WO2022024930A1

WO2022024930A1 - Method for producing perforated cast product

Info

Publication number: WO2022024930A1
Application number: PCT/JP2021/027371
Authority: WO
Inventors: 英雄中嶋
Original assignee: 岩谷産業株式会社; 英雄中嶋
Priority date: 2020-07-28
Filing date: 2021-07-21
Publication date: 2022-02-03
Also published as: JPWO2022024930A1

Abstract

[Problem] To provide a method for producing a perforated cast product of a metal or a semiconductor material having one or more holes opened in the surface, said holes being formed by pulling out one or more heat-resistant wires, which had been provided within a casting mold, after supplying a molten metal or semiconductor material into the casting mold and subsequently solidifying the molten metal or semiconductor material therein, said method being capable of forming a longer and narrower pull-out hole having a large aspect ratio, or a curved pull-out hole, while being also capable of efficiently producing the perforated cast product having a plurality of pull-out holes at low cost. [Solution] Not later than a molten metal or semiconductor material is supplied, the surface of a heat-resistant wire is provided in advance with a coating layer having a multilayer structure, said coating layer comprising a first coating layer that is formed by adhering a mold release agent to the surface, said mold release agent not generating a gas even if brought into contact with the molten metal or semiconductor material, and a second coating layer that is formed by adhering a gas generation compound onto the first coating layer, said gas generation compound being decomposed by heat when brought into contact with the molten metal or semiconductor material, thereby generating a gas.

Description

Manufacturing method of perforated casting

INDUSTRIAL APPLICABILITY The present invention can be effectively used as a novel material in various fields such as heat sinks, heat exchangers, aircraft engine turbines, medical instruments, machine tools, thermoelectric conversion materials, and lightweight structural materials for transport moving objects such as automobiles. The present invention relates to a method for manufacturing a perforated cast product of a metal or semiconductor material.

Porous metal materials and foamed metal materials have a low density and a large surface area, and are expected to be applied mainly as lightweight materials, catalysts, electrodes, vibration absorbers, sound absorbers, and shock absorbers. A lotus metal molded body is known as one of the porous metal materials. The lotus metal molded body is a metal molded body produced by a known method such as a high pressure gas method (Pressurized Gas Method) or a thermal decomposition method (Thermal Decomposition Method), and has pores extended in one direction (for example, Patent Document 1). reference.). By cutting this into a plurality of plates, a porous metal plate (lotus metal plate) having a large number of through holes can be obtained. The lotus metal plate has excellent heat transfer properties, and its use as a heat sink for electronic devices and various heat exchange fins has been proposed (see, for example, Patent Documents 2 and 3).

However, since the lotus metal molded body has a limited length of pores, the hole of the lotus metal plate is used as a through hole, so that the plate thickness after cutting is limited. In order to secure more excellent cooling ability as a fin of a heat sink or the like, it is desirable to form a long hole. The ability to form long holes is also advantageous when applied as the catalyst, electrodes, vibration absorbers, sound absorbers, and shock absorbers.

Other methods for manufacturing porous metal materials include a method of mechanically drilling holes in post-processing, and a method of melting and evaporating metal using an electron beam or a laser to drill holes. However, the smaller the hole, the easier it is to break, the longer the machining time is, the higher the cost, and the length of the hole is limited by the length of the drill tool. The electron beam requires high vacuum equipment, is expensive, and is unsuitable for industrialization. Laser machining is possible in the atmosphere, but drilling requires a great deal of money and time. Processing with a drill, electron beam, or laser has a length ratio (aspect ratio) of at most 10 to the diameter of the hole, and there is a limit to drilling a long and thin hole.

Furthermore, all of the above-mentioned conventional porous metal materials could have only linear holes extending in one direction. This is because the lotus metal molded body uses unidirectional solidification due to its manufacturing method, and drilling, electron beam processing, etc. are also linear drilling processes. In response to such a situation, the present inventor has already provided a single or a plurality of heat-resistant wires in a mold, supplied a molten metal or semiconductor material to solidify the heat-resistant wire, and then pulled out the heat-resistant wire. We are proposing a method for manufacturing a perforated cast product, which comprises obtaining a cast product of a metal or semiconductor material in which one or more heat-resistant wire drawing holes are opened on the surface (international patent application: PCT / JP2020 / 22310). .. Such a perforated cast product is to be provided at a lower cost, a longer product, and a product having finer holes than a cut product of a lotus metal molded product or a post-processed product such as a drill, an electron beam, or a laser. It is also possible to make a hole that extends in a curved shape, and the overall shape and dimensions can be freely set depending on the mold, and the shape and dimensions of the hole that it has can also be the length and thickness of the heat-resistant wire. , Shape, etc. can be set freely.

In this perforated cast product, in order to efficiently create a large number of drawing holes, instead of drawing out the heat-resistant wires one by one, the heat-resistant wires are arranged simultaneously on the pedestal like a sword mountain, and a large number of heat-resistant wires ( It is desirable to pull out n) at once. However, in this case, the resistance at the time of pulling out the heat-resistant wire takes n times as much as the case where the heat-resistant wire is pulled out one by one, which inevitably increases the size of the equipment and the cost. In addition, when forming a more thin and long drawing hole with a large aspect ratio or a drawing hole that is greatly bent, the resistance at the time of pulling out increases by the length and bending, and the heat-resistant wire is easily broken, so that a normal mold release agent is used. There was a limit to the aspect ratio and the degree of bending that could be obtained only by using.

