WO2023231352A1

WO2023231352A1 - High-thermal-conductivity die-cast aluminum alloy product and preparation method therefor, and radiator

Info

Publication number: WO2023231352A1
Application number: PCT/CN2022/136577
Authority: WO
Inventors: 党年钊; 王恒德; 聂志东; 刘金
Original assignee: 中兴通讯股份有限公司
Priority date: 2022-05-30
Filing date: 2022-12-05
Publication date: 2023-12-07
Also published as: CN117187630A

Abstract

A high-thermal-conductivity die-cast aluminum alloy product and a preparation method therefor, and a radiator prepared from the aluminum alloy product. The preparation method comprises: putting an aluminum-silicon alloy into a smelting furnace, heating, melting and refining same, leaving same to stand, then pouring same into a transfer ladle, adding an aluminum-strontium intermediate alloy thereto, melting same to obtain a mixed molten material, followed by die-casting formation, and then subjecting the die-cast aluminum alloy product to a heat treatment.

Description

High thermal conductivity die-cast aluminum alloy product and preparation method thereof, radiator

Cross-references to related applications

This disclosure claims priority to Chinese patent application CN202210602171.6 titled "High Thermal Conductivity Die-cast Aluminum Alloy Products and Preparation Methods and Radiators" submitted on May 30, 2022, the entire content of which is incorporated into this disclosure by reference. .

Technical field

The present disclosure relates to the field of communications, and specifically to a high thermal conductivity die-cast aluminum alloy product, a preparation method thereof, and a radiator.

Background technique

With the rapid development of 5G communication technology, the high integration of components and the increase in packaging density have put forward higher requirements for the heat dissipation technology of wireless base station equipment. At present, most of the radiators of wireless base station equipment are prepared by aluminum alloy die-casting process. The die-casting process is also a cost-effective manufacturing process for radiators.

Die casting, also known as pressure casting, is a special casting process with high production efficiency and low cutting. It is a process in which molten metal fills the mold cavity at high speed and high pressure, and then crystallizes and solidifies under high pressure to form a casting. Because die-cast aluminum alloy has the characteristics of high thermal conductivity, light weight, easy manufacturing, corrosion resistance, and good mechanical properties, its products are widely used in aviation, automobiles, electrical appliances, communications and other industries.

The metal thermal conductivity of pure aluminum has the best cost performance. Most related high thermal conductivity die-cast aluminum alloy products obtain high thermal conductivity by increasing the mass proportion of aluminum in the die-cast aluminum alloy composition and improving the purity of the alloy. However, as the mass proportion of aluminum increases, castings often have problems such as easy mold sticking, poor molding, and a significant decrease in mechanical properties during die casting.

Contents of the invention

Embodiments of the present disclosure provide a high thermal conductivity die-cast aluminum alloy product, a preparation method thereof, and a radiator.

According to a first aspect, an embodiment of the present disclosure provides a method for preparing a high thermal conductivity die-cast aluminum alloy product, which includes: putting an aluminum-silicon alloy into a smelting furnace, raising the temperature to melt the aluminum-silicon alloy; Add a refining agent for refining; let the molten metal in the smelting furnace stand and then pour it into a transfer bag; add an aluminum strontium master alloy to the transfer bag to melt the aluminum strontium master alloy and mix it with the metal The molten liquid is mixed to obtain a mixed molten liquid, and the strontium content in the mixed molten liquid is 0.02%-0.04%; the mixed molten liquid is subjected to a die-casting process to obtain a die-cast aluminum alloy product, and the components and contents of the die-cast aluminum alloy product are They are: silicon, content is 7.5%-9%; iron, content is 0.7%-0.95%; copper, content is <0.02%; magnesium, content is <0.02%; manganese, content is <0.01%; chromium, content is <0.01%; titanium, content is <0.01%; vanadium, content is <0.01%; strontium, content is 0.02%-0.04%; the rest is aluminum and impurity elements, the content of a single impurity element in the impurity elements is <0.05% , the total content of the impurity elements is less than 0.15%; and heat treatment is performed on the die-cast aluminum alloy product.

According to the second aspect, embodiments of the present disclosure provide a high thermal conductivity die-cast aluminum alloy product, which is prepared by using the aforementioned preparation method of a high thermal conductivity die-cast aluminum alloy product. The composition and content of the die-cast aluminum alloy product are: silicon , content is 7.5%-9%; iron, content is 0.7%-0.95%; copper, content is <0.02%; magnesium, content is <0.02%; manganese, content is <0.01%; chromium, content is <0.01% ; Titanium, content is <0.01%; Vanadium, content is <0.01%; Strontium, content is 0.02%-0.04%; the rest are aluminum and impurity elements, wherein the content of a single impurity element in the impurity elements is <0.05%, The total content of the impurity elements is <0.15%.

