INFLUENCE OF POLYMORPHIC TRANSFORMATIONS ON THE POROSITY OF PLASMA-SPRAYED PRODUCTS FROM PURE ALUMINUM OXIDE

1 BELYAEV Igor
Co-authors:
2 STEPNOV Alexey 3 BAZHENOV Viacheslav 4 PAVLOV Artem 1 KIREEV Andrei
Institutions:
1 Vladimir State University named after A.G. and N.G. Stoletovs, Vladimir, Russian Federation, belyaev-iv54@yandex.ru
2 Research and Production Enterprise “Center for Plasma Spraying” LLC, Vladimir, Russian Federation, stepnov86@mail.ru
3 National University of Science and Technology "MISiS", Casting Department, Moscow, Russian Federation, v.e.bagenov@gmail.com
4 "Coating Technologies", Vladimir, Russian Federation, pavlovaa@mail.ru
Conference:
28th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 22nd - 24th 2019
Proceedings:
Proceedings 28th International Conference on Metallurgy and Materials
Pages:
968-972
ISBN:
978-80-87294-92-5
ISSN:
2694-9296
Published:
4th November 2019
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
23 views / 6 downloads
Abstract

In the present work, the influence of polymorphic transformations on the porosity of plasma sprayed products produced from pure aluminum oxide was investigated. Scanning electron microscopy, quantitative X-ray diffraction analysis, and X-ray computer tomography are used to quantify the porosity. It was established that the plasma sprayed products is a mixture of α, γ and δ aluminum oxides with different densities. When heating, these phase modifications undergo the polymorphic transformations which are accompanied by change in the volume. Opposite variations in the volume of the modifications can lead to both decrease and increase in porosity of material as the temperature of heat treatment increases. It was shown that the non-monotonic behavior of temperature dependence of the porosity is shown to be steadily repeated; this is related to the occurrence of polymorphic transformations. This allows us to change purposefully the porosity of plasma sprayed pure aluminum-oxide products by heat treatments.

Keywords: Plasma sprayed products, aluminum oxide, heat treatment, polymorphic transformations, porosity
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