WO2014050892A1 - Perforated cast product and method for manufacturing same - Google Patents

Abstract

A method for manufacturing a perforated cast product whereby a molten casting material is poured into a casting mold, after which rod-shaped forms arranged within the casting mold are withdrawn, thereby forming holes in the casting material where the rod-shaped forms existed, said method having: a pouring step, wherein the casting material is poured at less than 10 MPa; a withdrawal step, wherein the rod-shaped forms are withdrawn from the casting material in a temperature range of Tx≤Tp≤Th (where Tx=Ts-d and 0<d<100), or wherein an enlargement of the diameters of the holes is begun in a temperature range of Ts<Tp≤Th, after which the rod-shaped forms are withdrawn from the casting material, with Tp(°C) being the temperature of the cast material in the vicinity of the rod-shaped forms, Th(°C) being the upper limit temperature for which the hole walls do not collapse and the liquid phase does not penetrate and fill the holes during the withdrawal of the rod-shaped forms or after the withdrawal of the rod-shaped forms, Tx(°C) being the lower limit withdrawal temperature, and Ts(°C) being whichever is the lowest of the melting point, the eutectic temperature, or the peritectic temperature; and a removal step, wherein the cast product is removed from the casting mold.

Description

[Name of invention determined by ISA based on Rule 37.2] Perforated castings and their manufacturing method

The present invention relates to a method for producing a cast product having a through hole or a bottomed hole.

Porous materials (porous materials) have been proposed as metal materials used for heat sinks, shock absorbers, lightweight materials, and the like (see Non-Patent Document 1).
Since this type of porous material is porous, it is expected to be used as a heat sink because of its large specific surface area, good air permeability and water permeability, and excellent thermal characteristics.
Moreover, since the said porous material is a low density and is lightweight, the use to an impact-absorbing material or a lightweight material is anticipated.

Generally, the porous material is produced by dissolving a gas (foaming agent or the like) in a molten metal and releasing the gas during solidification to form bubbles (so-called “foaming method”). For this reason, it is difficult to adjust the size and position of the hole, and a vacuum vessel or the like is required to perform this operation. The manufacturing apparatus is expensive and it is difficult to increase the productivity. .

In addition, a lotus-type porous material in which a growth direction of bubbles is controlled by controlling a solidification direction of a molten metal material to form a long hole has been proposed (the same document).
However, even in this case, it is difficult to adjust the length and position of the hole, and it is not possible to form a hole penetrating the material.

On the other hand, Patent Documents 1 to 5 have been proposed as methods for forming through holes or bottomed holes (hereinafter simply referred to as “holes”) in a metal material. These patent documents utilize a die-cast method.

More specifically, in these patent documents, a die casting mold is opened by injecting a molten casting material into the die casting mold by a jet jet or the like and maintaining the casting pressure at 50 to 100 MPa or more. A hole is formed by inserting a core pin in a direction parallel to the direction and extracting the core pin before the molten metal solidifies. In Patent Document 5, a cast pin is inserted in a direction perpendicular to the mold opening direction of the mold.

Further, in Patent Document 6, there is a method in which a hole is formed while pouring molten metal into a mold in a state in which a cast pin is provided in a mold including a sand mold and vibrating the cast pin at 100 Hz or higher while cooling the cast pin. Proposed.

JP 2000-102850 A JP 2004-202539 A Japanese Patent Laid-Open No. 10-113758 JP 2008-229638 A Japanese Patent Application Laid-Open No. 07-40028 JP 2000-42707 A

However, since all of the above Patent Documents 1 to 5 are based on die-casting, and it is necessary to pour the molten metal under high pressure, a very large pressure-resistant mold and an apparatus for injecting and injecting molten metal at high pressure Need.
In the above-mentioned patent document, it is difficult to open a large number of through holes because there is a possibility that a long hole exceeding 100 mm is opened or the hole is crushed. The degree is low.
Furthermore, in the state where the core pin is previously arranged in the mold, the core pin may be deformed by the cast material to be injected. Moreover, when there are many cast pins or the space | interval between cast pins is narrow, a hot-water flow and a hot-water supply will be inhibited, and it will become difficult to produce a healthy product. For this reason, it is usually necessary to insert the cast pin after filling the casting material. In the post-insertion method, however, it is difficult to insert a thin core pin because it tends to buckle.
In addition, since a cast product having a thickness in the mold opening direction cannot be produced by die casting, the size and shape of the cast product that can be produced are also limited.

For Patent Document 6, a cooling mechanism for the core pin is necessary, and the core pin becomes expensive. Further, since a cooling mechanism is required, a cast pin having a small diameter cannot be used. The purpose is to homogenize the casting material around the core pin. Since the casting material is rapidly solidified by cooling, the hot water becomes worse and the distance between the core pins is not widened. I do not get. Therefore, there are significant restrictions on the size and interval of the holes to be formed. Furthermore, since the sand mold may collapse when vibration is applied, it is also difficult to improve the water temperature by vibrating the sand mold.

An object of the present invention is to provide a method for producing a perforated cast product capable of forming a through hole having a high degree of freedom with a simple apparatus and method.

The method for producing a perforated casting according to the present invention is as follows.
After pouring a molten metal of the casting material (except for Al-Mg alloy and Al-Si-Mg alloy) into the casting mold, the rod-shaped mold placed in the casting mold is pulled out, so that A method for producing a perforated cast product in which a hole is formed in a portion having the rod-shaped mold,
A pouring step of pouring the casting material at less than 10 MPa;
The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C.), the lower limit temperature for drawing is Tx (° C.), the melting point, the eutectic temperature or the peritectic temperature is the lower one, Ts (° C.)
The rod-shaped mold is pulled out of the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 0 <d <100), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
as well as,
Removing the cast from the casting mold;
Have

In the present invention, the eutectic temperature refers to the temperature of the eutectic point, and the peritectic temperature refers to the temperature of the peritectic point. The eutectic point and peritectic point of the present invention are the eutectic point or peritectic point that appears first in the direction in which the main component of the alloy decreases. Similarly, the solidus temperature is the temperature of the solidus that appears first in the direction in which the main component of the alloy decreases.

The casting material is an Al—Si based alloy or an Al—Cu based alloy, and the d may be 5 ° C.

The casting material is an Al—Mn alloy, and the d can be 90 ° C.

The casting material is a Cu—Zn alloy, and the d can be set to 50 ° C.

The casting material may be pure Al, and the d may be 115 ° C.

The casting material is pure Cu, and the d may be 18 ° C.

In addition, the method for producing a perforated casting according to the present invention is as follows.
A perforated casting in which a hole is formed in a portion of the casting material where the rod-shaped mold is present by pouring a molten Al-Mg alloy into the casting mold and then pulling out the rod-shaped mold disposed in the casting mold. A method for manufacturing a product,
A pouring step of pouring the casting material at less than 10 MPa;
The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C), the lower limit temperature for drawing is Tx (° C), and the solidus temperature is Ts (° C),
The rod-shaped mold is pulled out from the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 80 <d <110), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
as well as,
Removing the cast from the casting mold;
Have

In addition, the method for producing a perforated casting according to the present invention is as follows.
After pouring a molten Al—Si—Mg alloy into the casting mold, a hole is formed in the portion of the casting material where the rod-shaped mold is located by pulling out the rod-shaped mold disposed in the casting mold. A method for manufacturing a hole casting product,
A pouring step of pouring the casting material at less than 10 MPa;
The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C), the lower limit temperature for drawing is Tx (° C), and the solidus temperature or eutectic temperature is Ts (° C),
The rod-shaped mold is pulled out from the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 5 <d <110), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
as well as,
Removing the cast from the casting mold;
Have

In any method, the rod-shaped mold disposed in the casting mold has a longitudinal dimension of a (mm) and a cross-sectional area perpendicular to the longitudinal direction of b (mm ² ).
15 ≦ a / b, b ≦ 25
It is desirable that
The longitudinal dimension of the rod-shaped mold is the dimension of the portion inserted into the casting mold, but in the case of a casting mold divided into a plurality of sections, the total of the dimensions of each section is the longitudinal dimension of the rod-shaped mold.

