Rejuvenated metallic glass strips produced via twin-roll casting
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第3期
论文作者：Long Zhang Yi Wu Shidong Feng Wen Li Hongwei Zhang Huameng Fu Hong Li Zhengwang Zhu Haifeng Zhang
文章页码：73 - 79
摘 要：The energy state and atomic level structure of metallic glasses（MGs） are very sensitive to their cooling rates, and a lower cooling rate generally causes a lower energy and more relaxed state of MGs. In this work, the Zr41.2 Ti13.8 Cu12.5 Ni10 Be22.5（Vit. 1） ribbons with a thickness of 40 μm and 110 μm and the strips with a thickness of 320 μm and 490 μm were produced by single-roll melt spinning and twin-roll casting, respectively. The increase in thickness of either ribbons or strips results in a lower energy state with a smaller relaxation enthalpy, a lower content of free volume, and a higher hardness. Although the cooling rate of the twin-roll produced 320 μm-thick strip is almost one magnitude lower than that of the single-roll produced 110 μm-thick ribbon, the former, however, possesses a rejuvenated energy state as compared to the latter. Molecular dynamics simulations reveal that the squeezing force during twin-roll casting affects the evolution of connection types of clusters, and the 2-atom and 4-atom connections are prone to be retained, which results in a higher energy state of MGs. Such a rejuvenation process during twin-roll casting can overwhelm the relaxation process caused by the lower cooling rate. Therefore,twin-roll casting is not only a method being capable for producing strips with a large thickness, but also prone to obtain a high energy state of the MG strip.
Long Zhang1，Yi Wu1,2，Shidong Feng3,4，Wen Li2，Hongwei Zhang1，Huameng Fu1，Hong Li1，Zhengwang Zhu1，Haifeng Zhang1
1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences2. Shenyang Ligong University3. Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University4. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University
摘 要：The energy state and atomic level structure of metallic glasses（MGs） are very sensitive to their cooling rates, and a lower cooling rate generally causes a lower energy and more relaxed state of MGs. In this work, the Zr41.2 Ti13.8 Cu12.5 Ni10 Be22.5（Vit. 1） ribbons with a thickness of 40 μm and 110 μm and the strips with a thickness of 320 μm and 490 μm were produced by single-roll melt spinning and twin-roll casting, respectively. The increase in thickness of either ribbons or strips results in a lower energy state with a smaller relaxation enthalpy, a lower content of free volume, and a higher hardness. Although the cooling rate of the twin-roll produced 320 μm-thick strip is almost one magnitude lower than that of the single-roll produced 110 μm-thick ribbon, the former, however, possesses a rejuvenated energy state as compared to the latter. Molecular dynamics simulations reveal that the squeezing force during twin-roll casting affects the evolution of connection types of clusters, and the 2-atom and 4-atom connections are prone to be retained, which results in a higher energy state of MGs. Such a rejuvenation process during twin-roll casting can overwhelm the relaxation process caused by the lower cooling rate. Therefore,twin-roll casting is not only a method being capable for producing strips with a large thickness, but also prone to obtain a high energy state of the MG strip.
关键词：
