High-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting and preparation method thereof

Abstract

The invention discloses a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, which comprises the following components in percentage by mass: 5.8 to 6.8 percent of Si, 0.05 to 0.15 percent of Cu, 0.15 to 0.5 percent of Fe, 0.05 to 0.18 percent of Mn, 2.0 to 3.5 percent of Mg, 0.01 to 0.06 percent of Sr, 0 to 0.07 percent of Zn, 0 to 0.05 percent of Ti, 0 to 0.08 percent of Pr and Yb mixed rare earth and the balance of Al. The invention further discloses a preparation method of the high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting. According to the high-strength, high-toughness and high-thermal-conductivity aluminum alloy and the preparation method thereof, the strength and toughness of the aluminum alloy are improved, the good thermal conductivity of the aluminum alloy is kept, and the preparation method is simple, low in cost and suitable for large-scale production and has very high practical value and wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys, and specifically relates to a high-strength, high-toughness and high-thermal conductivity aluminum alloy for die casting and a preparation method thereof. Background Art

[0002] Aluminum alloy is a lightweight structural material with excellent performance, which is widely used in aerospace, automobile, electronic equipment and other fields. Among them, high thermal conductivity aluminum alloy is widely used in aerospace, home appliances, auto parts, computers and other high thermal conductivity parts due to its good thermal conductivity and mechanical properties. However, traditional high thermal conductivity aluminum alloys often have the problems of low strength and poor toughness, which limits its use in high-strength and high-toughness application fields. Summary of the invention

[0003] In view of this, in order to solve the problems of low strength and poor toughness of existing high thermal conductivity aluminum alloys, the present invention provides a high-strength, high-toughness and high thermal conductivity aluminum alloy for die casting.

[0004] The invention also provides a method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting.

[0005] The invention provides a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, which comprises the following components by mass percentage: 5.8-6.8% Si, 0.05-0.15% Cu, 0.15-0.5% Fe, 0.05-0.18% Mn, 2.0-3.5% Mg, 0.01-0.06% Sr, and the rest is Al.

[0006] Preferably, the high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die-casting further includes the following components: 0-0.07% Zn, 0-0.05% Ti, 0-0.08% Pr and Yb mixed rare earth.

[0007] Preferably, the high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die-casting comprises the following components: 6.2% Si, 0.10% Cu, 0.35% Fe, 0.12% Mn, 2.7% Mg, 0.03% Sr, 0.03% Zn, 0.02% Ti, 0.04% Pr and Yb mixed rare earth, and the rest is Al.

[0008] The present invention also provides a method for preparing a high-strength, high-toughness and high-thermal conductivity aluminum alloy for die casting, the method specifically comprising:

[0009] S1. Prepare raw materials: according to the composition and ratio set in the above-mentioned high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, weigh Al source, Si source, Cu source, Fe source, Mn source, Mg source and Sr source respectively;

[0010] S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt;

[0011] S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Si source, Cu source, Fe source, Mn source, Mg source and Sr source during the heating process, stirring and melting, to obtain aluminum alloy liquid;

[0012] S4, refining and slag removal: adding a sodium-free refining agent to the aluminum alloy liquid for refining, and slag removal after refining, removing the flux and scum on the liquid surface, and obtaining the aluminum alloy liquid after refining and slag removal;

[0013] S5, deslagging: deslagging the aluminum alloy liquid after the refining and deslagging, and smelting at 750-770° C., degassing with nitrogen, and vibrating under ultrasonic conditions to obtain an aluminum alloy melt;

[0014] S6, sampling and die casting: die casting the aluminum alloy melt to obtain an aluminum alloy die casting sample;

[0015] S7. Heat treatment: heat-treating the aluminum alloy die-casting sample and keeping it warm to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

[0016] Preferably, said S1 also includes weighing a Ti source and a Zn source; and said S3 also includes adding a Ti source and a Zn source.

[0017] Preferably, the step S1 further comprises weighing a mixture of a Pr source and a Yb source, and the step S3 further comprises adding the mixture of a Pr source and a Yb source.