Japanese Patent No. 4217865 Japanese Unexamined Patent Publication No. 2018-73869 Japanese Unexamined Patent Publication No. 2018-179412

Therefore, in view of the above-mentioned situation, the present invention is to solve the problem by providing a single or a plurality of heat-resistant wires in a mold, supplying a molten metal or semiconductor material to solidify the heat-resistant wire, and then pulling out the heat-resistant wire. By doing so, a perforated casting product obtained from a metal or semiconductor material in which a single or a plurality of heat-resistant wire drawing holes are opened on the surface, and a finer and longer drawing hole having a large aspect ratio or a bent drawing hole is produced. At the same time, it is possible to provide a method for efficiently producing the perforated cast product having a large number of drawing holes at low cost.

As a result of diligent studies in view of the current situation, the present inventor has drawn out the heat-resistant wire of the perforated casting with respect to the cross-sectional area of the heat-resistant wire, unlike the mold release in the case of general mold casting. The ratio of the contact area with the solidified metal is very large, especially the heat-resistant wire is easily broken at the initial stage of extraction, and the extraction distance becomes longer by the depth of the hole. Since the stress applied to the wire is very large, and even if the surface of the heat-resistant wire is coated with a mold release agent in advance, the contact surface with the solidified metal is large as shown in FIG. 11, the lubricating effect of the mold release agent is large. It was assumed that there would be a limit to the correspondence. Then, the present invention is conceived to apply the knowledge of the foamed metal produced by the addition of the gas-generating compound described in Non-Patent Document 1 to the molten metal, which the present inventors have demonstrated in the past, to the present extraction technique. Has been completed.

That is, the present invention includes the following inventions.
(1) A single or a plurality of heat-resistant wire is provided in a mold, a molten metal or semiconductor material is supplied and solidified, and then the heat-resistant wire is pulled out to open a single or a plurality of heat-resistant wire drawing holes on the surface. A method for manufacturing a perforated cast product for obtaining a cast product of the metal or semiconductor material, wherein the molten metal or semiconductor material is formed on the surface of the heat-resistant wire at the latest before the molten metal or semiconductor material is supplied. When the first coating layer formed by adhering a mold release agent that does not generate gas even when contacted and the molten metal or semiconductor material comes into contact with the first coating layer, the gas is decomposed by heat. A method for producing a perforated cast product, which comprises previously forming a coating layer having a multi-layer structure, including a second coating layer to which a gas-generating compound for generating metal is adhered.

(2) The release agent is boron nitride (BN), alumina (Al ₂ O ₃ ), magnesia (MgO), zirconia (ZrO ₂ ), mulite (3Al ₂ O ₃ , 2SiO ₂ ), silica (SiO ₂ ). ), Silicon carbide (SiC), and silicon nitride (SiN), which comprises one or more selected from the group, according to (1).

(3) The gas-generating compound is magnesium hydride (MgH ₂ ), titanium hydride (TiH ₂ ), zirconium hydride (II) (ZrH ₂ ), calcium carbonate (CaCO ₃ ), sodium hydrogen carbonate (י ₃ ). , Barium Carbonate (BaCO ₃ ), Magnesium Carbonate (MgCO ₃ ), Strontium Carbonate (SrCO ₃ ), Calcium Hydroxide (Ca (OH) ₂ ), Titanium Nitride (TiN), Tetrairon Nitride (Fe ₄ N), Chromium Nitride Consists of (CrN), Chromium Nitride (Cr ₂ N), Manganese Nitride (Mn ₄ N), Molybdenum Nitride (Mo ₂ N), Copper Oxide (I) (Cu ₂ O), Boron Oxide (B ₂ O ₃ ) The method for producing a perforated cast product according to (1) or (2), which comprises one or more selected from the group.

(4) The method for manufacturing a perforated cast product according to any one of (1) to (3), wherein the heat-resistant wire is a thin metal wire having predetermined shape retention and bending deformation possibility.

According to the invention of the present application as described above, as shown in Examples described later, the resistance at the time of drawing out the heat-resistant wire can be significantly reduced to about 1/3 as compared with the case where only the mold release agent is coated. confirmed. As shown in FIG. 12, a porous layer, which is a fine foam layer, is formed on the outer shell of the molten material as the molten material solidifies, and the solidified metal or the like and the heat-resistant wire 2 are released from the fine foam layer. It is considered that the cause is that the agent layer is interposed, the contact area between the fine foam layer and the release agent layer is small, and the sliding friction between the two is significantly reduced. As described above, since the resistance at the time of drawing out the heat-resistant wire can be significantly reduced by the present invention, it is possible to manufacture a thinner and longer drawing hole having a large aspect ratio or a bent drawing hole without cutting the heat-resistant wire. At the same time, the perforated cast product having a large number of drawing holes can be efficiently manufactured at low cost.

