Apparatus and method for producing a cast part formed from amorphous or partially amorphous metal, and cast part

Abstract

The invention relates to an apparatus (1; 1a; 1b; 1c; 1d; 1e) for producing a casting (36) formed from an amorphous or partially amorphous metal, which comprises a casting mold (3; 3a; 3b; 3c; 3d; 3e) having at least one filling opening (16; 16a; 16b, 41; 16c; 16d; 16e) for introducing a casting material (15; 15a; 15b; 15c; 15d; 15e) forming the casting (36) and a device for melting the casting material (15; 15a; 15b; 15c; 15d; 15e). The melting device expediently has at least one region (13; 13; 13b; 40, 13c; 13d; 13e) which is provided for melting the casting material (15; 15a; 15b; 15c; 15d; 15e). Advantageously, an apparatus is created that allows a particularly targeted application of melting energy into the casting material. In an embodiment, the melting device comprises a means for forming at least one electric arc (30; 30a, 39) in the at least one melting region (13; 13; 13b; 40, 13c; 13d; 13e), which in particular comprises at least two electrodes (32; 32a, 38; 32b; 32c) arranged at a distance from one another, between which the at least one electric arc (30; 30a, 39) can be formed.

Claims

1. An apparatus for producing a casting formed from an amorphous or partially amorphous metal, which comprises: a casting mold comprising a mold cavity and at least one filling opening for introducing a casting material forming the casting into the mold cavity; a device for melting the casting material, the melting device comprising at least one melting region in which to melt the casting material, at least two electrodes being arranged at a distance from one another, and at least one electric arc formed between the at least two electrodes, whereas a first one of the at least two electrodes has a fixed proximal end and a movable distal end, the movable distal end has a first extendable horizontal configuration and a second retracted horizontal configuration in the same horizontal plane, and whereas a second one of the at least two electrodes is at least partially formed by the casting material; and a casting plunger: the casting material being forced into the mold cavity by at least the casting plunger when the casting plunger is actuated in a downwards direction; whereas both the casting plunger and one of the at least two electrodes are arranged on the same side of the mold cavity in a single gas-tight housing, characterized in that the casting plunger, the casting mold and the at least two electrodes are arranged within the single gas-tight housing.

2. The apparatus according to claim 1, characterized in that the at least one melting region is integrally formed with the casting mold.

3. The apparatus according to claim 1, characterized in that the at least one melting region comprises a recess and/or a socket for receiving the casting material, wherein the recess and/or the socket is arranged at least partially around, and integrally formed with, the at least one filling opening.

4. The apparatus according to claim 1, characterized in that the at least one melting region is delimited by an end face of said casting plunger and an inner wall of a guiding means in which said casting plunger is mounted in a guided manner, the guiding means comprising a cylindrical sleeve.

5. The apparatus according to claim 1, characterized in that said casting plunger is movable relative to a guiding means in which said casting plunger is mounted in a guided manner against a direction of action of a restoring force of a restoring means.

6. The apparatus according to claim 1, characterized in that at least one said casting plunger, which is provided for pressing melted casting material into a mold cavity of the casting mold, is movable relative to a guiding means in which said casting plunger is mounted in a guided manner against a direction of action of a restoring force of a restoring means, wherein the at least one melting region has an annular groove and is provided for receiving the guiding means, the guiding means comprising a cylindrical sleeve that is configured to couple with the annular groove.

7. The apparatus according to claim 1, characterized in that a temperature of the casting mold is adjustable by a control device.

8. The apparatus according to claim 1, characterized in that the apparatus comprises a venting and/or sucking melted casting material into the casting mold with a suction device, the venting being activatable upon introduction of the casting material into the casting mold.

9. The apparatus according to claim 1, characterized in that the casting plunger and one of the at least two electrodes are arranged on the upper side of the mold cavity.

Description

(1) Embodiments of the invention are to be explained in more detail below on the basis of examples with reference to the non-limiting figures.

(2) FIG. 1a-e schematic representation of an apparatus according to the invention,

(3) FIG. 2 a schematic representation of another embodiment of an apparatus according to the invention,

(4) FIG. 3 a detail of an apparatus according to the invention,

(5) FIG. 4 a schematic representation of a further embodiment of an apparatus according to the invention,

(6) FIG. 5 a schematic representation of a special embodiment of an apparatus according to the invention,

(7) FIG. 6 Details of another special embodiment of an apparatus according to the invention.

(8) An apparatus (1) shown schematically in FIG. 1a-e in cross-section comprises a housing (2) into which a two-part, water-cooled copper casting mold (3) is implemented. Each of the two parts (4,5) of the casting mold (3) is connected by means of a rod (6,7) to a motor (8,9) mounted outside the housing for moving the rods (6,7). By moving the rods (6, 7), the casting mold (3) can be opened for removal of a casting in the direction of the double arrows (10, 11) and closed for the production of a further casting.

