Understanding the microstructure evolution characteristics and mechanical properties of an AlCoCrFeNi2.1 high entropy alloy fabricated by laser energy deposition
Understanding the microstructure evolution characteristics and mechanical properties of an AlCoCrFeNi2.1 high entropy alloy fabricated by laser energy deposition
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DOI：
10.1016/j.msea.2023.144795
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
W. Guo;Yan Zhang;N. Ding;Long Liu;Huixia Xu;N. Xu;L. Tian;Guoqiang Liu;Dexiao Dong;Xiebin Wang
中科院分区：
文献类型：
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作者：
W. Guo;Yan Zhang;N. Ding;Long Liu;Huixia Xu;N. Xu;L. Tian;Guoqiang Liu;Dexiao Dong;Xiebin Wang
在目前的工作中，通过激光能量沉积制备了AlCoCrFeNi2.1高熵合金。将试样分别加热至 700°C (2#)、850°C (3#) 和 1000°C (4#)，保温 1 h 并在水中冷却，以研究热处理条件对合金显微组织演变和力学性能的影响。所有四种沉积物均获得 FCC(L12) + B2 双相微观结构。 3#和4#中有序FCC(L12)消失并转变为B2颗粒。原始 B2 相和新形成的 B2 颗粒与相邻 FCC 晶粒表现出 K-S 取向关系 (OR)。四种沉积物的 FCC-BCC 相界均存在纳米级相颗粒，其含有单斜晶格结构，其成分与 FCC 相相似。 FCC-相边界是相干的。 Phasemin 4# 的存在表明它在高达 1000 °C 的温度下是稳定的。沉淀硬化对材料的强化起着重要作用，而沉淀颗粒的粗化则削弱了其强化作用。该合金组的高强度还归因于两相界面强化效应。分析了颗粒形成的可能原因及其对材料强度的影响。
In the present work, an AlCoCrFeNi2.1high entropy alloy is fabricated by laser energy deposition. Specimens are heated to 700 °C (2#), 850 °C (3#) and 1000 °C (4#), respectively, held for 1 h and cooled in water to investigate the effect of heat-treating conditions on microstructure evolution and mechanical properties of the alloys. FCC(L12) + B2 dual-phase microstructure is acquired from all the four deposits. Ordered FCC (L12) disappears and transforms into B2 particles in 3# and 4#. Original B2 phase and newly formed B2 particles show K–S orientation relationship (OR) with adjacent FCC grains. Nano-sized phasemparticles, which contain monoclinic lattice structure and have a composition similar with FCC phase, exist on FCC-BCC phase boundary in all the four deposits. FCC-mphase boundary is coherent. Existence of phasemin 4# indicates that it is stable at temperatures as high as 1000 °C. Precipitate hardening plays an important role in strengthening the materials, while the coarsening of precipitate particles weakens their strengthening effect. The high strength of this alloy group is also attributed to the two-phase interface strengthening effect. Possible reasons for the formation ofmparticles and their effect on the strength of the material are analyzed.