The frictional energy dissipation and interfacial heat conduction in the sliding interface
The frictional energy dissipation and interfacial heat conduction in the sliding interface
复制标题
滑动界面的摩擦能量耗散和界面热传导
DOI：
10.1063/1.5054876
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发表时间：
2018
期刊：
影响因子：
1.6
通讯作者：
Chen Yunfei
中科院分区：
文献类型：
--
作者：
Wei Zhiyong;Kan Yajing;Zhang Yan;Chen Yunfei
滑动表面间的能量耗散率和界面导热系数是准确预测界面温升的重要参数，但其物理机制尚不清楚。在这项研究中，能量耗散和滑动硅膜和固定的硅衬底之间的界面热输运的分子动力学模拟研究。结果表明，平均摩擦力随法向载荷的增加先增大后减小;然而，当法向载荷超过约60 eV/A的临界值时，界面原子开始塌陷，导致平均摩擦力随着法向载荷的进一步增加而下降。我们的研究还表明，在摩擦过程中耗散的能量是定量等于传导热。通过提取界面温差，发现在10 ~ 60 eV/A的相同法向载荷下，滑动状态下的界面热导比静态下的高2 × 4倍。这是因为摩擦过程中界面原子受到较大的动力学冲击，激发出更多的非平衡声子，有利于提高声子界面透射系数。研究结果表明，摩擦过程中的动态激励可以修正摩擦界面的导热系数，这对准确预测摩擦界面的温升具有重要意义。
The energy dissipation rate and interfacial thermal conductance between two sliding surfaces are important to accurately predict the interface temperature rise, while their physical mechanism is not well understood. In this study the energy dissipation and interfacial thermal transport between a sliding silicon film and a fixed silicon substrate are investigated by molecular dynamics simulations. The results show that the mean friction force first increases with increasing normal load. However, when the normal load exceeds the critical value of about 60 eV/A, the interface atoms begin to collapse, causing the mean friction force to drop with the further increase of the normal load. Our study also shows that the energy dissipated during the friction process is quantitatively equal to the conducted heat. By extracting the interfacial temperature difference, it is found that the interfacial thermal conductance in sliding state is 2∼4 times higher than that in static state with the same normal load from 10 to 60 eV/A. This is because the interfacial atoms suffer great dynamic impacts during the friction process, which excites more non-equilibrium phonons and helps to enhance the phonon interfacial transmission coefficient. The present investigation demonstrates that the dynamic excitation induced by the friction process can modify the interfacial thermal conductance, which would be of great significance to accurately predict the temperature rise of the sliding interface.