The perforated casting according to the present invention is
A perforated cast product having holes in the cast product,
There is no abrupt change in tissue between the inner surface of the hole wall of the hole and the inside of 1 mm from the inner surface.

The hole has a longitudinal dimension of a (mm) and a cross-sectional area perpendicular to the longitudinal direction of b (mm ² ).
15 ≦ a / b, b ≦ 25
It can be.

The cast product is Al—Si, and Si ≧ 15% by mass.

The casting is Al—SiC _p , and SiC _p ≧ 10% by volume.

According to the method for manufacturing a perforated cast product according to the present invention, the rod-shaped mold is pulled out within the range of the temperature Tp (° C.) defined above, or the hole diameter is expanded within the temperature range of Tp (° C.). By pulling out the rod-shaped mold after starting the diameter, the trace of the rod-shaped mold being pulled out remains as a hole, so that a cast product with a hole can be easily produced.
In addition, the diameter, number, arrangement, depth, etc. of the holes can be easily adjusted by appropriately adjusting the thickness, number, arrangement, and penetration length of the rod-shaped mold provided in the casting mold.
Further, the present invention can be applied to a wide range of metals such as aluminum having a relatively low melting point, an aluminum alloy, a composite material having an aluminum base as a matrix, copper having a high melting point, and a copper alloy as a casting material.
Since the obtained perforated casting product is determined to be a simple casting mold and a rod-shaped mold, the width, length, size and shape in the height direction can be freely made. It can be suitably used for heat sinks, shock absorbing materials, sound absorbing materials, lightweight materials, and the like.
According to the method for manufacturing a perforated cast product according to the present invention, pouring into a casting mold can be performed under a low pressure of less than 10 MPa. It can be simplified and a perforated cast product can be obtained at low cost. In particular, as the casting mold, a simple mold having an open upper surface can be used, so that the mold cost is low.
In view of the above, the apparatus is inexpensive.
Moreover, the apparatus can be further simplified by pouring the molten metal directly into the casting mold from the crucible.
Further, even for an alloy such as Al—SiC _p that is difficult to pass through with a drill or the like, a perforated cast product can be easily manufactured.

FIG. 1 is a perspective view of a perforated cast product of the present invention. FIG. 2 is a perspective view showing a state in which the rod-shaped mold is removed from the casting mold for producing the perforated cast product of the present invention. FIG. 3 is a cross-sectional view showing a state in which a casting material is poured into the casting mold. FIG. 4 is a cross-sectional view showing a state where the rod-shaped mold is pulled out from the casting mold after pouring. FIG. 5 is a diagram showing a range of the temperature Tp (° C.) when the drawing step is performed without expanding the diameter and when the expansion is started in the hypoeutectic of the Al—Si binary alloy. FIG. 6 is a diagram showing a range of temperature Tp (° C.) when the drawing step is performed without expanding the diameter and when the expansion is started in the hypereutectic of the Al—Si binary alloy. FIG. 7 is a diagram showing a temperature range in which the rod-shaped mold can be drawn after the diameter of the Al—Si binary alloy is expanded in the temperature range indicated by the shaded area A in FIG. FIG. 8 is a diagram showing a range of temperature Tp (° C.) when the drawing step is performed without expanding the diameter of the Al—Cu binary alloy. FIG. 9 is a diagram showing a range of the temperature Tp (° C.) in the case where the drawing step is performed without expanding the diameter of the Al—Mn binary alloy. FIG. 10 is a diagram showing a range of the temperature Tp (° C.) when the drawing step is performed without expanding the diameter of the Cu—Zn binary alloy. FIG. 11 is a diagram showing a range of the temperature Tp (° C.) when the drawing step is performed without expanding the diameter of the Al—Mg binary alloy. FIG. 12 is a diagram showing a range of temperature Tp (° C.) when the drawing step is performed without expanding the diameter of the Al—Si—Mg ternary alloy (however, the Al—Si binary alloy is shown). . FIG. 13 is an enlarged photograph of the holes formed in the perforated casting formed in Al-6% Si. FIG. 14 is a photograph of the end face of a perforated casting formed on Al-25% Si. FIG. 15 shows an example of a bar-shaped mold having a different shape. FIG. 16 is an end view of a perforated cast product produced using the rod-shaped mold of FIG. FIG. 17 is an explanatory view showing a cross-section of a casting mold in which a rod-shaped mold is inserted vertically. FIG. 18 is an explanatory view showing a cross section of a casting mold partitioned into a plurality of parts by a partition plate. FIG. 19 is an explanatory view showing a cross section of an electric furnace for continuously carrying out the present invention. FIG. 20 is a cross-sectional view along a rod-shaped mold showing another embodiment of the casting mold. FIG. 21 is a cross-sectional view of the casting mold of FIG. 20 cut through the mounting bolt and the rod-shaped mold for the sake of explanation. FIG. 22 is an explanatory view showing a state in which vibration or the like is applied to the casting mold shown in FIGS. 20 and 21. FIG. 23 is a photograph of the end face of the perforated cast product produced as described in Example 1. FIG. 24 is a photograph of the end face of the perforated cast product produced in the manner of Example 2. FIG. 25 is a photograph of the end face of the perforated casting produced in the manner of Example 3. FIG. 26 is an enlarged photograph of the holes indicated by the circled numbers 1, 5 and 9 in FIG. FIG. 27 is a photograph of the end face of the perforated casting produced in the same manner as in Example 4. FIG. 28 is an enlarged photograph of the holes indicated by the circled numbers 1 to 3 in FIG. FIG. 29 is a photograph of the end face of the perforated cast product produced in the manner of Example 5. FIG. 30 is an overall photograph of a perforated cast product produced according to the procedure of Example 5. FIG. 31 is a photograph of the end face of the perforated cast product produced in the manner of Example 6. FIG. 32 is a photograph of the end face of the perforated casting produced in the same manner as in Example 7. FIG. 33 is a photograph of the end face of the perforated casting produced in the manner of Example 8. FIG. 34 is a photograph of the end face of the perforated casting produced in the same manner as in Example 9. FIG. 35 is a photograph of the end face of the perforated cast product produced in the manner of Example 10. FIG. 36 is a photograph of the end face of a perforated cast product produced in the manner of Example 11. FIG. 37 is a photograph of the end face of the perforated cast product produced in the manner of Example 12. FIG. 38 is a photograph of the end face of the perforated cast product produced in the manner of Example 13. FIG. 39 is a photograph of the end face of the perforated casting product created in the manner of Example 14. FIG. 40 is a photograph of the end face of the perforated cast product created in the manner of Example 15.

The perforated cast product (10) of the present invention is one in which one or a plurality of through holes (12) or a bottomed hole is formed in the longitudinal direction as shown in FIG.

The perforated cast product (10) of the present invention has one or more holes (12) formed therein, has a large specific surface area, and is lightweight, so that it can be used as a heat radiating member for CPUs, machine tools, electric vehicles and the like. It can be used for heat sinks used, shock absorbing materials for vehicles, sound absorbing materials, lightweight materials, and the like.

Casting materials used for the perforated casting product (10) having the above-described structure are aluminum, Al—Si alloy, Al—Mg alloy, Al—Cu alloy, Al—Mn alloy, Al—Si—Mg alloy. aluminum alloys such as, an aluminum group, such as Al-SiC _p can be exemplified composite material whose matrix, copper, copper alloys such as Cu-Zn alloys containing brass, magnesium, magnesium alloys. Of course, it is not limited to these materials.

The perforated casting product (10) of the present invention can be produced using a casting mold (20) having an open upper surface as shown in FIG. Note that the pouring can be performed not only under normal pressure but also under reduced pressure, and further under a pressure of less than 10 MPa. When casting is performed under reduced pressure or under pressure, the casting mold (20) may be accommodated in the cavity. The present invention can be produced using a very simple apparatus as compared with the above-described foaming method or die casting, which is usually performed in a sealed space under a pressure of 50 MPa or more.

