KR102426037B1 - Small diameter rod-typed aluminum alloy casting material and method of manufacturing the same - Google Patents

Abstract

The present invention provides a method for manufacturing a small-diameter bar aluminum alloy cast material capable of forming a small-diameter rod casting material by minimizing a decrease in fluidity by applying a fast casting speed. According to an embodiment of the present invention, the method comprises the steps of: injecting an aluminum alloy molten metal to the top of the stationary movable table through a through-type mold; maintaining the movable table in a stationary state for a predetermined period of time; and a casting step of lowering the movable table and casting at a preset set casting speed; after the holding step is completed, there is no transition section for gradually increasing the lowering speed of the movable table at the set casting speed. may include increasing.

Description

Small diameter rod-typed aluminum alloy casting material and method of manufacturing the same

The technical idea of the present invention relates to a method for manufacturing an aluminum alloy cast material, and more particularly, to a small diameter rod aluminum alloy cast material and a method for manufacturing the same.

Recently, due to fuel efficiency reduction of automobiles and development of electric vehicles, the demand for weight reduction of vehicles is increasing. Accordingly, the usage of vehicle parts using lightweight metals such as aluminum is rapidly increasing. Especially. An aluminum alloy is increasingly widely used in bumpers, door impact bars, seat rails, and the like, and it is also required that the aluminum alloy have high strength. In order to manufacture the high-strength aluminum alloy as described above, it is necessary to form an extruded material or a forged material, and for this, a manufacturing technology of an aluminum alloy cast material in the form of a billet is required as a base material.

As such an aluminum billet manufacturing method, continuous casting is known. Continuous casting is a method capable of forming a cast material having a long length without being limited to the height of the mold by using a through-type mold, and in general, the input molten metal is cooled by the mold. Direct chill casting (DC casting) is a type of continuous casting, in which a cooling fluid is directly supplied to a cast material that has passed through a penetration mold to cool it. The cast material formed by such direct cooling casting has excellent advantages in formability, microstructure, grain size distribution, and glossiness.

However, using this conventional direct cooling casting method, there is a problem in that it is difficult to manufacture a small diameter rod having a small diameter due to a decrease in fluidity due to a fast cooling rate. In particular, in the case of 7000 series aluminum alloy, which is a high-alloy-based aluminum alloy used as an ultra-high strength material, it was difficult to form a cast material for a small diameter rod with a diameter of 100 mm or less by using the conventional direct cooling casting method. In the case of conventional direct cooling casting, the molten metal is poured into a flow-through mold and maintained without casting for a certain period of time, then initially cast at a low speed, then the casting speed is gradually increased to reach the final casting speed and then cast at a constant casting speed. proceeds in stages. In the case of 7000 series aluminum alloy, since the solid-liquid coexistence area is wide, a semi-solid state is maintained at the side wall that is cooled first among the molten metal inlet in the initial stage of direct casting. can be extended to the center of In particular, in the case of casting a small diameter rod having a small diameter, it is easy to expand the semi-solid state from the side wall of the injection hole to the center of the injection hole. Therefore, in the holding section and the initial low-speed casting start section after pouring the molten metal at the beginning of casting, the semi-solid state of the molten metal from the sidewall of the inlet to the center of the inlet is expanded, and solidification may occur at the center of the inlet. As the inlet is clogged by this solidification, and thus casting is impossible, casting of a small diameter bar aluminum alloy cast material having a diameter of 100 mm or less is very difficult.

Korean Patent Publication No. 10-2010-0020729

The technical problem to be achieved by the technical idea of the present invention is a new direct cooling casting method that can stably manufacture all small diameter rods of aluminum alloys of various compositions, including high alloy-based aluminum alloys, and small diameter rod casting materials manufactured by this method. intended to provide. However, these tasks are exemplary, and the technical spirit of the present invention is not limited thereto.

According to one aspect of the present invention, there is provided a method for manufacturing an aluminum alloy small-diameter cast material by a direct cooling casting method of a hot top method.

According to an embodiment of the present invention, the method comprises the steps of: injecting the aluminum alloy molten metal into a stationary upper part of the movable table through a through-type mold; maintaining the movable table in a stationary state for a predetermined period of time; and a casting step of lowering the movable table and casting at a preset set casting speed; after the holding step is completed, there is no transition section for gradually increasing the lowering speed of the movable table at the set casting speed. may include increasing.

