Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2010 Sep 17;105(12):125503. doi: 10.1103/PhysRevLett.105.125503.
At low temperatures, monolithic bulk metallic glasses (BMGs) exhibit high strength and large elasticity limits. On the other hand, BMGs lack overall ductility due to highly localized deformation mechanisms. Recent experimental findings suggest that the problem of catastrophic failure by shear band propagation in BMGs can be mitigated by tailoring microstructural features at different length scales to promote more homogeneous plastic deformation. Herein, based on a continuum approach, we present a quantitative analysis of the effects of microstructure on the deformation behavior of monolithic BMGs and BMG composites. In particular, simulations highlight the importance of short-ranged structural correlations on ductility in monolithic BMGs and demonstrate that particle size controls the ductility of BMG composites. In broader terms, our results provide new avenues for further improvements to the mechanical properties of BMGs.
在低温下，整体块状金属玻璃（BMG）表现出高强度和大的弹性极限。另一方面，由于高度局部化的变形机制，BMG 缺乏整体延展性。最近的实验结果表明，可以通过在不同尺度上调整微观结构特征来促进更均匀的塑性变形，从而减轻 BMG 中剪切带传播引起的灾难性失效问题。在此，基于连续体方法，我们对微观结构对整体 BMG 和 BMG 复合材料变形行为的影响进行了定量分析。特别是，模拟突出了短程结构相关性对整体 BMG 延展性的重要性，并证明了颗粒尺寸控制了 BMG 复合材料的延展性。更广泛地说，我们的结果为进一步提高 BMG 的力学性能提供了新的途径。
