Author Topic: Molybdenum Foil Seals  (Read 250 times)
Mr. Orthosilicate
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Molybdenum Foil Seals « on: October 27, 2019, 03:14:50 PM » Author: Mr. Orthosilicate
How are molybdenum foil seals made? What’s the thickness of the foil? Also, how do they get the knife edge on the foil before making the seal?
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James
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Re: Molybdenum Foil Seals « Reply #1 on: November 04, 2019, 04:01:51 PM » Author: James
The molybdenum foil is made from wire.  First the wire is flattened, and then the edges are rolled to reduce their thickness.  With the better quality foils, they are then electrochemically etched to further sharpen the knife-edges.  The thickness is about 0.01 to 0.05mm.  The seals are made by first welding a metal wire or electrode to the ends of the foil, and then embedding it in quartz.  The quartz is heated in excess of 2000C with an inert atmosphere inside the tube (vacuum, or an argon flush).  When it is soft it is either collapsed around the moly foil due to the vacuum inside the tube, or in case of atmospheric pressure seals made under argon gas the softened quartz is pressed around the foil using a set of mechanical pinch hammers.
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Ash
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Re: Molybdenum Foil Seals « Reply #2 on: November 04, 2019, 09:04:14 PM » Author: Ash
Are the foils possible to handle/store or they must be made immediately before use ?
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