JPS6036631A - Production of aluminum alloy casting ingot - Google Patents

Abstract

PURPOSE:To enable production of a sound casting ingot having no segregation by allowing the melt of an Al-Li alloy or the like which is liable to segregate in the stage of solidifying to flow down from the bottom of a tundish, spraying the melt into a pulverous state by an inert gas, collecting the sprayed particles in an unsolidified state and molding the particles. CONSTITUTION:An Al-Li alloy contg. 2.3% Li is liable to segregate in the stage of forming an ingot. Such Al-Li alloy is melted in a melting furnace 14 in a housing 2 kept in an inert gaseous atmosphere 4. The molten Al-Li 12 is put into a tundish 10 and a stopper 22 is raised so that the molten alloy flows down from a nozzle 18. An inert gas such as Ar, He or the like is ejected from a gas ejecting nozzle 24 to spray and drop the melt of the Al-Li alloy to 10-500mum fine particles 50. The fine particles of which 30-70% are not solidified yet enter a molding device consisting of belts 42 circulated endlessly by means of pulleys 40 from which the particles are drawn out in the form of an Al-Li alloy casting ingot 52 having no segregation by a dummy block 48.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a july penium alloy ingot, particularly for A4 alloys that tend to segregate during solidification, such as Ap-Li.
The present invention relates to a method for producing ingots of (lithium) alloys, etc., in a healthy state.

For example, An 2.3 wL% Li alloy is lightweight and has a high Young's modulus of about 80.5 GPa, making it an Ap gold alloy with great promise. However, since it contains Li (lithium), it tends to absorb hydrogen gas and the Li component tends to segregate. Therefore, when an Aff-Li alloy ingot is manufactured by the conventional die casting method or the continuous casting method using a direct chill mold (Direct Chill method), AIl! Because the solidification conditions for the Li component and the Li component are different, the internal structure of the ingot has parts with a lot of Li and parts with a little Li, which deteriorates the physical properties that should originally be obtained and makes it impossible to produce a healthy ingot. It was difficult to do so.

This is not limited to the production of Ap-Li alloy ingots; for example, 7% [-5m (zamarium) or Ap
This problem also exists when producing alloy ingots such as -Ca (calcium).

Here, the present invention has been made in view of the above circumstances, and its purpose is to
It is an object of the present invention to provide a manufacturing method that can overcome segregation and produce high-quality and sound ingots such as i-alloy.

In order to achieve this object, the present invention (31''
At least a spraying means and a shaping means are disposed in a room maintained in an inert gas atmosphere, and after melting aluminum alloy interest such as A12-Li alloy abrasive using a predetermined melting means, the melting process is performed. 11.7 ~ The molten alloy is introduced into the above-mentioned spraying stage, and is atomized into fine particles by the spraying means, and while the fine particles formed by the spraying are not completely solidified, they are The particles were collected and formed into a desired ingot by the above-mentioned shaping means.

Note that the dissolving means can be installed together with the spraying means and the shaping means in a room maintained in an inert gas atmosphere, or
Alternatively, set up an outdoor C fort melting means in a state where oxidation by air is prevented (J, melted alloy ingot in a hot water supply line, etc.)
- It may be guided into the recording chamber.

In step 1~, by once spraying the alloy ingot into fine particles, A7! This improves the large gap between the precipitation timing of alloy components and alloy components, suppresses the segregation of alloy components such as Li, and furthermore, collects these fine particles before they are completely solidified to form an ingot. As a result, the structure of the ingot becomes uniform with fine particles arranged in a silky texture, making it possible to obtain a healthy ingot. In addition, even if segregation occurs in the fine grains t selected for spraying U7 from a MikuTel perspective, from a MikuTel perspective, the structure of the ingot where they are aggregated is substantially uniform. It is a thing,
It was decided that 1f of high-quality Ap alloy ingots would be produced.

7) In carrying out the present invention, a manufacturing apparatus as shown in the drawings is suitably used. In the following, we will first provide an overview of the device.

In the figure, reference numeral 2 denotes a device housing, inside which is formed a sealed chamber 4 that is to be maintained in an inert gas atmosphere. A chamber 4 is provided on the outside of the housing 2.
A vacuum pump 6 is provided to remove the air inside, and is operated with a valve 8 open. A predetermined molten aluminum alloy (e.g. 8e-L i alloy molten?&) is placed in the upper part of the sealed chamber 4 at 11
A molten alloy 12 accommodated in the Thandesh IO is disposed, and power is supplied from an external power source to a coil (not shown) provided on the outer periphery of the Thandesh IO. It is maintained at a predetermined temperature.

In order to supply the molten metal 12 to the tande sosh 10, a predetermined melting furnace I4 such as a high frequency induction furnace or an electric resistance melting furnace is provided as a melting means in the closed chamber 4, and the melting furnace I4 is provided as a melting means. Molten alloy 1 obtained in furnace 14
2 passes through the gutter (or hot water pipe) 16 to the tandem system 1
(Jj will be paid within 0.

