JP2005138159A - Aluminum die cast molding, die casting method, and die for die casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To an aluminum die cast molding, wherein the partial change in characteristics can widely be realized and the adhesion between the components therein is improved, and the rise of production cost is prevented. <P>SOLUTION: The aluminum die cast molding P1 is provided with a plurality of base metals M1 and M2 in which at least either is formed of molten metal. The main component of the plurality of base metals M1 and M2 is aluminum, and the contents of silicon are differentiated, respectively. The plurality of base metals M1 and M2 are metallurgically integrally formed each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an aluminum die cast product, a die casting method, and a die casting die.

  A general aluminum die-cast product consists of a base material formed by a molten metal obtained by melting a single type of aluminum alloy. Such an aluminum die-cast product is manufactured as follows (see, for example, Non-Patent Document 1). That is, first, a die casting die for forming a cavity communicating with the pressure inlet is prepared. Next, pressure is applied to the molten metal while pouring the molten metal into the cavity. Then, the molten metal is solidified in the cavity to form a base material. The aluminum die-cast product obtained in this way is used for many parts such as a compressor housing and a piston, which have a certain degree of strength and require light weight.

  Also known is an aluminum die-cast product in which a base material having a component different from that of a base material made of molten metal is inserted as an insert member. Such an aluminum die-cast product is manufactured as follows (see, for example, Non-Patent Document 2). Also in this case, first, a die casting mold for forming a cavity communicating with the pressure inlet is prepared. Next, after inserting an insert member into the cavity, pressure is applied to the molten metal while pouring the molten metal into the cavity. Then, the molten metal is solidified in the cavity to form a base material. Aluminum die cast products obtained in this way are also used for many parts.

Tomonobu Kanno and Yuzo Uehara “Introduction to Die Casting Technology-Second Edition”, Nikkan Kogyo Shimbun, December 18, 1997, P.I. 1-4 Takahashi Kiyoshi, Arai Kazuyoshi, Miyata Kiyozo and Yanagida Hiroaki “Industrial Materials Dictionary” Industrial Research Committee, October 20, 1997 105

  However, in general aluminum die-cast products formed only from a single type of molten metal, the base material formed by that molten metal is a single type, so the strength, wear resistance, thermal conductivity, wire, Physical or mechanical properties such as thermal expansion coefficient and workability are limited, and partially different physical or mechanical properties cannot be exhibited. When such partial characteristic changes are to be made, it is necessary to join members made of other components to the aluminum die-cast product, or to perform surface treatment such as plating or coating. In some cases, there is concern about the adhesion between the base material and these materials. In this case, an increase in manufacturing process is inevitable, resulting in an increase in manufacturing cost.

  In this regard, if an aluminum die-cast product with an insert member having a different component from that of the molten base material, the physical or mechanical characteristics partially differ depending on the base material made of the molten metal and the base material made of the insert member. Will be demonstrated. In this case, although there is a trouble of providing the insert member in the cavity, the manufacturing process is not increased so much and the manufacturing cost is not increased so much. However, according to the test results of the inventors, the aluminum die cast product thus obtained does not necessarily have sufficient adhesion between the base material and the insert member.

  Japanese Patent Laid-Open No. 2000-280277 discloses a mold and a method for forming two layers integrally with, for example, a molten magnesium and an unsolidified resin. However, this technique uses a different material having different main components such as magnesium and resin as a base material, and only uses a greatly different characteristic difference between different materials. For this reason, when manufacturing aluminum die-cast products that use the same type of material, the main component of which is aluminum, as the base material, the difference in characteristics between the same type of materials is not as great as that between different types of materials, and this technology is used as is. Can not do it.