More specifically, as shown in FIG. 2, the casting mold (20) has a casting portion (22) formed in a substantially rectangular parallelepiped shape in the drawing, and the upper surface of the casting portion (22) is open. Yes.

The rod-shaped mold (30) is inserted from the side into the cast-in part (22). The rod-shaped mold (30) can be formed so as to be able to penetrate the casting portion (22), and the casting mold (20) has an insertion hole (24) that matches the shape of the rod-shaped mold (30). .

The rod-shaped mold (30) can be exemplified by a rigid rod, a wire such as a piano wire, a needle-shaped material, a pipe and the like. Further, a taper can be provided at the tip in the insertion direction of the casting mold (20) or the whole. Furthermore, a curved shape such as an arc shape may be used as long as it can be extracted, but a straight shape is preferable because it can be easily extracted. The rod-shaped mold preferably has a portion inserted into the casting mold, a protruding portion, a grip margin for pulling out from the casting mold, and a member for gripping. Furthermore, in order to facilitate the diameter expansion and drawing, it is preferable that the end of the rod-shaped mold is bent in an L shape.

The rod-shaped mold (30) is made of a material that does not react with the casting material used. Examples of the rod-shaped mold (30) include metals such as iron-based materials having a melting point higher than that of the casting material (40), or ceramics. It is preferable to select an appropriate combination of the linear expansion coefficients of the rod-shaped mold (30) and the casting material (40). If necessary, the rod-shaped mold (30) can be coated or sprayed with a release agent such as boron nitride (boron nitride), graphite (graphite), or ceramic.

In the illustrated embodiment, there are four rod-shaped molds (30), each having a circular cross section. The number, diameter, and length of the rod-shaped mold (30) can be appropriately set according to the required number of holes (12), the inner diameter, and the depth. The rod-shaped mold (30) can be, for example, a wire having a diameter of 8 mm or less, a needle-shaped material having a diameter of 1 mm or less, which is impossible with a cast pin, and a length of 50 mm or more.

The rod-shaped mold used is 15 ≦ a / b, b ≦ b, where the longitudinal dimension of the portion inserted into the casting mold is a (mm) and the cross-sectional area perpendicular to the longitudinal direction is b (mm ² ). Even a thin rod-shaped mold such as 25 can be suitably implemented.

Such a small-diameter long hole could not be formed by drilling, bending or bending of the drill in drilling operations. Furthermore, with a material having high hardness such as Al—Si or Al—SiC _p , the drill was worn out, and thus a long hole could not be formed. In the processing by laser or water jet, there are problems that the length of the hole is limited, the inner wall of the hole is roughened, and it is difficult to control the cross-sectional shape in the longitudinal direction of the hole. For this reason, the application of the present invention is suitable.

In particular, the production method of the present invention is suitable for forming narrow and long holes (12) that could not be established conventionally. For example, when the diameter is 0.5 mm, the length is 50 mm or more. When the diameter is 5 mm, the length is 500 mm. These have a smooth inner surface and no deformation of the holes.
In principle, the hole diameter and the length are not limited as long as the rod-shaped mold can be pulled out, and the rod-shaped mold has enough strength to be pulled out. Desirably, the hole (12) to be opened has 15 ≦ a / b and b ≦ 25 when the longitudinal dimension is a (mm) and the cross-sectional area perpendicular to the longitudinal direction is b (mm ² ). is there.

In the figure, the rod-shaped mold (30) passes through the cast-in part (22), and the hole (12) formed is also a through-hole, but the rod-shaped mold (30) has a length up to the middle of the cast mold (20). By doing so, a bottomed hole can be formed.

It is desirable to arrange a heat insulating material (28) on the inner surface of the casting mold (20) so as to surround the casting portion (22). As the heat insulating material (28), for example, fibers in which alumina and silica or the like as main components are processed into a sheet-like, cotton-like, plate-like, or blanket-like woven or non-woven fabric can be exemplified.

By arranging the heat insulating material (28), it is possible to prevent rapid cooling due to the outside air of the casting material (40) at the time of casting, and when inserting the rod-shaped mold (30) from the side, the heat insulating material ( 28), during the pouring, after pouring, and even after pulling out the rod-shaped mold (30), the casting material (40) from the insertion hole (24) or the gap between the insertion hole (24) and the rod-shaped mold (30). ) Can be prevented from spilling.

The rod-shaped mold (30) may be inserted into the casting mold (20) before pouring, or may be inserted into the casting mold (20) after pouring. When inserting after pouring, the hole diameter is limited because the thin rod-shaped mold is easily deformed during insertion. Therefore, when forming a thin hole, it is desirable to insert it into the mold before pouring. In the following, an embodiment in which the rod-shaped mold (30) is inserted into the casting mold (20) before pouring will be described.

As shown in FIG. 3, with the rod-shaped mold (30) inserted into the casting mold (20), the molten casting material (40) is poured into the casting part (22). The pouring step can be performed using a crucible (42) as shown.

In addition, it is preferable to perform a flow promotion step that promotes the hot water flow between the rod-shaped molds (30) during and / or after pouring. The flow promotion step can be performed, for example, by applying vibration, swinging, rotation, and / or impact to the rod-shaped mold (30) and / or the casting mold (20). In particular, when the hole is long, or when the distance between the rod-shaped mold and the rod-shaped mold or the distance between the rod-shaped mold and the casting mold is narrow, it is important to promote the hot water run. For this reason, hot water can be further promoted by applying vibration, swinging, rotation, and / or impact to the casting mold (20) itself.

In order to measure the temperature in the casting part (22) of the casting material (40), a temperature sensor such as a thermocouple (50) (see FIG. 3) can be arranged in the casting part (22). It is desirable to arrange the temperature sensor so that the temperature in the vicinity of one or more rod-shaped molds (30) can be measured. Of course, when the manufacturing operation of the perforated cast product (10) is continuously performed, once the temperature is measured, the temperature measurement can be omitted in the subsequent operation.

It should be noted that the casting mold (20) may be provided with a temperature control function such as a heating mechanism or a cooling mechanism to control the temperature management and cooling rate of the casting material (40).

After the pouring, cooling is performed, and when the temperature of the casting material (40) falls within a temperature range in which holes can be formed, which will be described later, as shown in FIG. 4, a drawing step of pulling out the rod-shaped mold (30) from the casting material (40) To do. The cooling can be slow cooling or natural cooling so that the time width of the extraction timing can be taken, and the crystal can be enlarged. On the other hand, if it is cooled rapidly during cooling, the growth of the crystal structure can be suppressed. A cooling rate suitable for the production method of the present invention is 0.05 ° C./second to 500 ° C./second.

Also, if the entire casting mold is preheated with an electric furnace or the like before pouring (for example, 500 ° C.), the cooling rate can be suppressed, so the time width of the drawing timing can be taken and the hot water is also improved.

As will be described later, the drawing step may be performed by heating the once solidified casting material (40) to the following temperature range in which holes can be formed.

In the drawing step, the rod-shaped die (30) is pulled out from a state of standing in the casting material, and the rod-shaped die (30) is rotated, eccentrically rotated, vibrated, etc. so that the hole diameter formed in the casting material is expanded. There are two ways to pull out the rod-shaped mold (30) after performing the diameter expansion step.

First, in the case of a drawing step in which the rod-shaped die (30) is pulled out from a state of being left standing in the casting material, the temperature of the casting material in the vicinity of the rod-shaped die (30) is Tp (° C.), and the rod-shaped die (30) is being drawn or The upper limit temperature at which the hole wall does not collapse after drawing and the liquid phase oozes into the hole and does not fill the hole is Th (° C), the lower limit temperature for drawing is Tx (° C), the melting point, the eutectic temperature or If the lower peritectic temperature is Ts (° C.), Tx ≦ Tp ≦ Th (however, Tx = Ts−d, 0 <d <100). Pull out the mold (30). Note that d is determined by the composition of the casting material.

