Tribological Behavior Of Sliding Electrical Contact Materials Lubricated By Ionic Liquid Under Electrical Contact

The main task of tribology under electrical contact is to develop high-performance lubricating materials and reliable lubrication technology, The tribological properties and electrical properties are assessment indicators. Self-lubricating composite material based on noble metals can be used under atmospheric and vacuum conditions, but the copper and aluminum, which have excellent electrical properties and lower prices, can not be applied because of their tribology problems. Locking phenomenon of self-mated Cu and self-mated Al happens in vacuo or even in the atmosphere because of different degrees of adhesion when analysed with the principles of tribology. Can we solve the problem by using a class of medium with both good lubricity and conductivity? Ionic liquid is a good choice.In this paper, self-mated Cu and self-mated Al were used as friction pair using a small amounts of ionic liquid L-P106as lubricant, a self-made friction and wear tester(EMM-1) with an accessional current was testing instrument. With and without current, the friction and wear properties of Cu and Al was evaluated in dry sliding and using L-P106as lubricant. And the effects of various test parameters (speed, load, current) on the friction coefficient and wear rate were studied too.The results showed that ionic liquid L-P106have a good effect on the decrease of friction and wear of Cu/Cu. It performed well in a wide speed range (0.05-0.9m/s) and relatively high loads (up to61.7N) when in the current-carrying (0-5A). The friction coefficient is lower than the average0.065. The average wear rate of the pin is of the order of generally10-8mm/(N-·m), and the worn surface is very smooth. The wear mechanism of it is slight micro-cutting. Self-mated Cu was easily locked under the dry sliding. The wear of both pin and disc were very serious, and the wear mechanism is adhesive wear.For Al/Al, locking phenomenon of self-mated Al was observed due to strong adhesion under the dry sliding conditon. By using minimal quantity ion liquid L-P106in the sliding contact, the friction coefficient of self-mated Al was as low as0.1. Results indicate that the lubricating regime is boundary lubrication with or without current. The friction coefficient of self-mated Al under current-carrying was higher than that without current. The transition from moderate wear to severe wear at higher speeds (>0.79m/s) was observed. Erosive wear was induced by current aggravated the wear of self-mated Al. The wear mechanism of self-mated Al was slight abrasive wear under the condition without current-carrying, but when there was current, it turned into adhesive wear, and arc erosion wear happened at the same time.