According to an embodiment of the present invention, the method includes: after injecting the aluminum alloy molten metal through the through-type mold, moving the movable table without a holding time at a first casting speed; and transitioning the movable table to a second casting speed that is higher than the first casting speed and casting a lowering speed of the movable table during the transition from the first casting speed to the second casting speed. increasing directly from the first casting rate to the second casting rate without a progressively increasing transition period.

In one embodiment of the present invention, the set casting speed may have a range of 200 mm / min to 300 mm / min.

In one embodiment of the present invention, the set casting speed may be implemented using a servo motor.

In one embodiment of the present invention, the first casting speed may have a range of 50 mm / min to 180 mm / min.

In one embodiment of the present invention, the second casting speed may have a range of 200 mm / min to 300 mm / min.

In one embodiment of the present invention, the first casting speed and the second casting speed may be implemented using a servo motor.

In one embodiment of the present invention, the small diameter rod aluminum alloy cast material may include a 7000 series aluminum alloy.

In one embodiment of the present invention, the small diameter rod aluminum alloy cast material may have a diameter of 100 mm or less.

In one embodiment of the present invention, the small diameter rod aluminum alloy cast material may have a secondary dendrite distance in the range of 15 μm to 30 μm.

In one embodiment of the present invention, the small diameter rod aluminum alloy cast material may have a grain size in the range of 50 μm to 100 μm.

According to another aspect of the present invention, a cast material of a small diameter rod having a diameter of 100 mm or less made of a 7000 series aluminum alloy is provided.

In one embodiment of the present invention, the cast material of the small diameter rod may have a secondary dendritic distance in the range of 15 μm to 30 μm, and a grain size in the range of 50 μm to 100 μm.

According to the technical idea of the present invention, it is possible to manufacture small-diameter rods of aluminum alloy having various compositions, and in particular, high-alloy-based aluminum alloy small-diameter rods having a diameter of 100 mm or less, which were difficult to manufacture by the conventional method, can be easily and stably produced. can be manufactured. It can be seen that there is little change in the microstructure even when moving from the center to the surface of the small diameter rod aluminum alloy cast material, and thus has a uniform microstructure. A small diameter rod aluminum alloy cast material having such a fine and uniform microstructure can provide high strength.

The above-described effects of the present invention have been described by way of example, and the scope of the present invention is not limited by these effects.

1 is a schematic diagram showing a direct cooling casting apparatus for manufacturing a small-diameter bar aluminum alloy cast material according to an embodiment of the present invention.
2 is a flowchart illustrating a method of manufacturing an aluminum alloy cast material for small diameter rods according to the first embodiment of the present invention.
3 is a graph showing the casting speed over time in the method for manufacturing a small-diameter aluminum alloy cast material according to the first embodiment of the present invention.
4 is a flowchart illustrating a method of manufacturing an aluminum alloy cast material for small diameter rods according to a second embodiment of the present invention.
5 is a graph showing the casting speed over time in the method for manufacturing a small-diameter bar aluminum alloy cast material according to the second embodiment of the present invention.
6 is a photograph of a small-diameter rod aluminum alloy casting material formed by using the method for manufacturing a small-diameter rod aluminum alloy casting material according to an embodiment of the present invention.
7 is a graph showing the change in the secondary dendritic distance from the center to the surface of the small-diameter rod aluminum alloy casting material formed by using the manufacturing method of the small-diameter rod aluminum alloy casting material according to an embodiment of the present invention.
8 is a graph showing the change in grain size from the center to the surface of the small-diameter rod aluminum alloy casting material formed by using the method for manufacturing the small-diameter rod aluminum alloy casting material according to an embodiment of the present invention.
9 is a result showing the microstructure from the center to the surface of the small diameter rod aluminum alloy casting material formed by using the manufacturing method of the small diameter rod aluminum alloy casting material according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the technical idea of the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, The scope of the technical idea is not limited to the following examples. Rather, these embodiments are provided so as to more fully and complete the present disclosure, and to fully convey the technical spirit of the present invention to those skilled in the art. In the present specification, the same reference numerals refer to the same elements throughout. Furthermore, various elements and regions in the drawings are schematically drawn. Accordingly, the technical spirit of the present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

1 is a schematic diagram showing a direct cooling casting apparatus for manufacturing a small-diameter bar aluminum alloy cast material according to an embodiment of the present invention.

