Aluminum alloy recycled ingot

Abstract

This aluminum alloy recycled ingot for die casting is obtained by adjusting components of an aluminum alloy recycled ingot, and contains 7.0-9.0 mass% of Si, 0.1-0.6 mass% of Mg, 0.3 mass% or less of Cu, 0.5 mass% or less of Fe, 0.3-0.8 mass% of Mn, and 0.05-0.3 mass% of V when the total amount is taken as 100 mass%, with the balance composed of Al and inevitable impurities.

Description

Recycled aluminum alloy

[0001] The present disclosure relates to reclaimed aluminum alloys.

[0002] Aluminum alloys are lightweight, strong, and relatively inexpensive, and can be mass-produced using die casting, making them popular in a wide range of industrial applications, including automotive and aerospace parts.

[0003] However, the production of primary aluminum requires a large amount of electricity during the refining process and produces large amounts of CO ２ Therefore, with the recent increase in environmental awareness, the use of recycled aluminum alloys made from scraps etc. in die casting reduces CO emissions in the manufacturing process. ２ There was a need to obtain die-cast products made of aluminum alloys with low emissions.

[0004] JP 2023-510881 A JP 2023-054459 A

[0005] However, conventional recycled ingot aluminum alloys have a high Fe content, which tends to reduce ductility and impact resistance, and there is a problem that the mechanical properties, such as tensile strength and elongation, are inferior to those of die-cast products obtained from virgin aluminum ingots.

[0006] On the other hand, conventional techniques have also been proposed to improve the mechanical properties of aluminum alloys by adjusting the content of alloying elements. For example, Patent Document 1 discloses a technique for improving yield strength by increasing the Cu (copper) content. However, aluminum alloys with a high Cu content have a problem in that their corrosion resistance is reduced, which limits the products that can be used.

[0007] Furthermore, as a means for preventing deformation to a thin-walled shape when Cu is reduced and for improving castability, there is a method of increasing the Si (silicon) content to 9.6 mass % or more (see, for example, the above-mentioned Patent Document 2). However, in this case, new problems arise, such as a tendency for the ductility and impact resistance of the material to decrease.

[0008] The present disclosure has been made in consideration of the various problems present in the above-mentioned conventional techniques, and its purpose is to provide a die-cast product made of an aluminum alloy that can obtain mechanical properties equal to or better than those of a die-cast product made of conventional new aluminum ingot, and that can reduce the amount of CO generated in the manufacturing process. ２ To provide a recycled aluminum alloy having a new composition that allows die casting using recycled aluminum alloy with a small amount of waste.

[0009] The recycled ingot aluminum alloy according to the present disclosure is a recycled ingot aluminum alloy for die casting obtained by adjusting the composition of recycled ingot aluminum alloy, and is characterized by containing, when the whole is taken as 100% by mass, 7.0 to 9.0% by mass of Si, 0.1 to 0.6% by mass of Mg, 0.3% by mass or less of Cu, 0.5% by mass or less of Fe, 0.3 to 0.8% by mass of Mn, and 0.05 to 0.3% by mass of V, with the balance being Al and unavoidable impurities.

[0010] Furthermore, in the recycled ingot aluminum alloy according to the present disclosure, the Mg content can be set to 0.3 to 0.6 mass %.

[0011] According to the present disclosure, die-cast aluminum alloy products have mechanical properties equivalent to or better than those manufactured from conventional primary aluminum ingots, and are manufactured without CO ２ It is possible to provide a recycled ingot aluminum alloy having a new composition that enables die casting using recycled ingot aluminum alloy with low waste. In particular, the recycled ingot aluminum alloy of the present disclosure has excellent corrosion resistance, is less susceptible to distortion, and is capable of being used in thin-wall die casting with high ductility.

[0012] Fig. 1 is a diagram showing the content of alloy components contained in the recycled aluminum alloy according to the first to third embodiments. Fig. 2 is a perspective view showing the die-cast shape for which the inventor evaluated casting distortion. Fig. 3 is a diagram comparing the results of the evaluation of casting distortion using the die-cast shape shown in Fig. 2 with the results of casting distortion of a conventional material.

[0013] Preferred embodiments for carrying out the present disclosure will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0014] As a result of extensive research, the inventors have discovered a chemical composition of a recycled ingot aluminum alloy that is highly corrosion resistant, resistant to distortion, and highly ductile, making it possible to produce thin-walled die-cast products. The recycled ingot aluminum alloy according to the present disclosure, having this chemical composition, is characterized by comprising, when taken as 100% by mass, 7.0 to 9.0% by mass of Si (silicon), 0.1 to 0.6% by mass of Mg (magnesium), 0.3% by mass or less of Cu (copper), 0.5% by mass or less of Fe (iron), 0.3 to 0.8% by mass of Mn (manganese), and 0.05 to 0.3% by mass of V (vanadium), with the balance being Al (aluminum) and unavoidable impurities.

