Aluminum alloy casting material and method for producing aluminum alloy casting material

Abstract

Provided is an aluminum alloy casting material satisfying formula (A). Formula (A): −0.04 × msi − 0.14 × mMg − 0.35 × mFe + 1.21 > 1 In formula (A), msi is the mass ratio (mass%) of Si in the aluminum alloy casting material. mMg is the mass ratio (mass%) of Mg in the aluminum alloy casting material. mFe is the mass ratio (mass%) of Fe in the aluminum alloy casting material.

Description

Aluminum alloy casting material and method for manufacturing aluminum alloy casting material

[0001] The present disclosure relates to an aluminum alloy casting and a method for manufacturing the aluminum alloy casting.

[0002] Copper products are widely used as conductive materials. With the recent rise in copper prices, there is a demand for inexpensive conductive materials. Aluminum alloys, which are cheaper than copper, have been proposed as conductive materials. Aluminum alloys are disclosed in Patent Documents 1 to 5.

[0003] Japanese Patent Application Laid-Open No. 2002-226932 Japanese Patent Application Laid-Open No. 2003-119536 Japanese Patent Application Laid-Open No. 2010-144253 Japanese Patent Application Laid-Open No. 2004-217945 Japanese Patent Application Laid-Open No. 2002-309329

[0004] The aluminum alloy preferably has high electrical conductivity. In one aspect of the present disclosure, it is preferable to provide a cast aluminum alloy having high electrical conductivity and a method for producing the cast aluminum alloy having high electrical conductivity.

[0005] One aspect of the present disclosure is a cast aluminum alloy material in which the following formula (A) is satisfied:

[0006] Formula (A) -0.04×m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 (in the formula (A), m ｓｉ is the mass ratio (mass%) of Si in the cast aluminum alloy, and m Ｍｇ is the mass ratio (mass%) of Mg in the cast aluminum alloy, and m Ｆｅ is the mass ratio (mass %) of Fe in the cast aluminum alloy.) The cast aluminum alloy that is one aspect of the present disclosure has high electrical conductivity.

[0007] Another aspect of the present disclosure is a method for producing an aluminum alloy casting, comprising filling a mold with a molten metal satisfying the following formula (B), cooling the filled molten metal to solidify it, and holding the solidified material at a temperature of 300°C or higher and 430°C or lower for a time period of 10 minutes or higher and 650 minutes or lower:

[0008] Formula (B) -0.04×m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 (in the formula (B), m ｓｉ is the mass ratio (mass%) of Si in the molten metal, and m Ｍｇ is the mass ratio (mass%) of Mg in the molten metal, and m Ｆｅ is the mass ratio (mass %) of Fe in the molten metal.) According to the method for producing a cast aluminum alloy that is another aspect of the present disclosure, a cast aluminum alloy having high electrical conductivity can be produced.

[0009] Exemplary embodiments of the present disclosure will now be described.

[0010] 1. Cast Aluminum Alloy Material In the cast aluminum alloy material of the present disclosure, the following formula (A) holds true.

[0011] Formula (A) -0.04×m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 In formula (A), m ｓｉ is the mass ratio (mass%) of Si in the cast aluminum alloy. Ｍｇ is the mass ratio (mass%) of Mg in the cast aluminum alloy. Ｆｅ is the mass ratio (mass%) of Fe in the cast aluminum alloy.

[0012] In the aluminum alloy casting material of the present disclosure, aluminum is the main component. The main component is the component with the largest mass ratio. The mass ratio of aluminum is preferably 97.84 mass% or more, and more preferably 99.35 mass% or more.

[0013] The cast aluminum alloy of the present disclosure has, for example, the specific composition shown below (hereinafter referred to as the specific composition). In the specific composition, m in formula (A) ｓｉ In the specific composition, m in formula (A) is 0.2 mass % or more and 0.6 mass % or less. Ｍｇ In the specific composition, m in formula (A) is 0.45 mass % or more and 0.9 mass % or less. Ｆｅis 0 mass % or more and 0.35 mass % or less. In the specific composition, the balance consists of aluminum and unavoidable impurities.

