RU2620231C2 - Chill mould - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: chill mould contains at least two forming parts 1-3, forming cavities segments 7 and profitable part are performed at the surfaces of forming cavities. In a profitable part, a ceramic funnel with holes coaxial with the holes of forming cavities is installed. At the edges of the forming cavities, chamfers 9 are made, forming dross of specified shape and size, which prevents the formation of uncontrolled dross. The chill mould is made of copper or its alloys and is held by the clamping device 6.

EFFECT: increase the purity and quality of castings.

8 cl, 7 dwg

Description

The invention relates to the field of foundry, namely to chill molds, and can be used to obtain charge measured billets from alloys based on nickel, titanium, zirconium for subsequent redistribution, including using fast quenching technology.

Known chill mold (DE 10317441, publ. 04.11.2004), in which the forming cavity is formed by installing a plurality of rectangular guiding elements with thread from the outside, used for positioning the relative prefabricated mold body. The prefabricated housing is made of a metal alloy and consists of four rectangular-shaped side segments connected in pairs, one of which is at least movable, pressed by the force of the spring and, in turn, fastened by means of clamping device bolts. The chill mold is used for casting tool blanks for subsequent machining. The compression of the rectangular segments relative to each other and the walls of the chill mold is carried out after pouring the melt into the forming cavity with a force sufficient to overcome the hydrostatic pressure of the melt. To facilitate the preloading process, a layer of lubricant for the molds is applied to the mating surfaces. The chill mold is designed to form castings from low-temperature melts, with a melting point of several hundred degrees (for example, ZAMAK alloy with a melting point of 400 ° C), which is its significant drawback. The disadvantage of the design of this chill mold is the use of a large number of plug-in elements, which together with the difficulty of their positioning relative to each other, greatly complicates the process of assembly and use of the chill mold.

Also known chill mold (US 6354561, publ. 22.01.1998) adjustable type, consisting of many located along the axis of the chill mold rods held in the base plate by means of a threaded connection. The base plate, in turn, is connected to the housing element, and it is possible to move the plate in a direction perpendicular to the direction of the mold connector. To form a smooth surface of the casting on the ends of the molding rods, the application of a lubricant is allowed, which facilitates the separation of the casting from the surface of the mold. The disadvantages of this chill mold include the complexity of its design and the inability to use it for casting alloys with a high melting point.

An analogue of the present invention can serve as a chill mold (SU 1409407, publ. 15.07.88) for the manufacture of cast iron castings with protrusions, the purpose of which is to produce castings of high quality achieved by equalizing cooling rates. The composition of the chill mold includes forming parts that limit the working cavity with grooves for thermal shielding of small cavities. The grooves are filled with metal plates located perpendicular to the surface of the connector of the forming parts of the chill mold. Reducing the intensity of heat removal of small cavities excluded the possibility of the formation of white cast iron in them. The disadvantages include the lack of structural elements through which the connector is cast and removed, as well as the inability to use it to form castings from alloys with a melting point above 1300 ° C.

The closest analogue of the invention, which can be taken as a prototype, is a chill mold (RU 2188741, publ. 09/10/2002), which is designed to produce samples from alloys based on aluminum and magnesium, which contains two forming parts, the planes of which are coaxially vertical the axis is formed by forming cavities connected to each other and other cavities by the sprue channels, which in turn communicate with profit. Significant disadvantages of the invention include the formation of sample castings from light alloys based on magnesium and aluminum, as well as its design, which involves the use of only two forming parts with a developed gate system, which limits the number of castings obtained, complicates the design of the chill mold, requires its heating to relatively high temperatures immediately before pouring the melt, increases the consumption of metal and saturation of the melt with gas inclusions.

The technical task is to create a chill mold, which ensures the formation of high-quality non-porous non-porous castings of predominantly cylindrical shape with a diameter of 20-30 mm and a length of 200-220 mm from alloys based on iron, nickel, titanium, zirconium and hafnium with a cooling rate of at least 300 degrees per second low content of gas inclusions and without pollution by ceramic material.

The technical result achieved by the implementation of this invention is to improve the purity and quality of the material of the castings by eliminating the use of ceramic molding materials, to increase the productivity of the casting process of measured chargeable workpieces with the possibility of forming up to 30 kg of castings of a controlled form with a minimum burr for one melt, and also in increasing the utilization of the material by reducing the total mass of the profitable part.

