High-thermal-conductivity aluminum alloy for die casting and preparation process thereof

Abstract

The rare earth element Er is added into the Al-Zn-Mg-Cu-Cu-Ti-Mn series aluminum alloy, so that the heat-conducting property of the Al-Zn-Mg-Cu-Cu-Ti-Mn Researches show that along with the increase of the use amount of the rare earth element Er in the aluminum alloy, the heat conductivity of the aluminum alloy is in a rule of increasing firstly and then tending to be stable, and the tensile strength of the aluminum alloy is hardly influenced. However, the tensile strength of the aluminum alloy is sharply reduced due to the excessive use amount of Er, so that the use amount of Er should be controlled to be 0.8-2.4 parts by weight relative to 100 parts by weight of metal aluminum. In addition, when Er and Nb are added at the same time, the heat-conducting property of the aluminum alloy can be further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of alloys, in particular to a high-thermal-conductivity aluminum alloy for die casting and a preparation process thereof. BACKGROUND

[0002] Aluminum alloy is a lightweight metal material made of aluminum as a base element by adding alloying elements and heat treatment process. Among the many types of aluminum alloys, high-thermal-conductivity aluminum alloy is a kind of aluminum alloy material with excellent thermal conductivity, which has a wide range of applications in electronic heat dissipation, new energy vehicles, aerospace, etc. Based on this, the present application aims to obtain a new type of aluminum alloy material with excellent thermal conductivity and mechanical properties. SUMMARY

[0003] The present application aims to provide a preparation process of a high-thermal-conductivity aluminum alloy for die casting, which can obtain an aluminum alloy material with thermal conductivity and tensile strength.

[0004] The technical solution of the present application is as follows: A preparation process of a high-thermal-conductivity aluminum alloy for die casting, comprising the following steps: Take 5.8-6.2 parts by weight of Zn, 2.7-3.2 parts by weight of Mg, 1.9-2.5 parts by weight of Cu, 1.35-1.6 parts by weight of Cu, 1.05-1.3 parts by weight of Ti, 0.83-1.1 parts by weight of Mn and 0.8-2.4 parts by weight of Er based on 100 parts by weight of Al, put them into a smelting furnace for high-temperature melting and uniform stirring, then heat preservation for 12-15h, electromagnetic stirring at a speed of 280-300r / min during heat preservation; after moving the above molten metal liquid from the smelting furnace to the holding furnace, filter it using a high-temperature resistant filter, then cast it, heat treat it at 380-400℃ for 8-12h, and finally naturally age it for about 30-36h to obtain a high-thermal-conductivity aluminum alloy for die casting, the thermal conductivity of the high-thermal-conductivity aluminum alloy for die casting is greater than 145W·m -1 ·K -1 , and the tensile strength is greater than 220MPa.

[0005] Preferably, the speed of electromagnetic stirring is 300r / min.

[0006] Preferably, the heat treatment temperature is 380℃.

[0007] Preferably, the heat treatment time is 8h.

[0008] Preferably, the natural aging time is 36h.

[0009] Preferably, the heat preservation time is 12h.

[0010] Preferably, the preparation process further includes 0.6-1.2 parts by weight of Nb.

[0011] Furthermore, the present invention also provides a high thermal conductivity aluminum alloy for die casting, which is prepared by the above-described preparation process.

[0012] This invention demonstrates that adding the rare earth element Er to Al-Zn-Mg-Cu-Cu-Ti-Mn aluminum alloys can significantly improve their thermal conductivity. Studies show that as the amount of Er in the aluminum alloy increases, the thermal conductivity initially increases and then stabilizes, while the tensile strength remains almost unaffected. However, excessive Er content leads to a sharp decrease in the tensile strength of the aluminum alloy; therefore, the Er content should be controlled between 0.8 and 2.4 parts by weight relative to 100 parts by weight of metallic aluminum. Furthermore, the simultaneous addition of Er and Nb can further improve the thermal conductivity of the aluminum alloy. Detailed Implementation

[0013] The technical effects of the present invention will be verified through specific embodiments below, but the implementation of the present invention is not limited thereto.

