Effect of oxidation on the thermal expansion of a refractory multicomponent alloy
Effect of oxidation on the thermal expansion of a refractory multicomponent alloy
复制标题
氧化对难熔多元合金热膨胀的影响
DOI：
10.1080/09500839.2021.1881641
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发表时间：
2021-04
影响因子：
1.2
通讯作者：
Eric Osei-Agyemang;G. Balasubramanian
中科院分区：
文献类型：
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作者：
Eric Osei-Agyemang;G. Balasubramanian
我们采用第一性原理计算来研究氧化对难熔多组分合金热膨胀行为的作用。我们的结果表明，在一定温度范围内，氧化合金的线性膨胀和体积膨胀系数比纯材料具有更高的值。氧化合金的膨胀增强是由于合金的晶格参数在表面氧化时发生了显著变化。在氧化过程中，氧原子在合金表面完全覆盖后向亚表面层扩散，产生形成金属氧化物的组成元素的位移。这种损耗在晶格中产生空位，使氧化结构相对于纯耐火合金的膨胀性增强。
ABSTRACT We employ first-principles calculations to examine the role of oxidation on the thermal expansion behaviour of a refractory multicomponent alloy. Our results reveal that the linear expansion and the coefficient of volumetric expansion over a range of temperatures have higher values for the oxidised alloy than the pure material. The enhanced expansion for the oxidised alloy is attributed to significant changes in the lattice parameter of the alloy upon surface oxidation. During oxidation, the diffusion of oxygen atoms to the subsurface layer of the alloy after complete surface coverage produces a displacement of the constituent elements that form metal oxides. This depletion creates vacancy sites in the lattice for enabling enhanced expansivity in the oxidised structure relative to the pure refractory alloy.