The studied coatings containing composites based on Al₂O₃ and ZrO₂ are deposited by plasma spraying technology. These coatings belong to the  group of thermal barrier acting as thermal insulators in many technical branches among others in aeronautical and automotive industry. Therefore purpose of these works has both research and practical side.

Phase transitions caused by the conditions of plasma spraying process and subsequent coatings thermal treatment  are studied by X-ray diffraction. Microstructure and local changes in phase and chemical composition are observed by scanning and  transmission electron microscopy combining with electron diffraction.

Different phase transitions directed to appearance of ternary oxides, solid solutions and  crystal forms changing for separate oxides have been determined. In this work some results for composites belonging to Al₂O₃ – TiO₂ and ZrO₂ – Y₂O₃ are described. In the first beside transformations in separate oxides (α – γ in Al₂O₃,  anatase – rutile in TiO₂) aluminum titanate Al₂TiO₅ of high thermal resistance has been  occurred.  In the latter among others martensitic transformation from tetragonal to monoclinic crystal form has been observed. Transmission electron microscopy shows local areas of alternate layers: amorphous, nanocrystalline and polycrystalline of both equiaxial and columnar crystallites shape.  Different changes in microscopic image caused by coatings thermal treatment are also visible.

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1. Preparation  and structure analysis of gel-metal oxide composites as filling material for W-188/Re-188 generator  columns