A continuous casting and extrusion method and device for high performance alloy

Abstract

The present invention discloses a continuous casting and extrusion method and device for high-performance alloys, and belongs to the field of continuous extrusion technology. The continuous casting and extrusion method for high-performance alloys described in the present invention comprises the following steps: after the metal is melted, it is introduced into the extrusion wheel groove through a funnel, and is rapidly solidified into a U-shaped thin billet under the joint constraint and cooling of the extrusion wheel and the solidification shoe; then the thin billet moves forward with the extrusion wheel, and accumulates in the extrusion cavity when encountering a plug, and when the friction force of the extrusion wheel groove on the billet is large enough, the billet is pushed into the mold cavity, and flows out of the mold hole to form a product. The present invention constrains the metal melt to solidify into a U-shaped thin billet in the U-shaped solidification cavity in the solidification shoe and the extrusion wheel groove, so that it is rapidly solidified under the dual cooling of the extrusion wheel and the solidification shoe; and the cooling speed of each part of the U-shaped thin billet is consistent, and the performance of the obtained product is uniform; the solidified billet undergoes severe shearing under the friction of the extrusion wheel groove and the solidification shoe, and obtains a finer and more uniform structure.

Description

Technical Field

[0001] The invention belongs to the technical field of continuous extrusion, and in particular relates to a continuous casting and extrusion method and device for a high-performance alloy. Background Art

[0002] Continuous casting and extrusion is to put liquid metal directly into the extrusion cavity of the extrusion wheel and the fixed shoe block, and then extrude it through the die hole after dynamic crystallization. This technology that combines casting and continuous extrusion has the advantages of short process flow, fewer production steps, energy saving and material saving, etc. It is mainly used in the forming and production of small pipes, alloy wires, alloy profiles, electrical aluminum busbars, large-diameter pipes and Al-Ti-B grain refiners of low-melting-point aluminum, magnesium alloys and their composite materials, and can also be used for the continuous preparation of liquid-solid coated composite materials. However, the groove size of the casting and extrusion wheel is usually large, and the crystallization latent heat of the alloy melt is not easy to be quickly extracted, resulting in a low solidification rate, which limits the application of this technology in the field of high-performance alloy materials.

[0003] In response to this problem, Yin Jiancheng et al. proposed "A method and device for continuous preparation of high-performance alloys" (CN202211206410.2), which is to use the conduction heat transfer of water-cooled copper wheels and extrusion wheels to achieve non-equilibrium solidification of the melt, making it possible to continuously prepare high-performance alloys. However, this method also has some problems, such as the introduction of water-cooled copper wheels will increase the number of moving parts and affect the stability of the production system; the contact area between the water-cooled copper wheels and the melt is small, and the effect of improving the solidification speed is limited. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a continuous casting and extrusion method and device for high-performance alloys.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a continuous casting and extrusion method of a high-performance alloy, which specifically comprises the following steps:

[0006] (1) After the metal is melted, it is introduced into the extrusion wheel groove through a funnel, and is rapidly solidified into a U-shaped thin billet under the joint constraint and cooling of the extrusion wheel and the solidification shoe; the solidification shoe has a protrusion, and the protrusion extends into the extrusion wheel groove to form a U-shaped solidification cavity.

[0007] (2) The U-shaped thin billet moves forward with the extrusion wheel and accumulates in the extrusion cavity after encountering a plug. When the friction force of the extrusion wheel groove on the billet is large enough, the billet is pushed into the die cavity and then flows out of the die hole to form a product.

[0008] As a preferred embodiment of the present invention, the thickness of the U-shaped thin blank is 1-2 mm.

[0009] The present invention also claims to protect the device of the continuous casting and extrusion method of the high-performance alloy, including a funnel 2, an extrusion wheel groove 3, an extrusion wheel 4, an extrusion shoe 8, a mold 10, and a mold cavity 11; the extrusion wheel 4 is provided with an extrusion wheel groove 3, the funnel 2 is located above the extrusion wheel groove 3, the extrusion shoe 8 is provided on the left side of the extrusion wheel groove 3, the extrusion shoe 8 is provided with a mold cavity 11 inside the extrusion shoe 8, and the mold cavity 11 is provided with the mold 10; it also includes a solidification shoe 5, the inner side surface of the solidification shoe 5 is in an arc shape and is located at the upper left of the extrusion wheel groove 3, is arranged between the funnel 2 and the extrusion shoe 8, and contacts with the upper end of the extrusion shoe 8; the solidification shoe 5 is provided with a protrusion, the protrusion part extends into the extrusion wheel groove 3, and forms a U-shaped solidification cavity with the extrusion wheel groove 3.

