Tunable nanomechanical performance regimes in ceramic nanowires
Tunable nanomechanical performance regimes in ceramic nanowires
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DOI：
10.1088/1361-6528/ab3dcf
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发表时间：
2019-09
期刊：
影响因子：
3.5
通讯作者：
M. Maksud;Mathius Barua;Md. Ruhul A. Shikder;Bryan W. Byles;E. Pomerantseva;A. Subramanian
中科院分区：
文献类型：
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作者：
M. Maksud;Mathius Barua;Md. Ruhul A. Shikder;Bryan W. Byles;E. Pomerantseva;A. Subramanian
在宏观尺寸范围内，当陶瓷材料受到超过其特征强度的机械载荷时，它们表现出脆性断裂和灾难性失效。在这份报告中，我们提出了恢复塑性α相，钾稳定的二氧化锰纳米线（α-K0.13MnO2 NW）晶体时，他们受到原子力显微镜（AFM）为基础的三点弯曲试验在非常低的加载速率。从这些测量得到的力-挠度曲线和AFM扫描显示屈服和扩展的塑性在加载过程中的NW，而大的塑性变形在卸载过程中自发恢复。然而，当相同的材料系统在几乎高一个数量级的加载速率下经受弯曲试验时，其在显著更高的强度下通过断裂而表现出失效。这些结果突出了一个重要的新途径，以可控地调整这些技术上重要的纳米铈的纳米机械性能的应用特定的需求：要么实现自可逆和超大塑性，或实现更高的断裂强度，接近材料系统的内在极限。
At the macroscopic size regime, ceramic materials exhibit brittle fracture and catastrophic failure when they are subjected to mechanical loads that exceed their characteristic strength. In this report, we present recoverable plasticity in alpha-phase, potassium stabilized manganese dioxide nanowire (α-K0.13MnO2 NW) crystals when they are subjected to atomic force microscopy (AFM) based three-point bending tests at very low loading rates. The force-deflection curves and AFM scans obtained from these measurements reveal yielding and extended plasticity in the NWs during the loading process, while the large plastic deformation is recovered spontaneously during the unloading process. However, the same material system exhibits failure via fracture at substantially higher strengths when it is subjected to bending tests at nearly an order of magnitude higher loading rates. These results highlight an important new pathway to controllably tune the nanomechanical performance of these technologically important nanoceramics for application-specific needs: either achieve self-reversible and ultra-large plasticity, or achieve substantially higher fracture strengths that approach the intrinsic limits of the material system.