  Moreover, as described in Japanese Utility Model Publication No. 61-55188, the first base material formed by the first mixed powder and the first base material are integrally formed. It is also conceivable to use a sintered product composed of a second base material formed of different second mixed powders. In this sintered product, a first green compact made of a first mixed powder and a second green compact made of a second mixed powder are integrally molded by a cold isostatic pressure (CIP) molding method to form a composite green compact. After the body is obtained, the composite green compact is obtained by hot extrusion using a die having a die straddling the first green compact and the second green compact. Since the sintered product obtained in this manner is formed integrally while the components of the first base material and the second base material are different, there is no separation between the first base material and the second base material. , Partial property changes can be realized. However, such a sintered product is difficult to be formed into a complicated shape and needs to be made into a powder at the time of manufacture, which is disadvantageous in terms of manufacturing cost as compared with a cast product such as an aluminum die-cast product.

  Further, as described in JP-A-10-288079 and JP-A-10-323747, hard particles in the molten metal are partially aggregated by a filter medium while using a single molten metal. It is also possible to use an aluminum die-cast product. Partial changes in characteristics can also be realized by the aluminum die-cast product thus obtained. However, this aluminum die-cast product can realize only partial improvement in wear resistance due to aggregation of hard particles, and cannot realize partial changes in other characteristics.

  The present invention has been made in view of the above-described conventional situation, and in an aluminum die-cast product, it is possible to realize a wide range of partial changes in characteristics and excellent adhesion between the parts, and an increase in manufacturing cost. It is a problem to be solved to prevent the occurrence of complications.

  The inventors have intensively studied to solve the above problems. As a result, it was confirmed that an aluminum die-cast product having an insert member is effective for realizing a partial change in characteristics widely. However, aluminum die-cast products with conventional insert members use insert members that have been molded and cooled to room temperature, and the molten metal is poured while the insert members in the cavities remain at about room temperature. It was confirmed that the adhesion between the base material and the insert member was not always sufficient. One of the causes is that a strong oxide film exists on the surface of the insert member cooled to room temperature, and another reason is that the molten metal is poured while the insert member in the cavity remains at room temperature. However, they discovered that such an oxide film cannot be destroyed. Thus, the present invention has been completed.

  That is, the aluminum die-cast product of the present invention comprises a plurality of base materials, at least one of which is made of molten metal, and the main component of the plurality of base materials is aluminum, each having a different silicon content. The plurality of base materials are metallurgically integrated with each other.

  This aluminum die-cast product includes a plurality of base materials, at least one of which is formed of molten metal. The main component of the plurality of base materials is the same kind of material common to aluminum, but the silicon content is different. The plurality of base materials are integrally formed metallurgically. For this reason, this aluminum die-cast product can realize a wide range of partial changes in properties, such as partial strength, wear resistance, thermal conductivity, linear thermal expansion coefficient, and change in workability, depending on the base material. . More specifically, a base material with a high silicon content exhibits characteristics of high hardness and low linear thermal expansion coefficient, and a base material with a low silicon content exhibits characteristics of low hardness and high linear thermal expansion coefficient. To do.

  Metallurgically integrated is different from the base material with different silicon content, unlike the case where each base material is made by unevenly distributing the silicon arrangement of aluminum alloy with a certain content of silicon. This means that there is a portion where no oxide film exists at the boundary. For this reason, in this aluminum die-cast product, a plurality of base materials having different metal structures exist under excellent adhesion. In the aluminum die-cast product of the present invention, there are a case where there is no oxide film at the boundary and a case where the oxide film remains but the oxide film is not continuous and is partially broken. Of course, there is no brazing material or welding material at the boundary. Furthermore, this aluminum die-cast product does not cause a significant increase in the manufacturing process, and there is no shape limitation compared to the sintered product, and it is not necessary to powder the material at the time of production as in the sintered product, This is advantageous in terms of manufacturing cost.

Therefore, this aluminum die-cast product is capable of realizing a wide range of partial changes in characteristics, is excellent in adhesion between the portions, and does not cause an increase in manufacturing cost. If this aluminum die-cast product is used for, for example, a housing or piston of a CO ₂ compressor that requires higher local strength and easier machining, the CO ₂ compressor can be reduced in weight, size and cost. Can be realized.

  The plurality of base materials can all be formed by molten metal. In this case, it is easy to combine compared with the case where things other than molten metal are combined.

  The aluminum die-cast product of the present invention is not limited to two types of base materials, but when there are two types of base materials, it is easier to form than when there are three or more types.