[0018] Preferably, the step S4 is specifically:

[0019] The aluminum alloy liquid is controlled at a temperature of 750-770° C., electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770° C., and a sodium-free refining agent is added for secondary refining, and the slag is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed.

[0020] Preferably, the step S5 is specifically as follows:

[0021] The refined and deslagging aluminum alloy liquid is deslagging, smelted at 750-770°C, and then degassed with nitrogen under ultrasonic vibration conditions to prepare the refined and deslagging aluminum alloy liquid into an aluminum alloy melt with a temperature of 750-770°C.

[0022] Preferably, the specific method of S6 is:

[0023] The aluminum alloy melt was die-cast under the conditions of an injection speed of 0.5 m / s, an injection pressure of 90 MPa, a boost pressure of 130 MPa and a holding time of 10 seconds, and the cooling method was water cooling.

[0024] Preferably, the specific method of S7 is:

[0025] The aluminum alloy die-casting sample is placed in a heat treatment furnace, and the temperature is raised from 25°C to 165°C and then kept warm at a heating rate of 10°C / min. After keeping warm for 120 minutes, the sample is taken out and air-cooled to obtain a high-strength, high-toughness and high-thermal conductivity aluminum alloy after cooling.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Specific implementation methods The high-strength, high-toughness and high-thermal conductivity aluminum alloy for die casting of the present invention achieves balanced improvement in strength, toughness and thermal conductivity through specific chemical composition ratios and preparation processes, overcoming the problem in the prior art that a part of thermal conductivity needs to be sacrificed to improve strength and toughness.

[0028] 2. The preparation method of the present invention is simple, low-cost, and conducive to large-scale production. Compared with the complex preparation process in the prior art, the preparation method of the present invention is easier to implement and more suitable for practical application.

[0029] 3. When the high-strength, high-toughness and high-thermal-conductivity aluminum alloy of the present invention works in a high-temperature environment, its mechanical properties and thermal conductivity are stable and will not be significantly reduced. This is significantly superior to the situation in which the mechanical properties and thermal conductivity of the high-thermal-conductivity aluminum alloy in the prior art may be reduced when working in a high-temperature environment.

[0030] In general, the high-strength, high-toughness and high-thermal conductivity aluminum alloy and the preparation method thereof of the present invention not only improve the strength and toughness of the aluminum alloy, but also maintain its good thermal conductivity, and the preparation method is simple, low-cost, suitable for large-scale production, and has high practical value and broad application prospects. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Example 1

[0033] A high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting comprises the following components, calculated by mass percentage: 5.8% Si, 0.05% Cu, 0.15% Fe, 0.05% Mn, 2.0% Mg, 0.01% Sr, and the remainder is Al.

[0034] Its preparation method is:

[0035] S1. Prepare raw materials: according to the composition and ratio set in the above-mentioned high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, weigh Al source, Si source, Cu source, Fe source, Mn source, Mg source and Sr source respectively, wherein the raw materials are specifically metal Al ingot, industrial Si, metal Cu, Al-Fe master alloy, Al-Mn master alloy, Mg-Al master alloy and Sr alloy;

[0036] S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt;

[0037] S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Si source, Cu source, Fe source, Mn source, Mg source and Sr source during the heating process, stirring and melting, to obtain aluminum alloy liquid;

[0038] S4, refining and slag removal: the aluminum alloy liquid is controlled at a temperature of 750-770° C., electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770° C., and a sodium-free refining agent is added for secondary refining, and the mixture is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed;

[0039] S5, deslagging: deslagging the aluminum alloy liquid after the refining and slag removal, and smelting at 750-770° C., and then degassing with nitrogen under ultrasonic vibration conditions for about 30 minutes, and vibrating at an ultrasonic vibration frequency of 60 Hz and an ultrasonic vibration time of 40 seconds to prepare the aluminum alloy liquid after the refining and slag removal into an aluminum alloy melt with a temperature of 750-770° C.;

[0040] S6. Sampling die casting: the aluminum alloy melt is die-casted under the conditions of injection speed of 0.5 m / s, injection pressure of 90 MPa, boost pressure of 130 MPa and holding time of 10 seconds, and the cooling method is water cooling.

