Department of Materials Science and Engineering, MIT, Cambridge, MA, 02139, USA.
Institute for Soldier Nanotechnologies, MIT, Cambridge, MA, 02139, USA.
Nat Commun. 2018 Nov 29;9(1):5077. doi: 10.1038/s41467-018-07509-y.
Impact-induced erosion is the ablation of matter caused by being physically struck by another object. While this phenomenon is known, it is empirically challenging to study mechanistically because of the short timescales and small length scales involved. Here, we resolve supersonic impact erosion in situ with micrometer- and nanosecond-level spatiotemporal resolution. We show, in real time, how metallic microparticles (~10-μm) cross from the regimes of rebound and bonding to the more extreme regime that involves erosion. We find that erosion in normal impact of ductile metallic materials is melt-driven, and establish a mechanistic framework to predict the erosion velocity.
冲击侵蚀是指物质被另一个物体物理撞击而导致的磨损。尽管这种现象是已知的，但由于涉及的时间尺度和长度尺度很小，从机械角度研究它具有挑战性。在这里，我们以微米和纳秒级的时空分辨率原位解决了超音速冲击侵蚀问题。我们实时展示了金属微颗粒（~10-μm）如何从反弹和结合的区域进入更极端的侵蚀区域。我们发现，在韧性金属材料的正冲击中，侵蚀是由熔体驱动的，并建立了一个机械框架来预测侵蚀速度。
