Effect of Pre-Deformation of Austenite on Shape Memory Properties in Fe-Mn-Si-based Alloys Containing Nb and C

A. BARUJ; T. KIKUCHI; S. KAJIWARA; N. SHINYA

Materials Transactions

Japan Institute of Metals

Lugar: Sendai; Año: 2002 vol. 43 p. 585 - 588

1345-9678

The shape memory properties of Fe-Mn-Si-based alloys containing Nb and C are further improved by performing pre-rolling of the solution-treated austenite and the subsequent ageing treatment. For an Fe-28Mn-6Si-5Cr-0.53Nb-0.06C (mass %) alloy rolled by 6% and 14% at 870 K and aged at 1070 K for 10 min, 90% of an initial 4% strain is recovered on heating without any previous training treatment. In that same condition, the alloy develops a shape recovery strength of 255 MPa and 295 MPa, respectively, for an initial 4.5% deformation. TEM observations indicate that these features are related to a fine distribution of NbC precipitates in the fcc matrix and their interaction with stacking faults.