Additive manufacturing of CMCs with bimodal microstructure

The present work deal with the fabrication of TiC-based composites with green Fe-based binder via additive manufacturing such as selective laser melting/laser fusion bed process. The as-built specimen exhibits a bimodal microstructure consisting of fine/ultrafine dendritic and coarser TiC phases. By adopting a novel multiple scan strategy, process defects such as cracks were eliminated by careful control of the melt pool temperature/cooling rates. Even though the mechanical properties may be improved, the anisotropic distribution of the dual phase leads to anisotropic distribution of hardness within the CMC surface.