Letter 1280

How is black ceramic coating done?

--- I am looking for some information about "ceramic coating", any kind of black ceramic coating and what is the normal coating procedure and equipment? Thanks in Advance! Shunong Fang -- There are several ceramic coatings, thin and thick. Thin coatings like nitrides can be done by physical vapor deposition. Carbide coatings can be done by chemical vapor deposition. These require expensive equipment & temperatures ranging from 250 degree C to 1000 degree C. Thicker oxidic coatings can be deposited by plasma spray processes. These are also expensive and are done at temperatures near the fusion points of the ceramic powders. There are also chemically formed ceramic coatings which are the least expensive of all these coatings.These are done at very low temperatures. It is possible to produce black ceramic coating. Your actual requirement can determine the exact process and type of coating. K. Balasubramanian technical coatings -- Hello! My name is Cathy. I am currently working at the University of Oklahoma as a research assistant. The application we are currently looking at is as follows. We currently use a small (approx.1 cm diameter, .5 cm wide) ring of metal that is heated to high temperatures. This ring is fitted around the end of a magnesium fluoride tube with a small nozzle at the end of it. The ring is heated so that the fluorine that flows through the tube and nozzle enters a vacuum chamber at a known temperature and, therefore, a known velocity. Unfortunately the metal we use is very low in resistance and uses a lot of current to get it to the temperatures that we need. It was noticed that a substance called silicon carbide would use much less current. Unfortunately it is a very brittle material. It was also noticed, however, that alumina was a fluorine resistant material and has been bonded to silicon carbide for use in spark plugs and similar applications. We were thinking that if we could find a design or have someone make a sleeve of alumina/silicon carbide/alumina that would fit over our magnesium fluoride tube where on the end near the nozzle the appropriate amount of silicon carbide was exposed to create the heating element this would help solve our problems in less heater breakdowns and also have better resistance to fluorine.

As luck would have it, someone in the chemistry dept. here already has an element made of these materials that was made in Japan by Hitachi. Unfortunately it is a solid rectangular shape and contacting Hitachi has been very difficult as we have no contact names and I don't speak Japanese. As far as drawings go, we have only a few back-of-the-envelope sketches.

It was also recently suggested that the magnesium fluoride tube that we use could be coated with alumina, a sleeve of silicon carbide fitted over, and then the silicon carbide coated with alumina. Any information that you could provide would be greatly appreciated. Thank you very much.

Sincerely,

Cathy Truett, Undergraduate Research Assistant
University of Oklahoma - Norman, Oklahoma

Cathy, may I suggest a simpler method to verify what you are trying before spending too much money? Get an aluminum oxide or similar paste (free sample) form Zircar. This paste is used for furnace wall repairs, we have tried it in binding other things, and works well. The same company may sell you the SiC ring or sleeve. They will send you instructions. You could easily bind the ring over the fluoride tube.

Mandar Sunthankar
- Fort Collins, CO

I'm looking for a company that either produces 4" ceramic tubing or can coat stainless steel tubing in ceramic. I need the most heat dissipation or resistance possible while maintaining rigidity and a completely smooth interior surface. Any help would be appreciated.

Seth Perry
- San Jose California

Please let me know manufacture black ceramic paste for glass coating for automobile glasses, for press furnace, DBO furnace and gravity furnace Thank you

C. H. Low
trade & management - Kuala Lumpur, Malaysia.

I'm making a research on vanadium recovery from industrial Al sludge (Bayers Sludge) using activated charcoal. If someone knows something or wonders about I'll be glad to share my opinions.

Ahmet BurÁin AK 
- Turkey

I would like to know about metal coating on ceramic substrate using electroless and electroplating. Please send to me if you have any information regarding these two processes

C.S.Lim
- Malacca, Malaysia

I am looking for a vendor that can coat ceramic over 304 stainless steel formed sheet metal. The ceramic needs to be 1 mm thick and will be used in a ultra-high vacuum environment. The ceramic material type must have low outgassing and high voltage breakdown properties. The vacuum system may not see excessively high temperatures.

Larry Teresi
- Tempe, Arizona

I would be appreciative if anyone could give me the information about the manufacturers of black ceramic paste which will be coated on stainless steel tube and withstand at least 600 C in the acidic environment and electrical insulated. Thank you in advance. With best regards.

KS Fung
- Hong Kong

I am looking for some information about "ceramic coating", any kind of black ceramic coating and what is the normal coating procedure and equipment? Thank's

Fauzan Jatayu
- Bandung, Indonesia