Patent ID: 8623461

Claim:
A coating process for protecting a surface ( 14 ) of a substantially chromium-free metal component ( 10 ), the coating process comprising: combining a substantially chromium-free silicon-containing fluid composition comprising a silane liquid with a dopant that is dissolvable in the silane liquid and is selected from the group consisting of yttrium, hafnium, and combinations thereof; applying a layer ( 12 ) of the substantially chromium-free, silicon-containing fluid composition to at least a portion of the surface ( 14 ); curing the substantially chromium-fee, silicon-containing fluid composition after the layer ( 12 ) is applied to the surface ( 14 ); placing the cured substantially chromium-free, silicon-containing fluid composition in layer ( 12 ) in a non-oxidizing atmosphere before heating; and heating the cured substantially chromium-free, silicon-containing fluid composition in layer ( 12 ) to a temperature of about 70 percent of the melting temperature of the substantially chromium-free component ( 10 ) or to the eutectic temperature of silicon and the metal constituting the substantially chromium-free metal component to form a substantially chromium-free, silicon-containing protective coating ( 16 ) on the surface ( 14 ) that includes silicon from the cured silicon-containing fluid composition and metal from the metal component ( 10 ).