CN-122012958-A - Ultrahigh heat conduction integrated die-casting aluminum alloy and preparation process thereof

CN122012958ACN 122012958 ACN122012958 ACN 122012958ACN-122012958-A

Abstract

The invention discloses an ultrahigh heat conduction integrated die-casting aluminum alloy and a preparation process thereof, and belongs to the technical field of aluminum alloy material preparation. The preparation process comprises the steps of proportioning according to a specific proportion, strictly controlling impurity content, carrying out low-oxygen smelting under the protection of argon, controlling the oxygen content of a melt to be less than or equal to 0.003%, refining for 10-15 minutes under the protection of argon at 600-800W power and 720-740 ℃ melt temperature, standing for 10-20 minutes after refining, removing slag again, carrying out low-speed mold filling at a mold filling pressure of 30-60MPa and a mold cooling speed of 0.3-0.5m/s, keeping the temperature of a die casting at 440-460 ℃ for 1-2 hours, and carrying out forced air cooling. The total amount of Ti and Zr in the ingredients and the content of B meet a specific proportion, and part of elements are added in the form of intermediate alloy. The aluminum alloy disclosed by the invention has excellent thermal conductivity and mechanical properties, is suitable for preparing high-end heat dissipation components, and has strong practicability and remarkable industrial application value.

Inventors

QIN YIMING
ZHOU JIANWANG
PENG YUN
CHEN SHUILIANG

Assignees

梧州市鸿图精密压铸有限公司
东莞鸿图精密压铸有限公司
南宁学院

Dates

Publication Date: 20260512
Application Date: 20260120

Claims (10)

1. The preparation process of the ultrahigh heat conduction integrated die-casting aluminum alloy is characterized by comprising the following steps of: S1, proportioning and smelting, namely proportioning ：Si 5.0-7.5%、Mg 0.1-0.3%、Fe 0.08-0.2%、Cu≤0.05%、Ti 0.05-0.15%、Zr 0.03-0.08%、B 0.008-0.02%、P 0.005-0.015%、Sn 0.01-0.03%、In 0.003-0.01%, according to the following mass percent, wherein the balance of Al and unavoidable impurities is less than or equal to 0.002%, and carrying out low-oxygen smelting on the prepared raw materials in an argon protective atmosphere, and controlling the oxygen content of a melt to be less than or equal to 0.003%; S2, refining and purifying, namely performing argon plasma auxiliary refining on the melt obtained in the step S1, wherein the refining is performed under the coverage of argon, the power of a plasma generator is 600-800W, the temperature of the melt is kept at 720-740 ℃, the refining time is 10-15 minutes, the hydrogen content of the melt after treatment is less than or equal to 0.08ml/100g Al, and the size of inclusions is less than or equal to 3 mu m; s3, melt processing, namely standing the melt refined in the step S2 for more than 10 minutes, and then thoroughly removing surface scum; S4, die casting, namely die casting the melt processed in the step 3, wherein the die casting pressure is 30-60MPa, low-speed die casting is adopted, the die casting speed is 0.3-0.5m/S, and the cooling speed of a die after die casting is more than or equal to 50 ℃ per second, so that a die casting is obtained; S5, carrying out solution treatment, namely preserving the temperature of the die casting at 440-460 ℃ for 1-2 hours, and then carrying out forced air cooling.
2. The process for preparing the ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein the aluminum alloy comprises 6.0-7.0% of Si, 0.15-0.25% of Mg and 0.1-0.15% of Fe by mass.
3. The process for preparing the ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein the sum of the mass percentages of Ti and Zr and the mass percentage of B in the aluminum alloy are more than or equal to 5 and less than or equal to (Ti+Zr)/B and less than or equal to 15.
4. The process for preparing an ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein in the step S1, the B element and part of the Ti element are added in the form of an Al-5Ti-1B intermediate alloy.
5. The process for preparing the ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein in the step S1, the low-oxygen smelting is performed under an argon protective atmosphere with an oxygen partial pressure of less than or equal to 100 Pa.
6. The process for preparing an ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein in the step S1, the mass percentage of the single impurity element is less than or equal to 0.05% except C, and the total mass percentage of all the unavoidable impurity elements is less than or equal to 0.15%.
7. The process for preparing the ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein the hydrogen content in the melt processed in the step S2 is controlled to be 0.05-0.08ml/100g Al, and the size of the inclusion is controlled to be 1-3 mu m.
8. The process for preparing an ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein in the step S3, the melt is kept stand for 10-20 minutes.
9. The process for preparing an ultrahigh heat-conducting integrated die-casting aluminum alloy according to claim 1, wherein in the step S4, the cooling speed of the die is 60-100 ℃ per second.
10. An ultrahigh heat-conducting integrated die-casting aluminum alloy obtained by the preparation process according to any one of claims 1 to 9, wherein the aluminum alloy has a heat conductivity of not less than 210W/(m-K), a tensile strength of not less than 240MPa, and an elongation of not less than 8%.

