JP4038230B1 - Aluminum alloy die-cast product and manufacturing method thereof - Google Patents

Abstract

Disclosed is an aluminum alloy die-cast product that has good fluidity of molten metal in a mold, can easily form a thin-walled portion, has a good surface condition, is glossy, and has an excellent appearance. To do.
In an aluminum alloy die-cast product, the aluminum alloy contains 0.5 to 1.9% by weight of manganese, is cast at an injection speed of 3 m / s or more, and the cast product is anodized. Die-casting by melting a featured aluminum alloy die-cast product and an aluminum alloy containing 0.5 to 1.9% by weight of manganese, injecting it into a mold cavity at an injection speed of 3 m / s or more, and cooling and solidifying it. A method for producing an aluminum alloy die-cast product, comprising subjecting the resulting die-cast product to an anodizing treatment.
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Description

  The present invention relates to an aluminum alloy die-cast product and a manufacturing method thereof. More specifically, the present invention provides an aluminum alloy die-cast product that has good fluidity of the molten metal in the mold, can easily form a thin-walled portion, has a good surface condition, is glossy, and has an excellent appearance. It relates to the manufacturing method.

Die casting is a technique in which a molten non-ferrous metal alloy is poured into a precision mold at high speed and high pressure, and instantly formed. Die casting can achieve high dimensional accuracy and can produce a large number of products having complicated shapes, so that the cost can be significantly reduced. When alloying aluminum with copper, silicon, magnesium, zinc, iron, manganese, nickel, tin, etc., the mechanical properties at normal and high temperatures are remarkably improved due to solid solution hardening, work hardening, age hardening, and corrosion resistance. Properties such as wear resistance and low coefficient of thermal expansion are also added. Aluminum alloy die-cast products are used in a wide range of fields such as aviation, space, construction, transportation equipment, electricity, communications, etc., especially in the field of transportation equipment due to the need for weight reduction of vehicles for global environmental problems and various environmental technologies. Demand is growing.
Aluminum alloy die casting is defined in JIS H 5302 by classifying Al-Si, Al-Si-Mg, Al-Mg, and Al-Si-Cu alloys by chemical components, for example, for die casting. ADC12 which is most widely used as an aluminum alloy is Cu 1.5 to 3.5%, Si 9.6 to 12.0%, Mg 0.3% or less, Zn 1.0% or less, Fe 1.3% or less, Mn 0.3%. 5% or less, Ni 0.5% or less, Sn 0.3% or less, and Al balance.
Many aluminum alloys for die casting contain a relatively large amount of Si of about 7.5 to 18.0%. When Si is contained in the aluminum alloy, the fluidity of the molten metal is improved, the thin product can be easily molded, and the hardness and strength of the cast product are increased. However, when Si is contained, the cast product is less likely to be glossy and tends to have a brownish stain color. By including Cu in the aluminum alloy, the mechanical properties of the cast product are improved. It is said that when Mn is contained in an aluminum alloy, an intermetallic compound of Al—Si—Fe—Mn is generated, and the elongation, impact strength, and machinability of the cast product are lowered.
Various attempts have been made to improve the gloss of aluminum alloy die-cast products, many of which are secondary processing of castings. For example, as a plating layer structure of an aluminum die casting that can form a plating layer having a sufficient thickness also on the surface of a die casting product on a hot water bath or a recess, a semi-bright nickel plating layer and copper sulfate are formed on the surface of the aluminum die casting. An aluminum die casting is formed by forming a base plating layer formed by alternately laminating plating layers, and forming a surface plating layer by sequentially laminating a bright nickel plating layer and a decorative chromium plating layer on the base plating layer. A plating layer structure has been proposed (Patent Document 1). However, in order to form this plating layer, not only a long process of performing the plating process many times is required, but at present, it is desired to avoid the chromium plating process as much as possible to prevent pollution.
Further, as a method for producing a die cast aluminum wheel for automobiles having excellent gloss, Si: 7 to 12% by mass , Mg: 0.1 to 0.4% by mass , Fe: 0.3 to 0.6% by mass And after degassing and degassing the molten aluminum alloy containing Mn: 0.2-0.5% by mass , die-casting, and after T6 processing, machining is performed to ensure dimensional accuracy, and wheel design surface A method for manufacturing an automobile wheel is proposed in which the surface chill layer is buffed to give the chill layer a glossy surface as a design decorative surface, and further, a transparent clear coating is applied to the surface (Patent Document 2). . However, this manufacturing method requires four steps of T6 processing, machining, buffing, and coating as secondary processing after die casting, and is likely to be expensive.
Anodization is widely used to modify the surface of aluminum alloy die-cast products. By electrolyzing aluminum at the anode to form a thick oxide film, the appearance can be improved, and corrosion resistance and wear resistance can be imparted. Anodizing is also applied to impart metallic luster to aluminum alloy die-cast products. For example, as a method of converting the surface of an aluminum or aluminum alloy material into a three-dimensional crystal pattern as a metallic luster and decorativeness, a step is formed using an alkali or alkaline earth metal hydroxide solution on the aluminum or aluminum alloy material. A method has been proposed in which a type crystal precipitation process is performed, followed by an anodizing process, a PVD process, or a CVD process (Patent Document 3). However, the PVD or CVD process not only requires an expensive apparatus, but depending on the shape of the die-cast product, a uniform process may not be possible.
JP 7-316877 A Japanese Patent Laid-Open No. 9-272957 JP 2005-206862 A

