(1. 华南理工大学 广东省金属新材料制备与成形重点实验室，广州 510641；
2. 西南技术工程研究所，重庆400039)
摘 要: 采用XRD、SEM、TEM、万能试验机、振动样品磁强计，系统研究了TiC含量对Fe43Ni35Co22中熵合金微观组织、力学性能以及磁性能的影响。添加5%和10%(摩尔分数)Ti至中熵合金Fe43Ni35Co22，通过原位自生反应形成TiC/Fe43Ni35Co22合金块体，制备方法为“机械合金化(MA)+放电等离子烧结(SPS)”。结果表明：经40 h球磨后, Fe43Ni35Co22粉末相的组成为FCC主相+少量BCC，两种TiC/Fe43Ni35Co22粉末的相组成为BCC主相+FCC相。经SPS烧结后，Fe43Ni35Co22块体为单相FCC和少量的杂质；两种TiC/Fe43Ni35Co22块体均由FCC+TiC两相组成，其中FCC相呈现“微米晶+超细晶”构成的多尺度结构，且随着TiC含量的增加，超细晶区增多。性能上，TiC的添加大幅提高了Fe43Ni35Co22的压缩屈服强度和矫顽力，同时也导致了材料的塑性和饱和磁化强度的降低。Ti添加量为5%的TiC/Fe43Ni35Co22综合性能最优异，其压缩屈服强度为1352 MPa，压缩断裂应变为24.5%，矫顽力为992 A/m，饱和磁化强度为0.1387 A？m2/g。
关键字: 中熵合金；机械合金化；放电等离子烧结；力学性能；软磁性能
（1. Guangdong Key Laboratory for Advanced Metallic Materials Processing, South China University of Technology, Guangzhou 510641, China;
2. Southwest Institute of Technology and Engineering, Chongqing 400039, China）
Abstract:The influence of TiC on the microstructure, mechanical and magnetic properties of Fe43Ni35Co22 medium-entropy alloy (MEA) were investigated using XRD, SEM, TEM, universal testing machine and VSM systematically. Adding 5% or 10% (mole fraction) Ti to the Fe43Ni35Co22 MEA, the bulk TiC/Fe43Ni35Co22 composite was achieved via in-situ reaction, using the combination of mechanical alloying (MA) and spark plasma sintering (SPS). The results show that after 40 h of ball milling, Fe43Ni35Co22 MEA powder is composed of a major face-centered cubic (FCC) phase and a small amount of body-centered cubic (BCC) phase, and the two TiC/Fe43Ni35Co22 powders are composed of a primary BCC phase and an FCC phase. Following by SPS, the bulk Fe43Ni35Co22 MEA show a single FCC phase with a small amount of contamination, and the two bulk TiC/Fe43Ni35Co22 consisted of a primary FCC phase with some TiC. The FCC phase in the two bulk TiC/Fe43Ni35Co22 exhibits a multi-scale structure consisting of micron grains and ultra-fine grains. In addition, the volume fractions of ultra-fine grains increase as the TiC increasing. In terms of properties, the addition of TiC evidently improves the compressive yield strength and coercivity of Fe43Ni35Co22, there by leading to a decrease in the plasticity and magnetic saturation of the material simultaneously. The bulk TiC/Fe43Ni35Co22 with 5% Ti addition show the best performance, in detail, showing a compressive yield strength of 1352 MPa and a compressive fracture strain of 24.5%, along with a coercivity of 992 A/m and a saturation magnetization of 0.1387 A？m2/g.
Key words: medium-entropy alloys; mechanical alloying; spark plasma sintering; mechanical property; soft magnetic property