The perspective view which shows the perforated casting product which concerns on this invention. The perspective view which shows the perforated casting product which concerns on this invention. Explanatory drawing which also shows another example of a perforated casting. Explanatory drawing which also shows another example of a perforated casting. Explanatory drawing which also shows another example of a perforated casting. Explanatory drawing which also shows another example of a perforated casting. Explanatory drawing which also shows another example of a perforated casting. Explanatory drawing which also shows another example. Explanatory drawing which also shows another example. Explanatory drawing which also shows another example. Explanatory drawing which also shows another example. Explanatory drawing which shows an example of the procedure of the manufacturing method of the perforated cast product of this invention. Explanatory drawing which shows an example of the procedure of the manufacturing method of the perforated cast product of this invention. An explanatory diagram also showing an example of a manufacturing procedure. An explanatory diagram also showing an example of a manufacturing procedure. An explanatory diagram also showing an example of a manufacturing procedure. An explanatory diagram also showing an example of a manufacturing procedure. An explanatory diagram also showing an example of a manufacturing procedure. Explanatory drawing which also shows another example of a manufacturing procedure. Explanatory drawing which shows the specific example of the heat-resistant wire drawing process (during drawing). Explanatory drawing which shows the manufacturing apparatus and manufacturing procedure which made the sample of Example. Explanatory drawing which shows the manufacturing apparatus and manufacturing procedure which made the sample of Example. Explanatory drawing which shows the manufacturing apparatus and manufacturing procedure which made the sample of Example. Explanatory drawing which shows the manufacturing apparatus and manufacturing procedure which made the sample of Example. Explanatory drawing which shows still another example of the perforated cast product which concerns on this invention. Explanatory drawing which shows the state of pulling out when a mold release agent is applied to a heat-resistant wire. Explanatory drawing which shows the state of drawing when the coating layer of the multi-layer structure of a mold release agent and a gas generating compound is formed on a heat-resistant wire. Explanatory drawing which shows the state of drawing when the coating layer of the multi-layer structure of a mold release agent and a gas generating compound is formed on a heat-resistant wire. Explanatory drawing which shows the procedure of integration of a heat-resistant wire and a plate type. Explanatory drawing which shows the procedure of integration of a heat-resistant wire and a plate type. An explanatory diagram showing another example of the procedure for integrating the heat-resistant wire and the plate type. An explanatory diagram showing another example of the procedure for integrating the heat-resistant wire and the plate type. Explanatory drawing which shows still another example of the procedure of the manufacturing method of the perforated casting of this invention. Explanatory drawing which shows still another example of the procedure of the manufacturing method of the perforated casting of this invention. Explanatory drawing which shows still another example of the procedure of the manufacturing method of the perforated casting of this invention. Explanatory drawing which shows still another example of the procedure of the manufacturing method of the perforated casting of this invention. Explanatory drawing which shows still another example of the procedure of the manufacturing method of the perforated casting of this invention. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of Example 1. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of Example 1. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of Example 1. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of the comparative example 1. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of the comparative example 1. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of the comparative example 2. The graph which shows the measurement result of the measuring instrument at the time of drawing out the heat-resistant wire of the comparative example 2. Explanatory drawing which shows the result of having measured the pull-out force from aluminum of the heat-resistant wire when applying the mixture of BN and MgH ₂ which changed the composition of MgH ₂ . Explanatory drawing which shows the result of having investigated the length dependence of the heat-resistant wire of a pulling force. An explanatory diagram showing the result of investigating the thickness dependence of the heat-resistant wire of the pulling force. A photograph of holes formed by drawing out heat-resistant wires of different thicknesses.

Next, a detailed description will be given based on the attached drawings of the embodiment of the present invention.

The perforated cast product 1 of a metal or semiconductor material produced in the present invention and a method for producing the same are a multi-layered coating layer composed of a first coating layer of a mold release agent and a second coating layer of a gas generating compound on a heat-resistant wire. Basically, the above international, except that a thinner and longer heat-resistant wire can be used to form a thinner and longer drawing hole or a drawing hole with a larger degree of bending. It is the same as that described in the patent application (PCT / JP2020 / 22310), and the contents of PCT / JP2020 / 22310 are all incorporated by reference in the present specification. ).

As illustrated in FIGS. 1A and 1B, the perforated cast product 1 manufactured by the present invention is a cast product of a metal or semiconductor material in which one or more heat-resistant wire drawing holes 10 are opened on the surface. Various "metal or semiconductor materials" are possible, such as aluminum, copper, magnesium, iron, cobalt, nickel, chromium, zinc, titanium, zirconium, niobium, hafnium, tungsten, molybdenum, palladium, silver and gold. , Cadmium, indium, tin, platinum, tantalum, lead, bismuth and alloys thereof, silicon, germanium, compounds thereof and various other metal or semiconductor materials can be used.

The heat-resistant wire drawing hole 10 is a hole formed by drawing out a heat-resistant wire from a solidified casting, and its cross-sectional shape reflects the cross-sectional shape of the heat-resistant wire. Cross-sectional shapes such as a polygonal shape, a flat plate shape (rectangular cross section), an L shape, a V shape, a Y shape, a U (katakana) shape, a tube shape (hollow cylinder type), and a gear shape are also included. It is also possible to make a hole having an inner peripheral surface having a threaded groove (the heat-resistant wire has a spiral ridge on the outer peripheral surface like a male screw and is pulled out while rotating).

