Investigation of novel precursor routes for incorporation of oxynitride spinel phases into ceramic-metallic composites formed via the TCON process

Abstract

Fireline TCON Inc. has developed a process for the production of interpenetrating phase composites consisting of the phases of aluminum and alumina. These composites are formed via a process called reactive metal penetration. TCON composites made by taking precursors that are silica based, and then these precursors are placed inside a molten aluminum, or aluminum alloy bath. The resulting composites have unique physical properties that are a combination of the properties of both the aluminum and alumina phases. These properties can be adjusted by changing the composition of the precursor or the composition of the melt, with the goal of producing specific properties in the composites. According to research, silica is not the only ceramic that will work with this process. Other teams have transformed titanium with the goal of introducing titanium into the metallic phase. Another option can be to target the ceramic phase to find compounds that will have better bonds with the metal phase. To do that, a possible route is to start finding oxynitride ceramics that will work with the TCON process. To make these oxynitrides, many different methods were used with varying degrees of success, due to the instability of many of these compounds and the difficulty in keeping them from decomposing. Once formed, these compounds could then be reacted with molten aluminum in one of several ways, with the goal of producing a transparent spinel in the ceramic phase. These samples before and after transformation were examined using Powder X-ray Diffraction, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy.