The influence of the initial phase state of aluminum oxide on the melting process in a high-power beam of fast electrons

Abstract

The issues of accelerating the synthesis of oxide compounds are solved by improving certain stages of the ceramic manufacturing process. A new method is advanced, involving a short-term heating of the reaction agents to the melting temperature, which is aimed at manufacturing ceramic materials that are difficult or even impossible to be produced by other processes. In view of this circumstance, it is critical to optimize the initial states of the oxides of the reaction mixture to ensure their most effective melting under the electron-beam treatment. Using an aluminum oxide as an example, it is shown how important it is to control its initial phase state. It is demonstrated that in the cases where aluminum oxide consists of a few phases, specifically monoclinic and corundum, then during the electron-beam treatment the electron energy is primarily spent on a monoclinic-to-corundum phase transition. Only following this, the aluminum oxide powder undergoes melting. This makes the electron beam treatment less effective.