DIFFRACTION AND MICROSCOPIC STUDIES ON THE STRUCTURE OF PLASMA SPRAYED COATINGS CONTAINING COMPOSITES BASED ON AL_2O_3

摘要

Plasma sprayed coatings of thermal barrier type (TBC) based on Al_2O_3 and ZrO_2, with metallic bondcoat are studied byX-ray diffraction, scanning and transmission electron microscopy. Phase transitions and presence of various layers : amorphous,nano and polycrystalline of equiaxial and columnar shape are observed. Local fluctuations of chemi-cal and phase compositionare mainly connected with the conditions of plasma spraying process. In the result of thermal treatment changes directed tomore ordered state occur.