[0041] S7, heat treatment, placing the aluminum alloy die-casting sample into a heat treatment furnace, raising the temperature from 25°C to 165°C and then keeping it warm, with a heating rate of 10°C / min. After keeping warm for 120 minutes, take out the sample and air-cool it to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

[0042] Example 2

[0043] A high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting comprises the following components, calculated by mass percentage: 6.8% Si, 0.15% Cu, 0.5% Fe, 0.18% Mn, 3.5% Mg, 0.06% Sr, 0.07% Zn, 0.05% Ti, and the remainder is Al.

[0044] Its preparation method is:

[0045] S1. Prepare raw materials: according to the composition and ratio set in the above-mentioned high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, weigh Al source, Si source, Cu source, Fe source, Mn source, Mg source, Sr source, Zn source and Ti source respectively, wherein the raw materials are specifically metal Al ingot, industrial Si, metal Cu, Al-Fe master alloy, metal Mn, metal Mg ingot, Sr alloy, Zn ingot and Al-Ti master alloy;

[0046] S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt;

[0047] S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Si source, Cu source, Fe source, Mn source, Mg source, Sr source, Zn source and Ti source during the heating process, stirring and melting, to obtain aluminum alloy liquid;

[0048] S4, refining and slag removal: the aluminum alloy liquid is controlled at a temperature of 750-770° C., electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770° C., and a sodium-free refining agent is added for secondary refining, and the mixture is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed;

[0049] S5, deslagging: deslagging the aluminum alloy liquid after the refining and slag removal, and smelting at 750-770° C., and then degassing with nitrogen under ultrasonic vibration conditions for about 30 minutes, and vibrating at an ultrasonic vibration frequency of 60 Hz and an ultrasonic vibration time of 40 seconds to prepare the aluminum alloy liquid after the refining and slag removal into an aluminum alloy melt with a temperature of 750-770° C.;

[0050] S6. Sampling die casting: the aluminum alloy melt is die-casted under the conditions of injection speed of 0.5 m / s, injection pressure of 90 MPa, boost pressure of 130 MPa and holding time of 10 seconds, and the cooling method is water cooling.

[0051] S7, heat treatment, placing the aluminum alloy die-casting sample into a heat treatment furnace, raising the temperature from 25°C to 165°C and then keeping it warm, with a heating rate of 10°C / min. After keeping warm for 120 minutes, take out the sample and air-cool it to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

[0052] Example 3

[0053] A high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting comprises the following components, calculated by mass percentage: 6.2% Si, 0.10% Cu, 0.35% Fe, 0.12% Mn, 2.7% Mg, 0.03% Sr, 0.04% Pr and Yb mixed rare earth, and the rest is Al.

[0054] Its preparation method is:

[0055] S1. Prepare raw materials: according to the composition and ratio set in the above-mentioned high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, weigh a mixture of Al source, Si source, Cu source, Fe source, Mn source, Mg source, Sr source, Pr source and Yb source respectively, wherein the raw materials are specifically a mixture of metal Al ingot, industrial Si, metal Cu, Al-Fe master alloy, metal Mn, metal Mg ingot, Sr alloy, Yb alloy and Pr alloy;

[0056] S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt;

[0057] S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Al source, Si source, Cu source, Fe source, Mn source, Mg source and Sr source during the heating process, stirring and melting, and obtaining aluminum alloy liquid;

[0058] S4, refining and slag removal: the aluminum alloy liquid is controlled at a temperature of 750-770°C, electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770°C, and a sodium-free refining agent is added for secondary refining, and the mixture is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed; rare metals are added, and a mixture of Yb alloy and Pr alloy is added into the furnace according to a set percentage;

