JP2005527375A - Dimensionally high precision casting method and apparatus for parts from non-ferrous metal alloys and non-ferrous metal alloys for carrying out this method - Google Patents

Abstract

A method for highly dimensionally casting a part made of a non-ferrous metal alloy for use in an engine structure or the like includes a plurality of casting dies (22) corresponding to the external shape of the part to be manufactured in each case. Using a centrifugal casting method that uses a melt, the melt is delivered to the casting mold via a runner channel (14) that is relatively non-reactive for the alloy used and is hydrodynamically optimized. The casting mold is also hydrodynamically optimized with runner locating (19) and is arranged in a three-dimensionally adjustable manner relative to a rotatably mounted runner device (11) during the casting process. The whole can be inductively heated (30) for the purpose of temperature control, all without the cavity having a cavity due to the Coriolis force of the centrifugal force applied to the melt of FIG. completely It is arranged in such a way as to fill one.

Description

  In particular, precise casting of parts made of non-ferrous metal alloys, preferably TiAl, used in the field of turbine engineering is expensive and difficult. This is because the alloy components evaporate from the metal during the heating and casting process, there is a risk that a boundary layer having a negative effect on the casting process is formed, a casting cavity is formed, and the alloy microstructure is destabilized. Because there is. In this situation, it must be calculated that the time required for the actual casting process is negligible compared to the time required to heat the melt.

  Thus, this type of part made by precision casting is continuously processed by a process known as HIP, ie the casting cavity is compacted by Hot Isostatic Pressing. The microstructure of the parts that must be produced by casting must be stabilized by continuous heat treatment.

  Therefore, following the predetermined material specifications of the parts to be produced by this method is very expensive and a high scrap rate cannot be avoided.

  This is an intervening part of the present invention and the object of the present invention is to significantly improve the production of parts from non-ferrous metals used in the field of turbine engineering, in particular by precision casting.

  In view of the known centrifugal casting process, in which the centrifugal force affects the molding of the melt, the filling of the molded shell and the crystallization as a result of the rotation of a part of the casting apparatus, this object is Using a casting mold with a heated molding shell that corresponds to the outer shape of the part to be manufactured, the casting mold is completely removed by acceleration forces and Coriolis forces generated during rotation and centrifugal forces applied to the melt. This is achieved by a dimensionally accurate casting method in which the melt is fed to the casting mold via a heated runner device in such a way that it is filled.

  According to another feature of the invention, in the runner apparatus, in the casting process, the melt is turned in a range of approximately 30 ° to 180 ° by centrifugal force with respect to the direction of flow determined by gravity, When flowing into the mold, the casting mold is uniformly filled by Coriolis force.

  According to another feature of the invention, the heated runner device and the heated casting mold are maintained at a predetermined processing temperature, which is a non-ferrous metal alloy used for manufacturing by precision casting. The melting ability of the non-ferrous metal alloy is preferably maintained at 10 ° C. to 200 ° C.

  The method according to the invention includes a number of advantages.

  Surprisingly, it has been found that the treatment according to the invention reduces the evaporation rate of the lysate. The fact that the runner device is hydrodynamically optimized to take advantage of the Coriolis force means that the porosity of the casting can be reduced by reducing the pore size that can be achieved in the melt, As a result, a finer structure than the conventional one can be achieved. Accordingly, there is no need to further process the mold casting by applying HIP and then heat to stabilize the microstructure of the alloy. Thus, it is possible to significantly reduce the cost of manufacturing this type of part, as well as to reduce the material costs of the non-ferrous metal alloys used in terms of quantity, composition and purity. Furthermore, the processing costs are greatly reduced even if the scrap rate is reduced and not completely removed.

