Improved Casting Quality through Novel Engineered Ceramic Molten Metal Filters Improved Casting Quality through Additively Manufactured Ceramic Molten Metal Filters

US Air Force superiority over current and potential threats is largely based on the performance of advanced propulsion systems that rely on single-crystal turbine airfoils produced from complex investment castings.Production of these castings requires flow of molten metal through porous ceramic filters to capture contaminants and regulate metal flow. Current standard production filters are essentially ceramic sponges that can act as secondary sources of contamination, as pieces of the filter material break loose and enter the molten metal stream; this can result in secondary grain formation, compromising high temperature creep strength, acting as a nucleation site for high and low cycle fatigue failure.During the I-CODE Filters Phase I, it was demonstrated that 3D-printed engineered filters can solve problems associated with standard filters, enabling consistent and repeatable metal flow rates without becoming secondary sources of contamination.In head-to-head casting trials 3D-printed filters significantly outperformed standard filters, with more consistent flow and no inclusions or fragmentation.3D-printed filters can potentially reduce scrap and rework costs resulting from inclusions and contaminants by over 60%.The Phase II program expands on Phase I, increasing the volume, variety, and value associated with 3D-printed filters, working with multiple foundries, materials, and filter configurations.