Processing of Ceramic Preforms for TRIP-Matrix-Composites

Metal matrix composites have been produced by conventional infiltration of ceramic preforms. The magnesia partially stabilised ceramic foams were prepared by replication method. In terms of the present paper the second process step that comprises the cold spraying of the impregnated foam is optimised. The spray coating is essential in ceramic foam production. It eliminates defects that are caused due to the squeezing process and assists to reach the critical wall thickness for acceptable mechanical properties. For this reasons the rheology of the spraying slurry and the adjustment of the spraying system have been investigated. Quality of the spray coatings was evaluated by computer tomography. The obtained ceramic foams were infiltrated by a TRIP-steel (TRansformation Induced Plasticity) to create composite materials with improved mechanical properties. Phase composition of the composite material has been analysed using Electron Backscatter Diffraction Method (EBSD).