[0014] The surface roughness Ra of the casting surface of the aluminum alloy cast material of the present disclosure is, for example, 0.8 μm or more and 17.0 μm or less.

[0015] 2. Method for Producing Cast Aluminum Alloy Material In the method for producing a cast aluminum alloy material of the present disclosure, a molten metal satisfying the following formula (B) is filled into a mold.

[0016] Formula (B) -0.04×m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 In formula (B), m ｓｉ is the mass ratio (mass%) of Si in the molten metal. Ｍｇ is the mass ratio (mass%) of Mg in the molten metal. Ｆｅ is the mass ratio (mass%) of Fe in the molten metal.

[0017] The main component of the molten metal is aluminum, and the mass ratio of aluminum in the molten metal is preferably 97.8 mass % or more, and more preferably 99.35 mass % or more.

[0018] After the molten metal is filled into the mold, the filled molten metal is cooled and solidified, and the solidified material is then held at a temperature of 300° C. or higher and 430° C. or lower for 20 minutes or longer and 650 minutes or shorter.

[0019] In the manufacturing method of the aluminum alloy casting material of the present disclosure, for example, the molten metal used has a specific composition (hereinafter referred to as a specific molten metal composition). The specific molten metal composition is defined as m in formula (B). ｓｉ In the specific molten metal composition, m in formula (B) is 0.2 mass % or more and 0.6 mass % or less. Ｍｇ In the specific molten metal composition, m in formula (B) is 0.45 mass % or more and 0.9 mass % or less. Ｆｅ is 0 mass % or more and 0.35 mass % or less. In the specific molten metal composition, the balance of the molten metal consists of aluminum and unavoidable impurities.

[0020] In the method for producing an aluminum alloy cast material according to the present disclosure, the method of filling a mold with molten metal and cooling and solidifying the filled molten metal is, for example, low-pressure casting or gravity casting.

[0021] The aluminum alloy cast material produced by the method for producing an aluminum alloy cast material according to the present disclosure has, for example, the same composition as the molten metal. In this case, if formula (B) is true for the molten metal, formula (A) is true for the produced aluminum alloy cast material. Furthermore, if the molten metal used has a specific molten metal composition, the produced aluminum alloy cast material has the specific composition.

[0022] 3. Effects of the Cast Aluminum Alloy and the Manufacturing Method of the Cast Aluminum Alloy (1A) The cast aluminum alloy of the present disclosure satisfies formula (A), and therefore the electrical conductivity of the cast aluminum alloy is high.

[0023] (1B) The cast aluminum alloy of the present disclosure has, for example, a specific composition, in which case the cast aluminum alloy has higher electrical conductivity.

[0024] (1C) The surface roughness Ra of the casting surface of the cast aluminum alloy of the present disclosure is, for example, 0.8 μm or more and 17.0 μm or less. In this case, the electrical conductivity of the cast aluminum alloy is further increased.

[0025] (1D) In ​​the method for producing a cast aluminum alloy material according to the present disclosure, a molten metal satisfying formula (B) is used. The solidified material is maintained at a temperature of 300°C or higher and 430°C or lower for a time period of 20 minutes or higher and 650 minutes or lower. Therefore, the produced cast aluminum alloy material has high electrical conductivity.

[0026] (1E) In the method for producing a cast aluminum alloy according to the present disclosure, for example, the molten metal used has a specific molten metal composition. In this case, the produced cast aluminum alloy has higher electrical conductivity.

[0027] (1F) In the method for producing an aluminum alloy cast material according to the present disclosure, for example, a method in which a molten metal is filled into a mold and cooled to solidify is a low-pressure casting method or a gravity casting method, in which case the produced aluminum alloy cast material has higher electrical conductivity.

[0028] The reason for this is presumed to be as follows: When low-pressure casting or gravity casting is used, voids are less likely to occur in the aluminum alloy casting material, resulting in higher electrical conductivity of the aluminum alloy casting material.

