轧制处理对AlCrFe2Ni2高熵合金组织与力学性能的影响

目的 为了设计出成本低、性能优异的AlCrFe2Ni2高熵合金，并探究轧制处理对该合金微观组织与力学性能的影响。方法 使用真空电弧熔炼炉熔炼AlCrFe2Ni2合金样品，采用冷轧的方式进行塑性加工，轧制总下压量为60%，结合相图计算、X射线衍射、扫描电子显微镜等分析测试方法研究AlCrFeNi合金体系的相形成规律，以及合金变形前后微观组织、力学性能的变化情况。结果 铸态和冷轧态的AlCrFe2Ni2高熵合金由FCC_A1主相和BCC相构成，BCC区域由编织状的BCC_A2相和BCC_B2相构成。铸态下的屈服强度和抗拉强度分别为681 MPa和1 208 MPa。冷轧后的合金样品硬度和拉伸强度明显提高，经60%下压量的冷轧变形后，合金的屈服强度和抗拉强度分别提升到1 433 MPa和1 620 MPa，但伸长率由铸态的9.5%下降到轧态的2.0%。结论 相组成参数计算结合相图计算(CALPHAD)能够有效预测合金的相组成，轧制处理能够有效改善合金的力学性能。

Effect of Rolling Process on Micro-structure and Mechanical Strength of AlCrFe2Ni2 High Entropy Alloy

The work aims to design AlCrFe2Ni2 high entropy alloy with low cost and excellent performance and study the effect of rolling treatment on the microstructure and mechanical behavior of the alloy. The AlCrFe2Ni2 samples were first prepared by vacuum arc melting furnace, and cold rolling process of the as-cast samples was performed with a total reduction of 60%. Combined with CALPHAD, XRD, SEM and other test methods, the phase formation law of the AlCrFeNi alloy system was predicted, and the microstructure and mechanical strength before and after deformation were studied. The results showed that the as-cast and cold-rolled AlCrFe2Ni2 alloy consisted of FCC_A1 principle phases and BCC phases, and the BCC region was composed of weave-like BCC_A2 and BCC_B2 phases. The yield strength and tensile strength of the as-cast alloy were 681 MPa and 1 208 MPa, respectively. The harness and tensile strength of the cold-rolled alloy were improved significantly. After cold rolling with a reduction of 60%, the yield strength and tensile strength of the alloy were increased to 1 433 MPa and 1 620 MPa, whereas the ductility was decreased from 9.5% in as-cast state to 2% in cold-rolled state. The calculation of phase parameters combined with CALPHAD can effectively predict the phase constitute of the alloy. The cold rolling can effectively improve the mechanical properties of the alloy.