A lower flow nozzle 18 is provided at the bottom 1 of the tank 10, and the melt 12 can be flowed downward through the nozzle I8. Further, opening and closing of the 118-molten metal flow lower nozzle 18 (flow M control in some cases) is performed by a stopper rod 22 operated by a cylinder 20.

Furthermore, a gas jet nozzle 24 is provided adjacent to and below the /8 melt flow down nozzle 18 so as to surround the nozzle /I 8, and the molten metal flow down nozzle 18
A high-speed inert gas stream can be ejected from around the lower part of the gas ejection nozzle 24.
For example, it is connected to an external inert gas storage tank (not shown) through an inert gas supply pipe 26, and a valve 28 is provided at the end of the inert gas supply pipe 26 to supply inert gas. Supply can be controlled. This valve 28 and the aforementioned cylinder 20 are both connected to a starting switch 30, and are activated based on a signal from there.

Note that as the inert gas ejected from the gas ejection nozzle 24, for example, argon gas, helium gas, etc. can be used, and nitrogen gas can also be used, and this is also included in the inert gas. The inert gas ejected from the gas ejection nozzle 24 has the effect of atomizing the molten alloy 12 flowing down from the molten metal flowing down nozzle 8 in the form of fine particles. It also plays the role of maintaining an inert gas atmosphere.

The pressure inside the sealed chamber 4 is detected by the pressure gauge 32, and the pressure value is input into the automatic pressure regulator 34. .2kg/c+A gauge), JJI
Operate the air valve 36 to lower the pressure inside the sealed chamber 4 or higher.
・It is prevented from rising. Inside sealed room 4 again?
If more oxygen exists than this permissible amount, oxidation (in severe cases (11 ignition)) will occur in the sprayed alloy melt, so the oxygen M in the sealed chamber 4 can be monitored with oxygen a138. It looks like this.

On the other hand, further below the gas ejection nozzle 24, a pair of pulleys 40 are located in the sealed chamber 4 and are rotatably provided at a constant interval in the downward direction.
An endless belt 42 is passed between each set of pulleys 40, and the heald surfaces of each heald 42, which are opposite each other in the inside (...l), are arranged in parallel to each other so as to extend in the vertical direction. .

Although not shown, a pair of mold plates facing each other in the direction perpendicular to the plane of the paper are provided so as to extend vertically, so that the molten alloy is sprayed in the form of fine particles below the gas jet nozzle 24. A rectangular prism shaped space into which particles are introduced is formed.

Further, in order to cool the portion of the belt 42 in contact with such particles, for example, a water-cooled cooling device 44 is provided, and the heald 42 is also cooled from the outside.
A similar cooling device 46 is provided to obtain the same. Note that the cooling device 44 provided inside the belt 42 also functions to cool the fine particles of the molten alloy.

7. In the rectangular prism-shaped modeling space into which the alloy/8 molten metal particles are to be introduced, a dummy block 48 is housed at the stage of starting modeling, and receives the sprayed alloy molten metal particles therein. . In this case, the dummy two cock 48 and the pulley 40. Mugen Held 42 Oh,
L and mold plates (not shown), and L:l cooling device 44
．． 46, etc., constitute a forming (ingot-forming) means.

When carrying out the present invention using the manufacturing apparatus configured as described above, the vacuum pump 6 is operated with the valve 8 open in advance, and the inside of the sealed chamber 4 is preferably heated to 5 Torr.
The pressure is reduced to below r, and with the valve 8 closed, inert gas is introduced from the gas jet nozzle 24 to fill the sealed chamber 4 with the inert gas.

While the inside of the sealed chamber 4 is kept in an inert gas atmosphere, a predetermined aluminum alloy material, for example Aλ-L
Place the alloy material etc. in the melting furnace 14 and melt it using appropriate heating means such as high frequency induction heating or electric resistance heating,
The molten alloy is injected through the gutter 16 into the tandem housing 10 with the molten metal flowing down nozzle 18 closed by the stopper rod 22.

Then, when the start switch 30 is operated, the cylinder 20
is activated, the stopper rod 22 is raised, the molten metal flowing down nozzle 18 is opened, and the molten alloy 12 is caused to flow downward from there. At the same time, the valve 28 is opened and the gas jet nozzle 2 is opened through the inert gas supply pipe 26.
The inert gas introduced into the inert gas 4 is ejected from there as a high-speed inert gas stream, thereby spraying the flowing molten alloy 12 into fine particles.

Then, fine particles 50 of the molten alloy 12 are sprayed.
As the fine particles 50 fall and float downward, they are cooled by the inert gas atmosphere in the sealed chamber 4 and solidify. However, while the fine particles 50 are not completely solidified, they are passed through a gas jet nozzle. The particles are collected in a forming space provided below 24, that is, a space constituted by an endless belt 42 facing each other and a mold plate (not shown), and are coagulated and solidified using their own weight to form the target Ap-1,
An ingot 52 of i-alloy or the like is manufactured.

At the initial stage of ingot production, the dummy block 48 is positioned in the modeling space on the side closer to the gas jet nozzle 24, and gradually moves downward as the modeling progresses. Alloy ingot 52 of belt 42
The portion in contact with the gummy cock 48 moves in the same direction as the gummy cock 48, and accordingly, each set of pulleys 40 rotates in the direction shown by the arrow.