[0010] As a preferred embodiment of the present invention, a circulating cooling water channel 6 is provided inside the coagulation shoe 5 .

[0011] As a preferred embodiment of the present invention, a circulating cooling water channel 12 is provided inside the extrusion wheel 4 .

[0012] As a preferred embodiment of the present invention, the extrusion wheel 4 of the present invention rotates in a counterclockwise direction.

[0013] The metal melt is rapidly solidified by the dual cooling effect of the extrusion wheel 4 and the solidification shoe 5. The amount of the solidification shoe 5 extending into the extrusion wheel groove 3 gradually increases. The alloy is accompanied by severe shearing during the dynamic solidification process, which makes the structure more refined.

[0014] The principle of the present invention is as follows: after the alloy is melted in the crucible, it is introduced into the extrusion wheel groove 3 through the funnel 2, and then enters the U-shaped gap formed by the solidification shoe 5 and the extrusion wheel groove 3. The melt is rapidly solidified under the dual cooling action of the extrusion wheel 4 and the solidification shoe 5 to form a U-shaped thin billet; the solidified metal thin billet rotates under the friction force of the extrusion wheel groove 3 and enters the mold cavity 11 after encountering a plug and accumulates in the extrusion cavity. When the friction force of the extrusion wheel groove 3 on the billet is large enough, the billet accumulated in the cavity flows out of the mold 10 to form a product.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) Compared with the traditional continuous casting and extrusion technology, the present invention utilizes the protruding part of the solidification shoe to extend into the extrusion wheel groove to constrain the metal melt to solidify in the extrusion wheel groove to form a U-shaped thin billet, so that it can be rapidly solidified under the dual cooling action of the extrusion wheel and the solidification shoe, shortening the distance for the latent heat of crystallization inside the melt to be conducted outward, which is beneficial to the rapid extraction of heat, and can improve production efficiency while achieving rapid solidification.

[0017] (2) The solidification shoe compacts the crystallized and solidified billet in the extrusion wheel groove, making the billet fit more closely with the extrusion wheel groove, increasing the friction during the extrusion process, and allowing the metal to be extruded smoothly.

[0018] (3) The protruding part of the solidification shoe that extends into the extrusion wheel groove and the radial cross-section of the extrusion wheel groove are designed to be U-shaped, which can make the thickness of the billet in the wheel groove more uniform, so that the cooling rate of each part is consistent, and the performance of the subsequent extruded product is more uniform. The billet will produce friction with the protruding part of the solidification shoe that extends into the extrusion wheel groove during the rotation of the extrusion wheel. Designing the cross-section into a U shape can avoid stress concentration and make the billet rotate more smoothly with the extrusion wheel. In addition, the solidified billet will produce severe shearing under the friction of the extrusion wheel groove and the solidification shoe, which is convenient for obtaining a finer and more uniform structure.

[0019] (4) The continuous casting and extrusion method of the high-performance alloy described in the present invention can complete the continuous preparation of tube and rod mold wires with excellent performance in a one-step operation, and has the advantages of short process, low energy consumption, high efficiency and high stability. Compared with traditional continuous casting and extrusion, it has obvious cost and performance advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a continuous casting and extrusion device for the high performance alloy of the present invention;

[0021] Figure 2 This is a schematic diagram of the AA planing surface of the continuous casting and extrusion device of the high-performance alloy described in the present invention.

[0022] In the figure: 1-metal melt, 2-funnel, 3-extrusion wheel groove, 4-extrusion wheel, 5-solidification boot, 6-solidification boot circulating cooling water channel, 7-solidification thin billet, 8-extrusion boot, 9-product, 10-mold, 11-mold cavity, 12-extrusion wheel circulating cooling water channel. DETAILED DESCRIPTION

[0023] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] Example 1

[0025] The device used in this embodiment is as follows Figure 1 As shown, the device mainly includes a funnel 2, an extrusion wheel groove 3, an extrusion wheel 4, an extrusion shoe 8, a mold 10, and a mold cavity 11; the extrusion wheel 4 is provided with an extrusion wheel groove 3, the funnel 2 is located above the extrusion wheel groove 3, the extrusion shoe 8 is provided on the left side of the extrusion wheel groove 3, the extrusion shoe 8 is provided with a mold cavity 11 inside the extrusion shoe 8, and the mold cavity 11 is provided with the mold 10; it also includes a solidification shoe 5, the inner side surface of the solidification shoe 5 is in an arc shape and is located at the upper left of the extrusion wheel groove 3, is arranged between the funnel 2 and the extrusion shoe 8, and contacts with the upper end of the extrusion shoe 8; the extrusion shoe 8 is provided with a protrusion, the protrusion part extends into the extrusion wheel groove 3, and forms a U-shaped solidification cavity with the extrusion wheel groove 3.