To achieve the technical result described above, a chill mold is proposed for the manufacture of dimensional blanks containing at least two forming parts, the planes of which are made segments of the forming cavities and the profitable part. The chill mold is equipped with a ceramic funnel installed in the profitable part, in which holes are made, coaxial with the holes of the forming cavities. At least two centering elements of a cylindrical shape mounted in the undercuts of the mating forming parts and a clamping device. In this case, the chill mold is made of copper or its alloys, and chamfers are made on the edges of the forming cavities, ensuring the formation of a burr of a given shape and size.

Preferably, at least one additional forming part is installed between the two forming parts.

Preferably, each pair of plug-in cylindrical elements is located at an angle of 90 degrees relative to each other.

Preferably, the forming cavities are round, oval, triangular, rectangular or multifaceted.

Preferably, the forming cavities are staggered relative to each other.

Preferably, the ceramic funnel is made of zirconium and / or yttrium oxides.

Preferably, the inner surfaces of the forming parts are coated with complex zirconia with gadolinium, samarium, terbium, ytterbium, yttrium stabilized lanthanum oxide.

Preferably, the clamping device comprises wedge-shaped elements, with the possibility of pressing along the mating planes of the forming parts.

The present invention is illustrated by drawings:

Figure 1 - chill mold in the clamping device;

Figure 2 - double-row chill mold with an inserted forming part;

Figure 3 - General view of a multi-row chill mold;

Figure 4 is a cross section of the forming part;

Figure 5 - forming cavity with a bevel;

Figure 6 - insert centering element;

Figure 7 - pouring ceramic funnel.

As shown in figures 1 and 2, the proposed chill mold consists of at least two forming parts (1) and (3), the planes of which are made segments of the working cavities, in the aggregate representing the forming cavity (7). At least one plug-in forming part (2) can be located between the forming parts. The forming cavities (7) can have an arbitrary shape, for example, round, oval, triangular, rectangular, multifaceted shape, etc. By adding inserted forming parts (2), the capacity of the chill mold is increased (see figure 3). As shown in FIG. 5, a chamfer (9) is removed along the perimeter of the edge of each forming part, which, in combination with a mating chamfer (9 ') made in the conjugated forming part, forms a forming cavity (7) of a given shape and size, which prevents the formation of an uncontrolled burst of arbitrary irregular shape, and also facilitates the assembly and centering of the forming parts. Copper or its alloys were selected for the manufacture of the chill mold, which provides the required level of melt cooling rate, which, in turn, determines the structure of the ingot, and also ensures high purity of the material due to the exclusion of ceramic materials from the chill mold. As shown in FIG. 4, each of the forming parts is provided with at least one recess (4) of a cylindrical shape, designed to install cylindrical insert elements (see figure 6), which in turn are used to center the mating forming. To fix the forming parts relative to each other along the mating planes of adjacent forming parts, a clamping device (6) is used, consisting of two sidewalls conjugated along the conical surface with the side forming parts. Sidewalls can be made of various standard sizes. The sidewalls are preloaded, for example, by means of a screw connection sufficient to prevent the formation of a gap between the forming parts during the molding process under the influence of hydrostatic pressure of the melt. When all the forming parts of the chill mold are connected (see figure 4), the profitable part (8, figure 3) is formed in the upper part of the chill mold. A ceramic funnel (5) is installed in the profitable part formed in this way by the forming parts, which prevents the surface of the profitable part from being blurred by the molten stream. The holes in the ceramic funnel are formed in accordance with the number, size and location of the forming cavities formed by the forming parts of the chill mold at the place of their transition to the profitable part. During the casting process, a ceramic funnel (see figure 7) emerges under the action of the force of expulsion from the melt (flotation), interfering, among other things, with intense heat removal and, thus, ensuring the formation of defect-free castings.

Examples of the design of the chill mold for casting dimensional blanks.

Example 1

A copper chill mold was used for the manufacture of measured charge consumable cylindrical billets with a diameter of 20 mm from an alloy based on nickel (for example, heat-resistant nickel solder), in an amount of 27 pieces. In this case, the chill mold consisted of two lateral forming parts and five inserted forming parts, which are equipped with semicircular recesses, which in turn form cylindrical working cavities, the forming cavities being staggered coaxially with the vertical axis of the chill mold. Along the perimeter of the edge of the forming cavities of the forming parts, a 1 mm bevel was removed at an angle of 45 degrees, which made it possible to form an envelope of a controlled shape. The conjugated forming parts formed a profitable part in which a ceramic funnel was installed with 27 holes arranged coaxially with the forming cavities. The centering of the mating forming parts was carried out using two cylindrical metal inserts located at an angle of 90 degrees relative to each other and installed in cylindrical grooves in each pair of adjacent forming parts. After assembly, the chill mold was installed in the clamping device (6) and fixed using a screw connection (clamp).

