Influence of Al on shape memory effect and twinning induced plasticity of Fe-Mn-Si-Al system alloy

We have investigated the shape memory effect and ductility of Fe-30Mn-(6-x)Si-xAl (x = 0, 1, 2 and 3; in mass-%) alloys. The alloy with x = 0 shows a good shape memory effect but suffers from poor ductility, while the alloys with x = 2 and 3 are well-known TWIP (twinning induced plasticity) steels that show high ductility. In the present study, it was found that the shape memory effect is observed in the samples with x = 0 and 1, but disappears when x exceeds 2. On the other hand, the ductility almost linearly increases with increasing the amount of Al. A good combination of the shape memory effect and ductility was achieved in the alloy with x = 1.