Further, in the drawing step of drawing the rod-shaped die (30) after the diameter-expanding step, the diameter-expanding step is performed by setting the temperature of the casting material in the vicinity of the rod-shaped die (30) to Tp (° C.) and the rod-shaped die (30). The upper limit temperature at which the hole wall does not collapse during or after drawing and the liquid phase leaches into the hole and does not fill the hole is set to Th (° C), the lower limit temperature for drawing is set to Tx (° C), the melting point, When Ts (° C.) is the lower one of the crystallization temperature and the peritectic temperature, the temperature starts in a temperature range where Ts <Tp ≦ Th. After completion of the diameter expansion step, the rod-shaped mold (30) may be pulled out from the casting material. Since the hole is formed by the diameter expansion step, the temperature at which the rod-shaped mold (30) is extracted may be extracted even near room temperature depending on the casting material and the diameter expansion method, as shown in FIG. is there.

The temperature Tp (° C) varies depending on the alloy composition. Hereinafter, the casting material having the main composition and the temperature Tp (° C.) which is the temperature range in which the hole can be formed will be described.

<Al-Si binary alloys>
FIG. 5 shows an equilibrium diagram of an Al—Si based binary alloy with a temperature range in which the Al—Si based binary alloy can be drilled superimposed. As can be seen with reference to FIG. 5, the Al—Si binary alloy has a eutectic point when the Si content is about 12% by mass. A composition in which the Si content, which is the main component of the alloy, is smaller than the eutectic point is called hypoeutectic, and a composition having a large Si content is called hypereutectic.

In the range of hypoeutectic and hypereutectic, both become semi-solid (quasi-liquid phase) across the liquidus from the liquid phase in the molten state. The temperature crossing the liquidus is the liquidus temperature Tl (° C.).

The Al—Si binary alloy is further cooled, and when the Si content is less than about 1.6% by mass, it crosses the solidus and becomes an α phase. When the amount of Si is more than about 1.6% by mass, a (α + β) phase is formed across the eutectic isotherm.

In the Al—Si based binary alloy, the temperature Tp (° C.) of the temperature range in which the hole can be formed in the drawing step is indicated by the hatched portion A in FIG. 5 in the hypoeutectic range where the Si amount is smaller than the eutectic point. The region is Tx ≦ Tp ≦ Th. Here, Th can be approximated by Th = 660-9.5x (° C.) when the Si content is x%. Th ≦ Ts + 5 ° C. and the liquidus temperature near the eutectic point Below Tl (° C.), Tx is Ts (eutectic temperature: 577 ° C.) − D (= 5 ° C.).

With respect to the Al—Si based binary alloy, various components and the drawing temperature were changed, and the rod-shaped mold (30) was drawn to examine whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 5, those with through holes formed are marked with a circle, and those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross.
Referring to FIG. 5, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion A, and otherwise the through hole cannot be formed.

On the other hand, in the range where the Al—Si binary alloy is hypereutectic, that is, in the composition where Si exceeds about 12% by mass, Ts−5 ° C. ≦ Tp ≦ Ts + 5 ° C. and the liquidus temperature Tl (° C.) or less. A range indicated by a hatched portion A ″ in FIG. 6 is a temperature range in which holes can be formed.

In either case, the casting material changes from a molten phase to a semi-solidified state as it approaches the solidus from the liquidus, and solidifies when it exceeds the solidus, but is slightly soft under the solidus. The rod-shaped mold (30) can be pulled out.

In the above-described temperature range in which holes can be formed (shaded portion A in FIG. 5 and hatched portion A ″ in FIG. 6), the casting material 40 is semi-solidified or solidified but still in a soft state. As shown in FIG. 4, when the rod-shaped mold (30) is pulled out, the trace of the rod-shaped mold (30) remains as a hole (12).

In the Al—Si binary alloy, even when the solidus or eutectic temperature Ts (° C.) is less than −5 ° C., the temperature Tp (° C.) that is the temperature range in which the hole can be formed is By performing the diameter expansion step, the rod-shaped mold (30) can be pulled out in the range of the hatched portion B shown in FIG. When the diameter expansion step is performed at the temperature Tp (° C.) shown in FIG. 5, the rod-shaped mold (30) can be pulled out at the temperature Tp (° C.) or lower temperature, as shown by the circle in FIG. It can be seen that the through hole was formed.
In this example, a rod-shaped die having a diameter of 2 mm and a casting die having a hole diameter of 3 mm through which the rod-shaped die passes were used, and the diameter was increased by rotating or swinging the rod-shaped die.

<Al-Cu binary alloy>
FIG. 8 shows an equilibrium diagram of an Al—Cu binary alloy with a temperature range in which the Al—Cu binary alloy can be formed overlapped. As can be seen with reference to FIG. 8, in the Al—Cu based binary alloy, the temperature Tp (° C.) of the temperature range in which the hole can be formed in the drawing step is Tx ≦ Tp ≦ Th indicated by the hatched portion D in FIG. It becomes an area. Here, Th can be approximated by Th = 660−5.1x (° C.) when the Cu content is x%, and in the vicinity of the eutectic point, Th ≦ Ts + 5 ° C. and the liquidus temperature Tl. (° C.) The following can be expressed by: Tx is Ts (eutectic temperature: 450 ° C.) − D (= 5 ° C.).

With respect to the above-mentioned Al—Cu based binary alloy, various components and the drawing temperature were changed, the rod-shaped mold (30) was drawn, and it was examined whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 8, those with through holes formed are marked with a circle, and those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross.
Referring to FIG. 8, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion D, and the through hole cannot be formed otherwise.

In addition, even in the Al—Cu binary alloy, by performing the diameter expansion step at the temperature Tp (° C.), the drawing step of the rod-shaped mold (30) can be performed at the temperature Tp (° C.) or lower. Can be implemented.

<Al-Mn binary alloy>
FIG. 9 shows an equilibrium diagram of an Al—Mn binary alloy with a temperature range in which the Al—Mn binary alloy can be formed being overlapped. As can be seen with reference to FIG. 9, in the Al—Mn based binary alloy, the temperature Tp (° C.) of the temperature range in which the hole can be formed in the drawing step is Tx ≦ Tp ≦ Th indicated by the hatched portion E in FIG. It becomes an area. Here, Th is 660 ° C. which is the melting point of Al, and Tx is Ts (= 658.5 ° C.) − D (= 90 ° C.) = 568.5 ° C.

With respect to the Al—Mn binary alloy, the various components and the drawing temperature were changed, the rod-shaped mold (30) was drawn, and it was examined whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 9, those with through holes formed are marked with a circle, and those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross.
Referring to FIG. 9, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion E, and otherwise the through hole cannot be formed.

Even in the Al—Mn binary alloy, the diameter expansion step is performed at the temperature Tp (° C.), so that the rod-shaped mold (30) can be pulled out at the temperature Tp (° C.) or lower. Can be implemented.

<Cu-Zn binary alloys>
FIG. 10 shows the equilibrium state diagram of a Cu—Zn binary alloy with the temperature range in which the Cu—Zn binary alloy can be formed overlapped. As can be seen with reference to FIG. 10, in the Cu—Zn based binary alloy, the temperature Tp (° C.) in the temperature range in which the hole can be formed in the drawing step is Tx ≦ Tp ≦ Th indicated by the hatched portion F in FIG. It becomes an area. Here, Th can be expressed as Th = 1083-4x (° C.) where the Zn content is x%, and Tx is Ts (= 952 ° C.) − D (= 50 ° C.). .

With respect to the above Cu—Zn-based binary alloy, various components and the drawing temperature were changed, and the rod-shaped mold (30) was drawn to examine whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 10, those with through holes formed are marked with a circle, and those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross.
Referring to FIG. 10, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion F, and otherwise the through hole cannot be formed.

Even in the Cu—Zn binary alloy, the diameter expansion step is performed at the temperature Tp (° C.), whereby the drawing step of the rod-shaped mold (30) can be performed at the temperature Tp (° C.) or lower. Can be implemented.

