Formation of transition layer and its effect on mechanical properties of AlCoCrFeNi high-entropy alloy/Al composites
Formation of transition layer and its effect on mechanical properties of AlCoCrFeNi high-entropy alloy/Al composites
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AlCoCrFeNi高熵合金/Al复合材料过渡层的形成及其对力学性能的影响
DOI：
10.1016/j.jallcom.2018.11.364
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发表时间：
2019-04-05
影响因子：
6.2
通讯作者：
Liu, Jiangnan
中科院分区：
文献类型：
--
作者：
Liu, Yunzi;Chen, Jian;Liu, Jiangnan
采用放电等离子烧结技术，在540 ~ 600 ℃温度范围内成功制备了体积分数为5%AlCoCrFeNi高熵合金（HEA）增强铝基复合材料。在540 ℃时，HEA增强体与Al基体之间存在光滑的界面。当烧结温度高于560 ℃时，HEA增强体与Al基体之间的颗粒接触区熔化，形成具有单一FCC相的过渡层。此外，其厚度随着烧结温度的增加而增加。这有利于复合材料在变形过程中由等应力状态向等应变状态的转变。因此，屈服强度和延展性均显著提高。无过渡层的复合材料的屈服强度和压缩应变分别为96 MPa和36%。相比之下，含有平均厚度为7.6 μ m的过渡层的复合材料的屈服强度约为137 MPa，并且在50%压缩应变后在Al基复合材料中没有观察到宏观断裂。研究结果对制备高强度、高塑性的HEA/Al复合材料具有指导意义。(C)2018 Elsevier B. V.版权所有。
The 5 vol% AlCoCrFeNi high-entropy alloy (HEA) reinforced Al matrix composites were fabricated successfully by spark plasma sintering at the temperatures ranging from 540 degrees C to 600 degrees C. At 540 degrees C, there is a smooth interface between HEA reinforcement and Al matrix. At the sintering temperature above 560 degrees C, the melting of particle-contacting zone between HEA reinforcement and Al matrix leads to the formation of a transition layer with a single FCC phase. Furthermore, its thickness increases with increasing sintering temperature. This is favorable for the transformation of the stress state from the iso-stress condition to the iso-strain condition for the composites during deformation process. Therefore, both yield strength and ductility are significantly improved. The yield strength and compressive strain of composites without transition layer are 96 MPa and 36%, respectively. In contrast, the yield strength of composites containing the transition layer with an average thickness of 7.6 mu m is about 137 MPa and no macroscopic fracture can be observed in the Al matrix composite after 50% compression strain. This work can provide guidance for fabrication of HEA/Al composites with high strength and good plasticity. (C) 2018 Elsevier B.V. All rights reserved.