Fundamental Study on Tribological Properties of Ionic Liquid containing Self-lubricative Nano Particles

为了实现高功能的摩擦学系统，有必要研究适用于润滑剂的新材料的有效应用。在流体润滑领域，离子液体具有非挥发性和不可燃性，是广泛应用于各种环境的极具潜力的候选者之一。自润滑纳米颗粒作为一类新型的固体润滑剂，是固体润滑领域另一个有发展前景的材料。本研究的重点是这些新型润滑材料的复合体系，并研究了离子液体和纳米颗粒混合物的基本性质。将碳洋葱加入到咪唑基离子液体中形成凝胶。摩擦测量使用球盘摩擦计在空气和真空中进行，温度范围为20至200℃。结果表明，当正常载荷较大时，复合凝胶的摩擦系数低于离子液体本身。这可能是由于复合凝胶的粘弹性增加，其行为类似于油脂。在20 ~ 200℃的真空条件下，复合凝胶的摩擦学性能优于离子液体。另一方面，含有金刚石纳米颗粒的离子液体对滑动表面产生磨损，但没有表现出润滑性能。

In order to achieve highly functional tribological systems, it is necessary to study effective applications of new materials suitable for lubricants. In the field of the lubrication by fluids, ionic liquids that show non-volatility and non-combustibility are one of highly potential candidates for a wide range of environments. Another prospective material in solid lubrication is self-lubricating nano-particles as a new class of solid lubricants. This study focused on the compound system of these new lubricative materials and examined fundamental properties of the mixture of an ionic liquid and nano-particles. Carbon onions were added to imidazolium-based ionic liquid to form a gel. Friction measurements were conducted using a ball-on-disk tribometer in air and vacuum at the temperatures ranging from 20 to 200℃.As a result, the compound gel showed lower friction coefficients than the ionic liquid itself when normal load was high. This would be caused by the increasing viscoelasticity of the compound gel that behaves like grease. Furthermore, the tribological properties of the compound gel were superior to the ionic liquid in vacuum at 20-200℃.On the other hand, the ionic liquid containing nano-particles of diamond produced wear of sliding surfaces without showing lubricative property.