<Pure metal>
In the case of pure Al, the temperature Tp (° C.) in the temperature range in which the hole can be formed in the drawing step is a region of Tx ≦ Tp ≦ Th indicated by a line A ′ in FIG. Here, Th is a melting point of 660 ° C., and Tx is Ts (= 660 ° C.) − D (= 115 ° C.) = 545 ° C.

In the case of pure Cu, the temperature Tp (° C.) in the temperature range in which the hole can be formed in the drawing step is a region of Tx ≦ Tp ≦ Th indicated by a line E ′ in FIG. Here, Th is a melting point of 1083 ° C., and Tx is Ts (= 1083 ° C.) − D (= 18 ° C.) = 1065 ° C.

With respect to the pure Al and pure Cu, the rod-shaped mold (30) was pulled out at different pulling temperatures, and it was examined whether or not through holes were formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results for pure Al are shown in FIG. 5, and the results for pure Cu are shown in FIG. In FIG. 5 and FIG. 10, those with through holes formed are marked with a circle, those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross. .
Referring to FIGS. 5 and 10, it can be seen that the through hole was formed at the temperature Tp (° C.) indicated by the hatched portion E, and the through hole could not be formed otherwise.

For pure Al and pure Cu, the step of pulling out the rod-shaped mold (30) is performed at the temperature Tp (° C.) or lower by performing the diameter expansion step at the temperature Tp (° C.). Can do.

<Al-Mg based binary alloy>
FIG. 11 shows an equilibrium diagram of an Al—Mg-based binary alloy with a temperature range in which the Al—Mg-based binary alloy can be formed overlapped. As can be seen with reference to FIG. 11, in the Al—Mg based binary alloy, the temperature Tp (° C.) of the temperature range in which the hole can be formed in the drawing step is Tx ≦ Tp ≦ Th indicated by the hatched portion C in FIG. It becomes an area. Here, Th can be approximated by Th = 660-9.7x (° C.) when the Mg content is x%, and Tx is Ts (solidus temperature) −d (= 80 ° C <d <110 ° C)).

With respect to the Al—Mg-based binary alloy, various components and the drawing temperature were changed, and the rod-shaped mold (30) was drawn to examine whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 11, those with through holes formed are marked with a circle, and those with no through holes formed, or those with the rod-shaped mold (30) not pulled out are marked with a cross.
Referring to FIG. 11, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion C, and otherwise the through hole cannot be formed.

Even in the Al—Mg binary alloy, the diameter expansion step is performed at the temperature Tp (° C.), so that the rod-shaped mold (30) can be pulled out at the temperature Tp (° C.) or lower. Can be implemented.

<Al-Si-Mg ternary alloy>
FIG. 12 shows the temperature range in which Al—Si—Mg ternary alloy can be formed.
The eutectic temperature TEu of a multi-element alloy containing Al as a main component and containing Si is calculated by the B. R. Krohn equation (Modern Casting magazine 75 (1985) 21., Japanese Patent Laid-Open No. 2001-99797).

Formula 1:
TEu = 577-12.5 × (4.43 (% Mg) +1.43 (% Fe) +1.93 (% Cu) +1.7 (% Zn) +3.0 (% Mn) +4.0 (% Ni)) /% Si

According to the above formula 1, the AC4C alloy has TEu (Ts) = 572 ° C., and 6061 (JIS standard: A6061) has TEu (Ts) = 458 ° C.
With regard to the Al—Si—Mg ternary alloy, pure Al can be drawn up to 545 ° C., and when the eutectic temperature is higher than the temperature at which the pure Al can be drawn, the Al—Si type Tx = Ts ( The eutectic temperature) -d is applicable, and when the eutectic temperature of the alloy is lower than the temperature at which the pure Al can be drawn, the Al-Mg-based formula Tx = Ts (solidus temperature) -d can be applied. .

Therefore, in AC4C, Ts (572 ° C.)> 545 ° C., and by applying an Al—Si type equation, Tx = Ts (eutectic temperature) −d = 572-27 = 545 ° C. 6061 is Ts (458 ° C.) <545 ° C., and Al—Mg system is applied, and Tx = Ts (solidus temperature) −d = 582-55 = 527 ° C.

With respect to the Al—Si—Mg ternary alloy, the various components and the drawing temperature were changed, the rod-shaped mold (30) was drawn, and it was examined whether or not a through hole was formed. The rod-shaped mold (30) is made of stainless steel having a total length of 100 mm (cast mold inner dimension: 50 mm) and a circular section of 2 mm. The results are shown in FIG. In FIG. 12, a circle mark is given to those in which the through holes are formed, and a cross mark is given to those in which the through holes are not formed or those in which the rod-shaped mold (30) has not been pulled out.
Referring to FIG. 12, it can be seen that the through hole is formed at the temperature Tp (° C.) indicated by the hatched portion E, and otherwise the through hole could not be formed.

In the Al—Si—Mg ternary alloy, the rod-shaped mold (30) is drawn at the temperature Tp (° C.) or lower by performing the diameter expansion step at the temperature Tp (° C.). Steps can be performed.

The same temperature range in which holes can be made is also applied to the metals exemplified above, pure metals other than alloys, binary alloys, and ternary alloys or more. If the casting material is an Al—Si based binary alloy, it becomes hard when Si is contained, so if Si ≧ 15% by mass, the casting material is a composite with an aluminum group such as Al—SiC _p as a matrix. In the case of a material, since SiC _p is hard, when SiC _p is 10% by volume or more, drilling with a drill or the like becomes difficult, and the usefulness of the present invention increases.

In the drawing step, in FIG. 4, the upper rod-shaped mold (30) is pulled first, but this is because the heat-insulating material (28) is arranged and the casting mold (20) with the upper surface opened from above. This is because cooling begins.

When the rod-shaped mold (30) is pulled out at a temperature exceeding the above temperature range Tp (° C.), the shape of the hole (12) is crushed by the liquid phase casting material (40) that has oozed out. ) Is not formed. On the other hand, at a temperature lower than the above temperature range Tp (° C.), the casting material becomes solidified due to solidification, so that the drawing resistance becomes high. Therefore, if the diameter expansion step is not performed in the temperature range Tp (° C.), Can not be done.

Pulling out the rod-shaped mold (30), further cooling the casting material (40) naturally, and then removing it from the casting mold (20) to obtain a cast product (10) having a hole (12) as shown in FIG. Can do. The holes (12) of the casting (10) obtained as shown in FIGS. 13 and 14 have a structure in the shape, size, and distribution of crystals between the inner surface of the hole wall and the inside of 1 mm. There is no sudden change. This is because the structure grows evenly as a result of cooling the casting material (40) during the formation of the holes (12). Moreover, the grown dendrite is not cut.
On the other hand, when a hole is formed by drilling, laser, or water jet processing, the structure of the inner surface of the hole wall breaks or melts and re-solidifies. There are sudden changes in the organization.

The cast product (10) having the obtained hole (12) is used after being subjected to machining or grinding as necessary.

A modification of the method for producing the perforated cast product (10) of the present invention will be described below.

FIG. 15 is a different embodiment of the rod-shaped mold (30), and FIG. 15 (a) is an embodiment in which a plate material having a cross section bent at a substantially right angle is adopted as the rod-shaped mold (30), and FIG. FIG. 15 (c) is an embodiment in which a hollow pipe is used as the rod-shaped die (30), and the heat capacity compared to the solid state. Can be reduced.

FIG. 16 shows a cast product (10) having a hole (12) produced using the rod-shaped mold (30). FIG. 16 (a) shows a cast product (10) produced by adopting the rod-shaped mold (30) of FIG. 15 (a), and the hole (12) is bent at a substantially right angle. By forming the hole (12) having such a shape, it is possible to control plasticity and buckling deformation in the direction of shock absorption in applications such as shock absorbers. Similarly, FIGS. 16 (b) and 16 (c) show a cast product (10) produced by employing the rod-shaped mold (30) shown in FIGS. 15 (b) and 15 (c), respectively. .

