Abstract:The influences of Ca addition on the microstructure and room temperature mechanical properties of as cast TiAl based alloy were investigated.The results showed that Ca addition could improve markedly crystalline.the strength and ductility of TiAl at ambient temperature.Microstructure of Ca doped TiAl alloy was dendric crystalline.Fracture mode of Ti Al Ca ternary alloy was a mixed mode,including cleavage cracks vertical to lamellar direction and “river” pattern in γ single phase.In addition,a lot of tear ridges were found in the fractured surface.

Key words: TiAl based alloy alloying mechanical properties fracture