A great enhancement of both strength and plasticity in a dual-phase high-entropy alloy by multi-effects of high carbon addition
A great enhancement of both strength and plasticity in a dual-phase high-entropy alloy by multi-effects of high carbon addition
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DOI：
10.1016/j.matdes.2022.111571
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Cong-hui Hu;Jian-lei Zhang;Yunhu Zhang;C. Song;Qijie Zhai
中科院分区：
文献类型：
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作者：
Cong-hui Hu;Jian-lei Zhang;Yunhu Zhang;C. Song;Qijie Zhai
高熵合金（HEAs）已成为一个有趣的研究领域的新型合金化设计范例。间隙碳通常被引入以提高HEAs的机械性能。为了实现高碳添加，本工作设计了不含强碳化物形成元素的双相Al 10（FeNiCoMn）90 HEA。结果表明，添加3at.碳没有引起碳化物的析出，其屈服强度和塑性分别提高了237 MPa和26.2%，这是由于fcc相含量的增加、bcc相分布的改变和间隙强化所致。添加4 at.%碳只在基体中析出纳米级碳化物，屈服强度和塑性分别提高了455 MPa和5.5%，这主要是由于相调制、间隙强化和析出强化所致。同时，碳的加入使合金的塑性由波形滑移向平面滑移转变，并形成微带，从而提高了合金的塑性。本工作提供了一种很有前途的方法，如果可以避免粗大的碳化物，高碳添加量提高强度和塑性的双相HEA的多效应，包括相位调制，间隙强化，沉淀强化和变形机制的转变。
High-entropy alloys (HEAs) have become an interesting research area for the novel alloying design paradigm. Interstitial carbon has usually been introduced to enhance mechanical properties of HEAs. To achieve addition of high carbon, this work designed a dual-phase Al10(FeNiCoMn)90HEA without strong carbide-forming elements. The results showed that adding 3 at.% carbon did not cause the precipitation of carbides in this HEA, and its yield strength and plasticity increased by 237 MPa and 26.2 %, respectively, which was due to the increase of fcc phase fraction, the distribution change of bcc phase and interstitial strengthening. Addition of 4 at.% carbon only caused the precipitation of nano-scale carbides in the matrix and the yield strength and plasticity increased by 455 MPa and 5.5 %, respectively, resulted from phase modulation, interstitial strengthening and precipitation strengthening. Simultaneously, the transition from wavy slip to planar slip and the formation of microbands after carbon addition, which also led to an increase of plasticity. This work provides a promising method that if coarse carbides can be avoided, high carbon addition enhances both strength and plasticity in a dual-phase HEA by multi-effects including phase modulation, interstitial strengthening, precipitation strengthening and deformation mechanism transition.