  The present invention provides an aluminum alloy die-cast product having good fluidity of a molten metal in a mold, easily forming a thin-walled portion, having a good surface condition, having a gloss, and having an excellent appearance, and a method for producing the same. It was made for the purpose of providing.

As a result of intensive studies to solve the above problems, the present inventors have found that an aluminum alloy containing 0.5 to 1.9% by mass of manganese has good fluidity of the molten metal in the mold and injection. When casting at a speed of 3 m / s or more, defects such as seizure, hot water, and hot water are not generated even in a thin portion, the hardness and strength of the die-cast product are high, and the die-cast product is anodized. As a result, it was found that a beautiful metallic luster was developed, and the present invention was completed based on this finding.
That is, the present invention
(1) 0.5 to 1.9% by mass of manganese, 0.5 to 2.0% by mass of cobalt and 0.02 to 0.12% by mass of copper, and the silicon content is 1.0% by mass or less. Yes, the remainder is cast at an injection speed of 3 m / s or more using an aluminum alloy consisting of aluminum and inevitable impurities, and the cast product is anodized, so that the surface gloss of the cast product is 60 ° specular. An aluminum alloy die-cast product having a thickness of 1.5 mm or less, characterized by a glossiness of 55% or more,
(2) 0.5 to 1.9% by mass of manganese, 0.5 to 2.0% by mass of cobalt and 0.02 to 0.12% by mass of copper, and the silicon content is 1.0% by mass or less. Yes, the magnesium content is 4.0% by mass or less, and the balance is cast at an injection speed of 3 m / s or more using an aluminum alloy made of aluminum and inevitable impurities, and the cast product is anodized. An aluminum alloy die-cast product having a thin portion with a thickness of 1.5 mm or less, wherein the cast product has a surface glossiness of 60 ° and a specular glossiness of 55% or more, and
(3) The aluminum alloy described in (1) or (2) is melted, poured into a mold cavity at an injection speed of 3 m / s or more, and cooled and solidified to obtain a die-cast product, and the obtained die-cast product is an anode. A method for producing an aluminum alloy die-cast product having a thin portion with a thickness of 1.5 mm or less according to (1) or (2), characterized by performing an oxidation treatment;
Is to provide.

  The aluminum alloy die-cast product of the present invention uses an aluminum alloy containing a small amount of manganese, and stably casts at an injection speed of 3 m / s or more without causing defects in the product even if the die has a thin wall portion. A beautiful surface can be obtained. Since the aluminum alloy die-cast product of the present invention exhibits a beautiful metallic luster when anodized, it does not require complicated secondary processing such as plating. According to the method for producing an aluminum alloy die cast product of the present invention, a product having a beautiful appearance with high hardness and strength and a metallic luster can be easily produced.