Referring to FIG. 1 , the direct cooling casting apparatus 100 is a hot top method, and includes a tundish 10 , a penetrating mold 20 and a movable table 30 . In addition, a refractory cover 40 made of a refractory material is installed on the upper portion of the through-type mold 20 . A through hole 40a through which molten metal can pass is formed in the central portion of the refractory cover 40 .

The tundish 10 is a penetrating mold ( 20) is provided. As the refractory cover 40 is formed on the top of the penetration mold 20 , the flow of the molten metal can be stabilized, and the molten metal can be prevented from oxidation and heat loss can be reduced.

The through-type mold 20 solidifies the aluminum alloy molten metal 2 into an aluminum alloy solid phase 4 when the aluminum alloy molten metal 1 is provided from the tundish 10 to form a small diameter rod aluminum alloy casting material. A graphite chill 20a for cooling is formed on a portion of the inner surface of the through-type mold 20 . In addition, a discharge part 20b for discharging gas or liquid for directly cooling the aluminum alloy molten metal 2 injected into the through-type mold 20 is formed. The through-type mold 20 may have a circular shape or a polygonal shape.

Between the aluminum alloy molten metal 2 and the aluminum alloy solid phase 4, there is a solid-liquid coexistence zone 3 (mushy zone) in which the aluminum alloy molten metal 2 and the aluminum alloy solid phase 4 coexist.

The movable table 30 is provided under the through-type mold 20 , and is a pedestal on which the solid aluminum alloy 4 solidified while passing through the through-type mold 20 is placed. For continuous casting of the aluminum alloy solid phase (4), it moves downward by a motor (motor) linked to the movable table (30). That is, the movable table 30 continuously withdraws the solidified aluminum alloy phase 4 from the through-type mold 20 downward to form a small-diameter bar aluminum alloy cast material. The moving speed of the movable table 30 is interlocked with the casting speed, and therefore, the casting speed in the present specification is partially or completely solidified by the aluminum alloy molten metal passing through the through-type mold and seated on the movable table 30. It means the speed of moving in the downward direction.

In the direct cooling casting apparatus 100 according to an embodiment of the present invention, while passing through the through-type mold 20 , the aluminum alloy molten metal or aluminum alloy solid phase partially solidified by the cooling fluid is seated on the movable table 30 . After holding for a predetermined time, the movable table 30 is lowered at a high speed in order to immediately cast at a preset casting speed.

As another example of the present invention, after the aluminum alloy molten metal is seated on the movable table 30, the first casting speed is moved for a predetermined time without holding time, and then the second casting speed is higher than the first casting speed. Casting is performed by rapidly lowering the casting speed.

Therefore, the movable table 30 needs to be rapidly changed in movement speed, and for this purpose, a servo motor may be used as the interlocked motor.

Conventionally, a conventional stepper motor is used as a motor for moving the movable table. However, such a stepper motor has a problem in that it is difficult to control it to respond to a sudden speed change of the movable table. On the other hand, in the case of a servo motor, it is possible to quickly respond to an electrical signal applied from the outside for abrupt movement of the movable table, and therefore, by using the servo motor, it is possible to stably perform a change in the rapid movement speed of the movable table to be described later. can

2 is a flowchart illustrating a method ( S100 ) of manufacturing a small-diameter bar aluminum alloy cast material according to the first embodiment of the present invention.

Referring to FIG. 2 , the manufacturing method ( S100 ) of the small-diameter aluminum alloy casting material according to the first embodiment is a method for manufacturing the aluminum alloy small-diameter rod casting material by the hot-top method direct cooling casting method. The step of injecting the aluminum alloy molten metal through the mold into the upper part of the stationary movable table (S110), the maintaining step of maintaining the movable table in a stationary state for a predetermined time (S120) and the aluminum alloy molten metal at a preset casting speed It includes a step (S130) of casting after increasing the casting speed without a transition section.

The manufacturing method (S100) according to the technical idea of the present invention is a speed transition for gradually and gradually increasing the casting speed (that is, the descending speed of the movable table) for a predetermined time during the speed increase process from the stationary state to the set casting speed. It is characterized in that the section is not performed.

3 is a graph showing the casting speed over time in the method of manufacturing a small-diameter bar aluminum alloy cast material according to the first embodiment of the present invention. Figure 3 (a) shows the change of the casting speed with time during the conventional direct cooling casting as a comparative example, and (b) shows the change of the casting speed with time according to the first embodiment of the present invention.

