Microstructures and mechanical properties of Co₃(Al,W) with the LI₂ structure

Microstructures and deformation behavior of γ/γ' Co-Al-W single-crystals and γ'-Co₃(Al,W) polycrystals have been investigated. Single crystals with the γ/γ' two-phase microstructure with a large volume fraction of the γ' phase are obtained by the Bridgman method. These single crystals exhibit anomalies in yield stress in compression at temperatures above 700 °C. Polycrystalline Co₃(Al,W) alloys can be rolled in ambient atmosphere such that the nominal thickness was reduced by 40%. The values of tensile elongation obtained for the polycrystalline Co₃(Al,W) alloys in air is slightly smaller than that obtained in vacuum, indicating that the Co₃(Al,W) alloys are not severely susceptible to the environmental embrittlement in air.