  In order to carry out the method according to the invention, the invention is a cup-like container arranged vertically and rotatably mounted as a runner device, which container is advantageously configured hydrodynamically A casting mold having a bottom surface and having a molded shell disposed on a side surface and at a predetermined distance from the bottom surface is in communication with a cup-shaped container, and is advantageously configured hydrodynamically in the container. The three-dimensional set angle of the casting mold with respect to each communicating outlet opening between the container and the casting mold is adjustable, all of which are filled without causing the casting mold to separate the flow in the melt. Arranged in a way.

  According to a preferred embodiment of the invention, the container and the casting mold are relatively non-reactive with respect to the melt and consist of a ceramic containing metal particles, the container and the casting mold being a precisely controllable method. Preferably, an inductor known per se can be used inductively or heated by microwaves.

  According to a feature of the present invention, the runner channel used to supply the lysate is similarly advantageously designed with respect to the hydrodynamics of the lysate, is relatively non-reactive with respect to the lysate, It consists of a heatable ceramic with particles. However, according to yet another embodiment of the present invention, the lysate can be generated inside the container of the runner device while the runner device is rotating.

  Finally, the filling device and runner channel may consist of coated steel, coated graphite, tantalum, titanium or niobium.

  According to the present invention, the non-ferrous metal used is 30 to 33% by weight Al, 4 to 6% by weight Nb, 0.5 to 3% by weight Mn, and 0.1 to A TiAl alloy containing 0.5% by weight of B and the balance containing Ti.

  In the present invention, this type of TiAl alloy with 0.5-3 wt% Mn is 0 to 2000 ppm oxygen content, 0 to 2000 ppm, preferably 800 to 1200 ppm carbon content, 100 to 2000 ppm nickel. Content and 0 to 2000 ppm nitrogen content. Of course, it is also possible to use other non-ferrous metal alloys for carrying out the production by dimensionally precise casting according to the invention.

  Other features of the invention are indicated in the dependent claims.

  The invention will be described in terms of two exemplary embodiments schematically illustrated in the drawings.

  The device shown in FIG. 1 shows a runner device that can rotate about an axis 10, indicated in its entirety by 11. The runner apparatus is fed melt from the casting ladle 12 via a runner channel 14 which is advantageously designed hydrodynamically.

  The runner device 11 is arranged vertically and is rotatably mounted. The drive device required for this method has a rotationally symmetric side wall 16, which is not clearly shown, but is formed integrally with the side wall and is a fluid. It includes a cup-like container 15 having a bottom 18 that is mechanically optimized. The outlet openings 19 that are hydrodynamically optimized and communicate with a plurality of casting dies 22 having half-shell portions 20 are symmetrically distributed on the peripheral surface of the side wall 16 at a predetermined distance from the bottom 18.

  The casting mold is connected to the container 15 so that it can be adjusted within a three-dimensional angle sr with respect to the communicating outlet opening 19. The adjustment of the angle sr is such that the relative supply of the non-ferrous metal alloy used, the casting temperature, the vessel rotation speed n and the relative density of each alloy so that the overall supply is a hydrodynamically optimized design. As a function.

  The container 15 and the casting mold 22 communicated with the container 15 are arranged at their predetermined positions by a holder 23 made of suitable ceramics. The holder 23 functions as a base material thereof and is clamped between the base plate 24 and the cover plate 26. The melt heated to the casting temperature emerges from the casting ladle 12, passes through the runner channel 14 and is injected into the container 15 through the opening 28. For example, with a heating device 30 that can be controlled with appropriate accuracy, such as an inductor, the runner device 11, runner channel 14 and casting mold 22 are such that the melt remains at the casting temperature until casting is complete. Inductively heated by the method. These temperatures that maintain the ability of the melt to flow correspond to the non-ferrous metals used for manufacturing by precision casting. For this purpose, the runner channel 14, the container 15 and the casting mold 22 are made of a ceramic that is relatively non-reactive to the melt and contains metal particles. However, the container and casting mold can also consist of coated steel, tantalum, titanium or niobium.

  The term Coriolis force is known as the inertial force acting on the body moving in the rotating device in addition to the guiding and centrifugal forces. The Coriolis force is perpendicular to the plane formed by the velocity vector and the axis of rotation.

