Strain, stress and stress relaxation in oxidized ZrCuAl-based bulk metallic glass
Strain, stress and stress relaxation in oxidized ZrCuAl-based bulk metallic glass
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DOI：
10.1016/j.actamat.2020.09.049
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发表时间：
2020-11-01
期刊：
影响因子：
9.4
通讯作者：
Somers, Marcel A. J.
中科院分区：
文献类型：
--
作者：
Haratian, Saber;Niessen, Frank;Somers, Marcel A. J.
研究了通过低于玻璃化转变温度的气态氧化对 Zr51.3Al8.5Cu31.3Ni4Ti4.9 大块金属玻璃 (BMG) 进行表面工程，作为在表面区域引入残余压缩应力的一种方法。将 ZrCuAl 基 BMG 在 600 K 下暴露于 10(-41) bar 的极低氧分压下 60 小时。氧化处理导致内部氧化区的形成，该内部氧化区由精细分散的纳米晶立方ZrO2 (c-ZrO2)、与表面倾斜的金属区域和表面的铜小丘组成。与氧化相关的体积膨胀引入的应力通过 i) c-ZrO2 内的晶格应变（通过基于 X 射线衍射 (XRD) 的方法测定）和 ii）作为环形聚焦离子束 (FIB) 铣削响应的应变弛豫（通过数字图像相关 (DIC) 监测）进行评估。 XRD 分析在纳米晶 c-ZrO2 中产生 -1.5 GPa（压应力），而通过 FIB-DIC 分析监测的应变松弛表明内部氧化区的压残余应力为 -1.4 GPa。讨论了用独立测量方法确定的应变和应力。讨论了与内氧化区演化过程中的微观结构特征和应力松弛机制相关的定量宏观应变。 (C) 2020 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
Surface engineering of Zr51.3Al8.5Cu31.3Ni4Ti4.9 bulk metallic glass (BMG) by gaseous oxidizing below the glass-transition temperature is investigated as a means to introduce compressive residual stress in the surface region. The ZrCuAl-based BMG was exposed to an extremely low oxygen partial pressure of 10(-41) bar at 600 K for 60 h. The oxidizing treatment led to the formation of an internal oxidation zone, consisting of finely dispersed nano-crystalline cubic ZrO2 (c-ZrO2), metallic regions inclined with the surface and Cu-hillocks at the surface. The stresses introduced by the volume expansion associated with oxidation were evaluated from i) the lattice strains within c-ZrO2, as determined with an X-ray diffraction (XRD) based method, and ii) strain-relaxation as a response to annular focused ion beam (FIB) milling, as monitored with digital image correlation (DIC). XRD analysis yielded -1.5 GPa (compressive stress) in the nano-crystalline c-ZrO2, while the strain relaxation monitored with FIB-DIC analysis indicated compressive residual stresses of -1.4 GPa in the internal oxidation zone. The strains and stresses determined with the independent measurement methods are discussed. The quantitative macro-strains are discussed in relation to the microstructural features and stress relaxation mechanisms during evolution of the internal oxidation zone. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.