The cross-sectional area (opening area) of the drawn hole 10 reflects the cross-sectional area of the heat-resistant wire as it is, and it is possible to easily form a long thin hole that was difficult with conventional lotus molded bodies, drilling, laser machining, and the like. .. The cross-sectional areas of the heat-resistant wire and the drawn hole are not constant in the axial direction and may be non-uniform. As an example, the heat resistant wire and the drawn hole may be tapered so that the cross-sectional area becomes smaller (larger).

The length of the heat-resistant wire drawing hole 10 can be easily realized from 1 mm to 6000 mm by the manufacturing method of the present invention. Actually, it is preferably 5 mm to 3000 mm, more preferably 10 mm to 900 mm. The hole diameter (diameter) of the heat-resistant wire drawing hole is 20 μm to 50 mm, preferably 100 μm to 30 mm, and more preferably 170 μm to 15 mm. When the pore diameter is smaller than 20 μm, the heat-resistant wire also becomes considerably thin, which makes it difficult to manufacture and draw it.

The heat-resistant wire drawing hole 10 does not have to be a through hole, and may be a bottomed hole having at least one end open for drawing as shown in FIGS. 2A and 2B. Further, by using a thin metal wire having a predetermined shape-retaining property and bending deformation possibility, as shown in FIGS. 2C, 2D, 2E, or 3A, it is curved (wavy or spiral) or folded. It can also be a hole that extends in a curved shape.

Further, by appropriately setting the arrangement of the heat-resistant wire at the time of casting the perforated casting product 1, as shown in FIGS. 3B and 3C, a large number of penetrating or non-penetrating drawing holes 10 extending in different directions can be easily provided. You can also. Further, as shown in FIG. 3D, it is possible to easily realize a hole branched in the middle of the inside by using a heat resistant wire that is also branched. In addition to completely removing the heat-resistant wire to make it a through hole, or not removing it to make it a non-penetrating hole, as shown in FIG. 10, the heat-resistant wire 2 was pulled out halfway and pulled out. It is also included that a part of the heat-resistant wire is left inside by removing the protruding portion, the remaining side is closed by the heat-resistant wire, and the remaining side is formed as a drawing hole opened only on the other end side.

The perforated cast product 1 can be manufactured by using a mold 3 provided with a heat resistant wire 2, for example, as shown in FIG. 4A. In the illustrated example, the mold 3 has a plate-shaped plate type 30 that forms the bottom surface of the cast product and supports the heat-resistant wire 2 in a state of projecting upward, and the integrated plate type 30 and the heat-resistant wire 2. It is composed of a combination with a container-shaped outer mold 31 that is decorated and forms the outer peripheral surface of the cast product. FIG. 4B shows a state in which the plate mold 30 and the heat-resistant wire 2 are installed in the outer mold 31 and set. It is preferable that the upper surface of the plate mold 30 is formed with a supporting recess for inserting and supporting the lower end portion of the heat resistant wire 2.

In particular, in the present invention, as shown in FIG. 12A, gas is generated on the outer surface of the heat resistant wire 2 even if it comes into contact with the molten metal or semiconductor material before supplying the molten metal or semiconductor material at the latest. When the first coating layer 81 (layer of the release agent) to which the release agent is attached and the first coating layer are in contact with the molten metal or semiconductor material, the gas is decomposed by heat and gas is released. The coating layer 8 having a multi-layer structure including the second coating layer 82 (layer of the gas generating compound) formed by adhering the generated gas generating compound is formed in advance. The coating layer 8 is preferably formed before being set in the outer mold 31, but it is also possible after setting.

Examples of the release agent for the first coating layer include boron nitride (BN), alumina (Al ₂ O ₃ ), magnesia (MgO), zirconia (ZrO ₂ ), mulite ( ₃ Al ₂ O 3.2SiO ₂ ), and silica. Those containing one or more selected from the group consisting of (SiO ₂ ), silicon carbide (SiC), and silicon nitride (SiN) are preferable. It is also possible to use other known release agents.

The gas generating compounds in the second coating layer include magnesium hydride (MgH ₂ ), titanium hydride (TiH ₂ ), zirconium hydride (II) (ZrH ₂ ), calcium carbonate (CaCO ₃ ), and hydrogen carbonate. Sodium (NaHCO ₃ ), Barium Carbonate (BaCO ₃ ), Magnesium Carbonate (MgCO ₃ ), Strontium Carbonate (SrCO ₃ ), Calcium Hydroxide (Ca (OH) ₂ ), Titanium Nitride (TiN), Chromium Nitride (Fe ₄ ) N), Chromium Nitride (Cr N), Chromium Nitride (Cr ₂ N), Manganese Nitride (Mn ₄ N), Molybdenum Nitrate (Mo ₂ N), Copper Oxide (I) (Cu ₂ O), Boron Oxide (B ₂ ) Those containing one or more selected from the group consisting of O ₃ ) are preferable. It is also possible to use other known gas generating compounds.

The mold release agent and the gas generating compound forming the coating layer on the outer surface of the heat-resistant wire 2 can be appropriately selected depending on the type of the molten metal or semiconductor material used. Table 1 below shows examples of molten metals used, for each of aluminum or its alloys, magnesium or its alloys, copper or its alloys, iron or its alloys, preferred mold release agents and gas generators suitable for use, respectively. The compounds are listed. As for the specific combination of the release agent and the gas generating compound in the table in each case, any combination is possible. Graphite is also one of the typical mold release agents, but it has a mold release effect only at 400 ° C. or lower by itself. However, by mixing with the mold release agent in the table, there are effects such as improving the adhesiveness of the coating layer to the heat-resistant wire and improving the mold release effect, and there are cases where it is desirable to mix an appropriate amount of graphite. do.

