MODIFIED SLURRY COMPOSITIONS FOR FORMING IMPROVED CHROMIUM DIFFUSION COATINGS

摘要

Unique and improved chromium coatings derived from modified chromium-containing slurry formulations are disclosed. The slurry formulation includes a combination of a selected halide activator and buffer material that synergistically interact with each other to form chromium diffusion coatings with improved microstructure in comparison to chromium diffusion coatings produced from conventional chromizing processes. The coatings may be locally applied in a controlled manner with accuracy onto various parts, including those having internal sections with complex geometries, without masking any portion thereof.

主权项

1. A slurry composition comprising:
a chromium source comprising elemental chromium powder, alloyed chromium powder, chromium-containing compounds or a mixture thereof; a non-nitrogen halide activator characterized by the absence of ammonium halide; a buffer material selected from the group consisting of nickel, cobalt, silicon, aluminum, silicon, titanium, zirconium, hafnium, yttrium, manganese and any combination thereof; and a binder solution, said binder solution comprising a binder material dissolved in a solvent, said solvent compatible with each of the non-nitrogen halide activator and the binder material.