  It is preferable that the molten metal to be poured first is melted at a temperature about 200 ° C. higher than the molten metal to be poured later. As a result, even if the molten metal previously poured in the die casting mold that forms the cavity is cooled, the molten aluminum to be poured later is not extremely cooled, and the aluminum die-cast product of the present invention is reliably manufactured. Can do.

  In the aluminum die-cast product of the present invention, for example, one base material contains 16.0 to 18.0% by mass of silicon, and the other base material contains 9.6 to 12.0% by mass of silicon. The inventors manufactured such an aluminum die-cast product and confirmed its effect. According to this aluminum die-cast product, high wear resistance is achieved with one base material while easy machining is achieved with the other base material, realizing high performance, light weight, downsizing and cost reduction. Can do.

  In the die casting method of the present invention, the first molten metal and the second molten metal are mainly composed of aluminum, and a first step of applying pressure to the first molten metal while pouring the first molten metal into a small cavity; When the fluidity of the first molten metal in the small cavity becomes low, the small cavity is enlarged to form a large cavity, and the second molten metal having a different silicon content from the first molten metal in the large cavity. A second step of applying pressure to the second molten metal while pouring the molten metal, and a third step of solidifying the first molten metal and the second molten metal in the large cavity to obtain an aluminum die cast product. Features.

  In this die casting method, a first molten metal and a second molten metal whose main component is aluminum are used, and first, in the first step, pressure is applied to the first molten metal while pouring the first molten metal into the small cavity. Then, in the second step, when the fluidity of the first molten metal is lowered in the small cavity, the small cavity is enlarged to form a large cavity, and the second molten metal is different from the first molten metal in the large cavity. Pressure is applied to the second molten metal while pouring the molten metal. Thereafter, in the third step, the first molten metal and the second molten metal are solidified in the large cavity to obtain an aluminum die cast product. Thus, the aluminum die cast product of the present invention can be manufactured.

  In the second step, it is preferable to pour the second molten metal so as not to directly hit the first molten metal. Thereby, it is easy to maintain the shape of the base material formed by the first molten metal previously poured.

  The point in time when the fluidity of the first molten metal is lowered in the small cavity refers to the point in time when the first molten metal is in a molten state and the outer shell is in a solidified state. If a 2nd process is performed at this time, the outline of a 1st molten metal can be remelted with a 2nd molten metal at a 2nd process. The outer shell of the first molten metal can form an oxide film by solidification, but the oxide film is destroyed by the second molten metal in the second step.

  In the die casting method of the present invention, for example, the first aluminum alloy contains 16.0 to 18.0% by mass of silicon, and the second aluminum alloy contains 9.6 to 12.0% by mass of silicon. The inventors manufactured an aluminum die-cast product by such a die casting method, and confirmed its effect. In this case, it is preferable to melt the first aluminum alloy at 800 to 850 ° C. to make a molten metal, and to melt the second aluminum alloy at 650 to 700 ° C. to make a molten metal.

The die casting mold according to the present invention includes a first mold for forming a first pressure inlet for pouring a first molten metal whose main component is aluminum, and a small cavity communicating with the first pressure inlet. With a second mold,
The first mold and the second mold have a second pressure inlet for pouring a second molten metal whose main component is aluminum, expand the small cavity, and communicate with the second pressure inlet. It is configured to be relatively movable so as to form a large cavity.

  In this die casting mold, it is possible to apply pressure to the first molten metal by first pouring the first molten metal from the first pressure inlet by the first mold and the second mold. Then, the first mold and the second mold can apply pressure to the second molten metal while pouring the second molten metal into the large cavity when the fluidity of the first molten metal becomes low in the small cavity. it can. Thereafter, the first molten metal and the second molten metal can be solidified in the large cavity to obtain an aluminum die cast product. Thus, the aluminum die cast product of the present invention can be manufactured.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

  First, the die casting mold shown in FIGS. In this die casting mold, the fixed mold 1 and the movable mold 2 are provided so as to be movable in the horizontal direction away from each other. The first mold 3 is fixed to the left surface of the fixed mold 1 in the figure, and the movable mold 1 The second mold body 4 is fixed to the right side in FIG. By the horizontal movement of the fixed mold 1 and the movable mold 2, the first mold 3 and the second mold body 4 are configured to be openable in the horizontal direction.

