The wire electro-discharge machining characteristics of Fe–30Mn–6Si and Fe–30Mn–6Si–5Cr shape memory alloys

Electro-discharge craters and re-cast materials are observed in the wire electro-discharge machining (WEDM) surface of Fe–30Mn–6Si and Fe–30Mn–6Si–5Cr shape memory alloys. The re-cast layer consists of the γ-austenite, Cu0.83Si0.17 compound, η′-(Cu, Si) and (Fe, Cr) solid solutions, and Zn phase. The WEDM Fe–30Mn–6Si and Fe–30Mn–6Si–5Cr SMAs still exhibit a good shape recovery, but a slight degradation of shape recovery occurs due to the depression of the re-cast layer.