Abstract Bulk metallic glasses (BMGs) are promising engineering materials due to their high strength, high fracture toughness and excellent corrosion resistance. However, the wide application of BMGs has been limited by the casting sample size. Joining of BMGs in their supercooled liquid region (SCLR) has shown the possibility to get rid of the casting size limitation. In this work, the physical mechanism of joining BMGs in their supercooled liquid region is systematically investigated. Specifically, the effects of joining temperature and time on the joint strength are studied by experiments, and the effects of joint strain and bonding morphologies are simulated by finite element analysis. It is observed that the joint strength is solely determined by the area fraction of the bonded regions, and the bonded regions increase with the joining temperature and joining time but are almost independent of the bonding morphologies. Based on the experiments and simulations, three microscopic processes that are oxide deforming and cracking, pristine BMGs flowing to contact and forming metallic bonds are identified to optimize the joint performance. By correlating the joining conditions with the three responsible microscopic processes, BMGs can be joined with predictable performance. Our work provides the fundamental physical processes for joining of BMGs in their SCLR, which could offer solution to the size limitation in application of BMGs.

中文翻译：

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大块金属玻璃在其过冷液体区域的连接机制

摘要 块状金属玻璃（BMGs）具有高强度、高断裂韧性和优异的耐腐蚀性能，是很有前景的工程材料。然而，BMG 的广泛应用受到铸件样品尺寸的限制。在过冷液体区 (SCLR) 中加入 BMG 已显示出摆脱铸件尺寸限制的可能性。在这项工作中，系统地研究了 BMG 在其过冷液体区域中连接的物理机制。具体而言，通过实验研究了接合温度和时间对接合强度的影响，并通过有限元分析模拟了接合应变和接合形态的影响。据观察，接合强度仅由粘合区域的面积分数决定，接合区域随着接合温度和接合时间的增加而增加，但几乎与接合形态无关。基于实验和模拟，确定了氧化物变形和开裂、原始 BMG 流向接触并形成金属键这三个微观过程，以优化接头性能。通过将连接条件与三个负责的微观过程相关联，BMG 可以以可预测的性能连接。我们的工作提供了在其 SCLR 中加入 BMG 的基本物理过程，这可以为 BMG 应用中的尺寸限制提供解决方案。原始 BMG 流向接触并形成金属键被识别以优化接头性能。通过将连接条件与三个负责的微观过程相关联，BMG 可以以可预测的性能连接。我们的工作提供了在其 SCLR 中加入 BMG 的基本物理过程，这可以为 BMG 应用中的尺寸限制提供解决方案。原始 BMG 流向接触并形成金属键被识别以优化接头性能。通过将连接条件与三个负责的微观过程相关联，BMG 可以以可预测的性能连接。我们的工作提供了在其 SCLR 中加入 BMG 的基本物理过程，这可以为 BMG 应用中的尺寸限制提供解决方案。