  The movable mold 2 is formed with a slide hole 2a that faces the first mold 3, and the second mold body 4 is formed with a slide hole 4a that is continuous with the slide hole 2a and faces the first mold 3. In these slide holes 2a and 4a, as shown in FIGS. 1 to 3, a first slide mold 5a is provided so as to be horizontally movable by a pin 6a, and as shown in FIG. The pin 6b is provided so as to be horizontally movable.

  As shown in FIG. 1, the left surface of the first mold 3 and the first slide mold 5a form a small cavity C1. A fixing pin 3c protruding into the small cavity C1 is fixed to the first mold 3.

  As shown in FIGS. 2 to 4, the first slide mold 5a moves leftward in the slide holes 2a and 4a, and the second slide mold 5b is positioned in the slide hole 2a. 3 and the second slide mold 5b form a large cavity C2 larger than the small cavity C1. The second mold body 4, the first slide mold 5a, and the second slide mold 5b are second molds. The first mold 3, the second mold body 4, the first slide mold 5a, and the second slide mold 5b are made of a Ni—Cr—Mo alloy.

  The first mold 3 is formed with a first pressure inlet 3a that communicates horizontally with the small cavity C1 and a second pressure inlet 3b that communicates horizontally with the large cavity C2. The first pressure inlet 3a communicates below the small cavity C1, and the second pressure inlet 3b is separated from the small cavity C1 and communicates below the large cavity C2.

  A first injection 7 is provided at the first pressure inlet 3a. The first injection 7 includes a first injection sleeve 7a that communicates with the first pressure inlet 3a, a plunger 7b that slides inside the first injection sleeve 7a, and a cylinder 7c that moves the plunger 7b forward and backward by a rod. . A second injection 8 is provided at the second pressure inlet 3b. The second injection 8 includes a second injection sleeve 8a that communicates with the second pressure inlet 3b, a plunger 8b that slides inside the second injection sleeve 8a, and a cylinder 8c that moves the plunger 8b forward and backward by a rod. .

  Using the above die casting mold, first, in the first step, as shown in FIG. 1, the first slide mold 5a is positioned in the slide hole 4a, and the small cavity C1 is the first pressure inlet of the first mold 3. Communicate with 3a. In this state, a fixed amount of the first molten metal M1 is put into the first injection sleeve 7a of the first injection 7, and the plunger 7b is advanced by the cylinder 7c as shown in FIG. In the first molten metal M1, Cu is 4.0 to 5.0 mass%, Si is 16.0 to 18.0 mass%, Mg is 0.45 to 0.65 mass%, and Zn is 1.5 mass%. Hereinafter, ADC14 (first aluminum alloy) in which Fe is 1.3 mass% or less, Mn is 0.5 mass% or less, Ni is 0.3 mass% or less, Sn is 0.3 mass% or less, and Al is the balance. Yes, melted at 800-850 ° C. Thus, pressure is applied to the first molten metal M1 while pouring the first molten metal M1 into the small cavity C1.

  Then, in the second step, as shown in FIG. 3, when the fluidity of the first molten metal M1 becomes low in the small cavity C1, the first slide mold 5a is moved leftward, as shown in FIG. Next, the second slide mold 5b is positioned in the slide hole 2a. The time when the fluidity of the first molten metal M1 becomes low in the small cavity C1 is the time when the first molten metal M1 is in a molten state and the outer shell is in a solidified state. In this way, the small cavity C1 is enlarged to be a large cavity C2. Further, as shown in FIGS. 3 and 4, the large cavity C <b> 2 is communicated with the second pressure inlet 3 b of the first mold 3. At this time, as shown in FIG. 3, the portion made of the first molten metal M1 is held in the large cavity C2 by the fixing pin 3c. In this state, a predetermined amount of the second molten metal M2 is put into the second injection sleeve 8a of the second injection 8, and the plunger 8b is advanced by the cylinder 8c as shown in FIG. In the second molten metal M2, Cu is 1.5 to 3.5 mass%, Si is 9.6 to 12.0 mass%, Mg is 0.3 mass% or less, Zn is 1.0 mass% or less, Fe 1.3 mass% or less, Mn is 0.5 mass% or less, Ni is 0.5 mass% or less, Sn is 0.2 mass% or less, Al is the balance ADC12 (second aluminum alloy), 650 Melted at ~ 700 ° C. Thus, pressure is applied to the second molten metal M2 while pouring the second molten metal M2 into the large cavity C2.

