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

We investigated the shape memory effect and ductility of Fe-30Mn-(6-x) Si-xAl (x = 0, 1, 2 and 3, mass-%) alloys. The alloy for x = 0 is known as a shape memory alloy, which shows a good shape memory effect but poor ductility. The alloys for x = 2 and 3 are known as TWIP (Twinning Induced Plasticity) steels, which show a high ductility but the shape memory effect has not been reported in these alloys. In the present study, it was found that the shape memory effect is preserved for x = 0 and 1, but drastically disappears when x exceeds 2. On the other hand, the ductility almost linearly increases with increasing amount of Al. As a consequence, the best combination of the shape memory effect and ductility was found in the alloy for x = 1.