Microstructure evolution and mechanical properties of CrFeNixV0.64Ta0.36 eutectic high-entropy alloys
Microstructure evolution and mechanical properties of CrFeNixV0.64Ta0.36 eutectic high-entropy alloys
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DOI：
10.1016/j.matchar.2021.111449
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发表时间：
2021-09
影响因子：
4.7
通讯作者：
Xin Lin;Mingliang Wang;Guangyu Ren;Dongxu Qiao;Yiping Lu;Tongmin Wang;Tingju Li
中科院分区：
文献类型：
--
作者：
Xin Lin;Mingliang Wang;Guangyu Ren;Dongxu Qiao;Yiping Lu;Tongmin Wang;Tingju Li
共晶高熵合金因其优良的铸造流动性和优异的力学性能而引起了人们的极大兴趣。在本研究中，设计并制备了一种新型的EHEAs系统，即CrFeNixV0.64Ta0.36(1.3%≤×≤(1.9))。研究了CrFeNixV0.64Ta0.36EHEAs铸态组织演变和力学性能。结果表明，当x=1.3时，该合金由σ相、Fe7Ta3型金属间化合物和少量共晶相组成。在EHEAs中观察到一种罕见的双峰共晶组织[面心立方(Fcc)结构/σ+Fe7Ta3型IMC]，即使在高熵合金中也是如此。当x增加到1.9时，获得了典型的亚共晶组织。完全共晶成分CrFeNi1.85V0.64Ta0.36交替具有片状fcc和Fe7Ta3型IMC组织具有最好的力学性能，其压缩屈服强度、断裂强度和工程应变分别为1475.9、2799和38.095%。
Eutectic high entropy alloys (EHEAs) have attracted considerable interest because of their excellent casting fluidity and outstanding mechanical properties. In this study, a novel system of EHEAs, namely CrFeNixV0.64Ta0.36(1.3 ≤ x ≤ 1.9) was designed and prepared. The microstructure evolution and mechanical properties of CrFeNixV0.64Ta0.36EHEAs were investigated in as-cast state. The results showed that the alloy was composed of σ-phase, Fe7Ta3-type intermetallic compounds (IMC), and a small amount of the eutectic phase when x = 1.3. A rare bimodal eutectic microstructure [face-centered-cubic (FCC) structure /σ + Fe7Ta3-type IMC] was observed in EHEAs, even in high entropy alloys when x = 1.6, 1.7, 1.8, and 1.84. The typical hypo-eutectic microstructure was acquired when x was increased to 1.9. The fully eutectic composition, i.e., CrFeNi1.85V0.64Ta0.36with alternatingly lamellar FCC and Fe7Ta3-type IMC structures exhibited the best mechanical properties, with the compressive yield strength, fracture strength, and engineering strain being 1475.9 MPa, 2799 MPa, and 38.095%, respectively.