WO2009119701A1

WO2009119701A1 - Casting mold for magnesium alloy and method of casting magnesium alloy

Info

Publication number: WO2009119701A1
Application number: PCT/JP2009/056034
Authority: WO
Inventors: 高島正之; 米沢晋; 阿良田吉昭
Original assignee: 独立行政法人科学技術振興機構; 国立大学法人福井大学
Priority date: 2008-03-26
Filing date: 2009-03-18
Publication date: 2009-10-01
Also published as: JP2009233690A; EP2263817A4; US20110056644A1; EP2263817A1; CN101977710A; JP4748426B2

Abstract

A casting mold for magnesium alloys is provided with which the flowability of a magnesium alloy melt can be ensured while reducing the cost of casting apparatus production and the energy cost caused by heating. Also provided is a method of casting a magnesium alloy using the casting mold. The casting mold (1) for magnesium alloys includes a mold (11) comprising a gas-permeable material, the gas-permeable material being constituted of any of a net structure, a plate having holes, and a fabric or a combination thereof. Since the mold (11) of the casting mold (1) for magnesium alloys comprises the gas-permeable material, apparent thermal conductivity between a melt (3) and the casting mold (1) for magnesium alloys is low. Due to the low apparent thermal conductivity, the melt (3) does not solidify instantly even upon contact with the casting mold (1) for magnesium alloys, and the flowability of the melt (3) is ensured.

Description

Specification

Magnesium alloy mold and magnesium alloy fabrication method Technical Field

The present invention relates to a magnesium alloy mold and a magnesium alloy forging method, and more particularly to a magnesium alloy mold and a magnesium alloy forging method capable of ensuring the fluidity of a molten magnesium alloy. Background art

Magnesium is the lightest material for practical use, and its specific strength and specific rigidity are superior to those of steel and aluminum, and it also has excellent electromagnetic shielding properties, machinability, rise absorption, dent resistance and recyclability. As a result, the applicable range of magnesium has been expanded.

In particular, magnesium alloys are used as materials for parts for automobiles and portable terminals, and demand is growing rapidly.

Conventionally, when manufacturing such a component, a method of forming a magnesium alloy by forging has been employed. However, when forging a magnesium alloy using a metal saddle, the latent heat per unit volume of the magnesium alloy is small and the thermal conductivity s between the molten metal and the metal saddle is large. When the magnesium alloy melt contacted the metal mold, it instantly solidified and lost its fluidity, making it difficult to spread the melt throughout the mold.

In particular, when making small parts or thin parts, it was difficult to spread the molten metal power over the entire mold by closing the space where the molten magnesium alloy power s molten metal flows.

For this reason, forging has been carried out by a method that ensures the fluidity of the molten magnesium alloy by heating the metal mold. Forging performed by heating a metal mold in this manner is disclosed in Japanese Patent Application Laid-Open No. 2 0 02-1 2 9 2 7 2. In Japanese Patent Laid-Open No. 2000-0 1 2 9 2 7 2, metal metal molds are heated to 20.00 to ensure fluidity of the molten metal and forging.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-0 1 2 9 2 7 2 Disclosure of Invention

Problems to be solved by the invention

However, forging performed by heating a metal mold, a heating element and a temperature measuring device for heating the metal mold are required, which increases the manufacturing cost of the forging apparatus and further heats it. As a result, energy costs also increased.

In view of the above, the present invention provides a magnesium alloy mold that can secure the fluidity of the magnesium alloy melt while reducing the manufacturing cost of the forging apparatus and the energy cost generated by heating, and the magnesium alloy forging using the mold. The purpose is to provide a method. Means that the Invention is to Solve

In order to solve the above-mentioned problems, the magnesium alloy saddle according to claim 1 is formed of a breathable material for the mold and Z or the core.

In the magnesium alloy saddle according to claim 2, the breathable material is formed of any one of a net, a plate having a plurality of holes, a cloth, or a combination thereof.

According to a third aspect of the present invention, the mesh body, the plate or the cloth is made of a metal, chemical fiber, ceramics or a combination thereof.

In the saddle mold for magnesium alloy according to claim 4, the net, the board and the cloth have flexibility. The method for forging a magnesium alloy according to claim 5 uses a mold in which the mold and the core or the core are made of a breathable material.

