Forming of Ceramics During Firing without the Application of External Pressure

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

Forming ceramics into complex shapes has traditionally been accomplished by slip casting, injection molding, hot pressing, and machining. The subject of this proposal is a forming technique to shape thin ceramic bodies by introducing strains into the component during the firing operation, without the application of external pressure. The method can be considered a synthesis of mold-based and hot-forming methods in that while molds are not needed, complexity in a component is realized by operating at high temperature. The feasibility of this technique has been demonstrated by applying a chromia coating onto thin alumina substrates to deform the originally flat sample into an arc shape and into a ceramic wave spring. Preliminary calculations suggest that the internal stress that drives the deformation arises as a consequence of cation diffusion from the coating into the substrate. %%% The outcome of the research efforts proposed here will provide for a scientific understanding of this ceramic shape forming process, which in turn will lead to more wide-spread examination and possibly use of the methodology as a forming method. The potential advantages of such a forming method are that the costs of molds and machining can be eliminated and that a more rapid manufacturing process may be realized. These two advantages may help to advance the penetration of advanced ceramic materials into more widespread applications.