[Replenishment under Rule 26 10.08.2021]

The release agent constituting the first coating layer and the gas generating compound constituting the second coating layer are both coated and dried with a brush or the like in a state where granular substances are dispersed in a solvent and adhered. .. In addition, the liquid dispersed in the solvent can be sprayed instead of a brush, or other known grain-adhering means can be used. Further, a means for applying a mold release agent constituting the first coating layer and adhering the powder of the gas generating compound constituting the second coating layer on the wet state before it dries. Can also be used. It is preferable to use a mold release agent having an average particle size of 0.5 to 30 μm. In particular, when adhering by using a spray, there arises a problem that the nozzle is easily clogged when the size is larger than 30 μm.
Further, it is preferable to use a gas generating compound having an average particle size of 0.5 to 30 μm. If it is less than 0.5 μm, foaming / gas generation ends before the predetermined molten metal temperature is reached, and it becomes difficult to form a fine foamed layer. On the other hand, if it is larger than 30 μm, foaming / gas generation may be delayed and the formation of a fine foamed layer may not be achieved even if the molten metal temperature is maintained at a predetermined temperature for a predetermined time. The "average particle size" is the particle size at an integrated value of 50% of the particle size distribution obtained by the laser diffraction / scattering method.

Further, the thickness of the second coating layer made of the gas-generating compound is preferably 300 μm or less, more preferably 30 to 100 μm. If the thickness becomes thick and the amount of gas-generating compound is too large, a large amount of gas is generated and a cavity is formed in the casting.

It is preferable to apply a known mold release agent to the upper surface of the plate mold 30 and the inner peripheral surface of the outer mold 31 other than the heat-resistant wire 2.
Then, in a state where the mold 3 (outer mold 31) is appropriately heated, as shown in FIG. 5A, a separately melted metal or semiconductor material (for example, molten aluminum) (hereinafter referred to as “molten material”) is attached to the heat-resistant wire 2. After pouring hot water into the mold 3 on which the aluminum is erected, it is cooled and solidified in the state shown in FIG. 5B.

The molten material is filled in the gap between the heat resistant wires 2 and solidified in a state of being integrated with the heat resistant wires 2. At this time, among the above-mentioned coating layers previously formed on the outer surface of the heat-resistant wire 2, the second coating layer (layer of the gas-generating compound) comes into contact with the molten material, so that hydrogen is contained in the molten material and the second coating layer. As shown in FIG. 12B, a porous layer, which is a fine foam layer, is formed on the outer shell (the inner peripheral wall of the drawing hole which is the boundary with the heat-resistant wire 2) as the molten material solidifies. To. The fine foam layer is not a pure foam layer of a molten material, but an alloy or compound layer with a non-gas component decomposed by a gas-generating compound.

As shown in FIG. 12B, the fine foam layer and the release agent layer are interposed between the solidified metal or the like obtained by solidifying the molten material and the heat-resistant wire 2, and the fine foam layer and the release agent are separated from each other. The contact area between the layers is reduced and the sliding friction between the two is significantly reduced. Therefore, the resistance force at the time of pulling out one heat-resistant wire 2 is remarkably reduced.

The method of supplying the molten material may be one in which a solid metal or a semiconductor material (solid material) is set on the upper part of the mold, melted by heating, and moved into the lower mold. If the heat-resistant wire 2 is poured until it is completely buried, the drawing hole of the heat-resistant wire becomes a non-penetrating hole, and if the pouring is stopped until the upper end of the heat-resistant wire 2 protrudes from the hot water surface, the heat-resistant wire is pulled out. The hole becomes a through hole. In this way, the penetration / non-penetration of the extraction hole can be set by the length of the heat-resistant wire or the amount of hot water poured. Further, when the heat-resistant wires 2 are arranged and set at a high density, the molten metal may not be evenly filled in the gaps between the narrow heat-resistant wires 2 because the molten metal has viscosity and has surface tension. .. In that case, filling can be promoted by making full use of techniques such as pressure casting and vacuum casting. In particular, for pressure casting, in consideration of the case where air remains between the heat-resistant wires 2, the pressure is applied so as to prevent the heat-resistant wire 2 in the residual air region from bending at high pressure.

After the molten material has solidified, as shown in FIG. 6A, the plate mold 30 is separated from the outer mold 31 by pushing it up with a pin (not shown) from below, and a metal or semiconductor material casting integrated with the heat resistant wire 2 is formed. Take out the plate mold 30 with 4 placed on the upper surface side. Here, the outer wall of the outer mold 31 can be separated from the side wall and the bottom wall, and the bottom wall can be removed and taken out from the bottom side, of course.

Then, as shown in FIG. 6B, with the side surface 4b of the casting 4 being supported by being sandwiched by a jig 5, the plate mold 30 on the lower surface side is removed, and the lower end of each exposed (protruding) heat resistant wire 2 is removed. As shown in FIG. 6C, the portion 2a is picked using a holding jig 6 or the like and pulled downward as it is, whereby a drawing hole 10 is formed in the casting 4, and the perforated casting 1 is completed.