[0029] 4. Examples (1) Production of Cast Aluminum Alloy Materials of Examples 1 to 12 and Comparative Examples 1 to 4 Cast aluminum alloy materials of Examples 1 to 12 and Comparative Examples 1 to 4 were produced as follows. First, a molten alloy was prepared using an electric furnace. ｓｉ , m Ｍｇ , and m Ｆｅ was the value listed in Table 1.

[0030] m in Table 1 ｓｉ , m Ｍｇ , and m Ｆｅ The unit of was mass %. The balance of the molten metal consisted of aluminum and inevitable impurities. Table 1 shows the judged values ​​for each of Examples 1 to 12 and Comparative Examples 1 to 4. The judged values ​​are defined as "-0.04 × m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21". The judgment value is the left side of formula (B). In the judgment value, m ｓｉ is the mass ratio (mass%) of Si in the molten metal. Ｍｇ is the mass ratio (mass%) of Mg in the molten metal. Ｆｅ is the mass ratio (mass%) of Fe in the molten metal.

[0031] In Examples 1 to 12, the judged value was greater than 1. That is, formula (B) was established in Examples 1 to 12. In Comparative Examples 1 to 4, the judged value was less than 1. That is, formula (B) was not established in Comparative Examples 1 to 4.

[0032] Next, the molten metal was filled into a copper mold. The copper mold was a casting mold. The cavity of the copper mold had dimensions of 150 mm length, 150 mm width, and 30 mm height. Next, the molten metal was cooled and solidified. The casting method was gravity casting. Next, the solidified product was removed from the copper mold. The solidified product was an aluminum alloy cast material. For Examples 1 to 6 and Comparative Examples 1 and 2, aluminum alloy cast materials were completed through the above steps.

[0033] For Examples 7 to 12 and Comparative Examples 3 and 4, the aluminum alloy cast materials removed from the copper molds were further subjected to heat treatment. The heat treatment method was as follows.

[0034] The aluminum alloy cast material was cut into a rectangular parallelepiped shape having a length of 30 mm, a width of 30 mm, and a height of 15 mm.

[0035] Next, the cut aluminum alloy cast material was placed in an electric furnace and subjected to heat treatment. The atmosphere inside the electric furnace was air. During the heat treatment, the temperature of the aluminum alloy cast material was controlled based on the temperature of the aluminum alloy cast material. During the heat treatment, the temperature of the aluminum alloy cast material was maintained at 300°C or higher for the holding time shown in Table 1. After completion of the heat treatment, the aluminum alloy cast material was removed from the electric furnace. For Examples 7 to 12 and Comparative Examples 3 and 4, aluminum alloy cast materials were completed through the above steps.

[0036] Since the composition of the molten metal and the composition of the finished cast aluminum alloy material are the same, formula (A) also holds for the cast aluminum alloy materials of Examples 1 to 12. On the other hand, formula (A) does not hold for Comparative Examples 1 to 4 either.

[0037] (2) Measurement of electrical conductivity of cast aluminum alloy materials of Examples 1 to 12 and Comparative Examples 1 to 4 Electrical conductivity was measured for each of the cast aluminum alloy materials of Examples 1 to 12 and Comparative Examples 1 to 4. The electrical conductivity was measured by the following method.

[0038] One surface of the aluminum alloy casting was polished and smoothed. Next, the electrical conductivity was measured at three points on the polished surface using a Sigma Test 2.069 manufactured by Nippon Foerster Co., Ltd. Next, the average value of the electrical conductivity measured at the three points was calculated. The calculated average value was used as the electrical conductivity of the aluminum alloy casting.

[0039] The electrical conductivities of the cast aluminum alloy materials are shown in Table 1. The cast aluminum alloy materials of Examples 1 to 12 had high electrical conductivities. On the other hand, the cast aluminum alloy materials of Comparative Examples 1 and 2 had low electrical conductivities. Furthermore, the electrical conductivities of the cast aluminum alloy materials of Comparative Examples 3 and 4 were lower than those of Examples 7 to 12, which were provided with a holding time similar to that of Comparative Examples 3 and 4.

