Understanding the Molybdenum Disulfide Coating Process – Part I

Molybdenum disulfide is a solid film lubricant, which can be used in the manufacturing of different types of industrial products. These include gear oils, pastes, paint like coatings and other grease based lubricants. Also known as MoS2, the lubricant can perform in applications with wide temperature ranges and pressures, while maintaining its basic structure. For these reasons, MoS2 is often designed and used as a protective coating for metal substrates. In this post, we provide information regarding the various molybdenum disulfide coating processes.

Types of MoS2 Coating Methods

Molybdenum disulfide is known for its strength and lubricity. MoS2 has a layer-lattice structure that bonds easily to metal substrates. This allows an applicator to apply the coating in different ways. Essentially, four methods can be used to apply MoS2 onto a substrate. The steps of each process are described in the points below, for the best results we recommend using a professional applicator.

  1. Burnishing/Rubbing: In this method, molybdenum is used in powder form to help produce a lubricating film on the substrate. Generally, the powder is rubbed onto the metal using a soft fabric pad. However, a specialized coating applicator can also be used.
    • Place protective sheets on and around the work area to prevent the powder from spreading.
    • The substrate must be clean and free of rust and loose debris. A light (400-800 grit) aluminum oxide or similar grit blast is recommended.
    • Place the metal substrate onto the sheets, and spread the powder across its surface
    • Place the application pad on the powder. Apply a little bit of pressure, and spread the powder across the substrate surface. Keep the movement uniform, using smooth circular motions. Continue doing this till the powder has coated the surface completely.
  2. Physical Vapor Deposition (PVD): This method is not a method we utilize at Microsurface Corporation. If you require this method of application, we recommend finding a company with experience in PVD surface treatments. This molybdenum disulfide coating process requires a combination of a rotary diffusion pump, bell jar, spatula, and sample holder.
    • Remove the bell jar cover. Use the spatula to scoop up the MoS2 paste, and put it into the sample holder. Then replace the bell jar cover.
    • Place the substrate in the vacuum environment.
    • Define the paste’s evaporation temperature, and stabilization time using a computer. Use the rotary pump to lower the pressure and create a vacuum.
    • The lack of pressure will cause the temperature to rise, slowly converting the paste into vapor. The vapor will then form an even coating on the substrate surface.

These are the first two molybdenum disulfide coating processes, which can be used to apply this versatile lubricant onto a substrate. In the next post, we shall elaborate the points of the remaining two methods. In the meantime, if you have requirements for MoS2 coating please contact us. AMS2526, MIL-PRF-46010 and AS5272 are some of the specifications we apply the coating to.