According to the present invention, there is an advantage that the degree of freedom in design such as the number, shape, diameter and depth of the holes (12) can be increased as much as possible.

In the above embodiment, the rod-shaped mold (30) is arranged in advance in the casting mold (20), but after the pouring step, the rod-shaped mold (30) until the casting material (40) reaches the above temperature range. May be inserted through the insertion hole (24).
In this case, the rod-shaped mold (30) is preferably preheated in order to prevent solidification due to rapid cooling of the casting material (40). In order to improve the temperature of the casting material (40), it is more desirable that the rod-shaped mold (30) and / or the casting mold (20) is subjected to vibration, swinging, rotation and / or impact.

Also, when the diameter expansion step is performed, the rod-shaped mold (30) is rotated, eccentrically rotated, vibrated, reciprocated, or given an impact within the temperature Tp (° C.) range. As a result, solidification proceeds in a state where the inner diameter of the hole (12) to be opened is enlarged, so that the rod-shaped mold (30) can be easily pulled out.

FIG. 17 shows an embodiment in which the rod-shaped mold (30) whose upper surface is opened is inserted from the upper side of the casting mold (20). As shown in the figure, the rod-shaped mold (30) has a proximal end projecting downward from a plate-shaped holding member (32).
In the present embodiment, after pouring the casting material (40), as shown in FIGS. 17 (a) to 17 (c), the rod-shaped mold (30) is cast in the state of the liquidus temperature Tl (° C.) or higher. ) Lower the holding member (32) so as to enter. At this time, in order to improve the hot water flow between the rod-shaped molds (30), it is desirable to vibrate, swing, rotate and / or impact the rod-shaped mold (30).
Also, as shown in FIG. 17 (c), after the rod-shaped mold (30) reaches the bottom of the casting mold (20), the molten metal can be supplied while reducing the pressure in the casting portion (22) by a suction pump (not shown). By doing so, the amount of hot water between the rod-shaped molds (30) can be improved.

After the rod-shaped mold (30) is inserted into the casting material (40), when the temperature Tp (° C.) of the casting material (40) in the vicinity of the rod-shaped mold (30) reaches the temperature range similar to the above, the rod-shaped mold (30 ) May be pulled out together with the holding member (32).

FIG. 18 shows that a plurality of partition plates (60) are inserted into the casting mold (20), and the rod-shaped mold (30) is inserted into the insertion holes (24) and (62) penetrating the casting mold (20) and the partition plate (60). Is to be inserted. The casting material (40) is poured into each section partitioned by the partition plate (60), and the rod-shaped mold (30) is pulled out at the above-mentioned temperature range. A hole can be opened.

Further, in the above embodiment, the rod-shaped mold (30) is pulled out in the cooling process of the casting material (40) after pouring. However, for example, after solidifying the stick-shaped mold (30) while being pierced, the rod-shaped mold (30) can be pulled out by heating again to raise the temperature to the above temperature range.

FIG. 19 shows an electric furnace (70) having a heating mechanism (72) such as a heater, and in the electric furnace (70), a cast material (40) after pouring or a solidified cast material (40) is placed. A conveyor (74) for conveying the contained casting mold (20) is provided. By placing the casting mold (20) containing the casting material (40) from the upstream side on the conveyor (74), the casting material (40) is heated by the heating mechanism (72) until it reaches the downstream side, as described above. The rod-shaped mold (30) may be pulled out when the temperature reaches the temperature range and reaches the downstream side of the conveyor (74) (see the casting mold (20) at the right end in the figure). According to this, there is an advantage that the casting material (40) can be soaked and the drawing timing of the rod-shaped mold (30) can be easily determined. Further, the production efficiency of the perforated casting product (10) can be increased as much as possible by flowing the casting mold (20) containing the casting material (40) continuously onto the conveyor (74).

It should be noted that the casting material (40) is subjected to vibration while being conveyed by the conveyor (74), so that the formation of nests in the casting material (40) is also suppressed. Of course, this effect can be further enhanced by providing a mechanism for vibrating the casting mold (20) during conveyance by the conveyor (74).

20 to 22 show different embodiments of the casting mold (20). As shown in FIGS. 20 and 21, the casting mold (20) includes a groove mold (26) bent in a U-shape and a pair of horizontal molds (27) that close the groove mold (26) from both sides. Thus, the horizontal molds (27) can be assembled by connecting the mounting bolts (29). The horizontal mold (27) has one or more insertion holes (24) opened therethrough, and the assembled casting mold (20) has one or more rod-shaped molds (30 through the insertion hole (24). ) Can be inserted. The interior of the casting mold (20) is covered with a heat insulating material (28).

As shown in FIG. 22, the casting material (40) is poured from the crucible (42) into the casting mold (20). At this time, as shown, vibration, rotation, and impact are applied to the rod-shaped die (30), and the rod-shaped die (30) is reciprocated in the longitudinal direction to promote the hot water around the rod-shaped die (30). can do.

Further, as shown in FIG. 22, a direct impact may be applied to the casting mold (20) to promote the hot water around the rod-shaped mold (30).
Similarly, vertical and horizontal vibrations may be applied to the table (80) on which the casting mold (20) is placed to promote the hot water around the rod-shaped mold (30).
Furthermore, by swinging or rotating the base (80) on which the casting mold (20) is placed, the casting mold (20) is swung, thereby promoting the hot water around the rod-shaped mold (30). You can also.

A perforated cast product was produced by the production method of the present invention, and the end face was polished and a photograph was taken.
Regarding the experimental conditions listed below, “casting mold temperature” is the temperature at which the casting mold was preheated, “experimental sample” is the composition of the casting material,% means mass%, for example, Al-5% Si The notation means Si 5% by mass, the balance Al and unavoidable impurities. When the casting material has a material symbol, the material symbol is described first. The “liquidus temperature Tl (° C.)” and “solidus temperature Ts (° C.)” indicate the liquidus temperature and solidus temperature of each casting material.

Furthermore, “pouring temperature” means the temperature when the molten metal of the casting material is taken out of the electric furnace, and “bar-shaped mold” means the material and diameter of the rod-shaped mold. “Drawing temperature Tp (° C.)” indicates the temperature of the casting material when the rod-shaped mold is drawn, and for the various changes in the drawing temperature Tp (° C.), the corresponding temperature is shown in circles. Yes.

<Example 1>
Casting mold temperature: 500 ° C
Experimental sample: AC4CH (Al-6.5 to 7.5% Si-0.2% or less Fe-0.2% or less Cu-0.25 to 0.45% Mg)
Liquidus temperature (Tl): 610 ° C
Solidus temperature: 555 ° C
Eutectic temperature (Ts): 572 ° C
Hot water temperature: 800 ° C
Rod-shaped mold: diameter of 5 mm, hole length of stainless steel rod casting mold side plate having a total length of 100 mm (inner dimension of casting mold: 50 mm): diameter of 5.5 mm
Drawing temperature (Tp): 580 ° C

Implementation conditions Using an iron plate with a thickness of 3 to 5 mm, an iron bottom plate and upper and lower side plates are combined with left and right side plates with a 5.5 mm diameter hole penetrating a bar-shaped die at the corresponding position, and the upper part opens. A rectangular mold having a length of 50 mm, a width of 65 mm, and a depth of 40 mm is formed on the inner side, and an alumina / silica nonwoven fabric (isowool) is formed on the inner surfaces of the upper, lower, left and right side plates and the inner surface of the bottom plate. (Registered trademark) paper) 2 mm thick.
The alumina / silica non-woven fabric covering the holes was pierced into the holes of the left and right side plates in advance so that the other end of the rod-shaped mold protruded from the mold.

Next, AC4CH was melted in an electric furnace, the temperature of the molten metal in the electric furnace was measured, the molten metal at 800 ° C. was poured with a ladle, and poured from the upper surface opening of the mold. A temperature sensor terminal was installed in the vicinity of the rod-shaped mold in the molten metal in the mold and the temperature was measured. When the chamber was naturally cooled and the temperature in the vicinity of the rod-shaped mold reached 580 ° C., one end of the rod-shaped mold was grasped and pulled out by hand.

