Strong-plasticity rare earth Y modified ADC12 regenerated aluminum alloy and preparation method thereof

Abstract

The invention belongs to the technical field of non-ferrous metal processing, and particularly relates to a strong-plasticity rare earth Y modified ADC12 regenerated aluminum alloy and a preparation method thereof.The strong-plasticity rare earth Y modified ADC12 regenerated aluminum alloy comprises 0.05-0.15 wt% of rare earth Y, the product of strength and ductility of the regenerated aluminum alloy is 4.357-5.738 GPa%, and the ductility of the regenerated aluminum alloy is 14.36-17.38%. The ADC12 secondary aluminum alloy is prepared by carrying out pre-deformation treatment on the ADC12 secondary aluminum alloy modified by rare earth Y at the deformation amount of 4%-7.5% and then carrying out T6 treatment on the ADC12 secondary aluminum alloy. The regenerated aluminum alloy is high in product of strength and ductility and has excellent comprehensive strength and toughness level.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing, and in particular relates to a high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy and a preparation method thereof. Background Art

[0002] The commercial die-casting aluminum alloy JIS (Japanese Industrial Standard) ADC12 modified with rare earth Y is an Al-Si-Cu series secondary aluminum alloy, which belongs to a type of casting aluminum alloy. This alloy has the advantages of excellent casting performance, light weight and easy recycling and reuse, and is widely recognized in industrial production. However, for recycled secondary aluminum alloys, their mechanical properties are often affected by the morphology of the inclusion phase in the matrix. The coarse α-Fe phase and flaky eutectic Si phase in the alloy will seriously split the matrix, thereby affecting its mechanical properties, especially poor plasticity, easy brittle fracture, and inability to undergo large deformation, which greatly limits its scope of application.

[0003] Therefore, in order to improve the mechanical properties of the cast rare earth Y modified ADC12 recycled aluminum alloy, effective methods must be adopted to optimize the alloy structure. T6 heat treatment is the most commonly used heat treatment process for aluminum-silicon alloys. It can make the Al2Cu phase and the eutectic Si phase solid-dissolve in the α-Al phase, effectively strengthen the matrix α-Al phase, and refine the α-Fe phase and the blocky primary Si phase, thereby improving the various mechanical properties of the rare earth Y modified ADC12 recycled aluminum alloy. T6 heat treatment is divided into solid solution treatment and aging treatment. In T6 heat treatment, solid solution treatment is an important step in T6 heat treatment, and its function is to increase the hardness and strength of the material by rapid cooling. Solid solution treatment first heats the alloy material to a high temperature and keeps it warm for a certain period of time, so that the soluble elements in the impurity phase, such as magnesium and silicon, are dissolved in the matrix; then quenching is performed so that the solute elements in the solid solution have no time to precipitate, forming a supersaturated solid solution. When the alloying elements are solid-dissolved into the matrix metal (solvent) to form a solid solution, the strength and hardness of the alloy are generally improved, which is called solid solution strengthening. When the alloy is solid solution strengthened, the strength and hardness of the alloy are improved while the plasticity can be maintained at a good level. However, its strength-plasticity product is low, indicating that relying solely on T6 heat treatment cannot increase the comprehensive strength and toughness level of rare earth Y-modified ADC12 recycled aluminum alloy to a higher level. Summary of the invention

[0004] Based on this, the present application provides a strong-plastic rare earth Y-modified ADC12 recycled aluminum alloy and a preparation method thereof, in order to solve the problem that the strength-plasticity product of the rare earth Y-modified ADC12 recycled aluminum alloy after T6 heat treatment in the prior art is low, indicating that relying solely on T6 heat treatment cannot improve the comprehensive strength and toughness level of the rare earth Y-modified ADC12 recycled aluminum alloy to a higher level.

[0005] The technical solution of this application to solve the above technical problems is as follows:

[0006] A strong and plastic rare earth Y-modified ADC12 recycled aluminum alloy comprises 0.05 to 0.15 wt% of rare earth Y, and the strength-plasticity product of the recycled aluminum alloy is 4.357 to 5.738 GPa%.

