Methods for forming sintered-bonded high temperature coatings over ceramic turbomachine components are provided, as are ceramic turbomachine components having such high temperature coatings formed thereover. In one embodiment, the method includes the step or process of removing a surface oxide layer from the ceramic component body of a turbomachine component to expose a treated surface of the ceramic component body. A first layer of coating precursor material, which has a solids content composed predominately of at least one rare earth silicate by weight percentage, is applied to the treated surface. The first layer of the coating precursor material is then heat treated to sinter the solids content and form a first sintered coating layer bonded to the treated surface. The steps of applying and sintering the coating precursor may be repeated, as desired, to build a sintered coating body to a desired thickness over the ceramic component body.

Methods for forming sintered-bonded high temperature coatings over ceramic turbomachine components are provided, as are ceramic turbomachine components having such high temperature coatings formed thereover. In one embodiment, the method includes the step or process of removing a surface oxide layer from the ceramic component body of a turbomachine component to expose a treated surface of the ceramic component body. A first layer of coating precursor material, which has a solids content composed predominately of at least one rare earth silicate by weight percentage, is applied to the treated surface. The first layer of the coating precursor material is then heat treated to sinter the solids content and form a first sintered coating layer bonded to the treated surface. The steps of applying and sintering the coating precursor may be repeated, as desired, to build a sintered coating body to a desired thickness over the ceramic component body.

The present disclosure is directed to a metal-containing apparatus including a substrate member constructed of a metal that is highly resistant to pitting corrosion and wear in aggressive media. An exemplary metal-containing apparatus is a plate heat exchanger. The metal includes an oxidation layer on the surface thereof and a thin metal oxide nanoporous film on top of the oxidation layer. The nanoporous film is highly compliant and is comprised of oxygen and aluminum, titanium, silicon, zirconium and combinations thereof.

The present disclosure is directed to a metal-containing apparatus including a substrate member constructed of a metal that is highly resistant to pitting corrosion and wear in aggressive media. An exemplary metal-containing apparatus is a plate heat exchanger. The metal includes an oxidation layer on the surface thereof and a thin metal oxide nanoporous film on top of the oxidation layer. The nanoporous film is highly compliant and is comprised of oxygen and aluminum, titanium, silicon, zirconium and combinations thereof.

Provided are modified hybrid sol-gel precursor solutions and coatings formed from such solutions. A modified hybrid sol-gel precursor solution includes an inorganic precursor, cross-linkable inorganic-organic precursor, cross-linkable organic precursor, protic solvent, and aprotic solvent. The inorganic precursor may include a metal or metalloid and two or more hydrolysable groups. The cross-linkable inorganic-organic precursor may include a metal, hydrolysable group, and organic molecule. The cross-linkable organic precursor has another organic molecule with two or more second cross-linking groups. A combination of protic and aprotic solvents in the same solution may be used to control properties of the solutions, thermodynamics, and other processing aspects. The solution may also include nanoparticles. The nanoparticles may include functionalized surface to form covalent bonds with one or more precursors of the solution, such as a plasma treated surface. The nanoparticles may be sized to fit into the sol-gel network without substantially disturbing this network.

An inorganic coating solution composition including an alkali metal silicate, a curing agent, a dispersant, a defoamer, and a solvent, wherein the curing agent is phosphoric acid (H.sub.2PO.sub.4), the dispersant is at least one selected from among Tween 20, Tween 40, Tween 60, Tween 80, polyvinyl pyrrolidone, polyethylene glycol 400 and polyvinyl alcohol, and the defoamer is at least one selected from among a silicone-based defoamer, an alcohol-based defoamer, a mineral oil-based defoamer and a powder defoamer.

Provided is a barrier film, comprising: a base layer; and an inorganic layer including a first region and a second region, which have different elemental contents (atomic %) of Si, N, and O from each other as measured by XPS, and having a compactness expressed through an etching rate of 0.17 nm/s or less in the thickness direction for an Ar ion etching condition to etch Ta.sub.2O.sub.5 at a rate of 0.09 nm/s, wherein the second region has a higher elemental content of N than that of the first region, the first region has a thickness of 50 nm or more, and the ratio (d1/d2) of the thickness (d1) of the first region to the thickness (d2) of the second region is 2 or less, the barrier film having excellent barrier properties and optical properties. The barrier film can be used for electronic products sensitive to moisture or the like.

The invention discloses a preparation method of a carbon nitride (CN) electrode material. The preparation method comprises the following steps: (1) preparing a precursor film: immersing a clean conductive substrate A into a hot saturated CN precursor aqueous solution, then immediately taking out, after the surface being dried, a uniform precursor film layer on the conductive substrate A was formed. This step can be repeated several times to get different layers of precursor film on the substrate A; (2) preparing the CN electrode: the dry precursor film obtained in step (1) was encapsulated in a glass tube filled with N.sub.2. Then the glass tube was inserted into a furnace with N.sub.2 atmosphere to calcinate. After calcination, the uniform CN film electrode was obtained. The method provided by the invention is simple and easy to implement, and convenient in used equipment, suitable for industrial application and popularization.

The invention discloses a preparation method of a carbon nitride (CN) electrode material. The preparation method comprises the following steps: (1) preparing a precursor film: immersing a clean conductive substrate A into a hot saturated CN precursor aqueous solution, then immediately taking out, after the surface being dried, a uniform precursor film layer on the conductive substrate A was formed. This step can be repeated several times to get different layers of precursor film on the substrate A; (2) preparing the CN electrode: the dry precursor film obtained in step (1) was encapsulated in a glass tube filled with N.sub.2. Then the glass tube was inserted into a furnace with N.sub.2 atmosphere to calcinate. After calcination, the uniform CN film electrode was obtained. The method provided by the invention is simple and easy to implement, and convenient in used equipment, suitable for industrial application and popularization.

Provided is a barrier film, comprising a base layer and an inorganic layer including a first region and a second region, which have different elemental contents (atomic %) of Si, N, and O from each other as measured by XPS, and having a compactness expressed through an etching rate of 0.17 nm/s in the thickness direction for an Ar ion etching condition to etch Ta.sub.2O.sub.5 at a rate of 0.09 nm/s, wherein the second region has a higher elemental content of N than that of the first region, and the second region has a thickness of 10% or more relative to the total thickness of the inorganic layer. The barrier film has excellent barrier properties and optical properties and can be used for electronic products which are sensitive to moisture and the like.