Study on the frictional properties of micro-magnet arrayed surface lubricated with ferrofluids

Abstract

Ferrofluids (FF) are stable colloids exhibiting normal liquid behavior coupled with magnetic properties. As a kind of lubricant, the most obvious advantage is that FF can be maintained in the desired position without any leakage by applying a permanent magnet. For the above characteristics, a kind of micro-magnet arrayed surface for FF lubrication was introduced in this article. The tribological performances of the surface were tested under plane contact conditions using FF as a lubricant. Flat SUS316 steel and polytetrafluoroethylene (PTFE) were used as opposite pairs, respectively, for their different wetting properties with FF. The experimental results show that compared with normal surface/PTFE frictional pair, the magnetic surface/PTFE couple expresses distinct friction increasing, while the magnetic surface/SUS316 steel pair presents obvious advantages of antifriction especially at high sliding speeds. The higher the surface magnetic flux is, the better is the tribological performance it displays especially at a higher sliding speed.