[0007] Preferably, the above-mentioned strong-plastic rare earth Y-modified ADC12 recycled aluminum alloy has a strength-plasticity product of 4.495 to 5.738 GPa%.

[0008] Preferably, the above-mentioned strong-plastic rare earth Y-modified ADC12 recycled aluminum alloy has an elongation of 14.36% to 17.38%.

[0009] Preferably, the above-mentioned strong plasticity rare earth Y modified ADC12 recycled aluminum alloy includes 0.1wt% of rare earth Y.

[0010] A method for preparing a high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy comprises the following steps:

[0011] Pre-deformation treatment: The ADC12 recycled aluminum alloy modified with rare earth Y is pre-deformed with a deformation amount of 4% to 7.5%;

[0012] Heat treatment: The rare earth Y-modified ADC12 recycled aluminum alloy after pre-deformation treatment is heat treated.

[0013] Preferably, the above preparation method further comprises, before the pre-deformation treatment: adding 0.05 to 0.15 wt % of rare earth Y to the ADC12 recycled aluminum alloy, and obtaining the rare earth Y-modified ADC12 recycled aluminum alloy after centrifugal casting.

[0014] Preferably, in the above preparation method, the deformation amount is 5% to 7.5%.

[0015] Preferably, in the above preparation method, the heat treatment also includes: solution treatment: heating the pre-deformed rare earth Y-modified ADC12 recycled aluminum alloy to 400 to 600°C at a heating rate of 8 to 15°C / min and keeping it warm for 5 to 10 hours, and then quenching it in 0°C to boiling water for 10 to 20 seconds.

[0016] Preferably, in the above preparation method, the heat treatment comprises:

[0017] Aging treatment: put the quenched rare earth Y-modified ADC12 recycled aluminum alloy into a high-temperature drying oven within 5 minutes and keep it at 150 to 200°C for 7 to 12 hours.

[0018] The present invention adopts the above technical solution, and its beneficial effects are:

[0019] The high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy provided by the present invention contains 0.05 to 0.15 wt% of rare earth Y, and the strength-plasticity product of the recycled aluminum alloy is 4.357 to 5.738 GPa%, which is relatively high and has excellent comprehensive strength and toughness levels.

[0020] The preparation method of the high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy disclosed in the present invention comprises the following steps: pre-deforming the rare earth Y-modified ADC12 recycled aluminum alloy, wherein the deformation amount is 4% to 7.5%, and then performing solid solution treatment and aging treatment. The rare earth Y-modified ADC12 recycled aluminum alloy is pre-deformed before T6 heat treatment, and the internal structure of the material is fragmented, which significantly improves the effect of solid solution treatment in the next step of T6 heat treatment. The strength-plasticity product, as the product of tensile strength and elongation, can better reflect the comprehensive mechanical properties of the material. Experiments show that when the deformation amount of the pre-deformation treatment is 4% to 7.5%, the strength-plasticity product of the material can reach up to 5.738GPa%; in particular, when the deformation amount of the pre-deformation treatment is 5% to 7.5%, the strength-plasticity product of the material is maintained at 5.738 to 4.495GPa%, and has an excellent comprehensive strength and toughness level. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Tensile properties of ADC12 recycled aluminum alloy samples with different rare earth Y addition amounts.

[0022] Figure 2 Metallographic microstructure of ADC12 recycled aluminum alloy samples modified by rare earth Y and heat treated with different pre-deformation amounts.

[0023] Figure 3 Mechanical properties of ADC12 recycled aluminum alloy samples modified by rare earth Y and heat treated with different pre-deformation amounts. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The technical solution of the present invention will be further described below in conjunction with the drawings of the embodiments of the present invention, and the present invention is not limited to the following specific implementation methods.

[0025] In a specific embodiment of the present invention, a strong and plastic rare earth Y-modified ADC12 recycled aluminum alloy (hereinafter referred to as recycled aluminum alloy) includes 0.05 to 0.15wt% of rare earth Y, and the strength-plasticity product of the recycled aluminum alloy is 4.357 to 5.738GPa%.

