Solid film lubricants provide lubrication and wear protection in a broad range of industries and applications, specifically in harsh environments where conventional liquid or grease-based lubricants cannot be used. The limiting factor of solid film lubricants has often been poor adhesion. Historically, parts had to be roughened by blasting or binders and solvents had to be used with oven-bake procedures, all resulting in marginal adhesion of the solid film lubricant to the substrate. An alternate method has been to use vacuum plasma-based technologies with high expense, process complexity, and limitation on part size.
Air Force researchers have developed a novel method that provides durable adhesion of solid film lubricants. A synergistic effect is achieved by creating low friction, low wear and a long life. The burnished Sb2O3 technique is fast, environmentally friendly, and scalable. The burnished lubricant is as effective, or more so, than PVD or CVD lubricant coatings at a significant cost savings. The process is as follows:
- Surface of the substrate is properly cleaned of contaminants
- The clean surface may be further activated as appropriate: acid treatment for metals and ceramics, plasma treatment for composites and plastics
- A thin layer of a soft oxide material like Sb2O3 is burnished onto the surface in a uniform film
- The solid film lubricant is then deposited on top of the soft oxide bond layer
- The solid film lubricant can be molybdenum disulfide, dichalcogenides, oxides, boron nitride, calcium fluoride, graphite, or mixtures of these, as well as performance-enhancing additives, PTFE, or any other friction-reducing material
This US patent 9,475,089 is related to US patent 8,637,162.
- This is a non-vacuum process at ambient temperatures and requires no binders, adhesives, curing, or baking
- Lubricant performance is enhanced by orders of magnitude compared to conventional approaches (it provides a coating that does not chip, crack, or peel)
- Method is inexpensive, environmentally friendly, and applicable to almost any substrate material
- The final functional coating is about 1 μm thick (with a range of 0.5-3.0 μm), which will not affect part tolerances
- This technology may have excellent application with electroluminescent materials for sensors, detectors, scintillators, and displays
- US patent 9,475,089 available for license
- Potential for collaboration with Air Force researchers