We have investigated the lubrication alignment behavior of point-plane contact and plane-plane contact between the GCr15 steel and polyimide (PI) friction pair using nematic liquid crystals (LCs) as the lubricant. In this system, rubbing orients the macromolecular PI molecules, and the oriented PI molecules induce alignment of the LC molecules in contact with or close to the oriented PI molecules. The LC molecules are aligned in the wear scar grooves of the PI film, and alignment extends to the GCr15-steel counterpart. Alignment of the LC molecules is correlated with the strong interaction force between the PI and LC molecules, the stable coordination structure of the LCs and GCr15 steel, and the weak interaction between the LC molecules. We performed simulations of the pretilt angle of PI and LCs and discussed the relationship between the pretilt angle and the friction properties. Owing to the small pretilt angle between PI and the LCs, the LC molecules orient almost parallel to the PI material, which is beneficial for superlubricity of this type of friction system.

我们研究了使用向列液晶 (LC) 作为润滑剂的 ​​GCr15 钢与聚酰亚胺 (PI) 摩擦副之间的点-平面接触和平面-平面接触的润滑对准行为。在该系统中，摩擦使大分子PI分子取向，并且取向的PI分子诱导与取向的PI分子接触或靠近的LC分子排列。LC 分子在 PI 薄膜的磨痕凹槽中排列，并且排列延伸到 GCr15 钢对应物。LC分子的排列与PI和LC分子之间的强相互作用力、LC和GCr15钢的稳定配位结构以及LC分子之间的弱相互作用有关。我们对 PI 和 LC 的预倾角进行了模拟，并讨论了预倾角与摩擦性能之间的关系。由于PI和LC之间的预倾角较小，LC分子几乎平行于PI材料取向，这有利于此类摩擦系统的超润滑性。