[0026] In a preferred embodiment, the strength-ductility product is 4.495 to 5.738 GPa%. As the product of tensile strength and elongation, the strength-ductility product can better reflect the comprehensive mechanical properties of the material. The strength-ductility product value of the rare earth Y-modified ADC12 recycled aluminum alloy of the present invention is high, indicating that it has an excellent comprehensive strength and toughness level. At the same time, further, the elongation of the recycled aluminum alloy is 14.36% to 17.38%, indicating that it has high tensile properties and fracture resistance. Experiments show that adding 0.1wt% of rare earth Y has the best effect on improving the tensile strength and elongation of the aluminum alloy sample. Therefore, further, the recycled aluminum alloy includes 0.1wt% of rare earth Y.

[0027] In another specific embodiment of the present invention, a method for preparing a high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy comprises the following steps:

[0028] Pre-deformation treatment: the ADC12 recycled aluminum alloy modified by rare earth Y is subjected to pre-deformation treatment, and the deformation amount is 4% to 7.5%; heat treatment: the ADC12 recycled aluminum alloy modified by rare earth Y after the pre-deformation treatment is subjected to heat treatment.

[0029] T6 heat treatment is the most commonly used heat treatment process for aluminum-silicon alloys. It can make Al2Cu phase and eutectic Si phase dissolved in α-Al phase, effectively strengthen the matrix α-Al phase, and refine α-Fe phase and blocky primary Si phase, thereby improving the mechanical properties of rare earth Y modified ADC12 recycled aluminum alloy. T6 heat treatment is divided into solid solution treatment and aging treatment. In T6 heat treatment, solid solution treatment is an important step in T6 heat treatment, and its function is to increase the hardness and strength of the material by rapid cooling. Solid solution treatment first heats the alloy material to a high temperature and keeps it warm for a certain period of time, so that the soluble elements in the impurity phase, such as magnesium and silicon, are dissolved in the matrix; then quenching is performed so that the solute elements in the solid solution have no time to precipitate, forming a supersaturated solid solution. When the alloy elements are dissolved in the matrix metal (solvent) to form a solid solution, the strength and hardness of the alloy are generally improved, which is called solid solution strengthening. When the alloy is solid solution strengthened, while improving the strength and hardness, the plasticity can also be maintained at a good level. This supersaturated solid solution has higher hardness and strength, as well as good ductility and toughness. Therefore, the material is pre-deformed before T6 heat treatment to fragment the soluble phase inside the material, increase the contact area between the soluble phase and the matrix, and thus enhance the effect of solid solution strengthening and increase the plasticity and toughness of the material. Pre-deformation treatment plays a key role in the effect of T6 heat treatment. Different pre-deformation amounts have different effects on the fragmentation of the grains inside the material, which in turn affects the effect of T6 heat treatment. Selecting a suitable deformation amount can make the eutectic Si phase and α-Fe phase in the alloy have better refinement effects, especially the refinement effect of the eutectic Si phase is more significant, and the eutectic Si phase can be dissolved in the matrix α-Al phase to a greater extent, which can improve the solubility of the soluble phase in the matrix and better improve the mechanical properties of the alloy. Generally speaking, rolling deformation can improve the strength of metal materials but sacrifice some plasticity, but the application process proves that further T6 heat treatment after rolling can simultaneously improve the plasticity and strength of the alloy. However, excessive pre-deformation will cause the internal phases of the material to break, causing a significant decrease in mechanical properties. Therefore, in this application, the deformation amount of the pre-deformation treatment is 4% to 7.5%, and further 5% to 7.5%. And experiments show that when the deformation amount of the pre-deformation treatment is 4% to 7.5%, the strength-plasticity product of the material can reach up to 5.738GPa%; especially when the deformation amount of the pre-deformation treatment is 5% to 7.5%, the strength-plasticity product of the material is maintained at 5.738 to 4.495GPa%, with excellent comprehensive strength and toughness levels, and an elongation of 14.36% to 17.38%, indicating that it has high tensile properties and fracture resistance.

[0030] Preferably, the pre-deformation treatment further includes: adding 0.05 to 0.15wt% of rare earth Y to the ADC12 recycled aluminum alloy, and obtaining the rare earth Y-modified ADC12 recycled aluminum alloy after centrifugal casting. The addition of rare earth Y can help improve the thermal stability and corrosion resistance of the ADC12 recycled aluminum alloy, so that the material performs better in high temperature and corrosive environments.