Referring to Figure 3 (a), in the conventional direct cooling casting, the solidified aluminum alloy solid phase is seated on the movable table and then maintained without casting for a certain period of time (corresponding to the holding section), initially casting at a low speed After (corresponding to the starting section), the casting speed is gradually increased (corresponding to the transition section), and finally casting is performed at a constant casting speed of about 80 mm/min to 120 mm/min (corresponding to the stable section).

On the other hand, referring to Figure 3 (b), in the case of an embodiment of the present invention, the aluminum alloy molten metal is injected into the through-type mold, and after the injected molten metal is solidified and seated on the movable table, it is maintained (maintenance) section), and then cast at a preset casting speed (Vs in FIG. 3) (corresponding to the casting section) to form a small-diameter bar aluminum alloy cast material.

The set casting speed is in the range of 200 mm/min to 300 mm/min, which is a faster speed compared to about 100 mm/min, which is a conventional casting speed, preferably 220 mm/min to 280 mm/min, more preferably may range from 230 mm/min to 270 mm/min.

As shown in (b) of FIG. 3 , according to an embodiment of the present invention, the casting speed is quickly increased to a preset casting speed immediately without a transition section that is a gradual speed change section after the maintenance section. As described above, in order to stably implement a fast transition to the set casting speed, the movable table is driven by a servo motor.

4 is a flowchart illustrating a method ( S200 ) of manufacturing a small-diameter bar aluminum alloy cast material according to a second embodiment of the present invention.

Referring to FIG. 4 , the manufacturing method ( S200 ) of the small-diameter aluminum alloy casting material according to the second embodiment is a method of manufacturing the aluminum alloy small-diameter rod casting material by a hot-top method direct cooling casting method, a through-type Injecting molten aluminum alloy into the mold (S200), casting the molten aluminum alloy at a first casting speed without a holding time after pouring (S220), and pouring the molten aluminum alloy at a higher rate than the first casting speed 2 It includes the step of casting after transition to the casting speed (S230). At this time, in the process of transitioning from the first casting speed to the second casting speed, a transition section in which the casting speed is gradually accelerated for a predetermined time is not performed, and the first casting speed to the second casting speed is rapidly increased. do.

5 is a graph showing the casting speed over time in the manufacturing method of the small-diameter bar aluminum alloy cast material according to the second embodiment.

Referring to FIG. 5 , in the case of the second embodiment of the present invention, aluminum alloy molten metal is poured into a through-type mold, and at the same time, first direct cooling casting is performed at a first casting speed (corresponding to the first casting section), and then the Secondary direct cooling casting (corresponding to the secondary casting section) at a second casting speed higher than the first casting speed is performed to form a small-diameter bar aluminum alloy cast material.

In this case, the first casting speed may have a range of 50 mm/min to 180 mm/min, preferably 70 mm/min to 150 mm/min, more preferably 80 mm/min to 120 mm/min. Further, the second casting speed will be in the range of 200 mm/min to 300 mm/min, preferably in the range of 220 mm/min to 280 mm/min, more preferably in the range of 230 mm/min to 270 mm/min. can

As shown in FIG. 5 , according to an embodiment of the present invention, the casting speed is rapidly increased to the second casting speed without the transition section shown in FIG. 3 (a) after the first casting speed. do. That is, unlike the conventional method, a transition section in which the casting speed is gradually increased during the transition from the first casting speed to the second casting speed is not performed. In order to stably implement a fast transition from the first casting speed to the second casting speed, the movable table is driven by a servo motor.

The small-diameter aluminum alloy cast material manufactured according to the technical idea of the present invention may include aluminum alloys of various compositions (the aluminum alloy in the present specification includes not only aluminum including alloying elements, but also pure aluminum). For example, it may be a conventionally known cast material alloy or wrought material alloy. In particular, in the case of a high-alloy-based wrought material alloy, for example, a 6000 series or 7000 series alloy, a small-diameter bar having a diameter of 100 mm or less can be easily and stably manufactured according to an embodiment of the present invention.

As described above, the 7000 series aluminum alloy, which is a representative high-alloy-based aluminum alloy, is a small-diameter rod with a diameter of 100 mm or less in the conventional method. Due to the coagulation caused by the clogging of the injection port, there was a difficulty in manufacturing the small diameter rod.

