Existing solid lubricants are capable of enduring these ranges of temperatures, loads, and speeds. Gas phase lubrication is a process that can increase the lifetime of the lubricating film by replenishing the solid lubricant on the worn surfaces. There are a number of different ways in which a gas can activate the formation of a solid film on a surface. Many solid films are formed by a reaction between the gas and the surface material, a process which consumes part of the surface material in the formation of the lubricous film. The reaction between boric oxide and water vapour in the atmosphere will result in boric acid.
Boric acid is a lubricous lamellar solid at room temperature.
Polymers containing boric oxide fillers have shown excellent wear resistance properties and low friction coefficients as a result of this surface reaction with humid air. Hydrogen sulphide gas is capable of converting molybdenum and tungsten containing surfaces into molybdenum disulphide and tungsten disulphide respectively. Both molybdenum disulphide and tungsten disulphide are excellent lamellar solid lubricants, friction coefficients less than 0.1 are common. Solid films can also be formed by a reaction process which occurs on the surface rather than with the surface. This involves a gas which decomposes and deposits a lubricating film on the surface.