[0031] After the pre-deformation treatment, T6 heat treatment is required. Therefore, in another specific embodiment of the present application, the heat treatment includes solution treatment: the pre-deformed rare earth Y-modified ADC12 recycled aluminum alloy is heated to 400 to 600°C at a heating rate of 8 to 15°C / min and kept warm for 5 to 10 hours, and then quenched in water at 0 to 100°C for 10 to 20 seconds. Preferably, the solution treatment is to heat the pre-deformed rare earth Y-modified ADC12 recycled aluminum alloy to 500°C at a heating rate of 10°C / min and keep warm for 7 hours, and then quenched in water at 60°C for 15 seconds. T6 heat treatment improves the strength and hardness of the alloy by solid solution strengthening of Si in the rare earth Y-modified ADC12 recycled aluminum alloy and precipitating Si particles to increase the content of hard phase in the alloy. The precipitation of Si particles can effectively hinder the movement of grain boundaries, increase the deformation resistance and fatigue resistance of the alloy, and the distribution of hard phase particles can effectively hinder the movement of dislocations, thereby improving the tensile strength and hardness of the alloy.

[0032] Furthermore, the heat treatment also includes: aging treatment: placing the quenched rare earth Y-modified ADC12 recycled aluminum alloy in a high-temperature drying oven within 5 minutes, and keeping it at 150 to 200°C for 7 to 12 hours. Preferably, the aging treatment is placing the quenched rare earth Y-modified ADC12 recycled aluminum alloy in a high-temperature drying oven within 5 minutes, and keeping it at 170°C for 10 hours. The aging treatment in this application is artificial aging, which can rearrange the atoms inside the rare earth Y-modified ADC12 recycled aluminum alloy and further improve the mechanical properties of the material.

[0033] It is worth noting that the process temperature and process time involved in the above-mentioned embodiments are all temperatures or times used in the experimental process. Those skilled in the art can make reasonable adjustments within the error range based on the process temperature and process time provided by the present invention, which should be included in the protection scope of the present invention.

[0034] The technical solution and technical effects of the present invention are further illustrated below through specific experimental examples.

[0035] 1. Experimental Materials

[0036] Among them, ADC12 recycled aluminum alloy is a new type of die-casting Al-Si alloy, which is made by recycling waste aluminum alloy. Its chemical composition is shown in Table 1.

[0037] Table 1 Main chemical composition of ADC12 recycled aluminum alloy

[0038]

[0039]

[0040] 2. Experimental Example 1

[0041] Refer to Table 2 for the amount of rare earth Y added to prepare the experimental samples:

[0042] Table 2 Rare earth Y addition amount of different experimental samples

[0043]

[0044] The commercial ADC-12 recycled aluminum alloy was cut into suitable blocks using wire cutting, and the samples were weighed using an electronic balance. The surface oxide layer of the alloy was polished clean with coarse-grit sandpaper, and then ultrasonically cleaned with anhydrous ethanol to reduce the entry of surface impurities into the furnace.

[0045] ADC-12 recycled aluminum alloy is placed in a graphite crucible, and Al-Y master alloy is added. The actual addition amount is calculated according to the ratio and loss of the master alloy, so that the mass percentage of rare earth Y is shown in Table 2. The graphite crucible is placed in a small vacuum induction heating stirring furnace, and vacuumization is started after anti-volatilization treatment. When the vacuum degree reaches below 5Pa, close the valve and pass high-strength argon gas, and heat after preheating treatment. Heat to 750C °, keep warm for 30min, and centrifugal casting is performed. The rotation speed of the centrifugal casting plate is 2500r / min. After the casting is completed, cool and take out the casting to obtain the sample of Experimental Example 1.

[0046] 3. Experimental Example 1 Result Analysis

[0047] See also Figure 1 The tensile strength and elongation of the aluminum alloy sample without rare earth Y addition are low. When 0.05wt% rare earth Y is added, the tensile strength and elongation are significantly improved, and the tensile strength and elongation are 272.21MPa and 9.67% respectively; when 0.1wt% rare earth Y is added, the tensile strength and elongation reach the best, which are 293.84MPa and 11.52% respectively; with the addition of rare earth Y, the tensile strength and elongation show a downward trend compared with the addition of 0.1wt%, but are still better than the data without rare earth Y addition. It can be seen that the addition of 0.1wt% rare earth Y has the best effect on improving the tensile strength and elongation of aluminum alloy samples.

