Mechanism of lamellae deformation and phase rearrangement in ultrafine β-Ti/FeTi eutectic composites

Deformation mechanisms to ameliorate the mechanical properties of novel TRIP/TWIP Co-Cr-Mo-(Cu) ultrafine eutectic alloys

“…5. This indicates a stronger hardening behavior of the CCMC0.5 induced by the formation of GNDs associated with the strain gradient in the initial stage of plastic deformation19202425.…”

“…The estimated dislocation density also indicates a larger number of GNDs in CCMC0.5, which is associated with a higher strain gradient. Therefore, dislocation pile-ups or dislocation networks may have formed at the lamellar interfaces and can act as pinning sites leading to the formation of a large population of sessile dislocations, which increases the strain gradient19202425. Thus, the higher hardening behavior and the refined microstructure are correlated with the interrupted decrease of the yield strength.…”

Composition Dependence on the Evolution of Nanoeutectic in CoCrFeNiNbx (0.45 ≤ x ≤ 0.65) High Entropy Alloys

“…Therefore, Nb addition increases the vol% of Laves phase in CoCrFeNiNb x , which will increase both strength and hardness. Nevertheless, homogeneous nano‐lamellar EHEA ( x = 0.50) with fine lamellae thickness of 134 nm shows high strength ( σ y = 2060 MPa), high hardness of 521 Hv, and large plasticity ( ϵ p = 17.0%) under compression due to improved slip transfer between the adjacent lamellae, as depicted in Figure b and a, b . On the other hand, presence of micrometer size soft FCC proeutectic phase exhibits reduced hardness of 467 Hv and yield strength ( σ y = 1632 MPa) in x = 0.45 with large plasticity ( ϵ p = 17.2%) and strain hardening due to dislocation slip and their multiplication in the SS phase.…”

Influence of Nb on the Microstructure and Fracture Toughness of (Zr0.76Fe0.24)100−xNbx Nano-Eutectic Composites

“…ECs have a low melting temperature, high castability, a controllable microstructure, and widespread engineering applications. Recently, high strength (2 GPa) and a high plasticity of 20–25% was achieved in Ti–Fe-, Ni–Zr-based lamellar ultrafine eutectic composites (UECs) by tuning the composition of bulk metallic glass (BMG) to synthesize a bulk specimen via arc melting and solidifying at low cooling rates [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. In such cases, a high degree of constitutional super-cooling restricts the growth of eutectic phases within the nanometer scale towards the synthesis of nano-lamellar eutectic composites (NECs) [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…The microstructural features of lamellar composites are crucial for tuning the deformation behavior of ECs. Several NECs, such as Ti–Fe–(Sn) [ 2 , 3 , 4 , 5 , 6 , 7 ], Ni–Zr–(Al) [ 8 , 9 , 10 ], Al–Cu–(Sn) [ 11 ], Al–Cu–(Al) [ 12 , 13 ], Fe–Nb–(Al/Mn/Ni) [ 14 ], Fe–Si–Ti [ 15 ], and Fe–Nb–(Al) [ 15 ], have been reported to have outstanding fracture strength (>2 GPa) along with large plastic strain (>15% at RT) [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. It has been suggested that enhanced mechanical properties have been obtained through impingement of the propagating shear bands (SBs) and through the impingement of the movement of dislocations along with the pile-up of dislocations at the nano-/ultrafine lamellae interface, which promotes a strong work hardening behavior [ 14 , 15 , 16 , 17 ].…”