Mechanical properties and microstructural evolution of a novel (FeCoNi)86.93Al6.17Ti6.9 medium entropy alloy fabricated via powder metallurgy technique

Microstructure and tensile strength of electrodeposited Fe-rich bcc FeCoNi medium-entropy alloys

“…As described in the introduction section, simple FeCoNi MEAs do not exhibit exceptionally high strengths among the subsystems of CrMnFeCoNi HEA; the conventional FeCoNi MEAs exhibit a maximum strength of ∼ 0.5 GPa. It was recently reported that nanocrystalline FeCoNi MEAs with ∼ 20 nm grains [12,13,15,23,41]; open marks, FeCoNi-based MEAs strengthened by the introduction of a small fraction of solutes, strengthening phases, or precipitates [7,8,39,42].…”

“…Figure 5(a) compares the ultimate tensile strength and fracture elongation obtained in this study (blue point) with those reported in previous work. The filled marks indicate the performance of the equiatomic FeCoNi MEAs [12,13,15,23,41], and the open marks indicate the performance of the FeCoNi-based MEAs strengthened by the introduction of a small fraction of solutes, strengthening phases, or precipitates [7,8,39,42]. As described in the introduction section, simple FeCoNi MEAs do not exhibit exceptionally high strengths among the subsystems of CrMnFeCoNi HEA; the conventional FeCoNi MEAs exhibit a maximum strength of ∼0.5 GPa.…”

“…

Figure 5 Comparison of fracture elongation versus ultimate tensile stress in the as-electrodeposited FeCoNi MEA (blue filled circle) with previous work. Grey filled marks, equiatomic FeCoNi MEA [12,13,15,23,41]; open marks, FeCoNi-based MEAs strengthened by the introduction of a small fraction of solutes, strengthening phases, or precipitates [7,8,39,42].

…”

“…For example, the equiatomic CrMnFeCoNi HEA (one of the well-known HEAs) shows low strength arising from its face-centred cubic (fcc) structure, despite its high ductility and toughness. Therefore, several researchers have attempted to increase the strength using secondary phase or dispersive particles [7][8][9]. Other studies have developed body-centred cubic (bcc) and hexagonal close-packed HEAs/MEAs with limited slip systems compared to the fcc structure [10,11].…”

Review: Multi-principal element alloys by additive manufacturing

“…Since MPEAs have generated substantial research interest, various manufacturing techniques for processing MPEAs have been developed in the past decades. Arc melting and mechanical alloying are the two main manufacturing techniques for MPEAs [25][26][27]. Arc melting is the earliest and most widely used method for processing these alloys, which consists of several steps including first mixing different metals with a fixed ratio in a crucible and then melting the mixed metals by electrode discharge arc heating with argon as protective atmosphere, followed by casting into a mold.…”