Thermomechanical behavior of Fe-Mn-Si-Cr-Ni shape memory alloys modified with samarium

The deformation and training behavior of Fe-14Mn-3Si-10Cr-5Ni (wt.%) shape memory alloys containing samarium addition has been studied in the iron-based shape memory alloys. It is noticed that thermomechanical treatment (training) has significant influence on proof stress, critical stress and shape memory behavior of the alloys. The improvement in shape memory behavior can be attributed to the decrease in the proof stress and critical stress which facilitates the formation of epsilon (hcp martensite). It is also observed that alloy 2 containing samarium undergoes less softening as compared to alloy 1 with training which inhibits the formation of (alpha) over dot (bcc martensite) and thus enhances the shape memory behavior. The excessive thermomechanical treatment with increase in the training cycle has led to the formation of (alpha) over dot (bcc martensite) along with epsilon (hcp martensite) in the alloy 1 which appeared to have decline in the shape memory effect. This has been demonstrated by the examination of microstructure and identification of (alpha) over dot (bcc martensite) martensite in the alloy 1 as compared to alloy 2. (C) 2008 Elsevier B.V. All rights reserved.