  Thus, if the second step is performed at this time, the outer shell of the first molten metal M1 can be remelted by the second molten metal M2 in the second step. The outer shell of the first molten metal M1 can form an oxide film by solidification, but the oxide film is destroyed by the second molten metal M2 in the second step. Further, since the first molten metal M1 is melted at a temperature about 200 ° C. higher than the second molten metal M2, even if the first molten metal M1 is cooled by the die casting die, it is extremely cooled to the second molten metal M2. There is nothing. Further, since the second pressure inlet 3b communicates with the lower side of the large cavity C2, the second molten metal M2 does not directly contact the portion made of the first molten metal M1, and the shape of the portion made of the first molten metal M1 is maintained. Thus, an aluminum die-cast product P1 described later can be reliably manufactured.

  Thereafter, in the third step, the first molten metal M1 and the second molten metal M2 are solidified in the large cavity C2 to obtain an aluminum die cast product P1. In this way, as shown in FIG. 5A, the aluminum die-cast product P1 of Example 1 can be manufactured. As shown in FIG. 5 (B), the aluminum die-cast product P1 is integrally formed by the first base material M1 made of the first molten metal M1 and the first base material M1 at a boundary where there is no oxide film. And a second base material M2 made of the second molten metal M2.

Since this aluminum die-cast product P1 is different in the components of the first base material M1 and the second base material M2, the partial strength, wear resistance, thermal conductivity, linear thermal expansion coefficient, workability change, etc. A partial change in characteristics can be realized widely. More specifically, the first base material M1 made of ADC14 has a tensile strength of 320 MPa, a 0.2% yield strength of 250 MPa, an elongation of less than 1%, a hardness of 108 HB (10/500), and an impact strength of 3.8 kJ / m. ² , Young's modulus 81.2 GPa, density 2.73 g / cm ² , thermal conductivity 134 W / m · K, linear thermal expansion coefficient 18 × 10 ₋₆ / K, conductivity 37% (IACS), etc. . On the other hand, the second base material M2 made of ADC12 has a tensile strength of 310 MPa, a 0.2% proof stress of 150 MPa, an elongation of 3.5%, a hardness of 86 HB (10/500), an impact strength of 8.1 kJ / m ² , and a density. 2.68 g / cm ² , thermal conductivity 96 W / m · K, linear thermal expansion coefficient 21 × 10 ₋₆ / K, electrical conductivity 23% (IACS), etc. are exhibited.

  Further, in this aluminum die-cast product P1, since the first base material M1 is formed of the first molten metal M1, the same metal structure is formed based on the components, and the second base material M2 is formed of the second molten metal M2. Therefore, the same metal structure is formed on the basis of the components, and the boundary between the first base material M1 and the second base material M2 has a portion where the metal structure is different but there is no oxide film. For this reason, in the aluminum die-cast product P1, the first base material M1 and the second base material M2 having different metal structures exist under excellent adhesion. For this reason, this aluminum die-cast product P1 can exhibit excellent durability.

  Further, the aluminum die cast product P1 does not increase the number of manufacturing steps so much, and there is no limitation on the shape as compared with the sintered product, and it is not necessary to make the material powder at the time of manufacture unlike the sintered product. This is advantageous in terms of manufacturing cost.

Therefore, this aluminum die-cast P1 product can realize a wide range of partial changes in characteristics, is excellent in adhesion between the portions, and does not cause an increase in manufacturing cost. Using this aluminum die cast product P1 housing of CO ₂ compressor, the piston or the like, it is possible to achieve weight reduction of the CO ₂ compressor, the size and cost.