[0048] 3. Experimental Example 2

[0049] The ADC12 recycled aluminum alloy modified with 0.1 wt% rare earth Y in the above experiment was cut by wire cutting to produce sheet samples of 3 mm×20 mm×80 mm, and the surface of the sample was polished to smoothen and eliminate processing marks.

[0050] Comparative sample 2 is a rare earth Y-modified ADC12 recycled aluminum alloy sample that has not been pre-deformed (the pre-deformation amount is 0).

[0051] The experimental samples were first pre-deformed using a two-roll rolling mill with deformation amounts of 2.5%, 4%, 5%, 6%, 7.5% and 10%. The alloy was then subjected to T6 heat treatment, which was divided into two parts: solution treatment and aging treatment. An integrated intelligent muffle furnace was used for solution treatment, with a heating rate of 10°C / min. After heating to 500°C and keeping warm for 7 hours, it was placed in water at 60°C for quenching for 15 seconds; after quenching, it was placed in a high-temperature drying oven at 170°C for artificial aging within 5 minutes and kept warm for 10 hours.

[0052] 4. Experimental results analysis

[0053] According to the "GB / T228.1-2010 Metal Material Tensile Test Standard", the tensile test was carried out to test the tensile strength and other mechanical properties of the samples. Figure 2 and Figure 3 .

[0054] See also Figure 2 , the metallographic microstructure of the ADC12 recycled aluminum alloy samples modified by rare earth Y with different pre-deformation amounts is shown in the figure. It can be seen from the figure that the metallographic microstructure of the original sample of ADC12 recycled aluminum alloy modified by rare earth Y with a pre-deformation amount of 0% is as follows Figure 2 As shown in (a), the α-Al phase in the ADC12 recycled aluminum alloy that has not been pre-deformed is a large area of ​​irregular white phase, with unclear phase outlines and irregular distribution; the dark black structure in the shape of short rods, spheres or irregular blocks and irregular arrangement is the eutectic Si phase; the light black structure in the shape of irregular polygons, Chinese characters and fish bones is the α-Fe phase, in which the morphology of the Si phase and the α-Fe phase will significantly affect the plasticity of the material. Figure 2 (b) It can be seen that when the pre-deformation is 2.5%, the eutectic Si phase begins to refine, and the long rod-shaped eutectic Si phase is significantly reduced, but irregular blocks of eutectic Si phase still appear, and thin and long rod-shaped α-Fe phase begins to appear. Figure 2 (c) It can be seen that when the pre-deformation is 5%, there are some short rod-shaped eutectic Si phases, the eutectic Si phase has the best homogenization effect, and a large area is dissolved in the α-Al matrix, and the refinement effect and spheroidization effect are further improved. The large pieces of eutectic Si almost disappear, and the α-Fe phase is mostly small fishbone or Chinese character shapes, mixed with some thin and long rods. Figure 2(d) It can be seen that when the pre-deformation is 7.5%, the eutectic Si phase refinement and spheroidization effect is more obvious, and the short rod-shaped eutectic Si phase is significantly reduced. At this time, the α-Fe phase is mostly slender rods, Chinese characters and irregular blocks, and the blocky α-Fe phase begins to show obvious cracks. Figure 2 (e) It can be seen that when the pre-deformation amount is 10%, the eutectic Si phase begins to agglomerate, the uniformity decreases significantly, the slender rod-shaped α-Fe phase increases further, and obvious fracture marks appear on the irregular polygonal α-Fe phase, and the fracture marks of the Chinese character-shaped α-Fe phase are obvious.