The method of forging a magnesium alloy according to claim 6 includes: a breathable material mold and Z or medium The child is composed of a mesh body, a plate having a plurality of holes, a cloth, or a combination thereof. The invention's effect

According to the magnesium alloy mold of claim 1, the magnesium alloy mold and the Z or core are formed of a gas-permeable material, so that the gap between the molten metal and the magnesium alloy mold. The apparent thermal conductivity coefficient is reduced.

By reducing the apparent thermal conductivity coefficient, even if the molten metal comes into contact with the magnesium alloy mold, the molten metal does not harden instantaneously, ensuring the fluidity of the molten metal, and the molten metal spreads throughout the magnesium alloy mold. .

Therefore, since a heating element and a temperature measuring device for heating the magnesium alloy mold are not required, the manufacturing cost of the forging apparatus can be reduced.

In addition, since it is not necessary to heat the magnesium alloy mold during fabrication, the energy cost generated by heating can be reduced.

According to the magnesium alloy saddle according to claim 2, since the breathable material is composed of any one of a net, a plate having a plurality of holes, a cloth, or a combination thereof, a unit of molten magnesium alloy Due to the small latent heat per volume and the influence of surface tension, the molten metal that contacts the magnesium alloy mold is between the meshes. Solidify without flowing out from the weave and between.

In addition, since the breathable material is composed of a net, a plate or cloth having a plurality of holes, or a combination of these, a new hole for venting air is newly added to the magnesium alloy saddle. There is no need to provide it.

In addition, the effect of linear expansion due to the heat of the molten metal is relaxed and absorbed by the entire magnesium alloy mold, and the mold and Z or core are not easily distorted.

According to the magnesium alloy mold of claim 3, it is possible to select the most suitable net, board or cloth material for fabrication in consideration of the composition of the magnesium alloy, the size and shape of the fabricated product, etc. . According to the magnesium alloy mold of claim 4, the magnesium alloy mold can be easily manufactured by the flexibility of the net, the plate, and the cloth.

Furthermore, it is possible to easily change the shape of the magnesium alloy forged product by changing the shape of the magnesium alloy mold.

According to the magnesium alloy forging method of claim 5, the magnesium alloy saddle mold and the Z or core are formed of a breathable material, so that the gap between the molten metal and the magnesium alloy mold is between The apparent thermal conductivity coefficient is reduced.

By reducing the apparent thermal conductivity coefficient, even if the molten metal comes into contact with the magnesium alloy mold, it does not harden instantaneously, ensuring the fluidity of the molten metal, and the molten metal spreads throughout the magnesium alloy mold. .

Furthermore, since there is no need to heat the magnesium alloy mold during fabrication, the energy cost caused by heating can be reduced.

According to the magnesium alloy forging method of claim 6, since the breathable material is composed of any one of a net body, a plate having a plurality of holes, a cloth, or a combination thereof, per unit volume of the molten magnesium alloy. Due to the small latent heat and surface tension, the magnesium alloy saddle mold and the molten metal solidify without flowing out between the mesh, the holes, the texture and between.

In addition, the effect of linear expansion due to the heat of the molten metal is relaxed and absorbed by the entire magnesium alloy mold, and the mold, die, and core are less likely to be distorted. Brief Description of Drawings [Fig. 1] Cross-sectional view showing the process of forging a columnar magnesium alloy forged product. [Fig. 2] Cross section showing the process for forging a hollow spherical magnesium alloy forged product.

Type 1

2 core

3 Molten metal

4 crucible

1 1 Upper mold

1 2 Lower mold

3 1 Forged magnesium alloy! BEST MODE FOR CARRYING OUT THE INVENTION

For the purpose of ensuring the fluidity of molten magnesium alloy while reducing the manufacturing cost of the forging device and the energy cost generated by heating, the mold and / or the magnesium alloy mold made of a material with a core that is breathable And a magnesium alloy forging method using the mold.

Embodiments of the present invention will be described below with reference to the drawings. Example 1

FIG. 1 is a cross-sectional view showing a process of forging a columnar magnesium alloy forged product. The magnesium alloy used in this embodiment is AZ91D.

As shown in Fig. 1 (a), the vertical type mold 1 for the magnesium alloy is composed of a net body made of a breathable material.

The mesh body is made of stainless steel. The mesh wire diameter is 0.30 mm and the mesh is 20 mm. Mold 1 consists of upper mold 1 1 and mold 1 2.

