Data for Tailoring microstructure to achieve exceptional strength-ductility synergy in additively manufactured Al0.75Mn0.25CoCrFeNi eutectic high-entropy alloy via annealing heat treatment

A novel Al0.75Mn0.25CoCrFeNi eutectic high entropy alloy was additively manufactured using laser direct energy deposition (LDED). The effect of the annealing temperature on tailoring the microstructure to achieve exceptional strength-ductility synergy was studied. The as-deposited microstructure consists of ultrafine eutectic lamellae of face-centered cubic (FCC) and body-centered cubic (BCC) phases. In the low-temperature annealing (≤ 850 ℃), the eutectic lamellar structure showed good stability, except for the precipitation of Cr-Fe σ particles and Al-Ni BCC nanoparticles in the BCC and FCC lamellae, respectively. During the high-temperature annealing (1000 ℃-1150 ℃), the FCC/BCC phase lamellae were obviously coarsened. The Cr-Fe-rich B2 nanoparticles/nanoclusters precipitated at the FCC/BCC phase boundary and within the BCC lamellae when the annealing temperature reached 1150 ℃. Low-temperature annealing improved the microhardness but worsened the tensile properties owing to the synergetic effect of the incremental BCC phase content, precipitated s particles and BCC nanoparticles, whereas high-temperature annealing dramatically promoted the ductility with a reasonable ultimate tensile strength but severely deteriorates the microhardness owing to the synergetic effect of the precipitated B2 nanoparticles/nanoclusters, decremental BCC phase content and coarsened FCC/BCC eutectic lamellae. Exceptional strength-ductility synergy (961.6 MPa, 13.9%) was successfully achieved by the annealing at 1150 ℃采用激光直接能量沉积（laser direct energy deposition, LDED）增材制造了一种新型Al₀.₇₅Mn₀.₂₅CoCrFeNi共晶高熵合金。本研究探讨了退火温度对显微组织的调控作用，以实现优异的强塑性协同性能。沉积态显微组织由面心立方（FCC）相与体心立方（BCC）相构成的超细共晶层片组成。在低温退火（≤850℃）条件下，共晶层片结构表现出良好的稳定性，仅在BCC层片与FCC层片中分别析出了铬铁σ相粒子以及铝镍基BCC纳米颗粒。高温退火（1000℃~1150℃）过程中，FCC/BCC相层片发生明显粗化。当退火温度达到1150℃时，富铬铁的B2纳米颗粒/纳米团簇在FCC/BCC相界及BCC层片内部析出。低温退火虽提升了显微硬度，但由于BCC相含量升高、析出的σ相粒子与BCC纳米颗粒的协同效应，拉伸性能出现劣化；而高温退火则显著提升了塑性，同时保持了合理的抗拉强度极限，但由于析出的B2纳米颗粒/纳米团簇、BCC相含量降低以及粗化的FCC/BCC共晶层片的协同作用，显微硬度出现严重劣化。通过1150℃退火处理，成功实现了优异的强塑性协同性能（抗拉强度961.6 MPa，断后伸长率13.9%）