Phase transformations in ferrites during radiation-thermal sintering

Abstract

Electron microscopic studies of the phase composition, morphology, and defect structure of lithium-titanium ferrite powders and ceramic samples sintered under conditions of radiation-thermal and thermal effects were carried out. Radiation-thermal sintering of ferrite samples was carried out by irradiating the work pieces with a pulsed electron beam with energy of (1.5-2.0) MeV using the electron beam accelerator. The beam current in the pulse was (0.5–0.9) A, the irradiation pulse duration was 500 μs, the pulse repetition rate was (5–50) Hz, and the work piece heating rate was 1000 °C/min. The samples were irradiated in a box of lightweight fireclay with a bottom thickness of 15 mm. The microstructure studies were conducted by the methods of electron diffraction microscopy in the light using an electron microscope. It was shown that the most probable model of radiation intensification of the sintering process of ferrites can be the mechanism of radiation retardation of dislocations upon heating, which are formed during the decomposition of subgrain boundaries in grains of intermediate phases of ferrite.