As shown in FIG. 1 (b), molten magnesium alloy 3 melted in the crucible 4 is poured into the space formed by the upper mold 1 1 and the lower mold 1 2.

The temperature of the molten metal is 5600: ~ 80.

Since the upper mold 1 1 and the mold 1 2 are made of a breathable net, the apparent thermal conductivity coefficient between the molten metal 3 and the upper mold 1 1 and the lower mold 1 2 becomes small.

By reducing the apparent thermal conductivity coefficient, even if the molten metal 3 comes into contact with the upper mold 1 1 and the lower mold 1 2, the fluidity of the molten metal 3 is secured without instantaneously hardening, and the upper mold 1 1 and the lower mold 1 The entire space formed by 2 crosses the molten metal 3 digits (see Fig. 1 (c)).

After cooling, remove the upper mold 1 1 and the lower mold 1 2 to obtain a columnar magnesium alloy product 3 1 force S (see Fig. 1 (d)). Example 2

FIG. 2 is a cross-sectional view showing a process of forging a hollow spherical magnesium alloy forged product.

The magnesium alloy is A Z 9 1 D as in Fig. 1.

As shown in Fig. 2 (a), the cage mold 1 and the core 2 for the magnesium alloy are composed of a net body made of a gas-permeable material.

The mesh body is made of stainless steel. The mesh wire diameter is 0.30 mm and the mesh is 20 mm.

Mold 1 consists of upper mold 1 1 and mold 1 2.

As shown in FIG. 2 (b), molten magnesium alloy 3 melted in the crucible 4 is poured into a space formed by the upper 11, the lower mold 12 and the core 2.

The temperature of the molten metal 3 is 5 6 0 to ˜80 Ot :.

The upper mold 1 1, lower mold 1 2 and core 2 are made of a breathable net, so that there is a gap between the molten metal 3 and the upper mold 1 1, lower mold 1 2, core 2 and core. The apparent thermal conductivity coefficient is reduced. By reducing the apparent thermal conductivity coefficient force, even if the molten metal 3 comes into contact with the upper mold 1 1, the lower mold 1 2 and the core 2, the fluidity of the molten metal 3 is secured without instantaneously solidifying, and the upper mold 1 1 In addition, the molten metal 3 is spread over the entire space formed by the lower mold 12 and the core 2 (see Fig. 2 (c)).

After cooling, if the upper mold 11 and the lower mold 12 are removed, a hollow spherical magnesium alloy manufactured product 31 can be obtained (see FIG. 2 (d)).

Since the core 2 is inside the magnesium alloy fabrication 31, the finished fabrication is a composite of a magnesium alloy and stainless steel.

By changing the material of the core 2, it is possible to forge a molded article of a composite material of the magnesium alloy and the material of the core 2.

As described above, since the mold 1 and the core 2 are made of a mesh body, the fluidity of the molten metal 3 is ensured without heating the mold 1 and the core 2.

Accordingly, since the heating element and the temperature measuring device for heating the magnesium alloy mold 1 are not required, the cost of the forging apparatus can be reduced.

Furthermore, since it is not necessary to heat the magnesium alloy mold 1 during fabrication, the energy cost caused by heating can be reduced.

Even though it is composed of a mold 1 and core 2 force network, the molten metal 3 in contact with the mold 1 and Z or the core 2 due to the small latent heat per unit volume of the molten magnesium 3 and the effect of surface tension. Solidifies without flowing through the net.

In addition, since the mold 1 and the core 2 for the magnesium alloy are made of a net, it is not necessary to provide a new hole for venting air in the mold 1 and the core 2.

Furthermore, the influence of the linear expansion of the net due to the heat of the molten metal 3 is relaxed and absorbed by the entire magnesium alloy mold, and the magnesium mold mold 1 and core 2 are less likely to be distorted.

In the above embodiment, the case where the columnar and hollow spherical magnesium alloy fabrication 31 is fabricated has been described. However, the present invention is not limited thereto, and the present invention can be achieved by changing the shape of the magnesium alloy mold. The shape of the forged product can be changed arbitrarily. In the above-described embodiment, the case where a net is used as a breathable material and the entire bowl is formed of a breathable material is described. However, the present invention is not limited to this. May be formed of a breathable material.

By forming a part of the bowl shape with a breathable material, the fluidity of the molten metal reaches the details and thin parts where it is easy to lose power.

