Solid-solution strengthening in refractory high entropy alloys
Solid-solution strengthening in refractory high entropy alloys
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DOI：
10.1016/j.actamat.2019.06.006
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发表时间：
2019-08-15
期刊：
影响因子：
9.4
通讯作者：
Clarke, Amy J.
中科院分区：
文献类型：
--
作者：
Coury, Francisco Gil;Kaufman, Michael;Clarke, Amy J.
在室温至1000 ℃的温度范围内，生成了许多耐火高熵合金（RHEAS）的压缩应力-应变曲线。结果表明，在这些合金中的固溶强化具有非热和热的成分。从机械测试的结果与文献数据相结合，开发固溶体强化模型的两个组件，将单相体心立方（BCC）材料的特殊性。无热组分受到原子尺寸失配和弹性模量失配的组合的影响，这取决于来自每种合金的平均值，从而允许以高通量方式估计该组分。另一方面，热激活屈服应力分量与可以通过平均纯元素原子性质计算的任何参数不相关，并且观察到其大于纯BCC难熔金属及其稀释合金的值。总的来说，RHEAS被发现有更大的热和非热屈服应力分量相比，纯或传统的耐火合金，这解释了它们在室温下相对较高的强度。(C)2019 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Compression stress-strain curves of a number of refractory high entropy alloys (RHEAS) were generated at temperatures ranging from room temperature to 1000 degrees C. It is shown that solid-solution strengthening in these alloys has both an athermal and a thermal component. Results from mechanical testing are combined with literature data to develop solid-solution strengthening models for both components that incorporate the particularities of single-phase body centered cubic (BCC) materials. The athermal component is affected by a combination of atomic size mismatch and elastic modulus mismatch, which depend upon average values from each alloy, thereby allowing this component to be estimated in a high throughput fashion. On the other hand, the thermally-activated yield stress component does not correlate with any parameter that can be calculated by averaging pure elemental atomic properties and it is observed to be larger than the values found for pure BCC refractory metals and their dilute alloys. Overall, RHEAS are found to have larger thermal and athermal yield stress components compared to pure or conventional refractory alloys, which explains their relatively high strengths at room temperature. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.