The aluminum alloy die-cast product of the present invention is an aluminum alloy die-cast product in which the aluminum alloy contains 0.5 to 1.9% by mass of manganese, is cast at an injection speed of 3 m / s or more, and the cast product is anodized. It is a product. Aluminum alloy die-casting products of the present invention, an aluminum alloy, manganese 0.5 to 1.9 wt%, to contain cobalt 0.5 to 2.0% by weight and copper 0.02 to 0.12 wt% preferable.
In the method for producing an aluminum alloy die-cast product of the present invention, an aluminum alloy containing 0.5 to 1.9% by mass of manganese is melted, injected into a mold cavity at an injection speed of 3 m / s or more, and cooled and solidified. Thus, a die cast product is obtained, and the obtained die cast product is anodized.
In the present invention, an aluminum alloy containing 0.5 to 1.9% by mass of manganese is cast using a die casting machine at an injection speed of 3 m / s or more, more preferably at an injection speed of 3.5 m / s or more. By setting the injection speed to 3 m / s or more, the molten metal is injected at a high speed even in the thin wall portion of the mold, the viscosity of the molten metal is sufficiently low, and filling is completed before the molten metal begins to solidify. A cast product having a smooth surface can be obtained. The upper limit of the injection speed is not particularly limited, but in current die casting machines, hydraulic circuits and mechanical systems that emphasize high responsiveness, operability, and stability are built, and servo valves that are resistant to contamination are used and controlled. With the development of real-time feedback control technology, an injection speed of about 12 m / s has been realized.

The aluminum alloy die-cast product and the method for producing the same of the present invention can be particularly suitably applied to a product having a thin portion with a thickness of 1.5 mm or less, more preferably 0.4 to 1.0 mm. In mold cavities with a thin wall thickness of 1.5 mm or less, the fluidity of the molten aluminum alloy cannot be obtained sufficiently, and defects due to poor fluidity such as seizure, hot water bath, hot water boundary, poor water circulation, etc. However, according to the method of the present invention, an aluminum alloy die-cast product having a thin portion having a thickness of 1.5 mm or less can also be stably produced. An aluminum alloy die-cast product having a thin portion with a thickness of less than 0.4 mm may be difficult to manufacture even by the method of the present invention.
The aluminum alloy used in the present invention contains 0.5 to 1.9% by mass of manganese, more preferably 0.8 to 1.5% by mass . By including manganese in the aluminum alloy, the fluidity of the molten metal can be improved, the hardness and strength of the die-cast product can be increased, and excellent gloss can be imparted to the die-cast product. If the manganese content is less than 0.5% by mass , these effects may not be sufficiently exhibited. If the manganese content exceeds 1.9% by mass , a hot water bath and a hot water flow pattern are generated in the die-cast product, and there is a possibility that all of hardness, strength, and gloss will decrease.

In the present invention, the aluminum alloy for die casting contains 0.5 to 2.0% by mass of cobalt and 0.02 to 0.12% by mass of copper in addition to 0.5 to 1.9% by mass of manganese. preferably, and more preferably contains a cobalt 0.7-1.5% by weight and copper 0.04 to 0.09 wt%. By containing cobalt, castability and seizure resistance can be improved. If the cobalt content is less than 0.5% by mass , these improving effects may not be sufficiently exhibited. If the cobalt content exceeds 2.0% by mass , the casting temperature becomes high, which may make management difficult. By containing copper, hardness, strength, and machinability can be improved. If the copper content is less than 0.02% by mass , these improving effects may not be sufficiently exhibited. If the copper content exceeds 0.12% by mass , the elongation and corrosion resistance may be reduced.
In the present invention, the aluminum alloy can contain silicon, magnesium, zinc, iron, nickel, tin, etc. in addition to manganese, cobalt, and copper. When silicon is contained, hardness and strength are improved, and elongation and appearance are lowered. The silicon content is preferably 1.0% by mass or less. Inclusion of magnesium improves gloss, strength, and corrosion resistance, but may cause cracking. The magnesium content is preferably 4.0% by mass or less. When zinc is contained, the corrosion resistance decreases. The zinc content is preferably 3.0% by mass or less. Inclusion of iron can prevent seizure and galling, but excess iron reduces strength. The iron content is preferably 1.3% by mass or less. The nickel content is preferably 0.5% by mass or less. The tin content is preferably 0.3% by mass or less.

