Adaptive Solid Lubricant Transfer Films for Conductivity and Oxidation Control

The success of solid lubricants to exhibit ultra-low friction and wear behaviors in oil-prohibiting environments, has led to a major effort to optimize their performance and enhance their applicability. Depending on the operating conditions, solid lubricants may take on a plethora of forms including fabricated composite coatings, thick-film powder lubricants, nano-particle additives for hard surfaces or liquid lubricants, and self-replenishing transfer films. One of the benefits of transfer films are their freedom from the complex deposition techniques required for most other solid lubricant systems. In this work, the potential for adaptive self-replenishing transfer films was explored by creating composite powders of well-known powder lubricants and electrically conductive or anti-oxidation materials. MoS₂, WS₂, and Graphite Powders were mixed in varying composition with Cu, Sb₂O₃, and BO₃ additives and compacted to form “tuned” or adaptive powder pellets. Relationships between friction, wear, electrical resistance, tribo-induced oxidation and powder composition, will be presented in order to investigate the potential of composite property optimization for lubricious, highly conductive, and oxidation resistant transfer films.