A photograph of the perforated cast product of Example 1 is shown in FIG. 23 (band saw cut surface). As can be seen with reference to the figure, it can be seen that the holes penetrating the cast product were formed in a staggered manner.

<Example 2>
The procedure was the same as in Example 1 except for the conditions described below.
After pouring, the mold was struck multiple times to give an impact, and the hot water was promoted to obtain a perforated material as shown in FIG.
Casting mold temperature: 500 ° C
Experimental sample: AC4C (Al-6.5 to 7.5% Si-0.55% or less Fe-0.25% or less Cu-0.2 to 0.45% Mg)
Liquidus temperature (Tl): 610 ° C
Solidus temperature: 555 ° C
Eutectic temperature (Ts): 572 ° C
Hot water temperature: 800 ° C
Rod type: 2 mm diameter, 100 mm overall length (50 mm in the casting mold inner dimension) stainless steel bar casting mold side plate hole diameter: 3 mm diameter
Drawing temperature (Tp): 580 ° C

A photograph of the perforated cast product of Example 2 is shown in FIG. As can be seen with reference to the figure, it can be seen that the holes penetrating the cast product were formed in a staggered manner.

<Example 3>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: 6061 (Al-0.4 to 0.8% Si-0.7% or less Fe-0.15 to 0.4% Cu-0.8 to 1.2% Mg)
Liquidus temperature (Tl): 652 ° C
Solidus temperature (Ts): 582 ° C
Hot water temperature: 680 ° C
Rod-shaped mold: Diameter of stainless steel wire casting mold side plate of 0.5 mm in diameter and 100 mm in total length (50 mm in casting mold dimensions): 3 mm in diameter
Drawing temperature (Tp): 605 ° C to 645 ° C every 5 ° C

A photograph of the perforated cast product of Example 3 is shown in FIG. 25 (polished surface). As can be seen with reference to the figure, it can be seen that holes were formed in the cast product within the above-mentioned temperature range of the drawing temperature (Tp). FIG. 26 is an enlarged view of the circled numbers 1, 5 and 9 in the hole of FIG. Referring to the figure, it can be seen that the roundness of the hole increases as the rod-shaped mold is pulled out at a temperature close to the solidus temperature Ts (° C.). Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 4>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: 6061 (Al-0.4 to 0.8% Si-0.7% or less Fe-0.15 to 0.4% Cu-0.8 to 1.2% Mg)
Liquidus temperature (Tl): 652 ° C
Solidus temperature (Ts): 582 ° C
Hot water temperature: 670 ° C
Rod-shaped mold: Diameter of stainless steel wire casting mold side plate of 0.5 mm in diameter and 100 mm in total length (50 mm in casting mold dimensions): 3 mm in diameter
Drawing temperature (Tp): 605 ° C

A photograph of the perforated cast product of Example 4 is shown in FIG. 27 (polished surface). As can be seen from the figure, it can be seen that a hole has been opened in the cast product. FIG. 28 is an enlarged view of the circled numbers 1, 2 and 3 in the hole of FIG. It can be seen that a hole with a high roundness is opened in all cases. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 5>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: AC4C (Al-6.5 to 7.5% Si-0.55% or less Fe-0.25% or less Cu-0.2 to 0.45% Mg)
Liquidus temperature (Tl): 610 ° C
Solidus temperature: 555 ° C
Eutectic temperature (Ts): 572 ° C
Hot water temperature: 800 ° C
Rod-shaped mold: outer diameter 6 mm, total length 600 mm (inside casting mold dimension 500 mm), 1 mm thick stainless steel pipe casting mold side plate hole diameter: 6.5 mm diameter
Drawing temperature (Tp): 555 ° C

In Example 5, the experiment was conducted with a perforated cast product having a cross section of 25 mm × 25 mm and a length of 500 mm, and a rod-shaped mold (pipe) arranged in the longitudinal direction of the perforated cast product. FIG. 29 shows an end face of the obtained perforated cast product, and FIG. 30 shows an overall appearance. As can be seen with reference to FIG. 29 (band saw cut surface), it can be seen that a hole could be opened even in a cast product having a length of 500 mm. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 6>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-25% Si
Liquidus temperature (Tl): 760 ° C
Eutectic temperature (Ts): 577 ° C
Pouring temperature: 780 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 1 mm and a total length of 100 mm (inside casting mold size: 50 mm).
Drawing temperature (Tp): 579 ° C

A photograph of the perforated cast product of Example 6 is shown in FIG. 31 (polished surface). As can be seen with reference to the figure, it can be seen that holes were formed in a staggered pattern in the cast product. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 7>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-3% Si
Liquidus temperature (Tl): 641 ° C
Eutectic temperature (Ts): 577 ° C
Pouring temperature: 700 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (inside dimension of casting mold: 50 mm) Hole diameter of casting mold side plate: diameter 3 mm
Drawing temperature (Tp): 580 ° C to 630 ° C every 10 ° C

A photograph of the perforated cast product of Example 7 is shown in FIG. As can be seen with reference to the figure, it can be seen that even if the drawing temperature Tp (° C.) was changed, a hole was formed in the cast product. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 8>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-1% Si
Liquidus temperature (Tl): 654 ° C
Solidus temperature: 611 ° C
Eutectic temperature (Ts): 577 ° C
Hot water temperature: 720 ° C
Bar-shaped mold: 2mm diameter, 100mm overall length (cast mold inner dimension 50mm) stainless steel rod coated with BN, end bent into an L shape, hole diameter of casting mold side plate: diameter 3mm
Drawing temperature (Tp): 650 ° C to 655 ° C every 1 ° C

A photograph of the perforated cast product of Example 8 is shown in FIG. As can be seen with reference to the figure, it can be seen that even if the drawing temperature Tp (° C.) was changed, a hole was formed in the cast product. The circled number 1 indicates that the hole is closed. Although it is difficult to see in the figure, the hole penetrates the cast product.
Further, FIG. 7 shows a lower limit temperature at which pulling can be performed when diameter is expanded by pressing another rod against the L-shaped portion of the rod-shaped mold and rotating the rod-shaped mold.

<Example 9>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-0.5% Si
Liquidus temperature (Tl): 657 ° C
Solidus temperature: 636 ° C
Eutectic temperature (Ts): 577 ° C
Hot water temperature: 720 ° C
Rod type: 2mm diameter stainless steel rod coated with BN Hole diameter of casting mold side plate: 3mm diameter
Drawing temperature (Tp): 625 ° C to 640 ° C every 5 ° C

FIG. 34 shows a photograph of the perforated casting product of Example 9. As can be seen with reference to the figure, it can be seen that even if the drawing temperature Tp (° C.) was changed, a hole was formed in the cast product. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 10>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-10% Si
Liquidus temperature (Tl): 594 ° C
Eutectic temperature (Ts): 577 ° C
Pouring temperature: 650 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (inside dimension of casting mold: 50 mm) Hole diameter of casting mold side plate: diameter 3 mm
Drawing temperature (Tp): 575 ° C to 590 ° C

FIG. 35 (milled surface) shows a photograph of the perforated cast product of Example 10. As can be seen from the figure, when the drawing temperature Tp (° C.) is higher than the liquidus temperature Ts (° C.) − 5 ° C., 590 ° C., 585 ° C., 2 585 ° C., and 583 ° C. Is not formed. This is because the casting material flowed into the hole after the rod-shaped mold was pulled out and closed the hole. On the other hand, when the drawing temperature Tp (° C.) after the circled number 4 is 580 ° C. or less, it can be seen that a hole was opened in the cast product. Although it is difficult to understand in the figure, the round numbers 4 to 9 indicate that the hole penetrates the cast product.

