High density of strong yet deformable intermetallic nanorods leads to an excellent room temperature strength-ductility combination in a high entropy alloy

Ultrastrong High‐Ductility Ni35Co35Fe10Al10Ti8B2 High‐Entropy Alloy Strengthened with Super‐High Concentration L12 Precipitates

“…However, the thermal processing ATB2 shows superb work hardening ability, which can guarantee a large safety margin in engineering applications and provide possibilities for subsequent deep processing. Figure 2c shows the strength-ductility combination of the thermal-processed ATB2 compared with other reported typical nanoprecipitate-strengthened HEAs [35][36][37][38][39][40][41][42][43][44][45][46][47] with excellent room temperature strength and ductility combinations. [35][36][37][38][39][40][41][42][43][44][45][46][47] A detailed comparison reveals that the tensile strength of our ATB2 alloy shows a 50% increase compared to conventional superalloys.…”

“…Figure 2c shows the strength-ductility combination of the thermal-processed ATB2 compared with other reported typical nanoprecipitate-strengthened HEAs [35][36][37][38][39][40][41][42][43][44][45][46][47] with excellent room temperature strength and ductility combinations. [35][36][37][38][39][40][41][42][43][44][45][46][47] A detailed comparison reveals that the tensile strength of our ATB2 alloy shows a 50% increase compared to conventional superalloys. Compared with the high-performance L1 2 phase-strengthened HEAs reported in recent years, our ATB2 alloy exhibits a hitherto unreported combination of ultrahigh strength and uniform elongation, making it well suited for structural applications.…”

“…However, low volume fractions of L1 2 precipitates in conventional alloys (nearly lower than 60%) tend to limit their practical usage, while the strengths of the alloys generally increase with L1 2 precipitation contents. Herein, a novel high-entropy alloy (HEA) Ni 35 Co 35 Fe 10 Al 8 Ti 10 B 2 with ultrahigh concentration L1 2 precipitates is successfully designed aided by the calculation of phase diagrams (CALPHAD). The volume fraction of L1 2 precipitates in this HEA is up to 75% and outperforms that of most of traditional superalloys.…”

“…The volume fraction of L1 2 precipitates in this HEA is up to 75% and outperforms that of most of traditional superalloys. The novel L1 2 -strengthened Ni 35 Co 35 Fe 10 Al 8 Ti 10 B 2 has an ultrahigh tensile yield strength of %1.45 GPa, ultimate tensile strength of %1.9 GPa, and great ductility of %23% at room temperature. The desirable strength-ductility combination is superior to most of conventional superalloys and reported HEAs, mainly due to the presence of ultrahigh concentration L1 2 precipitates that act as dislocation obstacles and the formation of numerous stacking faults and deformation twining.…”

Effect of Ti/Al Ratio on the Elemental Partitioning in the Face-Centered Cubic-Based γ-γ′ Dual-Phase High Entropy Alloy Studied by Atom Probe Tomography

“…The precipitation strengthening by introducing the dispersed hard nanoparticles such as L1 2structured gamma prime (γ′) or D 022 -structured gamma double prime (γ'') nanoparticles, into the FCC matrix (γ phase) has been proved to be one of the most promising methods to enhance the strength of the FCC HEAs (Shun et al, 2012;He et al, 2016;Gao et al, 2017;Zhao et al, 2017;Liang et al, 2018;He et al, 2019;Tong et al, 2019;Zhao et al, 2019;Gwalani et al, 2021). It is known that the composition of the γ′ or γ'' nanoparticles plays an important role in the structural stability and mechanical properties of the alloys.…”