In the method of the present invention, any of a cold chamber die casting machine and a hot chamber die casting machine can be used as the die casting machine. Since an aluminum alloy for die casting has a higher melting point than a zinc alloy or the like, a cold chamber die casting machine can be suitably used.
In the method of the present invention, a special die casting method can be applied in addition to the general die casting method. Special die casting methods include, for example, a vacuum die casting method in which the inside of the cavity is reduced to a vacuum state immediately before filling the molten metal, the inside of the cavity, runner, and sleeve is replaced with active gas immediately before filling the molten metal, and the active gas and molten metal Examples thereof include a non-porous die casting method in which the inside of the cavity is decompressed by an oxidation reaction with a metal, and a local pressure die casting method in which a part of the cavity is directly pressurized in the solidification process after filling the molten metal.
In the present invention, an anodizing treatment is performed on a cast product formed by die casting. In the anodic oxidation treatment, an aluminum alloy die cast product is electrolyzed as an anode to form an oxide film on the surface of the cast product. Prior to the anodizing treatment of the cast product, it is preferable to degrease the cast product. The degreased treatment of the cast product can be performed, for example, by immersing the cast product in an organic solvent such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate and ultrasonically cleaning the cast product.

Examples of the electrolytic solution used for the anodizing treatment include aqueous solutions of sulfuric acid, oxalic acid, phosphoric acid, sulfamic acid, sulfosalicylic acid, chromic acid, ammonium pentaborate, ammonium adipate, sodium carbonate, and the like. When a sulfuric acid aqueous solution or an oxalic acid aqueous solution is used as an electrolytic solution, a porous layer 4 having a barrier-type oxide film 2 on the surface of an aluminum alloy substrate 1 and further having fine pores 3 on the outside as shown in FIG. A duplex film is formed. When an electrolytic solution other than a sulfuric acid aqueous solution or an oxalic acid aqueous solution is used, a barrier type oxide film having a thin and uniform oxide film 6 on the surface of the aluminum alloy substrate 5 as shown in FIG. 2 is formed.
When an aqueous sulfuric acid solution is used as the electrolytic solution, the sulfuric acid concentration is preferably 5 to 15% by mass , the temperature is 20 ° C. or less, and the current density is 0.5 to ^{2 A} / dm ² . When an aqueous sulfuric acid solution is used as the electrolyte, a film that is colorless and transparent and excellent in dyeability is formed. When an oxalic acid aqueous solution is used as the electrolytic solution, it is preferable that the oxalic acid concentration is 3 to 5% by mass , the temperature is 25 to 35 ° C., and the current density is ² to 3 A / dm ² . When an aqueous oxalic acid solution is used as the electrolyte, a yellowish brown and somewhat hard fluorescent film is formed. When using a phosphoric acid aqueous solution as the electrolytic solution, the phosphoric acid concentration is preferably 0.5 to 2% by mass , the temperature is 15 to 25 ° C., and the current density is 0.5 to ^{2 A} / dm ² . When a phosphoric acid aqueous solution is used as an electrolytic solution, a film that is milky white and highly porous and is suitable for the base of plating is formed. When sulfamic acid is used as the electrolytic solution, the sulfamic acid concentration is preferably 5 to 10% by mass , the temperature is 25 to 35 ° C., and the current density is 0.5 to ^{2 A} / dm ² . When sulfamic acid is used as the electrolyte, a milky white and slightly hard film is formed.

