Chemical vapor deposition process and coated article
A chemical vapor deposition process and coated article are disclosed. The chemical vapor deposition process includes positioning an article in a chemical vapor deposition chamber, then introducing a deposition gas to the chemical vapor deposition chamber at a sub-decomposition temperature that is below the thermal decomposition temperature of the deposition gas, and then heating the chamber to a super-decomposition temperature that is equal to or above the thermal decomposition temperature of the deposition gas resulting in a deposited coating on at least a surface of the article from the introducing of the deposition gas. The chemical vapor deposition process remains within a pressure range of 0.01 psia and 200 psia and/or the deposition gas is dimethylsilane. The coated article includes a substrate subject to corrosion and a deposited coating on the substrate, the deposited coating having silicon, and corrosion resistance.
1. A chemical vapor deposition process, comprising:
positioning an article in a chemical vapor deposition chamber; then
purging and evacuating the chemical vapor deposition chamber; then
introducing a deposition gas to the chemical vapor deposition chamber at a sub-decomposition temperature that is below the thermal decomposition temperature of the deposition gas; and then
heating the chamber to a super-decomposition temperature that is equal to or above the thermal decomposition temperature of the deposition gas resulting in a deposited coating on at least a surface of the article from the introducing of the deposition gas;
wherein the chemical vapor deposition process remains within a pressure range of 0.01 psia and 200 psia, wherein the deposition gas is selected from the group consisting of an organosilane, dimethylsilane and a silane gas.
2. The process of claim 1 , wherein the sub-decomposition temperature is between 100° C. and 450° C.
3. The process of claim 1 , wherein the sub-decomposition temperature is between 100° C. and 300° C.
4. The process of claim 1 , wherein the heating of the chamber heats from the sub-decomposition temperature to the super-decomposition temperature at a rate of between 6° C. per minute and 10° C. per minute.
5. The process of claim 1 , wherein the thermal decomposition temperature is between 440° C. and 460° C.
6. The process of claim 1 , wherein the super-decomposition temperature is greater than 440° C.
7. The process of claim 1 , wherein the chemical vapor deposition chamber is substantially devoid of catalyst during the introducing of the deposition gas.
8. The process of claim 1 , wherein the chemical vapor deposition chamber is devoid of catalyst during the introducing of the deposition gas.
9. The process of claim 1 , wherein the surface is a stainless steel surface.
10. The process of claim 1 , wherein the surface is a nickel-based alloy.
11. The process of claim 1 , further comprising oxidizing the deposited coating at an oxidizing temperature of between 300° C. and 350° C. to form an oxidized coating.
12. The process of claim 11 , further comprising functionalizing the oxidized coating by introducing trimethylsilane to the deposited coating at a functionalizing temperature of between 400° C. and 500° C.
13. The process of claim 1 , wherein the deposited coating resists corrosion when exposed to 15% NaClO by a rate of at least 5% greater, in mils per year, than the corrosion rate of a coating applied with the same process but without introducing the deposition gas at the sub-decomposition temperature.
14. The process of claim 1 , wherein the deposited coating has a 15% NaClO corrosion rate of between 0 and 3 mils per year.