The martensitic transformation and shape memory (SM) effect in Co-Al alloys containing 0-16 at%Al were investigated by differential scanning calorimetry (DSC) and bending tests. It was found that the martensitic transformation temperatures decrease with Al content and an incomplete SM effect occurring in Co can be enhanced by the addition of Al over 10 at%. The SM effect was improved by the precipitation of β (B2) phase and about 2% recoverable strain was obtained in Co-14 at%Al alloy. The Co-Al SM alloys possessing high reverse transformation temperatures over 200℃ and martensitic transformation in the ferromagnetic state show promise as a new type of SM alloys.
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