  The duplex film formed on the die cast product can be colored by immersing the dye in the micropores by immersing in a dye aqueous solution. Examples of the dye used for coloring include C.I. Yellow 50, C.I. Red 79, C.I. Yellow 23, C.I. Violet 43, C.I. Green 25, and C.I. Black 1. , CI Black 52, and the like. If the micropores are left open, it absorbs contaminants and corrosive substances, is easily contaminated, and has low corrosion resistance. Therefore, it is preferable to perform sealing treatment to close the micropores on the surface of the film. As a sealing treatment method, for example, it is placed in a pressure resistant container, 0.3 to 0.5 MPa of water vapor is sent, and sealing treatment with pressurized water vapor kept for 20 to 30 minutes is immersed in pure water at 95 to 100 ° C. Examples thereof include a sealing treatment in boiling water maintained for 20 to 30 minutes, and a sealing treatment with acetate held by immersion in an aqueous solution of nickel acetate or cobalt acetate at 95 ° C. or higher for 10 to 20 minutes. The colored product is preferably sealed with acetate.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
FIG. 3 is a perspective view of test pieces produced in Examples and Comparative Examples. This test piece is formed on a semi-cylindrical base portion 7 having a radius of 25 mm and a height of 15 mm, a thin portion 8 having a height of 70 mm, a width of 50 mm, and a thickness of 1.0 mm, and a height of 40 mm and a width of 50 mm. And a thick portion 9 having a thickness of 5.0 mm, and a rib 10 having a length of 70 mm, a height of 8 mm, and a width of 3 mm from the base portion to the thick portion at the center on the surface side of the thin portion. The molten aluminum alloy is cast from a gate provided on the bottom surface of the base.
Example 1
Aluminum alloy for die casting [Mitsubishi Chemical Corporation, 5KDM3-Z, Co 0.94 mass %, Cu 0.06 mass %, Si 0.04 mass %, Fe 0.10 mass %, Al balance] 98.6 parts by weight of manganese 1 It added .4 parts by weight, Mn1.4 wt%, Co0.93 wt%, Cu0.06 wt%, Si0.04% by weight, Fe0.10 mass%, to prepare an aluminum alloy of Al balance a composition. Using this aluminum alloy, a test piece was produced by die casting and anodizing treatment.
Using a cold chamber die casting machine with a mold clamping force of 2,500 kN, the aluminum alloy was melted and degassing and degassing were performed, then the melt temperature was 730 ° C, the mold temperature was 150 ° C, the casting pressure was 64 MPa, and the injection speed A test piece was cast at 4.0 m / s.
The obtained test piece was washed with acetone and degreased, and then electrolyzed in a 10% by mass sulfuric acid bath at a bath temperature of 18 ° C. and a current density of 1.5 A / dm ² for 30 minutes to form an anodized film having a thickness of 10 μm. did. The test piece was further boiled in pure water for 30 minutes to perform sealing treatment.
With respect to the back surface of the thin part of the obtained test piece, the 60-degree specular gloss was measured according to JIS Z 8741 using a gloss meter, and it was 55%. The Vickers hardness of the back surface of the thin part of the test piece was 125 Hv. When a tensile test piece having a width of 12.5 mm in the parallel portion was cut out from the test piece and subjected to a tensile test, the tensile strength was 341 MPa.
Example 2
Die casting aluminum alloy [Mitsubishi Chemical (Co.), 5KDM3-Z] 98.8 Mn1.2 mass% which was prepared by adding manganese 1.2 parts by weight parts by weight, Co0.93 wt%, Cu0.06 mass%, A test piece was prepared and evaluated in the same manner as in Example 1 except that an aluminum alloy having a composition of Si 0.04 mass %, Fe 0.10 mass %, and the balance of Al was used.
The 60 ° specular gloss was 62%, the Vickers hardness was 119 Hv, and the tensile strength was 328 MPa.
Example 3
Die casting aluminum alloy [Mitsubishi Chemical (Co.), 5KDM3-Z] 99.0 Mn1.0 mass% which was prepared by adding manganese 1.0 parts by weight parts by weight, Co0.93 wt%, Cu0.06 mass%, A test piece was prepared and evaluated in the same manner as in Example 1 except that an aluminum alloy having a composition of Si 0.04 mass %, Fe 0.10 mass %, and the balance of Al was used.
The 60 ° specular gloss was 68%, the Vickers hardness was 110 Hv, and the tensile strength was 310 MPa.

Comparative Example 1
A test piece was produced in the same manner as in Example 1 except that the injection speed of the die casting machine was set to 0.5 m / s.
Since the injection speed was slow, a hot water bath and a hot water flow pattern were generated, and a good test piece was obtained although it was shaped, the physical properties were not evaluated.
Comparative Example 2
Die casting aluminum alloy [Mitsubishi Chemical (Co.), 5KDM3-Z "97.5 Mn2.5 mass% which was prepared by adding manganese 2.5 parts by weight parts by weight, Co0.92 wt%, Cu0.06 mass%, A test piece was prepared and evaluated in the same manner as in Example 1 except that an aluminum alloy having a composition of Si 0.04 mass %, Fe 0.10 mass %, and the balance of Al was used.
The 60 ° specular gloss was 15%, the Vickers hardness was 135 Hv, and the tensile strength was 535 MPa.
Comparative Example 3
Aluminum alloy for die casting [Summit Showa Aluminum Co., Ltd., 63SC, Mn 0.04 mass %, Cu 0.05 mass %, Si 0.65 mass %, Fe 0.27 mass %, Mg 0.62 mass %, Zn 0.05 mass %, Ni0.01 wt%, Cr0.03 wt%, Ti0.01 wt%, except for using Al remainder] was prepared a test piece in the same manner as in example 1.
In the anodic oxidation treatment, a beautiful surface was not obtained, so the physical properties were not evaluated.
Comparative Example 4
Example except that aluminum alloy for die casting [Mitsubishi Chemical Corporation, 5KDM3-Z, Co 0.94 mass %, Cu 0.06 mass %, Si 0.04 mass %, Fe 0.10 mass %, Al balance] was used. A test piece was prepared in the same manner as in Example 1 and evaluated.
The 60 ° specular gloss was 30%, the Vickers hardness was 88 Hv, and the tensile strength was 118 MPa.
The composition and injection speed of the aluminum alloys used in Examples 1 to 3 and Comparative Examples 1 to 4 are shown in Table 1, and the glossiness, hardness and strength of the obtained aluminum alloy die cast products are shown in Table 2.

