Coating methods and coated articles
View Patent ↗One aspect of the present invention includes an article. The article includes a substrate and a coating disposed on the substrate, wherein the coating includes a plurality of cermet particles bonded along their prior particle boundaries. The plurality of cermet particles have a median particle size less than about 5 microns and less than 25 percent of the plurality of cermet particles include melted and re-solidified particles. Gate valves are also presented.
1. An article, comprising:
a substrate and a coating disposed on the substrate,
wherein the coating comprises a plurality of cermet particles bonded along their prior particle boundaries, wherein the plurality of cermet particles have a median particle size less than 5 microns, and
wherein less than 25 percent of the plurality of cermet particles comprise melted and re-solidified particles.
2. The article of claim 1 , wherein at least 99% of the plurality of cermet particles have an aspect ratio less than 5.
3. The article of claim 1 , wherein the coating is substantially free of lamellae.
4. The article of claim 1 , wherein the plurality of cermet particles comprise a ceramic phase comprising carbides, nitrides, or combinations thereof.
5. The article of claim 1 , wherein the plurality of cermet particles comprise a metallic phase comprising cobalt, chromium, nickel, tungsten, or combinations thereof.
6. The article of claim 1 , wherein a density of the coating is greater than 99 percent of the theoretical density.
7. The article of claim 1 , wherein the coating is hermetic.
8. The article of claim 1 , wherein the coating has a thickness in a range from 100 nanometers to 1000 microns.
9. A gate valve, comprising:
a first component;
a second component; and
a hermetic coating interposed between the first component and the second component, wherein the coating comprises a plurality of cermet particles bonded along their prior particle boundaries, wherein the plurality of cermet particles have a median particle size less than 5microns,
wherein less than 25 percent of the plurality of cermet particles comprise melted and re-solidified particles.
10. The gate valve of claim 9 , wherein at least 99% of the plurality of cermet particles have an aspect ratio less than 5.
11. The gate valve of claim 9 , wherein the coating is substantially free of lamellae.
12. The gate valve of claim 9 , wherein the plurality of cermet particles comprise a ceramic phase comprising carbides, nitrides, or combinations thereof.
13. The gate valve of claim 9 , wherein the plurality of cermet particles comprise a metallic phase comprising cobalt, chromium, nickel, tungsten, or combinations thereof.
14. The gate valve of claim 9 , wherein the coating is free of a polymer sealant.
15. The gate valve of claim 9 , wherein a density of the coating is greater than 99 percent of the theoretical density.
16. The gate valve of claim 9 , wherein the first component comprises a seat and the second component comprises a gate.