In the above embodiment, a net is used as a breathable material. However, the present invention is not limited to this. A plate having a plurality of holes (punching metal) or a cloth or net, a plate having a plurality of holes (punching) It is composed of a combination of metal) or cloth and may be fc.

Even if a material having air permeability such as these is used, the apparent heat conductivity coefficient is reduced, so that even if the molten metal 3 takes the shape of the mold 1 and the core 2, it does not harden instantly. Fluidity is maintained, and molten metal 3 spreads over the entire mold 1 and core 2. In the above examples, AZ 9 1 D was used as the magnesium alloy, but the magnesium alloy is not limited to this, but magnesium, aluminum, zinc, manganese, rare earth, heavy rare earth, yttrium, calcium, strontium, silver, silicon, Zirconium, Bellium, Nickel, Iron, Copper, Konolt, Sodium, Potassium, Barium medium strength, etc .: Selected and added magnesium alloys may be used.

The net is woven in a weaving method such as plain weave, twill weave, twisted wire weave, cedar twill weave, satin weave, plain tatami weave, reverse tatami weave, stretch weave, chain-like vertical three-fold weave Can be used.

In the above embodiment, a force mesh using a mesh with a mesh of 20 can be selected in the range of 1.5 to 3600.

In the above embodiment, a net having a net diameter of 0.3 O mm is used, but the net diameter can be selected in the range of 0.02 mm to 6 mm.

Accordingly, it is possible to select the optimal net for forging in consideration of the composition of the magnesium alloy, the size and shape of the forged product, and the like.

When using a board with multiple holes, the shape of the hole will affect the board thickness and air permeability. The shape and the aperture ratio can be set to arbitrary values.

This makes it possible to select a plate having a plurality of holes optimal for forging in consideration of the composition of the magnesium alloy, the size and shape of the forged product, and the like.

In the case of using a cloth, it is possible to use a woven fabric and a non-woven fabric that are air permeable, and any woven fabric, nonwoven fabric manufacturing method, and fiber diameter can be selected. Examples of the woven fabric having air permeability include a carbon fiber pre-predder having air permeability.

This makes it possible to select an optimum fabric for forging in consideration of the composition of the magnesium alloy, the size and shape of the forged product, and the like.

In the above embodiment, the mesh body is made of stainless steel. Without being limited to this, the mesh body is, for example, aluminum alloy, nickel, monel, flame, red copper, phosphor bronze, copper, silver, gold, iron. Metals such as titanium, nichrome, hastelloy or inconel, PBO, heat-resistant chemical fibers such as carbon fiber or meta-aramide fiber, and heat-resistant ceramics such as carbon, mullite, alumina and zirconia Or a combination thereof.

Similarly, a plate and cloth having a plurality of holes may be formed of any one of the above metals, chemical fibers and ceramics, or a combination thereof.

This makes it possible to select the most suitable net, board or cloth material for forging in consideration of the composition of the magnesium alloy and the size and shape of the forged product.

Further, the net body, the board, and the cloth may have flexibility.

As a result, the mesh body, the plate, and the bottom have flexibility, so that the magnesium alloy saddle can be easily manufactured.

Furthermore, by changing the shape of the mold, it is possible to easily change the shape of the magnesium alloy forged product.

The present invention can also be applied to continuous forging. When applied to continuous forging, for example, a continuous forging apparatus, a continuous forging roll, and a belt are formed of a breathable material. Industrial application fields

It is possible to provide a magnesium alloy mold capable of ensuring the fluidity of the molten magnesium alloy while reducing the manufacturing cost of the forging apparatus and the energy cost generated by heating, and a magnesium alloy forging method using the mold.

Claims

The scope of the claims

1. The mold for magnesium alloy, characterized in that the mold and / or core is made of a breathable material.

2. The mold for a magnesium alloy according to claim 1, wherein the breathable material is composed of any one of a net, a plate having a plurality of holes, a cloth, or a combination thereof.

3. The mold for magnesium alloy according to claim 2, wherein the net body, the plate or the cloth is made of any one of metal, chemical cord and ceramic, or a combination thereof.

4. The mold for a magnesium alloy according to claim 2, wherein the net body, the board and the cloth are flexible.

5. A method for producing a magnesium alloy, characterized by using a mold and a mold in which Z or core is formed of a breathable material.

6. The method for producing a magnesium alloy according to claim 5, wherein the air-permeable material is composed of a net body, a plate having a plurality of holes, a cloth, or a combination thereof.