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Creation of heat-resistant nanostructure ceramics in ZrO2 – MgO systemстатья
Информация о цитировании статьи получена из
Scopus
Дата последнего поиска статьи во внешних источниках: 13 мая 2020 г.
- Авторы: Korableva E.A., Kharitonov D.V., Anashkina A.A., Lemeshev D.O.
- Журнал: Tsvetnye Metally
- Номер: 10
- Год издания: 2019
- Первая страница: 61
- Последняя страница: 66
- DOI: 10.17580/tsm.2019.10.10
- Аннотация: The article discusses potentiality of creating ceramics out of powder system based on ZrO2 – MgO with nanostructure responsible for heat resistance when in extensive contact with metal melts (special alloys, steels, precious metals). The research results on creation of nanostructured ceramic materials are presented, and the nanotechnologies intended to improve functional properties of zirconia ceramics are compared. Two ways of obtaining a nanostructure in zirconia ceramics are distinguished: with feedstock represented by nanocrystalline zirconium oxide powder produced by chemical precipitation from chloride salt; two-stage sintering of ceramic half-finished material, which is efficient and available approach to producing materials with controlled size of structural components. The experiments show that the developed method of two-stage sintering of half-finished calcinatories from chemically precipitated nanocrystalline magnesia-stabilized zirconia powders allows production of ceramics with nanostructured nests of tetragonal phase in coarse grains of monoclinic modification. It is revealed that the optimal structure is coarse (to 25–40 μm) grains in the monoclinic modification, with nanosize (25–35 nm) pockets of tetragonal crystalline phase, with open porosity in the range of 7–9 %. It is found that ceramics with optimal structure, thermally resistive in heating to the maximum temperature of 1750–1800 oC at a rate of 175 oC/min, without splitting and reacting to platinum alloys can be produced in two-stage sintering of calcinatories in the mode of 1700 oC for 1 h and 1000 oC for 10 h. The created nanostructure is responsible for resistance of ceramics under induction heating at high rates of heating and cooling in smelting of precious metals at 1750–1800 oC.
- Добавил в систему: Лемешев Дмитрий Олегович