In Situ Formed Bulk Nanostructured Ti-base Composites

摘要

The in situ formation of bulk metallic glass-based composites has recently been demonstrated in several multi-component alloy systems, where a high strength glassy matrix is combined with a ductile dendritic solid solution as a toughening phase. Taking advantage of the hints provided by this successful approach, a strategy has been developed for designing primary-dendrite/nano-eutectic in situ bulk composites in Ti-base alloy systems. The as-cast microstructure produced by copper mold casting is similar to that obtained upon arc-melting, thus covering the microstructure formation over a range of cooling rates. The multicomponent recipe stabilizes the β-Ti phase and helps to reduce the eutectic spacing to the nanometer scale. The promising benefit i.e., high strength and high ductility, from such a composite microstructure can be manipulated by choosing appropriate composition and adopted casting conditions to tailor the microstructure.