[0026] Taking Al-5Ti-1B alloy rod as an example, the method of the present invention is further described in detail in combination with the device. The method is as follows:

[0027] (1) Melting: Place commercial Al-5Ti-1B alloy into a crucible and place it in a resistance furnace for melting, setting the melting temperature to 800°C;

[0028] (2) Preparation process: preheat the funnel 2 to 800°C, preheat the mold cavity 11 and the mold 10 and install them into the extrusion shoe 8, turn on the main switch of the JL350 continuous extruder, adjust the extrusion wheel 4 to rotate counterclockwise, the speed of the extrusion wheel 4 is 10 rpm, turn on the circulating cooling water switch, and then pour the molten metal obtained by smelting in step (1) into the funnel 2, flow to the extrusion wheel groove 3 through the funnel 2, and enter the U-shaped solidification cavity formed by the solidification shoe 5 and the extrusion wheel groove 3 as the extrusion wheel 4 rotates. Since the protruding part of the solidification shoe 5 extends into the extrusion wheel groove 3, it will cause The melt solidifies into a U-shaped thin billet with a middle part thickness of about 1.5 mm. The thin billet is rapidly solidified under the joint cooling action of the extrusion wheel 4 and the solidification shoe 5. At the same time, the billet in the solidification process undergoes shear deformation under the friction between the extrusion wheel groove 3 and the solidification shoe 5. The solidified metal thin billet rotates under the friction of the extrusion wheel groove and enters the mold cavity 11 after encountering a plug and accumulates in the extrusion cavity. When the friction force of the extrusion wheel groove 3 on the billet is large enough, the billet accumulated in the cavity flows out of the mold 10 to form an Al-5Ti-1B alloy rod with a diameter of 9.5 mm.

[0029] The TiAl3 phase in the obtained Al-5Ti-1B alloy rod is uniformly distributed in the Al matrix in the form of blocks, with an average size of 8μm. The TiB2 particles are dispersed in the Al matrix in the form of fine particles, with an average size of 0.2μm, no obvious agglomeration, and the maximum agglomeration size is 5μm. Under the same other conditions, compared with the Al-5Ti-1B alloy rod prepared by conventional continuous casting and extrusion (i.e., there is no protrusion on the surface of the solidification shoe), the TiAl3 phase is more evenly distributed, and the average size is reduced by 20μm; the agglomeration of TiB2 particles is significantly improved, the average size is reduced by 1μm, and the maximum size of the agglomerate is reduced by 10μm. This is because the molten liquid forms a thinner melt layer under the constraint of the solidification shoe, and the contact area between the solidification shoe and the melt is large, and cooling water is passed through. At this time, the melt cools faster, and the large undercooling causes a large number of second phase nuclei to form, accompanied by shearing, resulting in a smaller size of the second phase and a more uniform dispersion.

[0030] Example 2

[0031] The device used in this embodiment is as follows Figure 1As shown, the device mainly includes a funnel 2, an extrusion wheel groove 3, an extrusion wheel 4, an extrusion shoe 8, a mold 10, and a mold cavity 11; the extrusion wheel 4 is provided with an extrusion wheel groove 3, the funnel 2 is located above the extrusion wheel groove 3, the extrusion shoe 8 is provided on the left side of the extrusion wheel groove 3, the extrusion shoe 8 is provided with a mold cavity 11 inside the extrusion shoe 8, and the mold cavity 11 is provided with the mold 10; it also includes a solidification shoe 5, the inner side surface of the solidification shoe 5 is in an arc shape and is located at the upper left of the extrusion wheel groove 3, is arranged between the funnel 2 and the extrusion shoe 8, and contacts with the upper end of the extrusion shoe 8; the extrusion shoe 8 is provided with a protrusion, the protrusion part extends into the extrusion wheel groove 3, and forms a U-shaped solidification cavity with the extrusion wheel groove 3.

[0032] Taking Al-1.5Zr alloy rod as an example, the method of the present invention is further described in detail in combination with the device. The method is as follows:

[0033] (1) Ingredients: Prepare the raw materials by mass percentage of Al 99% and Zr 1%;

[0034] (2) Melting: Place the prepared aluminum-zirconium alloy into a crucible, place it into a resistance furnace for melting, and set the melting temperature to 910°C;