<Example 11>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-12% Si
Liquidus temperature (Tl): 581 ° C
Pouring temperature: 650 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (inside dimension of casting mold: 50 mm) Hole diameter of casting mold side plate: diameter 3 mm
Drawing temperature (Tp): 575 ° C to 590 ° C

A photograph of the perforated cast product of Example 11 is shown in FIG. 36 (milled surface). As can be seen with reference to the figure, when the drawing temperature Tp (° C.) is higher than the liquidus temperature Ts (° C.) − 5 ° C. of 590 ° C. and 585 ° C. of 2 which are high, no holes are formed. This is because the casting material flowed into the hole after the rod-shaped mold was pulled out and closed the hole. On the other hand, when the drawing temperature Tp (° C.) after the circled number 3 is 580 ° C. or less, it can be seen that a hole was opened in the cast product. Although it is difficult to understand in the figure, the round numbers 4 to 9 indicate that the hole penetrates the cast product. In particular, for the round numeral 7, it seems that no hole is formed, but actually a hole is formed.

<Example 12>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Al-15% Si
Liquidus temperature (Tl): 613 ° C
Eutectic temperature (Ts): 577 ° C
Pouring temperature: 700 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (inside dimension of casting mold: 50 mm) Hole diameter of casting mold side plate: diameter 3 mm
Drawing temperature (Tp): 573 ° C to 580 ° C

FIG. 37 (milled surface) shows a photograph of the perforated cast product of Example 12. As can be seen with reference to the figure, it can be seen that even if the drawing temperature Tp (° C.) was changed, a hole was formed in the cast product. Although it is difficult to see in the figure, the hole penetrates the cast product.

<Example 13>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: 500 ° C
Experimental sample: Brass (Cu-15% Zn)
Hot water temperature: 1200 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (inside dimension of casting mold: 50 mm) Hole diameter of casting mold side plate: diameter 3 mm
Drawing temperature (Tp): 970 ° C, 990 ° C, 1010 ° C

A photograph of a perforated cast product of Example 13 is shown in FIG. 38 (milled surface). As can be seen with reference to the drawing, it can be seen that brass was able to open a hole in the cast product even when the drawing temperature Tp (° C.) was changed.

<Example 14>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: room temperature Experimental sample: Al-30% SiC _p (AC4C base: Si 6.5 to 7.5%, Fe 0.55% or less, Cu: 0.25% or less, Mg 0.2 to 0.45%)
Liquidus temperature of AC4C (Tl): 610 ° C
AC4C solidus temperature (Ts): 555 ° C
Hot water temperature: 800 ° C
Bar-shaped mold: BN coated on a stainless steel rod with a diameter of 2 mm and a total length of 100 mm (within casting mold dimensions of 50 mm).
Drawing temperature (Tp): 580 ° C

A photograph of the perforated cast product of Example 14 is shown in FIG. As can be seen with reference to the figure, it can be seen that Al-SiC _p was also able to open holes in the cast product.

<Example 15>
The procedure was the same as in Example 1 except for the conditions described below.
Casting mold temperature: room temperature Experimental sample: Al-30% SiC _p (AC4C base: Si 6.5 to 7.5%, Fe 0.55% or less, Cu: 0.25% or less, Mg 0.2 to 0.45%)
Liquidus temperature of AC4C (Tl): 610 ° C
AC4C solidus temperature (Ts): 555 ° C
Hot water temperature: 800 ° C
Bar-shaped mold: BN is coated on a stainless steel bar with a diameter of 5 mm and a total length of 100 mm (with a casting mold size of 50 mm). The end is bent in an L shape.
Hole diameter of casting mold side plate: diameter 5.5mm
Drawing temperature (Tp): 550 ° C
In addition, between 620 ° C. and 580 ° C., the diameter of the rod was increased by pressing another rod against the L-shaped bent portion of the rod and rotating the rod in one direction.

A photograph of the perforated cast product of Example 15 is shown in FIG. As can be seen with reference to the figure, it can be seen that Al-SiC _p was also able to open holes in the cast product.

The present invention is useful as a method for producing a perforated cast product in which through holes can be formed with a simple apparatus and method.

(10) Cast products
(12) Hole
(20) Casting mold
(24) Insertion hole
(30) Rod type
(40) Casting material

Claims (13)

1. After pouring a molten metal of the casting material (except for Al-Mg alloy and Al-Si-Mg alloy) into the casting mold, the rod-shaped mold placed in the casting mold is pulled out, so that A method for producing a perforated cast product in which a hole is formed in a portion having the rod-shaped mold,
   A pouring step of pouring the casting material at less than 10 MPa;
   The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C.), the lower limit temperature for drawing is Tx (° C.), the melting point, the eutectic temperature or the peritectic temperature is the lower one, Ts (° C.)
   The rod-shaped mold is pulled out of the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 0 <d <100), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
   as well as,
   Removing the cast from the casting mold;
   A method for producing a perforated cast product, comprising:
2. The casting material is an Al—Si based alloy or an Al—Cu based alloy, and the d is 5 ° C.
   The method for producing a perforated cast product according to claim 1.
3. The casting material is an Al—Mn alloy, and d is 90 ° C.
   The method for producing a perforated cast product according to claim 1.
4. The casting material is a Cu—Zn alloy, and the d is 50 ° C.
   The method for producing a perforated cast product according to claim 1.
5. The casting material is pure Al, and the d is 115 ° C.
   The method for producing a perforated cast product according to claim 1.
6. The casting material is pure Cu and the d is 18 ° C.
   The method for producing a perforated cast product according to claim 1.
7. A perforated casting in which a hole is formed in a portion of the casting material where the rod-shaped mold is present by pouring a molten Al-Mg alloy into the casting mold and then pulling out the rod-shaped mold disposed in the casting mold. A method for manufacturing a product,
   A pouring step of pouring the casting material at less than 10 MPa;
   The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C), the lower limit temperature for drawing is Tx (° C), and the solidus temperature is Ts (° C),
   The rod-shaped mold is pulled out from the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 80 <d <110), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
   as well as,
   Removing the cast from the casting mold;
   A method for producing a perforated cast product, comprising:
8. After pouring a molten Al—Si—Mg alloy into the casting mold, a hole is formed in the portion of the casting material where the rod-shaped mold is located by pulling out the rod-shaped mold disposed in the casting mold. A method for manufacturing a hole casting product,
   A pouring step of pouring the casting material at less than 10 MPa;
   The temperature of the casting material in the vicinity of the rod-shaped mold is Tp (° C.), the hole wall does not collapse during or after the rod-shaped mold is drawn, and a liquid phase oozes into the hole to fill the hole. If the upper limit temperature is Th (° C), the lower limit temperature for drawing is Tx (° C), and the solidus temperature or eutectic temperature is Ts (° C),
   The rod-shaped mold is pulled out from the casting material in the temperature range of Tx ≦ Tp ≦ Th (where Tx = Ts−d, 5 <d <110), or the hole diameter is expanded in the temperature range of Ts <Tp ≦ Th. After starting the diameter expansion, pulling out the rod-shaped mold from the casting material,
   as well as,
   Removing the cast from the casting mold;
   A method for producing a perforated cast product, comprising:
9. The rod-shaped mold disposed in the casting mold has a longitudinal dimension of a (mm) and a cross-sectional area perpendicular to the longitudinal direction of b (mm ² ).
   15 ≦ a / b, b ≦ 25
   The method for producing a perforated cast product according to any one of claims 1 to 8.
10. A perforated cast product having holes in the cast product,
    A perforated cast product characterized in that there is no sudden change in structure between the inner surface of the hole wall of the hole and the inside of 1 mm from the inner surface.
11. The hole has a longitudinal dimension of a (mm) and a cross-sectional area perpendicular to the longitudinal direction of b (mm ² ).
    15 ≦ a / b, b ≦ 25
    The perforated cast product according to claim 10, wherein
12. The casting is Al—Si, and Si ≧ 15% by mass.
    The perforated cast product according to claim 10 or 11.
13. The casting is Al-SiC _p , SiC _p ≧ 10% by volume,
    The perforated cast product according to claim 10 or 11.

Images