FIG. 8 shows an example of

jigs

5 and 6. In this example, with the side surface 4b of the casting 4 fixed with a vise (jig 5), the exposed lower end portion 2a of the heat-resistant wire 2 embedded in the casting 4 is pressed with a collet chuck (jig 6). Multiple pieces are pulled out at the same time. More specifically, a multi-core collet chuck is used as the jig 6, and as shown in the figure, the lower ends 2a of each of the plurality of heat-resistant wires 2 are grasped and moved downward to simultaneously generate a plurality of heat-resistant wires 2. Pulling out is a preferable example. According to the present invention, since the pulling force per line is remarkably suppressed by the coating layer provided on the heat-resistant wire 2, the equipment can be kept small even when a plurality of lines are blown out at the same time. The collet chuck jig 6 can be freely moved up, down, left and right, grasps the heat-resistant wire 2, and pulls out the heat-resistant wire 2.

In this example, as shown in FIGS. 6B and 6C, after the plate mold 30 is removed from the casting 4, the heat-resistant wire 2 is pulled out by the jig 6, but the plate mold 30 and the heat-resistant wire 2 are mutually connected. It is also preferable from the viewpoint of efficiency that the heat-resistant wire 2 is also configured to move downward together with the plate mold 30 and be pulled out when the plate mold 30 is firmly fixed.

In the example of the manufacturing apparatus shown in FIGS. 9A to 9D, as shown in FIG. 9A, the plate mold 30 and the heat resistant wire 2 firmly fixed to each other are set in the crucible type outer mold 31, and the inside of the outer mold 31 is set. By inserting a solid metal or semiconductor material (solid material 9) into the upper part of the heat-resistant wire 2 and heating it with a heater 7, the solid material 9 is melted as shown in FIG. 9B, and the molten material is melted into the heat-resistant wire 2. This is an example of filling and solidifying the gap between them. Then, after taking out the plate mold 30 in a state where the metal or semiconductor material casting 4 integrated with the heat resistant wire 2 is placed on the upper surface side as shown in FIG. 9C from the outer mold 31, the plate is as shown in FIG. 9D. By separating the mold 30 from the casting 4, the heat-resistant wire 2 is also pulled out together with the plate mold 30 at the same time, and a perforated cast product can be efficiently obtained.

As a method of firmly fixing the plate mold 30 and the heat-resistant wire 2 to each other in this way, as shown in FIG. 13A, the heat-resistant wire 2 is densely attached to the metal plate mold 30 (which serves as a pedestal) having a high melting point. There is a method in which a hole 30b having a diameter suitable for the thickness of the hole 30b is mechanically drilled, heat-resistant wires 2 are inserted into the holes one by one, and welding is stopped as shown in FIG. 13B. A laser or the like may be used to drill the hole 30b.

As another method, as shown in FIGS. 14A and 14B, the base end portion 2a of the heat-resistant wire 2 is immersed in a metal material 300 (for example, brass) to be a plate type 30 melted in a crucible, and the base end portion 2a thereof is immersed therein. A method of forming the plate mold 30 in a state where the heat-resistant wire 2 is integrated by cooling and solidifying in the state is also a preferable example. In this case, it is necessary to maintain the target form (posture) after holding and integrating the plurality of heat-resistant wires 2 until the solidification. As the holding means, as shown in FIG. 14A, a holding material 32 having a holding hole 32c that can be held in a state where a plurality of heat-resistant wires are penetrated can be used. Since the holding material 32 is made of graphite, it is preferable that the holding hole 32c can be easily drilled and that the holding material 32 can be used repeatedly as many times as necessary without deterioration, which leads to cost reduction. By molding the plate mold 30 integrally with the heat-resistant wire 2 as in this example, it is possible to save the time and labor of welding the heat-resistant wires one by one, reduce the cost, and increase the number of high densities. The heat-resistant wire can be efficiently arranged on the plate mold 30.

As yet another example, in the example of the manufacturing apparatus shown in FIGS. 9A to 9D, the holding material 32 described in FIG. 14 holding the plurality of heat-resistant wires 2 is omitted from the molding of the plate mold 30. Then, as shown in FIGS. 15A and 15B, the plate mold 30 is set in the crucible mold outer mold 31 without the plate mold 30. Here, the holding material 32 is held on the lower end side of each heat-resistant wire 2 in a state where the lower end portion 2a of the heat-resistant wire 2 is projected by a predetermined length, and the outer peripheral surface thereof is a crucible-shaped outer peripheral surface 31. A gap through which the molten material can pass downward is set between the two and the groove 32d by providing a groove 32d on the outer peripheral surface of the holding material 32. Further, the lower end portion 2a of the heat-resistant wire protruding toward the lower surface side of the holding material 32 is coated with the above-mentioned first coating layer (layer of mold release agent) and second coating layer (layer of gas generating compound). The layer 8 is not applied, but is applied to the upper surface side.

Then, as shown in FIG. 15C, when the molten material is filled in the gap between the heat-resistant wires 2, the molten metal passes downward through the gap between the holding material 32 and the inner peripheral surface of the outer mold 31, and the lower surface of the holding material 32. It is also filled between the lower ends of the heat-resistant wire 2 protruding to the side. When solidified in this state, the solidified portion 41 of the casting 4 that wraps around to the lower surface side of the holding material 32 functions as the plate mold 30 together with the holding material 32. That is, as shown in FIG. 15E, after the holding material 32 in a state where the metal or semiconductor material casting 4 integrated with the heat resistant wire 2 is placed on both the upper and lower sides as shown in FIG. 15D is taken out from the outer mold 31, as shown in FIG. 15E. By separating the holding material 32 and the solidified portion 41 that surrounds the casting from the casting 4, the heat-resistant wire 2 is also pulled out at the same time, and a perforated casting can be efficiently obtained.