Description

Ultrahigh heat conduction integrated die-casting aluminum alloy and preparation process thereof Technical Field The invention relates to the technical field of aluminum alloy material preparation, in particular to an ultrahigh heat conduction integrated die-casting aluminum alloy and a preparation process thereof. Background With the rapid development of new energy automobile industry and the wide popularization of 5G communication technology, the performance requirements of high-end heat dissipation components are becoming increasingly stringent. In the field of new energy automobiles, a large amount of heat is generated in the running process of a motor, if the heat cannot be timely dissipated, the working efficiency, the service life and the safety of the motor are seriously affected, and in the field of 5G communication, the heat dissipation pressure of base station equipment is greatly increased due to the high power of the base station equipment, and the communication quality and the equipment stability are directly determined by the heat dissipation efficiency. The aluminum alloy has the advantages of small density, high specific strength, excellent heat conduction performance, die-casting forming and the like, becomes a preferred material for preparing the high-end heat dissipation component, particularly the integrated die-casting aluminum alloy, can realize one-step forming of the component with a complex structure, effectively reduces assembly procedures, lowers production cost, and improves the structural integrity and mechanical reliability of the component at the same time, thereby becoming a research hot spot and development trend in the field of aluminum alloy materials. For the integrated die-casting aluminum alloy for high-end heat dissipation, the heat conduction performance is one of core performance indexes, and meanwhile, excellent mechanical properties and good die-casting forming performance are required to be considered so as to meet the preparation and use requirements of the heat dissipation part with the complex structure. At present, the existing integrated die-casting aluminum alloy is mainly based on Al-Si series alloy, and the mechanical properties are regulated and controlled by adding alloy elements such as Mg, cu, ti and the like, but the existing integrated die-casting aluminum alloy has the defects in the aspect of cooperative optimization of heat conduction properties and mechanical properties. In the smelting link, the prior art mostly adopts conventional atmospheric smelting or simple inert gas protection smelting, and is difficult to effectively control the oxygen content and impurity element content in the melt, so that a large number of oxide inclusions are formed in the melt, and the inclusions can obstruct heat transfer and obviously reduce the heat conduction performance of the aluminum alloy. In the refining link, the traditional refining mode is difficult to realize deep purification of the melt, so that the heat conduction efficiency is affected, and the tensile strength and the elongation of the alloy are reduced. In the die-casting forming link, the prior art mostly adopts higher filling speed, which easily leads to unstable melt filling, generates defects of gas coiling, oxidization and the like, and simultaneously leads to coarse alloy grains due to improper cooling speed control, thereby further reducing the synergy of heat conduction performance and mechanical property. In addition, the prior art lacks systematicness to the proportioning design of alloy components, does not fully consider the synergistic effect of trace elements on grain refinement and second phase morphology optimization, does not strictly control the content of unavoidable impurities, and causes that the heat conducting property and the mechanical property of the alloy are difficult to realize breakthrough promotion. Meanwhile, the existing integrated die-casting aluminum alloy is insufficient in matching between the thermal expansion coefficient and a high-end radiating component, and thermal stress is easily generated in the temperature change process, so that the component is deformed and cracked, and the use reliability is affected. In order to solve the problems, a person skilled in the relevant art tries to improve the comprehensive performance of the integrated die-casting aluminum alloy by adjusting the alloy components, optimizing the preparation process and the like, but does not find an effective scheme for combining the ultrahigh heat conductivity, the excellent mechanical property and the good forming property. In summary, the existing integrated die-casting aluminum alloy has a plurality of defects in component design rationality, preparation process accuracy and performance collaborative optimization, and is difficult to meet urgent demands of fields such as new energy automobiles, 5G communication and the like on the ultrahigh heat conduction and high strength integrat