[0040] (3) Production of Cast Aluminum Alloy Materials of Examples 13 to 15 Cast aluminum alloy materials of Examples 13 to 15 were produced basically in the same manner as in Example 1. However, the m ｓｉ , m Ｍｇ , and m Ｆｅ was the value listed in Table 2.

[0041] In Example 13, the casting method was low-pressure casting, and molten metal at about 740°C was poured into a plaster mold at about 200°C.

[0042] Comparative Example 5 shown in Table 2 is an extruded material of an aluminum alloy. ｓｉ , m Ｍｇ , and m Ｆｅ The values ​​were as shown in Table 2. The remainder of the extruded material of Comparative Example 5 consisted of aluminum and unavoidable impurities.

[0043] (4) Measurement of surface roughness of the cast aluminum alloy materials of Examples 13 to 15 and the extruded material of Comparative Example 5 The surface roughness Ra of the cast aluminum alloy materials of Examples 13 to 15 and the extruded material of Comparative Example 5 was measured using an OLYMPUS 3D measuring laser microscope LEXTOLS5100. The surfaces of the cast aluminum alloy materials of Examples 13 to 15 were casting surfaces. The measurement results of the surface roughness Ra are shown in Table 2. The surface roughness Ra of the cast aluminum alloy materials of Examples 13 to 15 was larger than the surface roughness Ra of the extruded material of Comparative Example 5.

[0044] 5. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modifications.

[0045] (1) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0046] (2) In addition to the above-described aluminum alloy cast material, the present disclosure can also be realized in various forms, such as a product including the aluminum alloy cast material as a component, or a heat treatment method for the aluminum alloy cast material.

Claims

1. Aluminum alloy casting material for which the following formula (A) is satisfied: Formula (A) -0.04 × m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 (in the formula (A), m ｓｉ is the mass ratio (mass%) of Si in the cast aluminum alloy, and m Ｍｇ is the mass ratio (mass%) of Mg in the cast aluminum alloy, and m Ｆｅ is the mass ratio (mass%) of Fe in the cast aluminum alloy.

2. The aluminum alloy casting material according to claim 1, wherein the m ｓｉ is 0.2 mass % or more and 0.6 mass % or less, Ｍｇ is 0.45 mass % or more and 0.9 mass % or less, Ｆｅ 1. An aluminum alloy casting material comprising: 0% by mass or more and 0.35% by mass or less of Zr, and the remainder consisting of aluminum and inevitable impurities.

3. An aluminum alloy cast material according to claim 1 or 2, wherein the surface roughness Ra of the casting surface of said aluminum alloy cast material is 0.8 μm or more and 17.0 μm or less.

4. A method for producing an aluminum alloy casting material, comprising: filling a mold with molten metal satisfying the following formula (B); cooling and solidifying the filled molten metal; and holding the solidified material at a temperature of 300°C or higher and 430°C or lower for 20 minutes or longer and 650 minutes or shorter. Formula (B) -0.04×m ｓｉ -0.14 x m Ｍｇ -0.35 x m Ｆｅ +1.21>1 (in the formula (B), m ｓｉ is the mass ratio (mass%) of Si in the molten metal, and m Ｍｇ is the mass ratio (mass%) of Mg in the molten metal, and m Ｆｅ is the mass ratio (mass%) of Fe in the molten metal.

5. The method for producing an aluminum alloy casting material according to claim 4, wherein the m ｓｉ is 0.2 mass % or more and 0.6 mass % or less, Ｍｇ is 0.45 mass % or more and 0.9 mass % or less, Ｆｅ and the remainder of the molten metal consists of aluminum and inevitable impurities.

6. A method for producing an aluminum alloy casting material according to claim 4 or 5, wherein the method of filling the molten metal into a mold and cooling and solidifying the filled molten metal is low-pressure casting or gravity casting.

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