[0059] S5, deslagging: deslagging the aluminum alloy liquid after the refining and slag removal, and smelting at 750-770° C., and then degassing with nitrogen under ultrasonic vibration conditions for about 30 minutes, and vibrating at an ultrasonic vibration frequency of 60 Hz and an ultrasonic vibration time of 40 seconds to prepare the aluminum alloy liquid after the refining and slag removal into an aluminum alloy melt with a temperature of 750-770° C.;

[0060] S6. Sampling die casting: die casting the aluminum alloy melt under the conditions of injection speed of 0.5 m / s, injection pressure of 90 MPa, boost pressure of 130 MPa and holding time of 10 seconds, and the cooling method is water cooling;

[0061] S7, heat treatment, placing the aluminum alloy die-casting sample into a heat treatment furnace, raising the temperature from 25°C to 165°C and then keeping it warm, with a heating rate of 10°C / min. After keeping warm for 120 minutes, take out the sample and air-cool it to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

[0062] Example 4

[0063] A high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting comprises the following components, calculated by mass percentage: 6.2% Si, 0.10% Cu, 0.35% Fe, 0.12% Mn, 2.7% Mg, 0.03% Sr, 0.03% Zn, 0.02% Ti, 0.04% Pr and Yb mixed rare earth, and the rest is Al.

[0064] Its preparation method is:

[0065] S1. Prepare raw materials: according to the composition and ratio set in the above-mentioned high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, weigh a mixture of Al source, Si source, Cu source, Fe source, Mn source, Mg source, Sr source, Zn source, Ti source, Pr source and Yb source respectively, wherein the raw materials are specifically a mixture of metal Al ingot, industrial Si, metal Cu, Al-Fe master alloy, metal Mn, metal Mg ingot, Sr alloy, Zn ingot, Al-Ti master alloy, Yb alloy and Pr alloy;

[0066] S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt;

[0067] S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Si source, Cu source, Fe source, Mn source, Mg source, Sr source, Zn source and Ti source during the heating process, stirring and melting, to obtain aluminum alloy liquid;

[0068] S4, refining and slag removal: the aluminum alloy liquid is controlled at a temperature of 750-770°C, electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770°C, and a sodium-free refining agent is added for secondary refining, and the mixture is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed; rare metals are added, and a mixture of Yb alloy and Pr alloy is added into the furnace according to a set percentage;

[0069] S5, deslagging: deslagging the aluminum alloy liquid after the refining and slag removal, and smelting at 750-770° C., and then degassing with nitrogen under ultrasonic vibration conditions for about 30 minutes, and vibrating at an ultrasonic vibration frequency of 60 Hz and an ultrasonic vibration time of 40 seconds to prepare the aluminum alloy liquid after the refining and slag removal into an aluminum alloy melt with a temperature of 750-770° C.;

[0070] S6. Sampling die casting: die casting the aluminum alloy melt under the conditions of injection speed of 0.5 m / s, injection pressure of 90 MPa, boost pressure of 130 MPa and holding time of 10 seconds, and the cooling method is water cooling;

[0071] S7, heat treatment, placing the aluminum alloy die-casting sample into a heat treatment furnace, raising the temperature from 25°C to 165°C and then keeping it warm, with a heating rate of 10°C / min. After keeping warm for 120 minutes, take out the sample and air-cool it to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

[0072] The properties of the high-strength, high-toughness and high-thermal-conductivity aluminum alloys for die casting prepared in Examples 1 to 4 are shown in Table 1.

[0073] Table 1

[0074]

[0075] From the results in Table 1, it can be seen that the high-strength, high-toughness, high-thermal-conductivity aluminum alloy for die casting of the present invention achieves a balanced improvement in strength, toughness, and thermal conductivity. It not only improves the strength and toughness of the aluminum alloy, but also maintains its good thermal conductivity. Moreover, the preparation method is simple, the cost is low, and it is suitable for large-scale production. It has high practical value and broad application prospects.

