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AssigneeALD Vacuum Technologies GmbH
InventorsAlok Choudhury, Matthias Blum, Harald Scholz, Georg Jarczyk
Estimating the term…
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.
A centrifugal casting mold for casting reactive metals, said mold comprising a body having a plurality of enclosed mold cavities therein with ends communicating with a common in-gate and configured for producing a plurality of castings from reactive metals, wherein each of said cavities is defined by a surface which contacts molten reactive metal, said surface consisting of at least one metal selected from the group consisting of tantalum, niobium, zirconium, and alloys based on at least one of tantalum, niobium, and zirconium, said casting mold having a reduced thermal conductivity and thereby decreasing the quenching rate of the castings produced with said mold compared with an equivalent copper mold.
A centrifugal casting mold for casting reactive metals, said mold comprising:
A centrifugal casting mold with an axis of rotation for centrifugal casting reactive metals, said mold comprising a body having a plurality of enclosed mold cavities therein with closed outer ends and inner ends communicating with a common central ingate and configured for producing a plurality of casting from reactive metals, each of said cavities being arranged in a concentric relationship to the axis and the in-gate, and defined by a respective surface which comes in contact with molten metal, said surface consisting of at least one metal selected from the group consisting of tantalum, niobium, zirconium, and alloys based on at least one of tantalum, niobium, and zirconium, thereby reducing thermal conductivity of the casting mold and quenching rate of the casting compared with an equivalent copper mold, said body being pre-heatable to a temperature higher than a pre-heating temperature possible in an equivalent copper mold, said casting mold having a reduced thermal conduction from said castings to the casting mold and whereby the quenching rate of the castings prepared with the mold are reduced.
Dependencies are inferred from the claim text.