  First, the die casting mold shown in FIGS. In this die casting mold, as shown in FIGS. 6 to 8, the fixed mold 11 and the first movable mold 12 are provided so as to be movable in the horizontal direction away from each other, and as shown in FIGS. Both the fixed mold 11 and the second movable mold 13 are provided so as to be movable in the horizontal direction away from each other. A first mold 14 is fixed to the left surface of the fixed mold 1 shown in FIGS. The first mold 15 of the second mold is fixed to the right surface of the first movable mold 12 shown in FIGS. 6 to 8, and the right surface of the second movable mold 13 shown in FIGS. A second mold 16 of two molds is fixed. As the fixed mold 11 and the first and second movable molds 12 and 13 move in the horizontal direction, both the first mold 14 and the first mold 15 and the first mold 14 and the second mold 16 open in the horizontal direction. It is configured to be possible.

  As shown in FIGS. 6 to 8, the left surface of the first mold 14 and the first mold 15 form a small cavity C1. A fixing pin 14c protruding into the small cavity C1 is fixed to the first mold 14.

  Further, as shown in FIGS. 9 to 11, the first movable mold 12 and the first mold 15 are moved in the left direction and the vertical direction, and the second movable mold 13 and the second mold 16 are closed with the first mold 14. Then, the left surface of the first mold 14 and the second mold 16 form a large cavity C2 that is larger than the small cavity C1. The first mold 15 and the second mold 16 are second molds. The first mold 14, the first mold 15 and the second mold 16 are made of a Ni—Cr—Mo alloy.

  As shown in FIGS. 6 to 11, the first mold 14 is formed with a first pressure inlet 14a that communicates horizontally with the small cavity C1, and as shown in FIGS. A second pressure inlet 16a that communicates horizontally with the large cavity C2 is formed on the opposite side of the first pressure inlet 14a. The first pressure inlet 14a communicates below the small cavity C1, and the second pressure inlet 16a is separated from the small cavity C1 and communicates below the large cavity C2. The first pressure inlet 14a is provided with a first injection 7 similar to that of the first embodiment, and the second pressure inlet 16a is provided with a second injection 8 similar to that of the first embodiment.

  Using the above die casting mold, first, in the first step, as shown in FIG. 6, the first movable mold 12 and the first mold 15 are closed, and the small cavity C1 is the first mold 14 of the first mold 14. It communicates with the pressure inlet 14a. In this state, as shown in FIG. 7, as in the first embodiment, pressure is applied to the first molten metal M1 while pouring the first molten metal M1 into the small cavity C1.

  In the second step, as shown in FIG. 8, when the fluidity of the first molten metal M1 becomes low in the small cavity C1, the first movable mold 12 and the first mold 15 are opened, 9 and 10, the second movable mold 13 and the second mold 16 are closed. In this way, the small cavity C1 is enlarged to be a large cavity C2. Further, the large cavity C <b> 2 is communicated with the second pressure inlet 16 a of the second mold 16. At this time, the portion made of the first molten metal M1 is held in the large cavity C2 by the fixing pin 14c. In this state, as shown in FIG. 11, pressure is applied to the second molten metal M2 while pouring the second molten metal M2 into the large cavity C2, as in the first embodiment.

  Thereafter, in the third step, the first molten metal M1 and the second molten metal M2 are solidified in the large cavity C2 to obtain an aluminum die cast product P2. Thus, as shown in FIGS. 5A and 5B, an aluminum die-cast product P2 of Example 2 can be manufactured. This aluminum die-cast product P2 can also exhibit the same effects as those of the first embodiment.

  It is also possible to manufacture the vane of the vane type compressor by the same die casting method as in the first and second embodiments. In this case, the tip portion of the vane is a high hardness base material, and the other portion is a low hardness base material.

  Moreover, it is also possible to manufacture a cylinder block on which the piston of the piston compressor slides by the same die casting method as in the first and second embodiments. In this case, the sliding part of the cylinder block is a high hardness base material, and the other part is a low hardness base material.

