Preparation of TiAl/Mo and TiAl/NiAl composites by powder processing

Processes for preparing TiAl/Mo and TiAl/NiAl composites are described and results of the investigation are reported. It was found that the hardness of the TiAl/NiAl composites was largely influenced by the amount of hard ternary phases formed through reactions between TiAl and NiAl. The possibility of ductilizing and toughening TiAl by introducing molybdenum as a ductile reinforcement has also been shown. For both composites, optimal process parameters still remain to be determined by further experiments to suppress the formation of hard ternary phases, which are believed to be detrimental to ductility and fracture toughness.