Ald Vacuum Technologies Gmbh

Ald Vacuum Technologies Ag

Leybold Durferrit Gmbh

Other

Harald Scholz

Alok Choudhury

Matthias Blum

Georg Jarczyk

David Francis Lupton

Marek Gorywoda

Ulrich Biebricher

Franz Hugo

Henrik Franz

Wilfried Goy

Arno Niebling

Alfred Henn

Peter Busse

Ivaylo Popov

Thomas Ruppel

Christian Lehnert

Norbert Ludwig

Frank-Werner Hoffmann

Hans-J&uuml;rgen Kemmer

Hans G&uuml;nther Fellmann

Ralf Oehler

Jan-Erwin Schindler

Jochen Schumann

Thomas Kilzer

Hans Johann Kemmer

Peter Zotz

A melting vessel for performing an electro-slag melting method and such a method are presented. Measuring devices measuring a temperature at different heights allow conclusions about position and height of a slag zone in the melting vessel during the method.

Electroslag remelting process and melting vessel

A method and a device for closed-loop control of an electrode gap in a vacuum arc furnace subjects an electrode gap of a melting electrode from the surface of a melt material to closed-loop control as a function of a droplet short-circuit rate. For this purpose, a histogram of detected droplet short-circuits is created on the basis of at least one droplet short-circuit criterion. The histogram is subdivided into sub-areas, a characteristic sub-area of the histogram is selected for closed-loop control purposes. The electrode gap is subjected to closed-loop control on the basis of the droplet short-circuits which can be associated with the selected sub-area.

Method and device for closed-loop control of the electrode gap in a vacuum arc furnace

In an electroslag remelting point with a mold ( ) for forming an ingot from the remelted material of at least one consumable electrode ( ), with a body ( ) having at least one vertically driven electrode rod ( ) for advancing a respective consumable electrode ( ), and with a hood ( ) which is disposed above the mold ( ) and has at least one opening ( ) which is concentric with the respective electrode axis (A), a pot-shaped boiler ( ) is provided which accommodates the mould ( ) and can be joined to the hood ( ) to form a chamber ( ) which is closed all round, completely encompasses the mould ( ) and can be connected via pipelines ( ) to a vacuum pump and/or a gas source, so that the chamber ( ) can be evacuated or filled with an inert gas.

Electroslag remelting plant with a mould and a hood

In the apparatus for distilling molten baths, substantially comprising a two-part vacuum tank ( ), a melting crucible ( ) disposed in the bottom housing part ( ) of the vacuum tank and surrounded by a heating coil ( ), a hat-shaped metal vapor condenser ( ) held in the top housing part ( ) of the vacuum tank ( ), and a draining channel ( ) disposed between the melting crucible ( ) and the metal vapor condenser ( ), a filter element ( ) penetrated by a metal vapor thermometer ( ) plus probe ( ) is provided above the metal vapor condenser ( ) in an opening ( ) of the top housing part ( ), wherein both the filter pot ( ) surrounding the filter element ( ), as well as the space ( ) behind the coil, as well as the top housing part ( ) are connected by separate individual vacuum lines ( ) to a vacuum source ( ).

Apparatus for distilling molten baths

Molds ( ) with annular mold parts ( ) divided by at least one plane of division (E&mdash;E) and forming a plurality of cavities ( ) disposed at least substantially radially to a centrifugation axis (A&mdash;A), serve for the production of precision castings by centrifugal casting, especially of parts made of materials containing titanium for internal combustion engines, the molds ( ) and a casting system being contained in a closed chamber. To automate production, at least one mold part ( ) is made to rotate in its own rotational guide, and two mold parts ( ) together with the corresponding rotational guides are brought to a closed position for the casting and solidification and to an open position for the removal of the precision castings. When cast, the precision castings are preferably joined together at their radially inward pointing ends by a circumferential ring of the solidified metal and thus a circle of castings can be removed from the opened mold by a manipulating system.

Method and apparatus for the production of precision castings by centrifugal casting

In the production of precision castings by centrifugal casting with controlled solidification, a melt is cast under vacuum or shield gas into a pre-heated mold ( ) with a central gate ( ) and several mold cavities proceeding from the gate toward the outer circumference (D ) of the mold ( ). To prevent the formation of shrinkholes and porous areas in the castings, to save energy, and to increase the production rate, the mold ( ) is operated at temperatures which decrease from the inside toward the outside. The mold consists of a material or material combination with a coefficient of thermal conductivity lower than that of copper. Before the melt is poured, the mold ( ) is heated, starting from the gate ( ), by a heating device ( ), which projects into the gate, so that the gate ( ) reaches a temperature which is a function of the material being cast. Heating is carried out at a rate sufficient to produce a temperature Gradient of at least 100&deg; C., preferably of 200-600&deg; C., even more preferably of 300-500&deg; C., between the inside circumference (D ) and the outside circumference (D ). The invention is used preferable for the production of precision castings of metals of the group titanium, titanium alloys with at least 40 wt. % of the titanium, and superalloys.