(9) On an upper side (12) of the casting mold (3) a melting region (13) is incorporated, which has a socket-like ridge (14) formed by both parts (4, 5) of the casting mold (3) and on which a pellet (15) of casting material is placed. A filling opening (16) through which a mold cavity (17) can be filled with the casting material is completely covered by the pellet (15). An annular groove (18) is arranged around the base (14), which is provided for receiving a cylindrical sleeve (19). The sleeve (19) is designed to guide a cylindrical casting plunger (20) and surrounds it. The casting plunger (20) and the sleeve (19) are simultaneously movable by a motor (24) in the direction of the double arrow (21) and the casting plunger (20) is arranged displaceably relative to the sleeve (19) in the axial direction thereof with or against a restoring force of a spring (22). To press a melted casting material (15), which can be superheated up to 1300° C., preferably up to 800° C., into the mold, the casting plunger (20) and the sleeve (19) are moved simultaneously in the direction of the casting mold (3) until a lower section (23) of the sleeve (19) engages with the annular groove (18). A further movement of the casting plunger (20) in the direction of the casting mold (3) takes place against a restoring force of the spring (22). A space (27) formed by an end face (25) of the casting plunger (20) and an inner wall (26) of the sleeve and the top (12) of the casting mold (3), as shown in FIG. 1c, is thereby reduced so that the melted casting material (15) is pressed vertically into the mold cavity (17).

(10) Furthermore, the device comprises a pyrometer (28), which detects a temperature of the pellet (15) during melting, and a feeding device (29) which is designed as a pellet magazine. Thus, a new pellet (15) can automatically be placed on the ridge (14) of the melting region (13) after each casting production.

(11) The cast material pellet (15) is heated by an electric arc (30) as shown in FIG. 1b, which is formed between a tungsten electrode (32) provided with a tip (31) and the pellet (15). For this purpose, the housing (2) as well as the casting mold (3) and the pellet (15) are electrically conductively connected to each other and form a counter-electrode to the tungsten electrode (32). The tungsten electrode (32) is movably arranged in the housing (2) and can be moved by a motor (33) in the direction of the double arrow (34) towards the melting region (13) and after melting away from the melting region (13).

(12) It is also conceivable that a device not shown in FIG. 1 is provided for forming a laser beam and/or an electron beam, which is set up to heat the casting material pellet (15) in the melting region (13).

(13) In addition, a not shown vacuum pump is provided to evacuate the housing (2) and a not shown means of introducing a protective gas such as argon. In addition, inside the housing (2) there is a so-called getter (35), which is designed as a titanium plate and which is heated before the casting material (15) is melted. Due to the very high affinity of titanium to oxygen and the very high solubility of oxygen in titanium, oxygen residues are removed from the housing atmosphere provided with the protective gas. This causes an additional cleaning of the atmosphere.

(14) A casting (36) can be removed through an airlock (37) shown schematically in FIG. 1a-e. This means that the entire housing (2) does not have to be evacuated again before each casting process.

(15) A production of the casting (36) comprises the following process steps, in particular in the order listed below: Movement of the tungsten electrode (32) from an initial position shown in FIG. 1a to an end position shown in FIG. 1b above a pellet of cast material (15) to be melted, Evacuation of the housing (2) and introduction of a protective gas, preferably argon, Heating a getter (35), preferably made of titanium, to a temperature greater than 600° C., Formation of an electric arc (30) between the tip (31) of the tungsten electrode (32) and the pellet (15) to melt the pellet (15) and superheat it to a temperature between 75 and 1300° C. above its melting temperature, Switching off the electric arc and moving the tungsten electrode (32) back to the initial position shown in FIG. 1a, moving the casting plunger (20) and the sleeve (19) in the direction of the melting region (13) until the lower portion (23) of the sleeve (19) engages with the groove (18) so that a space (27), as shown in FIG. 1c, enclosing the melted pellet (15) is formed between the casting plunger (20) and the filling opening (16), A relative movement of the casting plunger (20) to the sleeve (19) against a spring force of the spring (22) to reduce the space (27), whereby the melted casting material (15) is pressed through the filling opening (16) into the mold cavity (17) of the casting mold (3) to form the casting (36). This movement is a movement of the casting plunger (20) from an initial filling position shown in FIG. 1c to a final position shown in FIG. 1d in which the mold cavity (17) is filled with the casting material (15), Movement of the casting plunger (20) and the sleeve (19) to an initial position above the melting region (13) as shown in FIG. 1a, Moving the two parts (4, 5) of the casting mold (3) apart into a casting removal position as shown in FIG. 1e and removing the casting (36) through the airlock (37) in the direction of the arrow (38), Closing the casting mold (3) and feeding a new pellet (15) from the pellet magazine (29) into the melting region (13).

(16) An additional process step is conceivable, in which a suction device not shown in FIG. 1a-e which can be activated at the beginning of pressing in the casting material causes a negative pressure, through which the casting mold (3) is vented and the melted casting material (15) is additionally sucked into the casting mold (3).

(17) It is also conceivable that the cast material (15) is melted by a laser beam and/or an electron beam.

(18) Reference is now made to FIG. 2, where identical or equal-acting parts are designated with the same reference number as in FIG. 1a-e and the letter a is added to the respective reference number.

