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. •Novel process parameter sequence during SLM leading to bimodal CMC microstructure.•Bimodal microstructure leading to improved properties.•Anisotropy in microstructural features introduced.