The above example is a manufacturing method in which heat-resistant wires are arranged in the vertical direction and a drawing hole is formed in the vertical direction, but of course it can also be formed in the horizontal direction. In that case, for example, as shown in FIG. 7, a pair of plate molds 30 are provided on the left and right sides, and the same is set on the outer mold 31. Similarly, pouring, solidification, removal of the plate mold 30, and extraction of the heat resistant wire 2 are performed. Can be manufactured. In this case, the plate mold 30 forms the side surface of the cast metal or semiconductor material, and the outer mold 31 forms the bottom surface.

The heat-resistant wire has a predetermined shape retention property and bending deformation possibility, and a fine metal wire is preferably used. The heat-resistant wire 2 can be curved (for example, wavy, spiral, etc.) or bent (bent in a plurality of directions) in addition to the linear one as in this example, and remains in this shape. By drawing out the heat-resistant wire while bending and deforming it from the casting integrated with the metal material, the curved or bent heat-resistant wire drawing hole 10 can be obtained. Since the heat-resistant wire must maintain heat resistance in the state where the molten material is poured, its melting point must be higher than the melting point of the metal or semiconductor material used for the molten material. It is desirable that the temperature is at least 100 ° C. or higher.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it is needless to say that the present invention can be implemented in various forms without departing from the gist of the present invention.

Hereinafter, in order to confirm the effect of forming the coating layer on the outer surface of the heat-resistant wire, various heat-resistant wires are prepared and the result of measuring the force required for drawing will be described.

The equipment used in the experiment is as follows.
Manufacturing equipment: Equipment consisting of a crucible shown in FIG. 9A Molten material: Aluminum (purity 99.99%)
Heat-resistant wire: Stainless steel (SUS304) wire with a thickness (outer diameter) of 1.0 mm and a length of 70 mm Measuring instrument for pulling force (resistance force during pulling): Precision tensile tester "AG-100kND" manufactured by Shimadzu Corporation
Pulling speed: 3 mm / min

The heat-resistant wire coating layer is as follows. The coating thickness of the first coating layer, the second coating layer, and the single layer coating was 10 to 20 μm.
Example 1: Multi-layer structure (first coating layer: boron nitride (BN), second coating layer: magnesium hydride (MgH ₂ ))
-Comparative example 1: No coating layer (omitted)
-Comparative example 2: Single-layer structure (boron nitride (BN) (manufactured by Fine Chemical Japan Co., Ltd.))
Comparative Example 3: Single-layer structure (mixture of boron nitride (BN) and magnesium hydride (MgH ₂ ))
Comparative Example 4: Multi-layer structure (first coating layer: magnesium hydride (MgH ₂ ), second coating layer: boron nitride (BN))
Comparative Example 5: Single-layer structure (calcium hydroxide (Ca (OH) ₂ ))
-Comparative Example 6: Single-layer structure (titanium hydride (TiH ₂ ))

The above heat-resistant wire was commonly used, and a coating layer was formed or omitted on the outer peripheral surface as in Examples 1 to 6 (Comparative Example 1). Then, as shown in FIG. 9A, the heat-resistant wire is attached to the upper surface of a plate mold made of a columnar graphite disk forming the lower surface of the cast product in a state of protruding upward, and the heat-resistant wire and the plate mold are cast. It was inserted and set in a cylindrical graphite crucible type (inner diameter 15 mm) forming the outer peripheral surface of the product so that the heat resistant wire was on top.

As shown in FIG. 9A, a predetermined amount of solid aluminum (purity 99.99%) as a solid material is placed inside the crucible mold so as to be in contact with the upper end of the heat-resistant wire, and then the entire crucible mold is vertically formed. It was installed in a mold electric furnace and held at 953 K to melt the aluminum, and the molten aluminum was dropped between the heat-resistant wires and held for about 360 seconds to fill the voids between the heat-resistant wires. After heating and holding for about 360 seconds, the crucible type was taken out from the vertical electric furnace, cooled, and the aluminum inside was solidified.

Then, take out the heat-resistant wire and the aluminum casting integrally solidified with the plate mold from the crucible mold, remove the plate mold, and then pull out one heat-resistant wire for each example while measuring the pulling force with the above measuring instrument. rice field. However, the measurement was completed when the value of the pulling force became stable before it was completely pulled out. The results are shown in Table 2 (the pulling force of each example is the average value of the maximum pulling forces of a plurality of lines). For reference, FIGS. 16 to 22 show the measurement results (graphs) of the pulling force of each heat-resistant wire for each heat-resistant wire in Examples 1 and Comparative Examples 1 and 2.

