Tungsten Disulphide Dry Film Lubrication Coating
Tungsten Disulphide was developed by NASA as a lubricant for the Mariner deep space probes where the high vacuum and temperature render conventional lubricants unsuitable. Since then it has found uses as a specialised engineering lubricant and in the plastics industry as a permanent (coated on) release agent.
Application Details
The low friction coating is factory applied at ambient temperature to form a molecular bond with the substrate material, which can be metal or plastic. Parts need no special engineering as its 0.5 micron thickness is well below normal engineering limits of fit. The material does not bond with itself so cannot be 'built up'. Small holes, slots and fine surface detail can be coated.
Application Areas Include
High Vacuum, High Temperature, Clean Room, Aerospace, Nuclear, Cryogenics, Machine Tools, Racing Engines, Cutting Tools, Die Casting
Benefits and Capabilities of Tungsten Disulphide
- Solves problems such as: friction, excessive wear, seizing, galling and fretting
- Withstands loads up to 350,000psi at temperatures between -273°C to 650°C
- Enhances the performance of all oils and greases
- Overcomes or reduces mechanical lubrication problems improving performance and extending service life up to 300-500%
- Eliminates and reduces costly maintenance problems that cause breakdowns and expensive downtime by stopping galling fretting and friction caused by dissimilar metals and their different hardnesses
- Maintains the dimensional integrity of the substrate to within 0.5microns with no build up
- Is inert, inorganic, non-toxic, non-distortive, noncorrosive and resistant to most fuels and solvents
- Resists carbon build-up from burnt deposits due to its extremely low coefficient of friction - less than half that of Moly and Teflon
- Molecularly bonds to all materials and plating.
| Physical Properties of Tungsten Disulfide TD Coatings | |
|---|---|
| Composition | Tungsten Disulfide [>99% purity.] |
| Process | Ambient temperature high velocity impingement coating. |
| Binder | No binder used. No bake step required. |
| Appearance | Silver-grey. |
| Thickness | Thickness 0.5 – 1.00 microns. |
| Uniformity | Coating conforms uniformly to the substrate. No build-up occurs on corners (unlike plating operations). Coating "throws" well into features. In deep holes, coating tapers off from 1 to 7 diameters of depth. |
| Hardness | Approx. 30 HRc. |
| Adhesion | The coating forms a mechanical-molecular interlock to the substrate that will not flake, blister, chip or peel. |
| Coefficient of Friction | TD provides extremely low friction against steels, carbides, TiN, ceramics, platings, plastics, etc. The dynamic coefficient of friction of TD coating against steel is about .03. Static coefficient of friction of TD coating against steel is about .07. This corresponds to lower friction than Teflon, graphite, MoS2, and diamond. The coefficient of friction is a system property, not a material property. It is dependant on many factors such as material, countermaterial, lubrication, temperature, speed, loading force, surface finish, surface finish of the counter-material, and type of motion (reciprocating, rotating). Published values can have large variations. |
| Non-stick | TD is an excellent non-stick surface against most other materials. It is used to aid release of parts from plastic moulds and reduce drag of plastic through the mould for faster and more complete fill. |
| Toxicity | Non-toxic |
| Temperature Resistance | -450° F to 950° F at normal atmosphere |
| Melting Point | 1480°C (decomposition at 1250°C) |
| Deposition Temperature | Ambient (room temperature). |
| Chemical Resistance | Fairly inert |
| LOX Compatibility | Insensitive to detonation by or in the presence of oxygen |
| Density | 7.4 g/cm³. |
| Molecular Weight | 248.02 |
| Crystal Structure | |
| Vacuum | Minimum Out gassing |