On the other hand, according to an embodiment of the present invention, after the molten metal is put into the penetrating mold and solidified while passing through the penetrating mold, the solid aluminum is seated on the movable table. After casting is performed by directly increasing the speed or by moving the movable table for a predetermined time at the first casting speed, the second casting speed is rapidly transferred without a transition period. During this process, the semi-solid state of the molten metal can be minimized and the fluidity of the molten metal can be secured. Therefore, it is possible to stably cast small-diameter bars by minimizing the possibility that the aluminum alloy in a semi-solid state is solidified near the inlet while the movable table is stopped or moved at low speed.

The small diameter bar aluminum alloy cast material manufactured according to an embodiment of the present invention may have a diameter of 100 mm or less, for example, 20 mm to 100 mm, or 50 mm to 100 mm. When the small diameter rod casting material is a 7000 series aluminum alloy, the casting material may have a secondary dendritic arm spacing (SDAS) in the range of 15 μm to 30 μm, and may have a grain size in the range of 50 μm to 100 μm. .

Hereinafter, an experimental example for helping the understanding of the present invention will be described. The following experimental examples are presented to help the understanding of the invention, and are not limited to the following experimental examples of the present invention.

A7068 alloy was selected as the aluminum alloy for the small diameter bar aluminum alloy casting material, and the composition is shown in Table 1.

Al Zn Mg Cu Fe Zr Si Ti Cr Mn Bal 7.46 2.40 1.92 0.12 0.10 0.027 0.026 0.009 0.003

The hot top type direct casting cooling apparatus shown in FIG. 1 was used. The primary casting speed was 100 mm/min, and the secondary casting speed was 240 mm/min. The diameters of the small diameter rod aluminum alloy cast material of the experimental example were 50 mm, 70 mm, and 100 mm. As a comparative example, a cast material cast in the same manner as in (a) of FIG. 3 was manufactured. The holding section was maintained for 23 seconds, the casting speed in the starting section was 90 mm/min, and the casting speed in the stable section was 115 mm/min. Under these casting conditions, a small-diameter rod having a diameter of 100 mm or less could not be manufactured due to the clogging of the injection hole, and therefore a small-diameter rod having a diameter of 150 mm of the cast material was manufactured as a comparative example.

Figure 6 (a) is the result of observing the small diameter rod aluminum alloy casting material manufactured by using the manufacturing method of the small diameter rod aluminum alloy casting material according to the experimental example, Figure 6 (b) is a cross section of the small diameter rod with a diameter of 50 mm It's a photo.

Referring to (a) and (b) of Figure 6, by using the manufacturing method of the small diameter rod aluminum alloy casting material, the diameter of 50 mm, 70 mm, and 100 mm, respectively, the small diameter rod aluminum alloy casting materials were successfully formed. . These are referred to as Experimental Examples 1, 2 and 3, respectively. It can be seen that the small diameter rod aluminum alloy cast materials have excellent surface quality and no internal cracks.

7 is a graph showing the change in the secondary dendritic distance from the center to the surface of the small diameter bar aluminum alloy cast material according to the experimental example.

Referring to FIG. 7 , in the case of a 150 mm diameter, which is a comparative example, the secondary dendrite arm spacing (SDAS) from the center of the cast material to the surface portion sharply decreased from about 46 μm to about 33 μm. On the other hand, the experimental examples showed a smaller secondary dendritic distance than the comparative examples, and the degree of change was also small. Specifically, in the case of the 100 mm diameter of Experimental Example 3, the change in the secondary dendritic distance was relatively small from about 25 μm at the center to about 23 μm at the surface. In addition, in the case of the 70 mm diameter of Experimental Example 2, the secondary dendritic distance was almost the same at the center and the surface, and there was little change to about 23 μm. In the case of the 50 mm diameter of Experimental Example 3, the secondary dendritic distance was the smallest value, and there was almost no change to about 18 µm in the center and the surface part.

8 is a graph showing the change in grain size from the center to the surface of the small diameter bar aluminum alloy cast material according to the experimental example.

Referring to FIG. 8 , in the case of a 150 mm diameter as a comparative example, the grain size decreased from about 115 μm to 90 μm from the center to the surface of the cast material. The experimental examples of the present invention showed smaller grain sizes than the comparative examples, and the degree of change was also small. Specifically, in the case of the 100 mm diameter of Experimental Example 3, the grain size was about 90 μm at the center and about 60 μm at the surface. In the case of the 70 mm diameter of Experimental Example 2, the crystal grain size was about 85 μm at the center and about 70 μm at the surface. In the case of the 50 mm diameter of Experimental Example 1, the grain size was about 82 μm at the center and about 60 μm at the surface.

