Abstract The potential benefits of nanocrystalline (NC) alloys for use in various structural applications stem from their enhanced mechanical strengths. However, deformation-induced grain growth in NC materials reduces the strength and is a widely reported phenomenon occurring even at low-temperatures. Controlling such behavior is critical for the maturation of bulk nanocrystalline metals in various advanced engineering applications. Here, we disclose the mechanism by which grain boundary sliding and rotation are suppressed when a NC material is truly thermo-mechanically stabilized against grain growth. Unlike in any other known nanocrystalline metals, the absence of sliding and rotation during loading, at extreme temperatures, is related to short-circuit solute diffusion along the grain boundaries causing the formation of solute clusters and thus a significant change of the grain boundary structures. The departure of this unusual behavior from the well-established norm leads to a strong enhancement of many mutually exclusive properties, such as thermo-mechanical strength, creep resistance, and exceptionally high electrical/thermal conductivity. This work demonstrates that Cu-based nanocrystalline alloys can be used in applications where conventional Cu-based polycrystalline materials are not viable.

中文翻译：

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纳米技术使设计具有极高强度以及热和电性能的结构材料成为可能

摘要 纳米晶 (NC) 合金在各种结构应用中的潜在优势源于其增强的机械强度。然而，NC 材料中变形诱导的晶粒生长会降低强度，并且是一种广泛报道的现象，即使在低温下也会发生。控制这种行为对于大块纳米晶金属在各种先进工程应用中的成熟至关重要。在这里，我们公开了当 NC 材料真正热机械稳定以防止晶粒生长时抑制晶界滑动和旋转的机制。与任何其他已知的纳米晶金属不同，在加载过程中没有滑动和旋转，在极端温度下，与沿晶界的短路溶质扩散导致溶质簇的形成以及晶界结构的显着变化有关。这种不寻常的行为与既定规范的背离导致了许多相互排斥的特性的强烈增强，例如热机械强度、抗蠕变性和异常高的导电/导热性。这项工作表明，铜基纳米晶合金可用于传统铜基多晶材料不可行的应用中。以及极高的导电性/导热性。这项工作表明，铜基纳米晶合金可用于传统铜基多晶材料不可行的应用中。以及极高的导电性/导热性。这项工作表明，铜基纳米晶合金可用于传统铜基多晶材料不可行的应用中。