Martensitic transformation and shape memory effects in Co-V-Al alloys at high temperatures

Martensitic transformation in Co-V-Al ternary systems was investigated by means of the structural and thermal analysis in single phase martensite alloys. The martensite phase presents a non-modulated L10 structure transformed from a B2 parent phase. With the increase of V content, martensitic transformation temperatures exceeding 100 °C and occurring at approximately 200–300 °C. A two-step shape memory effect occurring at different temperature ranges was found for the first time in Co60V30Al10 alloys, and considerable recoverable strains reaching up to 3.0% were observed. This study shows that Co-V-Al alloys have potential as new candidates for high-temperature shape memory alloys operating in a large temperature range. [Display omitted] •A B2/L10 martensitic transformation is firstly observed in Co-V-Al alloys.•Martensite stabilization is observed in Co60V30Al10 and Co60V32Al8 alloys.•A two-step reverse martensitic transformation tales place in Co60V30Al10 alloy.