The movement of machinery components often results in resistance due to friction. Lubricants reduce this friction and make it easier for surfaces to move. Solid lubricants, made up of particles like graphite, MoS2, silicon or polytetrafluoroethylene (PTFE) do this by creating a film between moving components or coating them.

These particle-based lubricants, sometimes called dry lubricants or solid film lubricants, can be used alone, as extreme pressure (EP) additives in grease formulations or in combination with liquid lubricants in sprays or dispersions. They are designed to be non-toxic and environmentally safe, as well as less abrasive than traditional oil and grease.

Getting the right material for a lubricant application depends on a variety of factors. For example, the lubricant must withstand temperature and load variations while promoting smooth operation and minimizing contamination. It must also be resistant to moisture and corrosion and be compatible with the material being lubricated.

For instance, the lubricants used in ITER, an international project aimed at producing fusion energy for power, operate under cryogenic temperatures, high radiation levels and in a vacuum. For these types of applications, solid lubricants are crucial, says STLE member Brandon Krick, associate professor of mechanical engineering at Florida State University in Tallahassee. He notes that many medical instruments, metalworking tools and seals also require solid lubricants for the same reasons. The lubricants must also be chemically stable and work under cold, a corrosive atmosphere and in space. To achieve these goals, materials must have good lubrication, but they must also be electrically conductive and promote easy cleaning.