This liquid lubricant protects the surfaces of metal contacts, allowing manufactured parts to last longer. Sliding metal contacts are used in motors, gears and other machinery. These contacts are essential to the metal manufacturing industry and the global metals market is expected to reach $872 billion by 2015. Metal-to-metal contacts exhibit increased current density compared to graphite-to-metal contacts, but are they more susceptible to corrosion and friction-induced wear. Long-term fatigue wear of metal sliding electrical contacts increases the rate of oxidation. Oxidation can cause subsurface fatigue cracks, resulting in delamination and the formation of debris particles that destroy the primary anti-wear additive in metal sliding contacts. Researchers at the University of Florida have developed a liquid lubricant for reducing friction between metal contacts and preventing oxidation.
A liquid lubricant for application on the surface of metal contacts to reduce friction while preventing oxidation and cold-welding
University of Florida researchers have developed a liquid lubrication scheme that, when applied to a sliding contact of non-noble metals (e.g. copper fiber brushes and copper slip rings), mitigates damage to the sliding surfaces and promotes low friction and electrical contact resistance. This lubricant reduces friction between metal contacts and the contacts’ exposure to oxygen, preventing oxidation. Oxidation rates can be reduced by minimizing the presence of oxygen in the environment in which the contacts are used, but the lack of a surface lubricating film can lead to cold welding and gross adhesive wear. Instead of removing the oxygen, the contacts are immersed in a fluid that simultaneously reduces friction and mitigates the growth of electrically insulating films.
