Endress U. Hauser Gmbh U. Co.

Heinz Breitenstein

Peter Reimann

Stephan Messmer

Frank Hegner

Elke Maria Schmidt

Thomas Klahn

The method for forming rings of uniform thickness from an active brazing alloy by melt-spinning the liquid alloy has the following steps: The alloy is liquefied in a crucible having a lateral opening whose height is approximately equal to the width of the ring material; the liquid alloy is forced out of the crucible onto the side surface of a metal drum of high thermal conductivity at a radial distance from the drum center approximately equal to the ring diameter, said metal drum rotating at a high circumferential velocity at a distance from the crucible approximately equal to the ring thickness; after an,,,approximately quarter to three-quarter turn of the active brazing alloy solidified on the metal drum into ring material, the latter is lifted off the metal drum by a mechanical deflector or a gas stream blown onto it in a direction opposite to the direction of rotation of the metal drum, and guided past the crucible; the ring helix being formed is guided around a lateral, coaxial extension of the metal drum which is located on one side of the crucible, serves as a winding mandrel, and has an end flange and a diameter slightly smaller than the inner diameter of the rings, and from the ring helix, the rings are cut off.

Method and apparatus for forming rings from an active brazing alloy

This active brazing serves to braze ceramic parts or single crystals or metal parts or to braze ceramic parts to single crystals or ceramic parts or single crystals to metal parts. In addition to the zirconium-nickel alloy, which is composed of 70 atom % to 85 atom % zirconium and 15 atom % to 30 atom % nickel, it contains titanium. In an apparatus for fabricating a foil (6) from this ternary active-brazing alloy by melt spinning which has a uniform thickness and two surfaces that are as smooth as possible, the alloy, after being melted by high-frequency heating in a cylindrical crucible (1) made completely of a high-temperature-resistant and highly thermally conductive nonmetallic material, particularly of high-density graphite or of boron nitride, is forced through an opening (3) in the bottom of the crucible onto a metal drum (5) of high thermal conductivity rotating at a high circumferential speed, on which the liquid alloy solidifies at a cooling rate on the order of 10.sup.3 to 10.sup.6 .degree. C./s. A product made using this ternary active brazing is a pressure sensor (10) having a substrate (12) and a diaphragm (11) of ceramic, particularly alumina ceramic, preferably with a purity of 96 wt.%, which are thermally joined around the periphery in a defined spaced relationship (d) and parallel to each other by means of the active brazing, e.g., by means of a preform (20) made therefrom, thus forming a chamber (13).

Apparatus for fabricating a foil

This active brazing preferably serves to braze (join) ((aluminum-)oxide-)ceramic parts or single crystals or metal parts or to braze (join) ((aluminum-)oxide-)ceramic parts to single crystals or ((aluminum-)oxide-)ceramic parts or single crystals to metal parts. In addition to the zirconium-nickel alloy, which is composed of 70 atom % to 85 atom % zirconium and 15 atom % to 30 atom % nickel, it contains titanium. In an apparatus for fabricating a foil (6) from this ternary active-brazing alloy by melt spinning which has a uniform thickness and two surfaces that are as smooth as possible, the alloy, after being melted by high-frequency heating in a cylindrical crucible (1) made completely of a high-temperature-resistant and highly thermally conductive nonmetallic material, particularly of high-density graphite or of boron nitride, is forced through an opening (3) in the bottom of the crucible onto a metal drum (5) of high thermal conductivity rotating at a high circumferential speed, on which the liquid alloy solidifies at a cooling rate on the order of 10.sup.3 .degree. to 10.sup.6 .degree. C./s. A product made using this ternary active brazing is a pressure sensor (10 ) having a substrate (12) and a diaphragm (11) of ceramic, particularly alumina ceramic, preferably with a purity of 96 wt. %, which are thermally joined around the periphery in a defined spaced relationship (d) and parallel to each other by means of the active brazing , e.g., by means of a preform (20) made therefrom, thus forming a chamber (13) .

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Battwil, Switzerland

Heinz Breitenstein