Super high strength of annealed Fe32Cr33Ni29Al3Ti3 manufactured by selective laser melting

Selective laser melting (SLM) of high entropy alloys (HEAs) shows great potential in industry applications and annealing was always used as a post-processing method after SLM. A dual-phase (DP) Co-free HEA was manufactured by SLM and annealed at 900 °C in this work. The annealed HEA exhibited super high yield and tensile strengths (∼1224 and ∼1363 MPa, respectively), higher than those of the as-printed sample, primarily attributed to grain refinement and spinodal decomposition with FCC phase (rich in Ni/Al/Ti) and BCC phase (rich in Cr/Fe) decomposing into FCC (rich in Fe), B2 (rich in Cr, poor in Ni), and L1 2 (rich in Ni/Al/Ti, poor in Fe/Cr) during annealing. The annealed DP Co-free HEA exhibits notably superior strength to other Co-free HEAs or medium entropy alloys (MEAs) produced via SLM. Due to their affordability, Co-free HEAs show immense potential for widespread commercial use, and this study explores annealing in SLM to improve the mechanical properties of HEAs. The high-strength annealed DP Co-free HEA could be especially valuable for structural elements in construction applications.