An Investigation of Silver-Nanoparticle-Laden Lubricants for Electrical Contacts

Electrical contacts are critically important for a wide variety of applications, including computing, automotive, manufacturing, and renewable energy technologies. Due to a combination of vibrations and environmental conditions, these contacts are often susceptible to fretting corrosion and other wear mechanisms. In many cases, it is not possible to design a stable dry contact system that is also within cost restraints. Therefore, lubricants are often employed. Liquid lubricants can reduce wear, but cause problems due to the nonconductive nature of typical lubricants. If a film develops between the surfaces due to tribofilm formation, lubricant degradation, or hydrodynamic lift, this can result in an increase in the electrical contact resistance. Fairly recently, researchers have explored the use of nanoparticles to enhance the friction and wear properties of lubricants. Some of the nanoparticles are metallic and could also improve the conductivity of the lubricant within an electrical contact. In this paper, the performance of silver-nanoparticle-laden dodecane lubricants is observed relative to pure dodecane and zinc dialkyl dithiophosphate-enhanced dodecane. These results suggest that the nanoparticles produce a reduced and more stable contact resistance while also reducing friction and wear.