Microstructure and shape memory properties of Fe–15Mn–5Si–9Cr–5Ni melt-spun ribbons

Characterization of phases in an Fe–Mn–Si–Cr–Ni shape memory alloy processed by different thermomechanical methods

“…From TEM micrographs presented in Section 4.1, and in previous works, we have found that the PP crystallites spread not only along austenite and ferrite grain boundaries but are also present within the grains [23,24].…”

“…Other common phases found in this system are δ-ferrite in the P6 sample [23] and stress-induced ε-martensite observed in E8 and E9. The δ-ferrite phase crystallizes in a BCC structure, W-type, cI2, Im3m #229 [43].…”

“…During melt-spinning, the rapid solidification can stabilize the high-temperature ferritic phase, as stated by Druker et al [23]. The ribbons were completely ferritic in the as cast condition.…”

“…Ribbons approximately 0.03 mm thick and 10 mm wide were produced by a melt-spinning technique [23] and then encapsulated in quartz glass in Ar atmosphere for annealing at 600°C for 60 min. At first, the starting material was cut into small pieces that were induction-coil melted in a quartz crucible, and ejected by argon pressure onto a Cu-(Co, Be) rotating substrate wheel.…”

“…In a previous paper [23], we showed results on Fe-15Mn-5Si-9Cr-5Ni ribbons produced by the melt-spinning technique, and analysed the ribbon's microstructure and phase stability, evaluating their shape memory properties. The compositional Cr eq/ Ni eq ratio, approximately 1.7, predicts that the solidification sequence should be Liquidus → L + δ → L + δ + γ → γ + δ [10].…”