Microstructure and elastic properties of plasma-spayed alumina

摘要: On deposition, plasma-sprayed ceramics are typically far from thermodynamic equilibrium, i.e., they contain metastable phases and also exhibit an extremely high density of lattice other defects at many microstructural levels. Exposure to temperatures is known result in a consolidation the material can lead both subtle radical changes meso microstructure. The effective elastic properties must be governed by variety structural change as defect structure during annealing. In present study development alumina (Al2O3), function annealing temperature investigated using techniques electron microscopy, X-ray diffraction porosimetry. addition, this have been studied ultrasonic spectroscopy technique which especially suited for porous, highly attenuating materials. results show that even moderate homologous already has noticeable effect on properties. Upon higher temperatures, very strong constant observed: increases about 300% compared with as-sprayed material. underlying discussed detail. It found plasma sprayed largely aspect ratio arrangement internal porosity.