As can be seen from the results in Table 2, if a two-layer coating layer of a mold release agent and a gas generating compound is formed on the outer surface of the heat-resistant wire as in the present invention, it is compared with the case where only the mold release agent is used (Comparative Example 2). It can be seen that the resistance at the time of pulling out can be significantly reduced to 1/3. When the release agent and the gas generating compound are mixed together to form a single-layer coating layer (Comparative Example 3), the withdrawal force is larger than that with the release agent alone (Comparative Example 2), and the withdrawability is improved. It got worse. This is because by adding MgH ₂ powder to BN, the adhesiveness to the surface of the heat-resistant wire is lower than when only the mold release agent BN is applied, the coating property is reduced, and a part of it is peeled off when it comes into contact with molten aluminum. It is thought that this is because of this.

When the layer of the gas-generating compound was used as the first coating layer and the second coating layer of the release agent was formed on the first coating layer (Comparative Example 4), the pullability was significantly deteriorated. It is presumed that this is because gas is generated in the first coating layer, the release agent layer coated on the gas is disturbed, and the sliding resistance of the contact surface with the solidified aluminum is increased. When a single layer of the gas-generating compound was coated without using a release agent (Comparative Examples 5 and 6), the pullability was further deteriorated. It is presumed that this is because calcium and titanium decomposed by the gas-generating compound alloy or react with aluminum, which is a molten metal, and stainless wire, which is a heat-resistant wire, and the resistance increases.

In FIG. 23, in order to prevent peeling due to a mixture of boron nitride (BN) and magnesium hydride (MgH ₂ ), a thin BN of 10 μm or less is first applied to the heat-resistant wire, and then the composition of MgH ₂ is changed. The results of measuring the pulling force of the heat-resistant wire from aluminum when the mixture of BN and MgH ₂ is applied are shown (the coating thickness of the mixture of BN and MgH ₂ is about 50 μm). When the weight ratio of MgH ₂ to BN was about 1.5, the pulling force was reduced to 1/4 as compared with the case where only the release agent BN was applied. The pulling force did not change even if more MgH ₂ was added. From this, it was found that the addition of MgH ₂ having a weight ratio of about 1.5 makes the extraction much easier.

FIG. 24 shows the results of investigating the length dependence of the heat resistant wire of the pulling force. The diameter of the heat-resistant wire was 1 mmφ, and a mixture of MgH ₂ and BN having a weight ratio of MgH ₂ / BN of 1.5 was applied on a BN layer of 10 μm or less in an amount of about 50 μm. It was found that the pull-out force increases with increasing length in proportion to the length of the heat-resistant wire.

FIG. 25A shows the result of investigating the thickness dependence of the heat resistant wire of the pulling force. FIG. 25B is a photograph of observing the holes formed by drawing out the heat-resistant wire in each example. The length of the heat-resistant wire was 40 mm, and a mixture of MgH ₂ and BN having a weight ratio of MgH ₂ / BN of 1.5 was applied on a BN layer of 10 μm or less in an amount of about 50 μm. It was found that the pull-out force increases with increasing diameter in proportion to the diameter of the heat-resistant wire. By the way, the contact area S of the heat-resistant wire embedded in the solidified aluminum can be expressed as S = πdLn, where d is the diameter of the heat-resistant wire, L is the length, and n is the number of heat-resistant wires. According to the measurement results of FIGS. 24 and 25A, since the pulling force F is proportional to d or L, it is clarified by the above equation that the pulling force F is proportional to the contact area S of the heat-resistant wire. .. This makes it possible to estimate the pulling force if the diameter, length, and number of heat-resistant wires are known. Can be carried out.

1 Perforated casting 10 Pull-out hole 2 Heat-resistant wire 2a End 3 Mold 30 Plate type 30b Hole 300 Metal material 32 Holding material 32c Holding hole 32d Groove 31 Outer type 4 Casting 4b Side surface 41 Solidification part 5 Jig 6 Jig 7 Heater 8 Coating layer 81 First coating layer 82 Second coating layer 9 Solid material

Claims

One or more heat resistant wires are provided in the mold,
After feeding and solidifying the molten metal or semiconductor material,
A method for manufacturing a perforated cast product, which obtains a cast product of a metal or semiconductor material having one or a plurality of heat-resistant wire drawing holes opened on the surface by drawing out the heat-resistant wire.
At the latest, before supplying the molten metal or semiconductor material
A first coating layer formed by adhering a mold release agent that does not generate gas even when in contact with the molten metal or semiconductor material on the surface of the heat-resistant wire.
A coating layer having a multi-layer structure, including a second coating layer formed by adhering a gas-generating compound that decomposes by heat to generate gas when in contact with the molten metal or semiconductor material on the first coating layer. A method for manufacturing a perforated cast product, which comprises forming in advance.
The method for producing a perforated cast product according to claim 1, wherein the release agent comprises one or more selected from the group consisting of boron nitride, alumina, magnesia, zirconia, mullite, silica, silicon carbide, and silicon nitride.
The gas-generating compound is magnesium hydride, titanium hydride, zirconium hydride (II), calcium carbonate, sodium hydrogen carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium hydroxide, titanium nitride, tetrairon nitride, chromium nitride. The method for producing a perforated cast product according to claim 1 or 2, which comprises at least one selected from the group consisting of dichrome nitride, manganese nitride, molybdenum nitride, copper (I) oxide, and boron oxide.
The method for manufacturing a perforated cast product according to any one of claims 1 to 3, wherein the heat-resistant wire is a thin metal wire having predetermined shape retention and bending deformation possibility.