Ald Vacuum Technologies Gmbh

Leybold Durferrit Gmbh

Leybold Aktiengesellschaft

Other

Leybold-heraeus Gmbh

Ald Vacuum Technologies Ag

Alok Choudhury

Harald Scholz

Matthias Blum

Georg Jarczyk

Felix Muller

David Francis Lupton

Franz Hugo

Marek Gorywoda

Wilfried Goy

Gerhard Bruckmann

Otto W Stenzel

Alfred Henn

Peter Busse

Thomas Ruppel

Norbert Ludwig

Hans-Gunter Fellmann

Hans G&uuml;nther Fellmann

Wolfgang Schwarz

Hardy Weisweiler

Jan-Erwin Schindler

Jochen Schumann

Mathias Blum

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

In a melting crucible (3) a central bottom portion (27) is formed of a plurality of palisades (5) and is shaped so that the palisades together form a vessel or a pot (7) having a centrally disposed spout or outlet (8). Two independently powered induction coils (10, 11) are provided, one coil (10) externally surrounding the collar or upper part of the central bottom portion (27), and the other coil (11) externally surrounding the spout (8). The palisades (5) are separated from one another by individual gaps (6) running radially outwardly from the center, while the electromagnetic field of at least the upper coil (10) acts on the charge contained in the melting crucible through the gaps (6).

Apparatus for fusing a solid layer of electrically conductive material

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.

Method for remelting reactive metals

The invention relates to a process for producing superconductive ceramics wherein, first, a liquid alloy melt is made of metals; this is carried out at a temperature at which the melt is chemically homogeneous. The melt is subsequently atomized with an inert gas or with oxygen. In the first case, a powder develops which is oxidized in a further step whereas in the second case the oxide powder is a direct result. By means of sintering, for example, the oxide powder can be pressed to superconductive bodies of any desired form.

Process for producing superconductive ceramics by atomization of alloy

Apparatus for the detection and evaluation of process parameters arising during the remelting of an electrode (31) to a metallic block (32) in a vacuum arc furnace detects deviations of at least one process parameter from a predetermined course and uses them to locate faults in the electrode and/or in the metal block (32).

Fault detection during remelt of electrodes into blocks

Method for the electroslag refining of metals of which at least 50 weight-percent are in the form of at least one current-carrying consumable electrode, especially one having alloy components with an affinity for oxygen, wherein the metals are remelted to an ingot through a molten bath of slag. To achieve the object of preventing oxidation, freckling, rings and white spots and at the same time produce a degassing, the following measures are undertaken: (a) the refining process is performed at a subatmospheric pressure, (b) the slag is an at least 80 weight-percent oxidic slag of oxides whose boiling points are above 2000.degree. C., and (c) the slag is heated by means of alternating current.

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Puttlingen, Germany

Alok Choudhury