Martensitic transformation and shape memory effect in ausaged Fe–Ni–Si–Co alloys

The effect of Co addition on the microstructure, hardness, martensitic transformation and shape memory (SM) effect in Fe–Ni–Si alloys was investigated by means of optical and transmission electron microscopy, Vickers micro-hardness testing, differential scanning calorimetry and bending tests. The addition of Co was found to increase the hardness of the austenite phase and to facilitate the formation of thin-plate martensite. Furthermore, the SM effect was improved by the addition of Co.