论文标题
微观循环裂纹生长的新方法，从缺口微型管理器和应用到单晶钨和金属玻璃
A new method for microscale cyclic crack growth characterization from notched microcantilevers and application to single crystalline tungsten and a metallic glass
论文作者
论文摘要
大多数金属的寿命受环载量的限制，以疲劳失败结束。裂纹的逐渐生长最终导致灾难性的失败。提出了一种先进的方法，用于使用纳米插入术来测定微观上的循环裂纹生长，该方法允许表征> 10,000个载荷周期。它使用焦点的离子束制造的凹口微管。该方法已通过循环弯曲金属玻璃和钨微接头验证。实验表明在两个样品的寿命中都有稳定的裂纹生长。由于缺口，金属玻璃显示出较少的可塑性，但显示由变形引起的剪切。测试中确定的裂纹增长速度是在巴黎的权力法关系之后的。结果可靠，可再现且与宏观设置相当。由于该方法的灵活性，它适合表征特定的微观结构特征，例如单相，晶界或不同的晶粒方向。
The lifetime of most metals is limited by cyclic loads, ending in fatigue failure. The progressive growth of cracks ends up in catastrophic failure. An advanced method is presented for the determination of cyclic crack growth on the microscale using a nanoindenter, which allows the characterization of > 10,000 loading cycles. It uses focused ion beam fabricated notched microcantilevers. The method has been validated by cyclic bending metallic glass and tungsten microcantilevers. The experiments reveal a stable crack growth during the lifetime of both samples. The metallic glass shows less plasticity due to the absence of dislocations, but shows shearing caused by the deformation. The crack growth rates determined in the tests follow Paris' power law relationship. The results are reliable, reproducible and comparable with macroscopic setups. Due to the flexibility of the method, it is suitable for the characterization of specific microstructural features, like single phases, grain boundaries or different grain orientations.