[0055] See also Figure 3 , Mechanical properties of ADC12 recycled aluminum alloy samples modified by rare earth Y with different pre-deformation amounts. As can be seen from the figure, with the increase of pre-deformation, the tensile strength of the alloy first decreases, then increases, and then decreases, and the elongation first increases and then decreases, reaching the best at 5%, which corresponds to the change trend of the metallographic structure; compared with the samples without pre-deformation treatment, the elongation is increased by 65.2%. The strength-ductility product, as the product of tensile strength and elongation, can better reflect the comprehensive mechanical properties of the material. When the pre-deformation amount is 5%, the strength-ductility product of the material reaches the best value of 5.738GPa%.

[0056] In summary, the strong and plastic rare earth Y-modified ADC12 recycled aluminum alloy of the present application contains 0.05 to 0.15 wt% of rare earth Y, and the strength-plasticity product of the recycled aluminum alloy is 4.357 to 5.738 GPa%, and the further strength-plasticity product is 4.495 to 5.738 GPa%, and the elongation is 14.36% to 17.38%.

[0057] The ADC12 recycled aluminum alloy modified with rare earth Y is pre-deformed to a deformation amount of 4% to 7.5%, and the material's strength-plasticity product can reach up to 5.738GPa%; in particular, when the deformation amount of the pre-deformation treatment is 5% to 7.5%, the material's strength-plasticity product remains at 5.738 to 4.495GPa%, with excellent comprehensive strength and toughness levels, and an elongation of 14.36% to 17.38%, indicating that it has high tensile properties and fracture resistance. In addition, as a recycled aluminum alloy, ADC12 has the advantages of large output and low price. The high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy of this application can be widely used in transportation, daily packaging, aerospace and other fields, especially in automobile manufacturing, and is used to manufacture gearbox parts, wheel covers, body structural parts, engine cylinders, etc.

[0058] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A strong plastic rare earth Y modified ADC12 recycled aluminum alloy, characterized in that: The recycled aluminum alloy includes 0.05 to 0.15 wt % of rare earth Y, and has a strength-ductility product of 4.357 to 5.738 GPa %.

2. The high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy according to claim 1, characterized in that: The strength-ductility product of the recycled aluminum alloy is 4.495 to 5.738 GPa%.

3. The high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy according to claim 1, characterized in that: The elongation of the recycled aluminum alloy is 14.36% to 17.38%.

4. The high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy according to claim 1, characterized in that: Includes 0.1 wt% of rare earth Y.

5. A method for preparing a high-plasticity rare earth Y-modified ADC12 recycled aluminum alloy, characterized in that: The following steps are involved: Pre-deformation treatment: The ADC12 recycled aluminum alloy modified with rare earth Y is pre-deformed with a deformation amount of 4% to 7.5%; Heat treatment: The rare earth Y-modified ADC12 recycled aluminum alloy after pre-deformation treatment is heat treated.

6. The preparation method according to claim 5, characterized in that: Before the pre-deformation treatment, the method also includes: adding 0.05 to 0.15wt% of rare earth Y into the ADC12 recycled aluminum alloy, and obtaining the rare earth Y-modified ADC12 recycled aluminum alloy after centrifugal casting.

7. The preparation method according to claim 5, characterized in that: The deformation amount is 5% to 7.5%.

8. The preparation method according to claim 5, characterized in that: The heat treatment comprises: Solution treatment: the pre-deformed rare earth Y-modified ADC12 recycled aluminum alloy is heated to 400 to 600°C at a heating rate of 8 to 15°C / min and kept warm for 5 to 10 hours, and then placed in 0°C to boiling water for quenching for 10 to 20 seconds.

9. The preparation method according to claim 8, characterized in that: The heat treatment further comprises: Aging treatment: put the quenched rare earth Y-modified ADC12 recycled aluminum alloy into a high-temperature drying oven within 5 minutes and keep it at 150 to 200°C for 7 to 12 hours.

10. The preparation method according to claim 8, characterized in that: The solution treatment comprises heating the pre-deformed rare earth Y-modified ADC12 recycled aluminum alloy to 500°C at a heating rate of 10°C / min and keeping the temperature for 7 hours, and then quenching the alloy in 60°C water for 15 seconds. The aging treatment comprises placing the quenched rare earth Y-modified ADC12 recycled aluminum alloy in a high-temperature drying oven within 5 minutes and keeping the temperature at 170°C for 10 hours.

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