(19) An apparatus (1a) shown in FIG. 2 differs from that shown in FIG. 1a-e in that two electrodes (32a, 38) are provided which are arranged to melt a pellet of cast material (15a) by forming two electric arcs (30a, 39). Advantageously, a faster heating, a higher superheating and processing of large cast material pellets (15a) is possible.

(20) Reference is now made to FIG. 3, where identical or equal-acting parts are designated with the same reference number as in FIGS. 1a-e and 2 and the letter b is added to the respective reference number.

(21) A casting mold (3b) of an apparatus (1b) according to the invention shown in FIG. 3 in top view differs from that shown in FIGS. 1 and 2 in that two melting regions (13b, 40) with a socket-like ridge are provided, on which two pellets (15b) are placed, covering two filling openings (16b, 41) shown in dashed lines. It goes without saying that at least one electric arc is required for melting in each melting region (13b, 40), as well as an casting plunger with sleeve which is not shown in FIG. 3. In particular, the two pellets (15b) are melted simultaneously and a melted casting material pellet (15b) is pressed into the casting mold (3b) by a preferably synchronized movement of the two casting plungers and sleeves.

(22) Either a single mold cavity can be filled or several mold cavities can be filled simultaneously. Thus, the apparatus according to the invention can be used to produce either very large castings or several castings simultaneously with one single casting mold.

(23) Reference is now made to FIG. 4, where identical or equal-acting parts are designated with the same reference number as in FIGS. 1a-e, 2 and 3 and the letter c is added to the respective reference number.

(24) An apparatus (1c) shown in FIG. 4 differs from that shown in FIG. 1 in that a casting plunger (20c) and a sleeve (19c) are provided for pressing a casting material (15c) into a casting mold (3c) from a bottom side (42) thereof. A particularly laminar filling can be achieved advantageously. For reasons of clarity, neither a feeding device for the pellets nor a pyrometer is shown in FIG. 4.

(25) A crucible-shaped melting region (13c) in which a pellet (15c) is located is formed by an end face (25c) of the pouring plunger (20c) and an inner wall (26c) of the sleeve (19c). The casting plunger (20c) and the pellet (15c) form a counter electrode to a tungsten electrode (32c), between which and the pellet (15c) an electric arc, not shown in FIG. 4, can be formed to melt the pellet (15c).

(26) Reference is now made to FIG. 5, where identical or equal-acting parts are designated with the same reference number as in FIGS. 1a-e, 2, 3 and 4 and the letter d is added to the respective reference number.

(27) An apparatus (1d) shown in FIG. 5 differs from the device (1d) shown in FIG. 1 to 4 in that a suction device (43) is provided which is fluidically connected to a casting mold channel (45) by a suction channel (44). The suction device (43) can be activated and, when an casting plunger (20d), through which a melted casting material (15d) is pressed into a casting mold (3d), moves, it additionally sucks a melted casting material into the casting mold (3d) from a side preferably facing away from the casting plunger (20d). This additional suction force is advantageous for better filling of the casting mold.

(28) It goes without saying that the suction device (43) can also be located outside the housing (2d). It is further understood that a transition region from the suction channel (44) to the casting mold channel (43) is designed in such a way that an opening of a multi-part casting mold is still possible.

(29) Reference is now made to FIG. 6, where identical or equal-acting parts are designated with the same reference number as in FIGS. 1a-e, 2, 3, 4 and 5 and the letter e is added to the respective reference number.

(30) A two-part casting mold (3e) shown in FIG. 6 differs from the casting molds (3; 3a; 3b; 3c; 3d) shown in FIGS. 1 to 5 in that horizontal filling of a mold cavity (17e) is possible. A melting region (13e) comprises a recess (14e) in a portion (5e) of the casting mold (3e) in which a melted pellet of casting material (15e) shown in FIG. 6a is located.

(31) A sleeve (19e) has an opening (46) in a lower sleeve portion (23e) through which melted casting material (15e) can be pressed into the mold cavity (17e) of the casting mold (3e).

(32) An outside of the sleeve (19e) and an outside of the casting mold (3e), as well as an end surface of the sleeve (19e) and an upper surface of the casting mold (3e) also form a sealing surface.

(33) It is conceivable that several electric arcs (30; 30a, 39) are formed between an electrode and a single, in particular pellet-shaped cast material (15; 15a; 15b; 15c; 15d; 15e).

(34) It is further conceivable that a casting mold (3; 3a; 3b; 3c; 3d; 3e) is provided with several filling openings (16; 16a; 16b, 41; 16c; 16d; 16e) of different sizes. For this purpose, it is advantageous if a size of an casting plunger (20; 20a; 20b; 20c; 20d; 20e) is adapted to a size of the filling openings (16; 16a; 16b, 41; 16c; 16d; 16e) and/or a size of the casting pellets (15; 15a; 15b; 15c; 15d; 16e). In an apparatus (1; 1a; 1b; 1c; 1d; 1e) casting plungers (20; 20a; 20b; 20c; 20d; 20e) of different sizes can be provided for this purpose, which, for example, have different diameters.