Reducing gun erosion by transfer and diffusion coating

A method of treating the steel surfaces of gun components which are exposed to erosive environments comprising

• (a) fitting, around the body of a projectile, a hollow ring of frangible or easily rupturable material, said ring containing a composition which comprises a viscous paste containing metallic aluminium and a liquid vehicle, and
• (b) firing the projectile from the gun so that the ring disintegrates, the gun components are coated with the composition, the coated components are exposed to the hot compressed gases formed on firing the gun and the aluminium diffuses into the surface of the gun components.

A method for reducing erosion of the steel surfaces of gun components which are exposed to hot corrosive gases when a cartridge is fired in a gun, said method comprising

• (a) applying to the surface of the components, in a liquid vehicle, a coating material containing aluminium,
• (b) drying the coating material, and
• (c) firing a cartridge in the gun whilst the aluminium remains on the surface, so that the aluminium is caused to diffuse into the surface by exposure of the coated surface to the hot compressed gases produced by firing the cartridge.

A method of treating the steel surfaces of gun components which are exposed to erosive environments comprising

• (a) applying to the surface of a projectile, in a liquid vehicle, a coating material containing metallic aluminium,
• (b) drying the coating material, and
• (c) firing the projectile from the gun so that a proportion of the coating material is transferred to the surface of the components, the coated components are exposed to the hot compressed gases formed on firing the gun and the aluminium diffuse into the surface of the gun components.