As seen in Table 2, manganese 1.4 wt%, was cast in an injection speed 4.0 m / s from an aluminum alloy containing 1.2 wt% or 1.0 wt%, obtained by anodizing The obtained aluminum alloy die-cast products of Examples 1 to 3 have high 60 degree specular gloss, Vickers hardness, and tensile strength, and have well-balanced characteristics. On the other hand, even if the manganese content is 1.4% by mass , a good test piece cannot be obtained with the aluminum alloy die-cast product of Comparative Example 1 cast at an injection speed of 0.5 m / s. The aluminum alloy die-cast product of Comparative Example 2 having a manganese content of 2.5% by mass has high tensile strength but low 60 degree specular gloss. In the aluminum alloy die-cast product of Comparative Example 3 having a manganese content of 0.04 mass % and a silicon content of 0.65 mass %, a beautiful surface cannot be obtained in the anodizing treatment. The aluminum alloy die cast product of Comparative Example 4 that does not contain manganese has low 60 ° specular gloss, Vickers hardness, and tensile strength.

  The aluminum alloy die-cast product of the present invention uses an aluminum alloy containing a small amount of manganese, and stably casts at an injection speed of 3 m / s or more without causing defects in the product even if the die has a thin wall portion. A beautiful surface can be obtained. Since the aluminum alloy die-cast product of the present invention exhibits a beautiful metallic luster when anodized, it does not require complicated secondary processing such as plating. According to the method for producing an aluminum alloy die cast product of the present invention, a product having a beautiful appearance with high hardness and strength and a metallic luster can be easily produced.

It is a typical explanatory view of a duplex coat. It is a typical explanatory view of a barrier type oxide film. It is a perspective view of the test piece produced in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum alloy base material 2 Barrier type oxide film 3 Micropore 4 Porous layer 5 Aluminum alloy base material 6 Oxide film 7 Base part 8 Thin part 9 Thick part 10 Rib

Claims (3)

  It contains 0.5 to 1.9% by mass of manganese, 0.5 to 2.0% by mass of cobalt and 0.02 to 0.12% by mass of copper, the silicon content is 1.0% by mass or less, and the balance Is cast using an aluminum alloy made of aluminum and inevitable impurities at an injection speed of 3 m / s or more, and the cast product is anodized to give a surface glossiness of 60 ° specular gloss of 55 °. % Aluminum alloy die-cast product having a thin portion of 1.5 mm or less in thickness.   Containing 0.5 to 1.9% by mass of manganese, 0.5 to 2.0% by mass of cobalt and 0.02 to 0.12% by mass of copper, and having a silicon content of 1.0% by mass or less; The content is 4.0% by mass or less, and the balance is cast using an aluminum alloy composed of aluminum and inevitable impurities at an injection speed of 3 m / s or more, and the cast product is anodized. An aluminum alloy die-cast product having a thin part with a thickness of 1.5 mm or less, wherein the cast product has a surface gloss of 60 degrees and a specular gloss of 55% or more. The aluminum alloy according to claim 1 or 2 is melted, poured into a mold cavity at an injection speed of 3 m / s or more, and cooled and solidified to obtain a die-cast product, and the obtained die-cast product is subjected to anodizing treatment. The method for producing an aluminum alloy die-cast product having a thin portion having a thickness of 1.5 mm or less according to claim 1 or 2, characterized in that it is applied.

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