The pulley 40, the endless belt 42, etc. have the function of guiding the downward movement of the alloy ingot 52 that is solidifying or in the process of solidifying.

By the way, when A1-L4 alloy material etc. is melted and guided into a mold according to the conventional method and directly cooled and solidified, the Li component is This causes significant segregation, making it difficult to obtain a healthy ingot.

On the other hand, if the molten alloy 12 is atomized into fine particles by blowing out an inert gas according to the present invention, the contact area that comes into contact with each inert gas atmosphere increases, and the cooling of these fine particles occurs rapidly. (4), it is possible to avoid a large difference in the precipitation timing between the Aβ component and the i component.

This makes it possible to effectively suppress the segregation of the i component.

Moreover, in the process in which these particles are collected and solidified in the above-mentioned modeling space, it is virtually difficult for crystal precipitation to occur beyond one individual fine particle, and therefore, it is difficult for the atomized fine particles to linger in the air. Even if some degree of segregation occurs from a microscopic perspective,
Once U2 is collected and solidified in the forming space, the influence of such segregation on the structure of the alloy ingot 52 can be almost ignored from a macroscopic perspective. As a result, a substantially uniform organization,
In other words, it is possible to form a structure in which the Li component is substantially uniformly distributed in the Ap component, resulting in a high-quality and healthy A7 with excellent physical properties. An alloy ingot 52 is obtained.

Also, alloy? Since the hot water 12 is atomized in an inert gas atmosphere, the interface between the inert gas and the fine particles is wide, and therefore hydrogen gas can be effectively degassed. It also effectively prevents the embrittlement of the ingot.

In addition, alloy/8 hot water 1 formed by inert gas spraying
If the fine particles of 2 are collected in a state too close to droplets, the effect of spraying them into fine particles will not be as effective, and when these particles are collected and solidified, segregation will easily occur across the particles, - On the other hand, if the degree of solidification of such fine particles is too high, it becomes difficult to solidify and bond the IN particles.

For this reason, it is preferable that the fine particles obtained by spraying the molten alloy 12 have a solid phase ratio of 30 to 70%, in other words, a liquid phase ratio of about 70 to 30%. It is desirable to collect the alloy ingots 52 to form the alloy ingot 52.

In order to obtain such a solid phase ratio, the flow rate per unit time of the inert gas ejected from the gas ejection nozzle /l<24, the shape of the nozzle 24, and the molten metal flowing down nozzle 18 with Kumptsushi = L10 are adjusted. It is recommended to appropriately select the flow rate of the molten metal per unit time, the residence time of the fine particles 50, and the temperature of the inert gas atmosphere.

In addition, the particle size of the fine particles to be atomized must be in the range of approximately 10 to 50,077 m, although it cannot be generalized, since there is a balance with the various conditions mentioned above. To maintain such particle size and solidity as desired, it is preferable to use an ultra-high 3-speed atomizing nozzle 24 capable of producing a fairly high velocity inert gas flow.

In the specific example shown in the figure, two sides of the space into which the fine particles are introduced are defined by infinite healds 42, but the remaining two sides are also defined by the same infinite healds 42. , a cooling device may also be provided there. Alternatively, instead of using such an endless belt 42, the molding space may be formed by positionally fixing and facing an appropriate number of mold plates equipped with appropriate cooling devices.

Furthermore, it is also possible to use a shaping means that not only guides the introduced fine particles but also presses them, for example, a pressurizing device having a plurality of pressurizing rollers arranged at narrow intervals. be.

Furthermore, the present invention provides AA! Although it can be suitably applied to the production of -Li alloy ingots, it is not limited thereto, for example, A7! -3m alloy ingot or A6-
It can be suitably applied to Ca alloy ingots, etc., where conventional die casting or direct chill methods could not produce healthy ingots due to gas absorption or segregation4. .

(1!!) Without departing from the spirit of the present invention,
It goes without saying that the present invention can be practiced with various changes, improvements, etc. based on knowledge in the art.

[Brief explanation of drawings]

The figure shows an ingot manufacturing apparatus suitable for carrying out the present invention.
It is a schematic diagram conceptually showing a specific example, and is also a diagram illustrating a specific example of the method of the present invention. 2: Apparatus housing 4: Closed chamber 10: Tandesocipu, 12-alloy molten metal 14: Melting furnace
18: /8 Hot water flow down nozzle 22 Ni stopper rod 24;
Gas jet nozzle 40: Pulley 42: Infinite held 44.46: Cold J, ll device 48; Dummy block 5
0: Fine particles 52: A4 alloy ingot Applicant: Sumitomo Light Metal Industries, Ltd. 5

Claims (1)

[Claims] disposing at least a spraying means and a shaping means in a room maintained in an inert gas atmosphere, melting a predetermined aluminum alloy material with a predetermined melting means, and then guiding the melted molten alloy to the spraying means; The spraying means is used to spray into fine particles, and then, while the fine particles formed by the spraying are not completely solidified, the particles are collected and formed into a desired ingot by the shaping means. A method for producing an aluminum alloy ingot, characterized by: