Sealed anodic coatings
Metal and metal alloys with sealed anodic oxide coatings with at least partial crystallinity are disclosed. Associated articles are correspondingly disclosed. The sealed anodic coatings exhibit steam, superheated steam, alkaline and acidic resistance. The crystalline sealed anodic oxide coating can be prepared by impregnation of pores of a metal or metal substrate with metal precursor species, conversion of the metal precursor species into metal hydroxides, thermal treatment to dry out moisture and to promote phase transformation of the metal hydroxide product into metal oxides solids and bonding with metastable metal oxide substance in the pore structure of the metal or metal alloy substrate, and hydrothermal sealing, to create sealed anodic coating.
1. A sealed anodized metal comprising:
a metallic substrate comprising a first metal;
an anodic region contiguous with at least a portion of the metallic substrate, the anodic region having a plurality of cells comprising an amorphous first metal oxide, each of the plurality of cells having a pore with a pore filler in at least a portion thereof, the pore filler comprising at least one of a crystalline transition metal oxide, a crystalline precious metal oxide, a metalloid oxide, an alkali earth metal oxide, and an alkali metal oxide; and
a seal region adjacent to at least a portion of the anodic region, the seal region comprising at least one of a crystalline first metal oxide, a crystalline precious metal oxide, a crystalline alkali metal oxide, a crystalline first metal hydroxide, a crystalline precious metal hydroxide, and a crystalline alkali metal hydroxide.
2. The sealed anodized metal of claim 1 , wherein the precious metal is one of silver, ruthenium, palladium, iridium, platinum, gold, and alloys thereof.
3. The sealed anodized metal of claim 1 , wherein the first metal is aluminum or an alloy thereof.
4. The sealed anodized metal of claim 3 , wherein the pore filler comprises one of crystalline nickel oxide, tin oxide, cobalt oxide, magnesium oxide, silicon oxide, and sodium oxide.
5. The sealed anodized metal of claim 3 , wherein the anodic region comprises columnar cells of aluminum oxide and pore fillers of crystalline nickel hydroxide, and wherein the seal region comprises crystalline aluminum hydroxide.
6. The sealed anodized metal of claim 1 , wherein the seal region comprises aluminum hydroxide that has a level of crystallinity that increases with a depth of the seal region.
7. The sealed anodized metal of claim 1 , further comprising an interfacial region positioned between the anodic region and the seal region, the interfacial region comprising at least one of crystalline transition metal hydroxide, crystalline alkali metal hydroxide, and crystalline precious metal hydroxide.