[0035] (3) Preparation process: preheat the funnel 2 to 910°C, preheat the mold cavity 11 and the mold 10 and install them into the extrusion shoe 8, turn on the main switch of the JL350 continuous extruder, adjust the extrusion wheel 4 to rotate counterclockwise, the speed of the extrusion wheel 4 is 10 rpm, turn on the circulating cooling water switch, and then pour the molten metal obtained by smelting in step (1) into the funnel 2, flow to the extrusion wheel groove 3 through the funnel 2, and enter the U-shaped solidification cavity formed by the solidification shoe 5 and the extrusion wheel groove 3 as the extrusion wheel 4 rotates. Since the protruding part of the solidification shoe 5 extends into the extrusion wheel groove 3, The melt will solidify to form a U-shaped thin billet with a middle part thickness of about 2 mm. The thin billet is rapidly solidified under the joint cooling action of the extrusion wheel 4 and the solidification shoe 5. At the same time, the billet in the solidification process is sheared and deformed under the friction between the extrusion wheel groove 3 and the solidification shoe 5. The solidified metal thin billet rotates under the friction of the extrusion wheel groove and enters the mold cavity 11 after encountering a plug and accumulates in the extrusion cavity. When the friction force of the extrusion wheel groove 3 on the billet is large enough, the billet accumulated in the cavity flows out of the mold 10 to form an Al-1Zr alloy rod with a diameter of 10 mm.

[0036] The obtained Al-1Zr alloy rod has a fine grain structure with a grain size of 0.1μm. After aging at 350℃ / 200h, the tensile strength can reach 300MPa. Under the same other conditions, compared with the Al-1Zr alloy rod prepared by conventional continuous casting and extrusion (i.e., there is no protrusion on the surface of the solidification shoe), the grain size is reduced by ~20μm and the tensile strength can be increased by about 150MPa. This is because a thinner melt layer is formed under the constraint of the solidification shoe, and the contact area between the solidification shoe and the melt is large, and cooling water is passed. At this time, the melt cools faster and is accompanied by shearing, which refines the matrix grain size and increases the solid solubility of Zr in the Al matrix. After aging, more and finer Al3Zr phases can be formed, which significantly improves the strength of the alloy.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A continuous casting and extrusion method for a high performance alloy, characterized in that: The specific steps include: (1) The melted metal is introduced into the extrusion wheel groove through a funnel, and is rapidly solidified into a U-shaped thin billet with a thick middle and thin ends under the joint constraint and cooling of the extrusion wheel and the solidification shoe; The solidification shoe has a protrusion, and the protrusion extends into the extrusion wheel groove to form a U-shaped solidification cavity that is thick in the middle and thin at both ends; (2) The U-shaped thin billet moves forward with the extrusion wheel and accumulates in the extrusion cavity after encountering a plug. When the friction force of the extrusion wheel groove on the billet is large enough, the billet is pushed into the die cavity and then flows out of the die hole to form a product.

2. The continuous casting and extrusion method of high performance alloy according to claim 1, characterized in that: The thickness of the middle part of the U-shaped thin blank which is thick in the middle and thin at both ends is 1-2 mm.

3. A device for continuous casting and extrusion of high-performance alloys, characterized in that: The invention comprises a funnel (2), an extrusion wheel groove (3), an extrusion wheel (4), an extrusion shoe (8), a mold (10), and a mold cavity (11); the extrusion wheel (4) is provided with an extrusion wheel groove (3), the funnel (2) is located above the extrusion wheel groove (3), an extrusion shoe (8) is provided on the left side of the extrusion wheel groove (3), a mold cavity (11) is provided inside the extrusion shoe (8), and the mold cavity (11) is provided inside the mold cavity (11), and the mold (10) is provided inside. The invention is characterized in that: the invention also comprises a solidification shoe (5), the inner side surface of the solidification shoe (5) is in an arc shape and is located at the upper left of the extrusion wheel groove (3), is arranged between the funnel (2) and the extrusion shoe (8), and contacts with the upper end of the extrusion shoe (8); the solidification shoe (5) is provided with a protrusion, the protrusion part extends into the extrusion wheel groove (3), and forms a U-shaped solidification cavity with a thick middle and thin ends together with the extrusion wheel groove (3).

4. The device for the continuous casting and extrusion method of high performance alloy according to claim 3, characterized in that: A coagulation boot circulating cooling water channel (6) is provided inside the coagulation boot (5).

5. The device for the continuous casting and extrusion method of high performance alloy according to claim 3, characterized in that: An extrusion wheel circulating cooling water channel (12) is provided inside the extrusion wheel (4).

6. The device for the continuous casting and extrusion method of high performance alloy according to claim 3, characterized in that: The inner side surface of the solidification shoe (5) is in an arc shape and covers the roller surface of the extrusion wheel (4). The arc radius of the inner side surface of the solidification shoe (5) is 0.8 to 1.2 mm larger than the arc radius of the wheel surface of the extrusion wheel (4).

7. The device for the continuous casting and extrusion method of high performance alloy according to claim 3, characterized in that: The extrusion wheel (4) rotates in a counterclockwise direction.

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