[0076] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, characterized in that: Calculated by mass percentage, it includes the following components: 5.8-6.8% Si, 0.05-0.15% Cu, 0.15-0.5% Fe, 0.05-0.18% Mn, 2.0-3.5% Mg, 0.01-0.06% Sr, and the rest is Al.

2. The high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 1, characterized in that: It also includes the following ingredients: 0-0.07% Zn, 0-0.05% Ti, 0-0.08% Pr and Yb mixed rare earth.

3. The high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 2, characterized in that: Calculated by mass percentage, it includes the following components: 6.2% Si, 0.10% Cu, 0.35% Fe, 0.12% Mn, 2.7% Mg, 0.03% Sr, 0.03% Zn, 0.02% Ti, 0.04% Pr and Yb mixed rare earth, and the rest is Al.

4. A method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting, characterized in that: The method specifically includes: S1. Prepare raw materials: according to the composition and proportion set in the high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to any one of claims 1 to 3, weigh Al source, Si source, Cu source, Fe source, Mn source, Mg source and Sr source respectively; S2. Heating and melting: The symmetrical Al source is heated and melted at a temperature of 660-680°C until the Al ingot is completely melted to obtain an aluminum melt; S3, adding materials: heating the aluminum melt to 750-770° C., gradually adding Si source, Cu source, Fe source, Mn source, Mg source and Sr source during the heating process, stirring and melting, to obtain aluminum alloy liquid; S4, refining and slag removal: adding a sodium-free refining agent to the aluminum alloy liquid for refining, and slag removal after refining, removing the flux and scum on the liquid surface, and obtaining the aluminum alloy liquid after refining and slag removal; S5, deslagging: deslagging the aluminum alloy liquid after the refining and deslagging, and melting it at 750-770° C., degassing it with nitrogen, and vibrating it under ultrasonic conditions to obtain an aluminum alloy melt; S6, sampling and die casting: die casting the aluminum alloy melt to obtain an aluminum alloy die casting sample; S7. Heat treatment: heat-treating the aluminum alloy die-casting sample and keeping it warm to obtain a high-strength, high-toughness and high-thermal-conductivity aluminum alloy after cooling.

5. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The step S1 also includes weighing a Ti source and a Zn source; the step S3 also includes adding a Ti source and a Zn source.

6. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The step S1 further comprises weighing a mixture of a Pr source and a Yb source, and the step S3 further comprises adding the mixture of a Pr source and a Yb source.

7. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The step S4 is specifically as follows: The aluminum alloy liquid is controlled at a temperature of 750-770° C., electromagnetically stirred for 6 minutes, and a sodium-free refining agent is added during the stirring process for refining; after refining, the slag is removed, and the flux and scum on the liquid surface are removed; the temperature of the smelting furnace is maintained at 750-770° C., and a sodium-free refining agent is added for secondary refining, and the slag is uniformly stirred for 10 minutes. The interval between the two refinings is controlled within 30 minutes. After refining, the slag is removed, and the flux and scum on the liquid surface are removed.

8. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The step S5 is specifically as follows: The refined and deslagging aluminum alloy liquid is deslagging, smelted at 750-770°C, and then degassed with nitrogen under ultrasonic vibration conditions to prepare the refined and deslagging aluminum alloy liquid into an aluminum alloy melt with a temperature of 750-770°C.

9. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The specific method of S6 is: The aluminum alloy melt was die-cast under the conditions of an injection speed of 0.5 m / s, an injection pressure of 90 MPa, a boost pressure of 130 MPa and a holding time of 10 seconds, and the cooling method was water cooling.

10. The method for preparing a high-strength, high-toughness and high-thermal-conductivity aluminum alloy for die casting according to claim 4, characterized in that: The specific method of S7 is: The aluminum alloy die-casting sample is placed in a heat treatment furnace, and the temperature is raised from 25°C to 165°C and then kept warm at a heating rate of 10°C / min. After keeping warm for 120 minutes, the sample is taken out and air-cooled to obtain a high-strength, high-toughness and high-thermal conductivity aluminum alloy after cooling.

Images