Influence of polyethylene wax on wear resistance for polyurethane composite material under low speed water-lubricated conditions

Abstract

The water-lubricated bearing is one of the most important components in machine systems, and significantly affects safe operation. Poor lubrication makes it very difficult to ensure good wear resistance in water-lubricated bearings, especially at low speed or in complex load conditions. However, polyethylene wax (PEW) offers good self-lubricating performance, which may provide lubrication and the required wear resistance in water-lubricated bearing materials. In this reported study, a new water-lubricated bearing composite material comprised of polyurethane (PU) and a small amount of PEW were fabricated to improve the wear resistance of the PU-based water-lubricated bearings. The wear behavior of the PU-PEW composite material and the PU material was investigated at low speed and at different load conditions at room temperature using the CBZ-1 friction and wear tester. The wear resistance of these materials was evaluated based on the experimental results of the friction coefficient and wear morphologies. The experimental results indicated that the PEW additive was heated by the developed friction and was deposited on the surface of the composite material to form a lubricant film with good lubricity. As a result, the load bearing capacity of the lubricant film was improved, which effectively improved the lubrication conditions of the composite material, thereby improving the wear resistance and decreasing the effect of the load. These results suggest that this study may provide a novel approach for improving the wear resistance and lubrication condition of PU-based water-lubricated bearings.