  Further, the heat sink component can be manufactured by the same die casting method as in the first and second embodiments. In this case, the heat receiving portion is a high thermal conductivity base material.

  Moreover, it is also possible to manufacture bearing parts of various compressors by the same die casting method as in the first and second embodiments. In this case, the rotating portion is a base material having a linear thermal expansion coefficient close to the drive shaft made of an iron-based material.

  INDUSTRIAL APPLICABILITY The present invention can be used for many parts such as a compressor housing and a piston, which have a certain degree of strength and require light weight, and a method for manufacturing the same.

1 is a cross-sectional view of a die casting mold of Example 1. FIG. 1 is a cross-sectional view of a die casting mold of Example 1. FIG. 1 is a cross-sectional view of a die casting mold of Example 1. FIG. 1 is a cross-sectional view of a die casting mold of Example 1. FIG. FIG. A is a cross-sectional view and FIG. B is an enlarged view of a main part of the aluminum die cast product of Examples 1 and 2. 6 is a cross-sectional view of a die casting mold of Example 2. FIG. 6 is a cross-sectional view of a die casting mold of Example 2. FIG. 6 is a cross-sectional view of a die casting mold of Example 2. FIG. 6 is a cross-sectional view of a die casting mold of Example 2. FIG. 6 is a cross-sectional view of a die casting mold of Example 2. FIG. 6 is a cross-sectional view of a die casting mold of Example 2. FIG.

Explanation of symbols

M1 ... 1st molten metal, 1st base material M2 ... 2nd molten metal, 2nd base material C1 ... Small cavity C2 ... Large cavity P1, P2 ... Aluminum die-cast product 3a, 14a ... 1st pressure inlet 3, 14, ... 1st gold | metal | money Mold 4, 5a, 5b, 15, 16 ... second mold

Claims (10)

  At least one has a plurality of base materials formed of molten metal, the main component of the plurality of base materials is aluminum, each having a different silicon content, and the plurality of base materials are metallurgical to each other Aluminum die-cast product, characterized by being formed in one piece.   The aluminum die-cast product according to claim 1, wherein the plurality of base materials are all formed of molten metal.   The aluminum die-cast product according to claim 1 or 2, wherein the plurality of base materials are of two types.   The aluminum die-cast product according to claim 3, wherein the one base material contains 16.0 to 18.0% by mass of silicon, and the other base material contains 9.6 to 12.0% by mass of silicon. A first step in which the main component of the first molten metal and the second molten metal is aluminum, and pressure is applied to the first molten metal while pouring the first molten metal into a small cavity;
When the fluidity of the first molten metal in the small cavity becomes low, the small cavity is enlarged to form a large cavity, and the second molten metal having a different silicon content from the first molten metal in the large cavity. A second step of applying pressure to the second molten metal while pouring
A die casting method comprising: a third step of solidifying the first molten metal and the second molten metal in the large cavity to obtain an aluminum die cast product.   The die casting method according to claim 5, wherein in the second step, the second molten metal is poured so as not to directly contact the first molten metal.   When the first molten metal is in a molten state and the outer shell is solidified, the second step is performed, and the outer shell of the first molten metal is remelted by the second molten metal in the second step. Item 7. The die casting method according to Item 5 or 6.   The first molten metal is a first aluminum alloy containing silicon, and the second molten metal contains less silicon than the first molten metal and is melted at a lower temperature than the first aluminum alloy. The die casting method according to any one of claims 5 to 7, wherein the die casting method is an alloy.   The die casting method according to claim 8, wherein the first aluminum alloy contains 16.0 to 18.0 mass% of silicon, and the second aluminum alloy contains 9.6 to 12.0 mass% of silicon. A first mold and a second mold for forming a first pressure inlet for pouring a first molten metal whose main component is aluminum, and a small cavity communicating with the first pressure inlet;
The first mold and the second mold have a second pressure inlet for pouring a second molten metal whose main component is aluminum, expand the small cavity, and communicate with the second pressure inlet. A die casting mold characterized by being configured to be relatively movable so as to form a large cavity.

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