Properties of Tungsten Disulfide (Dicronite®)
Dry Film Lubrication
Once engineers learn that Dicronite® dry film lubrication may very well solve their lubrication challenges, the conversation often turns to the solid lubricant’s properties. Dicronite® DL-5® is a modified tungsten disulfide powder (also spelled “tungsten disulphide”). Tungsten disulfide can be mined naturally as tungstenite, or it can be synthetically produced by combining Tungsten and Sulfur (WS2). The inorganic WS2 compound has a lamellar, or crystalline structure similar to that of MoS2. The Dicronite® process modifies the WS2 compound without changing molecular structure and produces an extremely lubricious powder that, when impingement applied to customer parts, creates an exceptionally thin, remarkably slick film that molecularly adheres to the substrate surface.
One of the most valued Dicronite® properties is the coating’s thickness. Because the particles will not bond to themselves and are of a controlled size, the solid lubricant film is not more than 0.5 microns thick. This makes it very attractive to designers challenged with adding the lubricant to already designed parts and components. The coating is a beautiful silver-gray, polished rhodium color, but the finished coating color can differ depending on the color and finish of the substrate underneath. Dicronite® dry lube can be applied on many substrates, including all metals and most plastics, and is often applied on top of other coatings such as TiN, CrN, CrC or Nickel. With a hardness rating of 1.0-1.5 on the Moh’s scale, it is relatively soft. This, along with the material’s low shear stress between molecular layers, enables Dicronite® to provide exceptional lubricity. It can be applied in soft–soft, soft–hard, hard–hard, or many other variations of substrate surfaces.
In order to bond Dicronite® to customer parts, the powder is sprayed at very high velocity onto the substrate at one of 12 Dicronite® licensed facilities. This impingement process requires no binders, adhesives, solvents or cure time, and occurs at ambient temperatures.
Dicronite® solid lubricant does not affect surface electrical properties. It is also stable in extreme temperatures: -350° F to +1000° F or (-188° C to +538° C). In a vacuum, this WS2 coating withstands temperatures from -350° F to +2400F (-188° C to +1316° C), which is partly why it was developed for use on NASA’s Apollo missions and continues to be used in harsh environments today. Other properties to consider are:
- It is inert, non-magnetic and completely safe for the environment
- It withstands loads to 350,000 psi (approximately 2,450 MPa)
- It is compatible with oils, greases, hydraulic fluids, and fuels
Dicronite® dry lubrication is biocompatible. It has been tested in accordance with ISO-10993 and United States Pharmacopoeia (USP) Class 6. Application specific approvals have been received from both the United States Food and Drug Administration (US-FDA) and the United States Department of Agriculture (USDA).
Dicronite® dry film lubrication can be applied to holes, inside diameters and/or inside surfaces. It is possible to mask off or protect portions of the substrate or part so that they do not receive Dicronite® dry lubrication.
For more information or to download Dicronite® Dry Lubrication Technical Data Sheet, click here.
© Lubrication Sciences International, Inc. 2021. Dicronite® and DL-5® are registered trademarks of Lubrication Sciences International, Inc.