[0015] More specifically, the recycled ingot aluminum alloy according to the present disclosure can be a recycled ingot aluminum alloy having the component configuration of any of the first to third embodiments shown in Fig. 1. Fig. 1 is a diagram showing the content of alloy components contained in the recycled ingot aluminum alloy according to the first to third embodiments.

[0016] The recycled aluminum alloys according to the first to third embodiments are obtained by using recycled Al-Si-Mg-based aluminum alloys for thin-wall die casting and adjusting the content of alloying elements contained therein. The basis for the content of each alloying element will be explained below.

[0017] The Si content was set to a relatively low level of 9.0 mass % or less, which improved ductility and impact resistance.

[0018] Furthermore, the Cu content was kept low at 0.3 mass % or less. By keeping the Cu content low at 0.3 mass % or less, it was possible to improve corrosion resistance.

[0019] The distortion and reduced castability of thin-walled die-cast products, which are a result of keeping the Si and Cu contents low, can be compensated for by adding Mn and V. Mn has the effect of increasing high-temperature strength, and a Mn content of 0.3 mass% or more is effective. However, excessive Mn content generates coarse intermetallic compounds and reduces ductility, so a content of 0.3 to 0.8 mass% is preferable. Adding 0.05 mass% or more of V further increases high-temperature strength and reduces casting distortion (see Figures 2 and 3). Figure 2 is a perspective view of the die-cast shape for which the inventors evaluated casting distortion. Figure 3 compares the results of the casting distortion evaluation using the die-cast shape shown in Figure 2 with those of a conventional material. Excessive V content crystallizes V-based compounds, reducing ductility, so a V content of 0.05 to 0.3 mass% is recommended. Materials prone to casting distortion can also cause products to cling to the mold, preventing release and significantly reducing continuous castability. That is, by adding Mn and V in the above-mentioned contents, it becomes possible to prevent casting distortion and deterioration of castability.

[0020] Furthermore, while conventional recycled aluminum alloys tend to have reduced ductility and impact resistance due to their high Fe content, the recycled aluminum alloys according to the present embodiments 1 to 3 allow for a condition of Fe: 0.5 mass % or less, and have succeeded in finding conditions under which the components can be adjusted while suppressing the reduction in ductility and impact resistance.

[0021] The recycled ingot aluminum alloys according to the first to third embodiments described above have alloy components that satisfy the content ratios shown in FIG. 1, and therefore have excellent corrosion resistance, are less susceptible to distortion, and are highly ductile, making it possible to carry out thin-wall die casting.

[0022] Furthermore, compared to the reclaimed ingot aluminum alloy according to the first embodiment, the reclaimed ingot aluminum alloy according to the second embodiment has a Mg content of 0.3 to 0.6% by mass, compared to 0.1 to 0.6% by mass in the first embodiment. That is, in the reclaimed ingot aluminum alloy according to the second embodiment, by shifting the Mg range to a higher side instead of increasing the Cu content in the same alloy, it is possible to maintain high corrosion resistance, minimize the decrease in ductility, and increase yield strength even without heat treatment. Specifically, the reclaimed ingot aluminum alloy according to the second embodiment exhibits a yield strength of 130 MPa or more and an elongation of 5% or more. As a result, the reclaimed ingot aluminum alloy according to the second embodiment can be used in a wide range of industrial applications, such as for thin-walled die-cast products obtained by die casting, for a variety of automotive parts.

[0023] As described above, the recycled aluminum alloys according to the first to third embodiments can provide mechanical properties equivalent to or better than those of die-cast aluminum alloys manufactured from conventional virgin aluminum ingots, and can also reduce the amount of CO ２ Die casting using recycled aluminum alloys is possible, as it is environmentally friendly and produces less emissions.

Claims

1. A reclaimed ingot aluminum alloy for die casting obtained by adjusting the composition of a reclaimed aluminum alloy ingot, characterized in that, when the total is taken as 100 mass%, it contains: 7.0 to 9.0 mass% Si, 0.1 to 0.6 mass% Mg, 0.3 mass% or less Cu, 0.5 mass% or less Fe, 0.3 to 0.8 mass% Mn, and 0.05 to 0.3 mass% V, with the remainder being Al and unavoidable impurities.

2. The regenerated aluminum alloy according to claim 1, characterized in that the Mg content is 0.3 to 0.6 mass%.

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