Abstract:

Metal-ceramic composite materials, FGM, with a compositional gradient ranging from fully ceramic to fully metallic composition were subject of intense RAndamp;D efforts for many years. Unfortunately, the expected synergetic combination of mechanical and thermo-mechanical properties of metals and ceramics could not be fully utilized, because the real microstructure of the metal-ceramic FGM usually is dominated by a high degree of discontinuity between ceramic and metallic phases, unable to provide a continuous gradation of thermo-mechanical properties. The paper presents a new architecture and processing approach to metal-ceramic FGM: porous tiles processed by co-sintering of composite tape laminates of NiCr8020 gradually enhanced by a ceramic ZrO2-ZrSiO4-phase are sealed at the ceramic and metallic side after sintering. The sealing process is achieved by melting and rapid solidification using a Laser Assisted Microwave Plasma Process, LAMPP, developed at the Chair of Materials Processing to enable formation of an Environmental Barrier Coating on top of a porous thermal barrier coating.