Indentation into an Al/Si composite: enhanced dislocation mobility at interface
Indentation into an Al/Si composite: enhanced dislocation mobility at interface
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DOI：
10.1007/s10853-017-1495-6
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发表时间：
2017
影响因子：
4.5
通讯作者：
Zhibo Zhang;H. Urbassek
中科院分区：
文献类型：
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作者：
Zhibo Zhang;H. Urbassek
采用分子动力学模拟方法，研究了金属-陶瓷（Al/Si）复合材料的压痕，并与纯元素的压痕进行了比较。垂直于表面的Al/Si界面在中心缩进。 我们发现，由于其较高的刚度和屈服强度，硅扩展到铝侧。结果，Al侧的塑性增强，导致复杂位错网络的形成。在Si侧，从立方金刚石到bct 5结构的相变以及随后的压头附近的非晶化被加速，而在幸存的立方金刚石相中形成的位错的数量减少。在这两种材料中，位错的移动性增强，特别是因为位错容易在界面上滑动;因此，复合材料比其组分的平均值更软。
Using molecular dynamics simulation, we study the indentation of a metal–ceramics (Al/Si) composite and compare it to that of the pure elements. An Al/Si interface running perpendicular to the surface is indented centrally. We find that—due to its higher stiffness and yield strength—Si expands into the Al side. As a consequence, the plasticity on the Al side is enhanced, leading to the formation of complex dislocation networks. On the Si side, the phase transformation from cubic diamond to bct5 structure, and subsequent amorphization near the indenter are accelerated, while the number of dislocations formed in the surviving cubic diamond phase is reduced. In both materials, the mobility of the dislocations is enhanced, in particular because the dislocations glide easily on the interface; as a consequence the composite is softer than the average of its constituents.