Really high temperature glass
Really high temperature glass
(OP)
I have searched the forums and have not found an answer to this, usually beucase the temperatures are too low.
I am working on a device that requires that I hold a vacuum at 1000-1300 degrees. Throughout the products life, the vacuum will go down to room temperature only to return to the high temperature from time to time (once a day or once a week, i am not sure)
I know of only two choices. Fused quartz and sapphire. Sapphire may be too expensive and fused quarts has an issue where it devitrifies and becomes opaque at these high temperatures.
I am currently under the impression that if I can keep the temp below 1100 degrees, then the devitrification will not happen, is this correct?
If I am unable to do that, is there another glass that would stay clear at these temperatures?
I realize there are a number of engineering challenges associated with holding that vacuum, especially at these changing temperatures, but for now I am only interested in the clarity of the glass.
thoughts?
I am working on a device that requires that I hold a vacuum at 1000-1300 degrees. Throughout the products life, the vacuum will go down to room temperature only to return to the high temperature from time to time (once a day or once a week, i am not sure)
I know of only two choices. Fused quartz and sapphire. Sapphire may be too expensive and fused quarts has an issue where it devitrifies and becomes opaque at these high temperatures.
I am currently under the impression that if I can keep the temp below 1100 degrees, then the devitrification will not happen, is this correct?
If I am unable to do that, is there another glass that would stay clear at these temperatures?
I realize there are a number of engineering challenges associated with holding that vacuum, especially at these changing temperatures, but for now I am only interested in the clarity of the glass.
thoughts?





RE: Really high temperature glass
You need to explain your problem more clearly. What does "hold a vacuum at 1000-1300 degrees" mean, exactly? Are you heating the quartz to 1100ºC? or just the contents?
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RE: Really high temperature glass
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RE: Really high temperature glass
Besides the temperature what is the enviroment?
RE: Really high temperature glass
RE: Really high temperature glass
The quartz will be a tube. It must remain clear to let through light. THe inside of the quartz will be a vacuum. the outside of the quartz will be air. The thing making everything hot is at the center of the quartz tube (i cant go into more deatil on that, just know that between the hot thing and the quartz is a vacuum)
I am not married to quartz, but sapphire will probably be too expensive (but I am not throwing it out, yet). If there are other crystal clear (i.e. passes visible light) glasses that can withstand this temperature, i'm all for it, especially if they do not devitrify.
SO, am i correct that if I make sure that the glass does not go over 1050 deg C then I can expect it not to cloud up? Is it the surface that clouds (fixable), or is it impurities within the glass that cause the clouding (probably not fixable)?
as for "holding the vacuum at 1000-1300 deg c", i mean that the hot thing in the center will be between 1100-1500 deg C (not sure yet) and the 'quartz' tube will be at a diameter around it that keeps it at 1000-1300 deg (i am just not sure yet). The space in between will obviously be somewhere between the two and held in vacuum.
ok I dont know how to describe this any clearer. I hope it is enough info.
RE: Really high temperature glass
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RE: Really high temperature glass
RE: Really high temperature glass
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RE: Really high temperature glass
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