Challenges in Wire-Arc Additive Manufacturing of Fe-Based Shape Memory Alloy

Iron-based shape-memory alloys are considered as an inexpensive alternative to Ni–Ti alloy suitable for seismic isolation application in civil structures. Fe–17Mn–10Cr–5Si–4Ni–0.5V–0.5C alloy contains 37 wt% of total solute elements. Such rich multi-component metallurgical system leads to wide solidification temperature range which often subsequently leads to severe solute segregation and solidification cracking. Wire-arc additive manufacturing (WAAM) of Fe–17Mn–10Cr–5Si–4Ni–0.5V–0.5C alloy was attempted using a cold-wire fed plasma arc torch attached to a CNC gantry. Self-standing walls were manufactured. The melt-pool solidification conditions were modelled using Schiel Gulliver model to generate the solute segregation profiles and solidification paths. Later, different solidification cracking theories were used to calculate the cracking propensity at different locations of the wall or at different process conditions.