Method and apparatus for the production of precision castings by centrifugal casting with controlled solidification

In the production of precision castings by centrifugal casting with controlled solidification, a melt is cast under vacuum or shield gas into a pre-heated mold (,) with a central gate (,) and several mold cavities proceeding from the gate toward the outer circumference (D,) of the mold (,). To prevent the formation of shrinkholes and porous areas in the castings, to save energy, and to increase the production rate, the mold (,) is operated at temperatures which decrease from the inside toward the outside. The mold consists of a material or material combination with a coefficient of thermal conductivity lower than that of copper. Before the melt is poured, the mold (,) is heated, starting from the gate (,), by a heating device (,), which projects into the gate, so that the gate (,) reaches a temperature which is a function of the material being cast. Heating is carried out at a rate sufficient to produce a temperature gradient of at least 100&deg; C., preferably of 200-600&deg; C., even more preferably of 300-500&deg; C., between the inside circumference (D,) and the outside circumference (D,). The invention is used preferably for the production of precision castings of metals of the group titanium, titanium alloys with at least 40 wt. % of the titanium, and superalloys.

Method for the production of precision castings by centrifugal casting with controlled solidification

For the oriented solidification of molten silicon to form an ingot in a bottomless crystallization chamber (9, 41) with a cooling body (11), which can be lowered relative to the chamber, the flat bottom surface of a seed body (25) of solid silicon is laid on the surface of the cooling body. The top surface of the seed body (25) is melted, and the ingot is grown on top of it as the cooling body is lowered by relative motion with respect to the crystallization chamber (9, 41) at a rate which is dependent on the supply of additional silicon and the solidification rate. For the purpose of producing large ingots with a coarsely crystalline to monocrystalline structure, a seed body (25) with a crystalline structure selected from the group ranging from coarsely crystalline to monocrystalline is used. Either lump silicon is placed on top of the seed body (25) and melted by induction, or molten silicon is produced in a forehearth (37) and poured onto the seed body (25). The seed body (25) has a thickness of 0.3-20 mm, and preferably of 1-10 mm.

Method and apparatus for the oriented solidification of molten silicon

A crucible (10) for the inductive melting or superheating of metals, alloys, or other electrically conductive materials is provided with palisades of approximately equal length, arranged vertically, parallel to, and a certain distance away from, each other around a circle so as to surround the melt. A plate-shaped or ring-shaped part (4) at the bottom ends of the palisades (3, 3', . . . ) holds the palisades (3, 3', . . . ). At least part of the palisades (3, 3', . . . ) are provided with cavities (5, 5', . . . ) or channels, through which a coolant flows. An induction coil (6), through which an alternating current flows surrounds the palisades (3, 3', . . . ) spaced from their outside surfaces. The palisades (3, 3', . . . ) have slots (7a, 7b, 7c;, 7a', 7b', 7c', . . . ), which extend vertically from the palisade-holding part (4) up to a point near the top edge. The inside wall (9, 9', 9', . . . ) formed by all the palisades together circumscribes a straight, regular prism with sides in the form of identical parallelograms and congruent top and bottom surfaces.

Crucible for the inductive melting or superheating of metals, alloys, or

In the production of castings from a melt of a reactive metal selected from the group consisting of titanium, titanium alloys, and titanium-based alloys, a reusable casting mold (20) is used; the mold, at least in the area of the surface which comes in contact with the melt, consists of at least one metal selected from the group consisting of tantalum, niobium, zirconium, and/or their alloys. The casting mold (20) preferably consists, at least in the area of the surface which comes in contact with the melt, of a tantalum based alloy containing at least 50 wt. % of tantalum. The casting molds can be made of a homogeneous metal, but it is also possible to insert shells of the metals in question into a base body to form the boundaries of the mold cavities, whereas the base body itself consists of some other metal or alloy or of a nonmetal such as graphite or silicon nitride. Insofar as the casting molds in question are molds for centrifugal casting, it is preferable to use titanium, a titanium alloy, or titanium aluminide as the nonmetal for the base body.

Process for manufacture of cast parts made of reactive metals and

In a process for the production of alloys from at least two alloy components (A, B, C, D, . . . ) with different melting points by melting in an inductively heated cold-walled crucible (1) with a cooled crucible base (3), in order to obtain an exact and homogeneous alloy composition at least a part of the alloy components (A, B, C, D, . . . ) are introduced into the cold-walled crucible (1) consecutively and in stacked fashion where either

Process for the production of alloys in an inductively heated

Process for manufacture of castings of reactive metals

In a method for melting and treating metals and metal alloys, especially steels, solid charge material is melted in a ladle. Then while passing a gas through the melt at least part of the time, at least one of the treatments of decarburization, dephosphorization, deoxidation, desulfurization, alloying and removing nonmetallic inclusions is performed in the same ladle. An apparatus for the practice of the method has two tracks (W1, W2) for the ladle (5), which are aligned in an approximate T-shape to one another, a preheating station (9) and a slag removal station (14) being arranged in the top part of the T and, at the intersection between the top part and the stem between the preheating station (9) and the slag removal station (14), the first treatment station (10) with a heating system is disposed, and at the free end of the stem of the T a second treatment station (16) for the vacuum treatment is disposed.

Apparatus for the melting and treatment of metal

For the remelting of titanium or zirconium, the electroslag remelting method is used. To prevent any reaction of the melt with oxygen or nitrogen, the remelting is performed in an inert gas atmosphere. Fluorspar with an addition of calcium oxide is used as the slag forming substance. This calcium oxide dissolves in the fluorspar and reacts with oxygen, nitrogen and hydrogen in the titanium, so that the reactive metal is purified of these substances.

Growing community of inventors

Rodenbach, Germany

Harald Scholz