Casting process: after assembling and fixing the chill mold in the clamping device, it was installed in an induction-type vacuum foundry. A ceramic funnel preliminarily calcined at 900 ° С was installed in the profitable part of the chill mold. Alloy casting in the amount of 30 kg was carried out in one go, and during the casting process, the ceramic funnel took on the mechanical and thermal effects of the melt jet, surfaced also under the force of expulsion from the melt, and after cooling and solidification of the melt was removed from the top of the profit.

Example 2

A chill mold made of a copper-based alloy was used for casting triangular samples from a zirconium-based alloy. The chill mold consisted of two mold-forming parts, and the mold-forming cavities were staggered coaxially with the vertical axis of the mold. A ceramic funnel with 4 holes arranged coaxially with the forming cavities was installed in the profitable part of the chill mold formed by the connected forming parts. Centering of the forming parts was carried out using a pair of metal inserts of a cylindrical shape located at an angle of 90 degrees relative to each other. Along the perimeter of the edge of the forming cavities of the forming parts, a 1 mm bevel was removed at an angle of 60 degrees, which made it possible to form an envelope of a controlled shape. To prevent smearing of the material of the chill mold by melt, a coating of complex zirconium oxide formed by at least one rare-earth metal oxide and stabilized by yttrium oxide was applied to the surface of the working cavity segments of each forming part. After assembly, the chill mold was installed in the clamping device (6) and fixed using a screw connection (clamp).

Casting process: after assembling and fixing the chill mold in the clamping device, it was installed in an induction-type vacuum foundry. A pre-calcined ceramic funnel made of yttrium-stabilized zirconia was installed in the profitable part of the chill mold. Alloy casting in the amount of 15 kg was carried out in one go, and during the casting process, the ceramic funnel took on the mechanical and thermal effects of the melt jet, surfaced under the force of expulsion from the melt, and after cooling and solidification of the melt was removed from the top of the profit.

Example 3

A copper chill mold was used for the manufacture of measured chargeable consumables of a rectangular shape with a diagonal of 30 mm in a split line of titanium-based alloy (for example, heat-resistant titanium solder), in an amount of 5 pieces. In this case, the chill mold consisted of three forming parts with recesses of a triangular shape, and the recesses were staggered coaxially with the vertical axis of the chill mold. Centering of the forming parts was carried out using four (two pairs) of metal inserts of a cylindrical shape located at an angle of 90 degrees relative to each other. Along the perimeter of the edge of the forming cavities of the forming parts, a 1 mm bevel was removed at an angle of 30 degrees, which made it possible to form an envelope of a controlled shape. A ceramic funnel with 5 holes arranged coaxially with rectangular shaped cavities was installed in the profitable part of the chill mold formed by the connected forming parts. After assembly, the chill mold was installed in the clamping device (6) and fixed using a screw connection (clamp).

Casting process: after assembling and fixing the chill mold in the clamping device, it was installed in an induction-type vacuum foundry. A pre-calcined ceramic funnel was installed in the profitable part. Alloy casting in the amount of 18 kg was carried out in one go, and during the casting process, the ceramic funnel took on the mechanical action of the melt jet, surfaced also under the force of expulsion from the melt, and after cooling and solidification of the melt was removed from the top of the profit.

Claims (8)

1. The chill mold for the manufacture of dimensional blanks containing at least two forming parts, the planes of which are made segments of the forming cavities and the profitable part, characterized in that it is equipped with a ceramic funnel installed in the profitable part, in which holes are made, aligned with the holes of the forming cavities, at least two centering elements of a cylindrical shape installed in the undercuts of the mating forming parts, and a clamping device, while the chill mold is made of m one or its alloys, and chamfers are made on the edges of the forming cavities, ensuring the formation of a flash of a given shape and size. 2. A chill mold according to claim 1, characterized in that at least one additional forming part is installed between the two forming parts. 3. Chill mold according to claim 1, characterized in that each pair of inserted cylindrical elements is located at an angle of 90 degrees relative to each other. 4. Chill mold according to claim 1, characterized in that the forming cavities have a round, oval, triangular, rectangular or multifaceted shape. 5. The chill mold according to claim 1, characterized in that the forming cavities are staggered relative to each other. 6. Chill mold according to claim 1, characterized in that the ceramic funnel is made of zirconium and / or yttrium oxides. 7. The chill mold according to claim 1, characterized in that the inner surfaces of the forming parts are coated with complex zirconium oxide with gadolinium oxide, samarium, terbium, ytterbium, lanthanum stabilized with yttrium oxide. 8. The chill mold according to claim 1, characterized in that the clamping device comprises wedge-shaped elements that provide a clamp along the mating planes of the forming parts.

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