[0014] Example 1

[0015] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 0.8 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, and electromagnetic stirring was performed at a speed of 300 r / min during the holding period. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0016] Example 2

[0017] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 1.2 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at the temperature for 12 hours, and electromagnetic stirring was performed at a speed of 300 r / min during the holding period. After the molten metal was transferred from the melting furnace to the holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0018] Example 3

[0019] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 1.6 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, during which time it was electromagnetically stirred at a speed of 300 r / min. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0020] Example 4

[0021] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 1.96 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, and electromagnetic stirring was performed at a speed of 300 r / min during the holding period. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0022] Example 5

[0023] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 2.4 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, during which time it was electromagnetically stirred at a speed of 300 r / min. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0024] Example 6

[0025] Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn, 1.2 parts by weight of Er and 0.76 parts by weight of Nb were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, during which time it was electromagnetically stirred at a speed of 300 r / min. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0026] Comparative Example 1 Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, and 0.83 parts by weight of Mn were placed in a melting furnace and melted at high temperature and stirred evenly. The mixture was then held at this temperature for 12 hours, during which time it was electromagnetically stirred at a speed of 300 r / min. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter and then cast. The mixture was then heat-treated at 380℃ for 8 hours and finally naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0027] Comparative Example 2 Based on 100 parts by weight of Al, 5.8 parts by weight of Zn, 2.7 parts by weight of Mg, 1.9 parts by weight of Cu, 1.35 parts by weight of Cu, 1.05 parts by weight of Ti, 0.83 parts by weight of Mn and 4.5 parts by weight of Er were placed in a melting furnace and melted at high temperature and stirred evenly. Then, the mixture was held at this temperature for 12 hours, during which time it was electromagnetically stirred at a speed of 300 r / min. After the molten metal was transferred from the melting furnace to a holding furnace, it was filtered using a high-temperature resistant filter, then cast, and heat-treated at 380℃ for 8 hours. Finally, it was naturally aged for 36 hours to obtain a high thermal conductivity aluminum alloy for die casting.

[0028] Next, we evaluated the thermal conductivity and tensile strength of the experimental samples from Examples 1-6 and Comparative Examples 1-2. To ensure the comparability of the tests, all process conditions were identical except for the amounts of Er and / or Nb. The test results are shown in Table 1.

[0029] Table 1 Test data for each sample ; As shown in Table 1, the addition of the rare earth element Er to Al-Zn-Mg-Cu-Cu-Ti-Mn aluminum alloys significantly improves their thermal conductivity. Studies have shown that as the amount of Er increases, the thermal conductivity of the aluminum alloy initially increases and then stabilizes, while the tensile strength remains almost unaffected. However, excessive Er content leads to a sharp decrease in the tensile strength of the aluminum alloy; therefore, the Er content should be controlled between 0.8 and 2.4 parts by weight relative to 100 parts by weight of metallic aluminum. Furthermore, the simultaneous addition of Er and Nb can further improve the thermal conductivity of the aluminum alloy.

[0030] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The preparation process of the high thermal conductivity aluminum alloy for die casting includes the following steps: Based on 100 parts by weight of Al, 5.8-6.2 parts by weight of Zn, 2.7-3.2 parts by weight of Mg, 1.9-2.5 parts by weight of Cu, 1.35-1.6 parts by weight of Cu, 1.05-1.3 parts by weight of Ti, 0.83-1.1 parts by weight of Mn, and 0.8-2.4 parts by weight of Er are placed in a melting furnace and melted at high temperature and stirred evenly. The mixture is then held at this temperature for 12-15 hours, during which time it is electromagnetically stirred at a speed of 280-300 r / min. The molten metal is then transferred from the melting furnace to a holding furnace and filtered using a high-temperature resistant filter. The resulting solution is then cast and heat-treated at 380-400℃ for 8-12 hours, followed by natural aging for approximately 30-36 hours to obtain a high thermal conductivity aluminum alloy for die casting. The thermal conductivity of this high thermal conductivity aluminum alloy for die casting is greater than 145 W·m. -1 ·K -1 The tensile strength is greater than 220 MPa.

2. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The electromagnetic stirring speed is 300 r / min.

3. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The heat treatment temperature is 380℃.

4. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The heat treatment time is 8 hours.

5. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The natural aging period is 36 hours.

6. A preparation process for a high thermal conductivity aluminum alloy for die casting, characterized in that, The heat preservation time is 12 hours.

7. A high thermal conductivity aluminum alloy for die casting, characterized in that, The high thermal conductivity aluminum alloy for die casting is prepared by the preparation process described in any one of claims 1-6.