Referring to FIGS. 7 and 8 , in the case of the comparative example, the small-diameter rod having a diameter of 150 mm, the overall microstructure was coarse, and the size difference between the surface portion and the center microstructure was large. However, in the case of a small-diameter rod having a diameter of 100 mm, a diameter of 70 mm, and a diameter of 50 mm, manufactured according to the technical idea of the present invention, it can be seen that the microstructure deviation between the center and the surface is very small. Therefore, it can be expected that the small-diameter rods manufactured according to the experimental examples have high mechanical strength and show a uniform value with a small strength deviation for each location.

In general, the secondary dendrite distance is directly related to the cooling rate, and if the cooling rate is slow, the secondary dendrite distance becomes large. In the case of the comparative example, a small-diameter rod having a diameter of 150 mm, since the secondary dendritic distance is large, the cooling rate is slow overall including the surface part, and it can be seen that the cooling rate tends to decrease significantly toward the center. On the other hand, in the case of the small-diameter rods having a diameter of 100 mm, a diameter of 70 mm, and a diameter of 50 mm, which are the experimental examples of the present invention, the secondary dendritic distance is small, so that the overall cooling rate is fast and the deviation by region is insignificant.

9 is a result of observing the microstructure from the center to the surface of the 50 mm diameter small diameter rod aluminum alloy cast material according to Experimental Example 1 of the present invention.

Referring to FIG. 9 , it can be seen that there is almost no change in the microstructure even when moving from the center to the surface of the aluminum alloy cast material of the small diameter rod, and thus it can be seen that the small diameter rod has a uniform microstructure. A small diameter rod aluminum alloy cast material having such a fine and uniform microstructure can provide high strength.

The technical spirit of the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is the technical spirit of the present invention that various substitutions, modifications and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in the art to which this belongs.

Claims (12)

A method for producing a 7000 series aluminum alloy small diameter bar casting by a hot top method direct cooling casting method, comprising:
Injecting the aluminum alloy molten metal to the top of the stationary movable table through the through-type mold;
maintaining the movable table in a stationary state for a predetermined period of time; and
A casting step of lowering the movable table and casting at a preset casting speed;
After the holding step is completed, directly increasing the set casting speed to the set casting speed without a transition section for gradually increasing the descending speed of the movable table;
By driving the movable table with a servo motor to set the set casting speed in the range of 200 mm/min to 300 mm/min, the molten metal in the semi-solid state is solidified at the inlet of the through-type mold and the inlet is blocked It is possible to cast a 7000 series aluminum alloy small diameter rod having a diameter in the range of 20 mm to 100 mm by preventing it,
A method for manufacturing a small-diameter rod aluminum alloy casting. A method for producing a 7000 series aluminum alloy small diameter bar casting by a hot top method direct cooling casting method, comprising:
After injecting the aluminum alloy molten metal through the through-mold, moving the movable table without a holding time at a first casting speed; and
Transitioning the movable table to a second casting speed higher than the first casting speed and casting;
In the process of transitioning from the first casting speed to the second casting speed, increasing the descending speed of the movable table directly from the first casting speed to the second casting speed without a transition section for gradually increasing the lowering speed;
By driving the movable table with a servo motor, the first casting speed is set in the range of 50 mm/min to 180 mm/min, and the second casting speed is set in the range of 200 mm/min to 300 mm/min. , The molten metal in a semi-solid state is solidified at the inlet of the through-type mold to prevent the inlet from clogging, so that a 7000 series aluminum alloy small diameter rod having a diameter in the range of 20 mm to 100 mm can be cast,
A method for manufacturing a small-diameter rod aluminum alloy casting. delete delete delete delete delete delete delete 3. The method according to claim 1 or 2,
The small diameter rod aluminum alloy cast material has a secondary dendrite distance in the range of 15 μm to 30 μm, a method of manufacturing a small diameter rod aluminum alloy casting material. 3. The method according to claim 1 or 2,
The small diameter rod aluminum alloy cast material has a grain size in the range of 50 μm to 100 μm, the method of manufacturing a small diameter rod aluminum alloy casting material. delete

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