  The non-ferrous metal alloys used are 30 to 33% by weight aluminum, 4 to 6% by weight niobium, 0.5 to 3% by weight manganese, 0.1 to A TiAl alloy composed of 0.5% by weight of boron and the rest of titanium. Use a TiAl metal alloy having an oxygen content of 0 to 2000 ppm, a carbon content of 0 to 2000 ppm, preferably 800 to 1200 ppm, a nickel content of 100 to 2000 ppm, and a nitrogen content of 0 to 2000 ppm. preferable.

  In the casting process, the non-ferrous metal alloy in the casting ladle 12 is converted into a desired melt by a general method as described above, and sent to the heated runner device 11 through the heated runner channel 14. Rotate as well. In this case, it is sent to the bottom 18 of the container 15 by gravity. Centrifugal force that causes a change in the direction of the lysate flow of about 30 ° to 180 ° acts on the lysate by rotation of the container, which is relative to the inner wall of the side wall 16 until the height of the outlet opening 19 is reached. Rise. Since the three-dimensional set angle sr of the casting mold 22 is selected in such a way as to coincide with the direction of the Coriolis force vector, the Coriolis force acts on the melt in addition to the centrifugal force. Not only can the object be injected into the casting mold through the opening 19, but also quickly, reliably and completely and uniformly fill the casting mold cavity adjacent to the opening 19. After the melt has solidified, the casting mold is removed and the corresponding precision cast part is removed in the usual manner.

  In the embodiment of the runner apparatus shown in FIG. 2, the runner apparatus is generally designated by reference numeral 40, the parts corresponding to the runner apparatus 11, the casting mold 22 are represented by the same numbers, and the angular position sr is adjusted. The casting mold 22 that can be held by the holding means 23 is arranged at the upper edge of the container 15. The holding device 23 is rotatably attached to the runner device 11. In this region, the container 15 has a distributor 42 which acts as a melt nozzle. As in the embodiment shown in FIG. 1, the outlet opening 19 communicating with the inside of the casting mold 22 is advantageously configured with respect to the fluid dynamics of the melt.

  In this case, since the nonferrous metal alloy is sent to the container 15 as an ingot that melts in the rotating container, it is not necessary to provide the casting ladle 12 and the runner channel 14 of the embodiment shown in FIG. For ingots that are introduced and received in the container 15, the container 15 has a cover 44, which can be opened for this purpose, and the distributor 42 is fixed. For this purpose, the cover plate 26 is detachably coupled to the runner device 40. Similarly, the inductively heatable container 15 is mounted so as to be able to rotate by itself within the runner device 40, and is heat resistant between the inlet opening of the stationary casting mold 22 and the outlet opening 19 of the rotating container 15. A seal 45 is provided. The manner in which the runner apparatus described above operates is that of the runner apparatus described in FIG. 1 except that the supply of melt to the casting mold 22 and thus the filling of the casting mold 22 is advantageously performed by a distributor 42 having a nozzle action. Corresponds to the method of operating.

  In both embodiments, ie, the embodiment shown in FIGS. 1 and 2, the cast part can be heated from 600 ° C. to 700 ° C. while in the casting mold, which is likewise the existing heating. This is done inductively by the device 30. In this way, the cooling rate of the cast part is maintained at a controlled low level to avoid cracks, cracks, etc. in the part. Thus, the cast part is only removed from the casting mold after reaching a certain desired degree of cooling, which should be selected as a function of the composition of the non-ferrous metal alloy used in each case.

  The presently described invention allows the centrifugal Coriolis force applied to the lysate to be applied in a controlled manner to the lysate in a manner similar to a pressure ram, thereby eliminating any cavity Deliver the melt completely uniformly to the casting mold so that it fills the casting mold completely uniformly without causing detrimental flow separation and differential solidification boundary layer formation within the article. By heating the casting part of the casting mold, the cooling rate is maintained at a controlled low level, thereby avoiding internal stresses and resulting cracks, cracks, etc. in the part during an uncontrolled cooling process. .

