Our diffusion process is a proprietary form of ferritic nitrocarburizing performed in a vacuum assist environment.  By a batch process, tool steel is heated to a safe temperature that is well below the final temper of the tool so final hardness is not affected.  Once heated, uniformly, a mixture of gases are introduced under pressure with the tooling experiencing the temperature, pressure, and gas environment for a prescribed time. 

Each type of steel receives a different combination or recipe of these parameters.  The gases contain both Nitrogen and Carbon atoms.  A thermo-chemical reaction occurs whereby a sub-zone and a compound layer are created as nitrogen and carbon atoms are diffused into the steel’s surface.  The diffusion zone is resistance to wear and corrosion.

The depth of diffusion can be anywhere from .004”-.006” (102 to 203 microns) depending on the recipe used.  The compound layer is both hard and much thinner .0002” to .0008” (5 to 20 microns) and somewhat ceramic in nature.  This compound layer is about 1200 to 1500 vickers in hardness.  If you try to abrade the steel with a 65Rc common file, it will not damage a ThermaLLife processed surface.  The compound layer forms a barrier that prevents soldering of aluminum to die cast die surfaces.

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