · Institute of Chemistry and Chemical Technology

   Affiliation as printed

   Institute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences, 660036, Krasnoyarsk, Russia

   Institute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia

8. А. Н. Залога

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

9. O. V. Yakivyuk

   Siberian Federal University

   Affiliation as printed

   Siberian Federal University, 660041, Krasnoyarsk, Russia

   Siberian Federal University, Krasnoyarsk, Russia

10. P. O. Yur’ev

    Siberian Federal University

    Affiliation as printed

    Siberian Federal University, 660041, Krasnoyarsk, Russia

    Siberian Federal University, Krasnoyarsk, Russia