Molten Salt Shielded Synthesis as a Route for Industrial Scale Production of High-Quality MAX Phases

There is a need to develop large scale synthetic protocols for the production of high-performance ceramic materials known as MAX phases. Here, MAX phases will be prepared on a kilogram scale with high phase purity and tested for stability in harsh industrial conditions. The goals for this program are to demonstrate the feasibility of the molten salt shielded synthesis route as a pathway for large scale MAX phase production without significant loss of purity and working to further reduce production costs through incorporation of recycled precursors. Our approach utilizes a molten salt bath to provide a protective environment during the synthesis process rather than expensive inert gas. This method provides several advantages over traditional MAX phase synthesis including improved heat transfer for lower reaction temperatures, and shorter dwell times, and can be done without specialized furnaces. The process is easily scalable and can be transferred to many different MAX phase compositions depending on the desired application. In this program, a method will be demonstrated for the large-scale production of high-quality MAX phases. The MAX phase powders will be tested by powder x-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy to monitor phase purity across different production scales. Material pricing shall be estimated during Phase I and included in the commercialization plan with a goal to reduce the overall capital cost and become a primary supplier of MAX phase powders. The proposed pathway differs from current production methods by the use of a molten salt bath rather than use of inert gas and the scale of material production. MAX phases have many potential applications in harsh environment energy applications such as high temperature coatings, heat exchangers, solar power materials, corrosion resistant coatings, and radiation protection. Large scale production methods that produce high purity material is critical to bring these new materials to the commercial marketplace.