1 shows a first embodiment of an apparatus for carrying out the method according to the invention. It is a figure which shows other embodiment of the apparatus shown in FIG.

Claims (14)

  Dimensionally high-precision casting method for parts made of non-ferrous metal alloys used in fields such as turbine engineering, etc., and having a heated molded shell corresponding to the outer shape of the part to be produced in each case Using a mold, via a runner device that is heated and rotatably mounted in such a way that the casting mold is completely filled with acceleration forces, including centrifugal Coriolis force applied to the melt. A method in which a melt is supplied to the casting mold.   In the runner apparatus, in the casting process, the melt is turned in a range of approximately 30 ° to 180 ° by a centrifugal force with respect to the direction of flow determined by gravity, and when flowing into the casting mold, acceleration including Coriolis force is performed. The method of claim 1, wherein the method is acted to uniformly fill the casting mold by force.   The heated and rotatably mounted runner and hot casting mold are maintained at a predetermined processing temperature, which corresponds to the non-ferrous metal alloy used for manufacturing by precision casting, 3. A method according to claim 1 or 2, characterized in that the ability to flow is maintained and above the melting point of the non-ferrous metal alloy, preferably between 10 ° C and 200 ° C.   The method according to claim 1, wherein the lysate is produced outside or inside the runner device.   5. The method according to claim 1, wherein the parts are heated from 100 ° C. to 900 ° C. for controlled lowering of the cooling rate of the precision cast parts in the casting mold. The method described in 1.   The runner device (11) used is a cup-shaped container (15) arranged vertically and rotatably mounted, the container (15) having a bottom that is advantageously configured hydrodynamically. The container has a surface and is in communication with a casting mold (22) having a molding shell disposed on a side surface (side wall 16) and at a predetermined distance (a) from the bottom surface (18), and the container (15 The three-dimensional set angle (sr) of the casting mold with respect to each communicating outlet opening (19) between the vessel and the casting mold, which is advantageously hydrodynamically configured in 6. The mold according to claim 1, wherein the casting mold is arranged in such a way that it is filled uniformly without causing separation of the flow in the melt. Apparatus for carrying out the method.   The container (15) of the runner device (40) is rotatably attached to a casting mold (22) that is adjustably disposed (three-dimensional angle sr), receives an ingot made of a non-ferrous metal alloy, 7. Apparatus for carrying out the method according to any one of the preceding claims, characterized in that it comprises a closable cover (44) corresponding to the inner diameter of the container.   The casting mold (22) is arranged in the vicinity of the upper edge of the container (15), and their inlet opening is assigned to a distributor (42) which has a nozzle action and is arranged inside the container (15). The device of claim 7, wherein:   The container (15) and the casting mold (22) are relatively non-reactive with the melt and are made of ceramic containing metal particles. The device according to item.   The runner channel (14) used to supply the lysate is advantageously configured with respect to the fluid dynamics of the lysate, and is also relatively non-reactive with respect to the lysate, The device according to claim 6, wherein the device is made of a ceramic containing metal particles.   The apparatus of claim 6, wherein the container and casting mold are made of coated steel, coated graphite, tantalum, titanium, or niobium.   12. A device according to any one of claims 6 to 11, characterized in that the runner device (10) and the casting mold (22) are heated inductively or by microwaves.   30 to 33% by weight Al, 4 to 6% by weight Nb, 0.5 to 3% by weight Mn, and 0.1 to 0.5% by weight B, the rest being Ti A non-ferrous metal alloy for carrying out the method according to claim 1 based on TiAl containing.   14. Based on a TiAl metal alloy having 0 to 2000 ppm oxygen content, 0 to 2000 ppm, preferably 800 to 1200 ppm carbon content, 100 to 2000 ppm Ni content and 0 to 2000 ppm nitrogen content. The non-ferrous metal alloy described.

Images