The additive manufacturing of multi-principal element alloys has remarkable potential for industrial applications. In this study, a (CoCrNi)₉₄Al₃Ti₃ medium-entropy alloy (MEA) with adequate strength-ductility synergy was prepared via laser powder bed fusion. The microstructural evolution, mechanical property, and deformation mechanisms of the MEA were investigated after post annealing for a short period (0.5 h) at a temperature range of 773–1373 K using various microstructural characterization techniques and quantitative analysis. The static recrystallization temperature of the (CoCrNi)₉₄Al₃Ti₃ MEA ranged from 973 to 1073 K. The average grain size first decreased and then increased, while the dislocation density persistently decreased and texture gradually weakened with increasing annealing temperature. Cr-rich σ-phase precipitates formed after 1073 K and then gradually dissolved at 1373 K, while Ni, Al, and Ti elements were aggregated to form a small amount of fine L1₂ coherent precipitates with an average diameter of approximately 70 nm at 1373 K. The evolution of the dislocation density, grain size, and precipitates significantly influenced the propensity of deformation twins and stacking faults, which consequently affected the strain hardening behavior and mechanical properties. The quantitative calculation of strengthening mechanisms showed that dislocation strengthening played a dominant role at annealing temperatures below 1073 K, and it significantly weakened at 1373 K. Precipitation and grain boundary strengthening both markedly increased owing to the formation of precipitation particles and recrystallization-induced grain refinement after annealing at 1073 K.

多主元素合金的增材制造具有显着的工业应用潜力。在这项研究中，通过激光粉末床熔合制备了具有足够强度-塑性协同作用的 (CoCrNi) ₉₄ Al ₃ Ti _{3中熵合金 (MEA)。}使用各种微观结构表征技术和定量分析，在 773-1373 K 的温度范围内进行短时间（0.5 小时）后退火后，研究了 MEA 的微观结构演变、机械性能和变形机制。(CoCrNi) ₉₄ Al ₃ Ti _{3的静态再结晶温度}MEA的变化范围为973~1073 K。随着退火温度的升高，平均晶粒尺寸先减小后增大，而位错密度持续降低，织构逐渐弱化。1073 K后形成富Crσ相析出物，1373 K后逐渐溶解，而Ni、Al、Ti元素聚集形成少量细小L1 ₂在 1373 K 时平均直径约为 70 nm 的共格析出物。位错密度、晶粒尺寸和析出物的演变显着影响了变形孪晶和层错的倾向，从而影响了应变硬化行为和力学性能。强化机制的定量计算表明，位错强化在退火温度低于 1073 K 时起主导作用，在 1373 K 时显着减弱。由于析出颗粒的形成和再结晶引起的晶粒细化，析出和晶界强化均显着增加在 1073 K 退火后。