According to a third aspect, an embodiment of the present disclosure provides a heat sink, which is made of the aforementioned high thermal conductivity die-cast aluminum alloy product.

Description of the drawings

The drawings described here are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the attached picture:

Figure 1 is a flow chart of a method for preparing a high thermal conductivity die-cast aluminum alloy product according to an embodiment of the present disclosure.

Detailed ways

The present disclosure will be described in detail below in conjunction with embodiments with reference to the accompanying drawings. It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

It should be noted that the terms "first", "second", etc. in the description and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Referring to Figure 1, embodiments of the present disclosure provide a method for preparing high thermal conductivity die-cast aluminum alloy products. The preparation method includes: putting aluminum-silicon alloy into a smelting furnace, raising the temperature to melt the aluminum-silicon alloy; adding refining material into the smelting furnace. The molten metal in the smelting furnace is allowed to stand and then poured into the transfer bag; the aluminum-strontium master alloy is added to the transfer bag to melt the aluminum-strontium master alloy and mix it with the molten metal to obtain a mixed molten liquid. The content of strontium in the liquid is 0.02%-0.04%; die-casting the mixed melt to obtain die-cast aluminum alloy products; and heat-treating the die-cast aluminum alloy products.

In the process of production and preparation, by adding aluminum strontium master alloy during the turnover process of the metal melt, and adopting a heat treatment process after die-casting, the thermal conductivity of the high thermal conductivity die-cast aluminum alloy products prepared by the above method can be improved. Reaching more than 180W/(m·K), the body of the radiator made of this material has good heat dissipation effect and can be used in wireless communication base station radiators, etc.

Aluminum-silicon alloy is put into the smelting furnace. Aluminum-silicon alloy has good casting performance and is suitable for large, thin-walled, complex-shaped castings. Aluminum-silicon alloy includes related brand alloy AlSi8. The content of silicon in the brand alloy AlSi8 is relatively high, and it is added The addition of other metals, such as magnesium and copper, makes the alloy have excellent casting properties, small thermal expansion coefficient, good wear resistance, high strength, and good heat resistance.

Similarly, aluminum-silicon alloys can also be partially recycled materials and pure aluminum, which are processed and prepared by using recycled materials and pure aluminum as raw materials, thereby realizing the recycling and reuse of materials and reducing costs. It should be noted that in actual use, the aluminum-silicon alloy includes but is not limited to the two aforementioned aluminum-silicon alloy materials.

For example, aluminum-silicon alloys include hypoeutectic aluminum-silicon alloys, and all alloys whose components are lower than the eutectic composition point are called hypoeutectic aluminum-silicon alloys. Hypoeutectic aluminum-silicon alloy is used as the matrix raw material and prepared by the above method, and the obtained material has high thermal conductivity.

In some embodiments, in order to improve the thermal conductivity of the die-cast aluminum alloy, the mass proportion of aluminum in the die-cast aluminum alloy is usually increased or the purity of the alloy is increased to obtain high thermal conductivity aluminum. However, in the actual production and preparation process, as the mass proportion of aluminum increases, problems such as easy mold sticking, poor molding, and low mechanical properties will gradually occur during die casting. It has been experimentally verified that the die-cast aluminum alloy product prepared by the aforementioned method of this embodiment does not need to further increase the mass proportion of aluminum, and can also achieve a product with higher thermal conductivity, which reduces the requirements for material purity. The method steps Can be used in mass production. At the same time, the method provided by this embodiment does not require additional steps to remove impurities in the product, thereby reducing costs. And after repeated experiments, it has been verified that problems such as easy mold sticking, poor molding, and low mechanical properties will not occur during the die-casting process, and the quality stability is higher.

Raising the temperature to melt the aluminum-silicon alloy includes: controlling the temperature in the smelting furnace to rise to 750°C-780°C to melt the aluminum-silicon alloy in the smelting furnace. During the smelting process of aluminum-silicon alloy, sufficient temperature and heat are required to ensure that the metal and alloy elements are fully melted and dissolved, and the higher the temperature, the faster the melting speed. At the same time, the interaction time between metal, furnace gas and furnace lining is also short. Therefore, it is required to melt as quickly as possible at high temperatures during operation. Rapid melting can shorten the melting time, improve productivity, and ensure melt quality.

In addition, in actual production, the selection of melting temperature can also be determined based on the melting point temperature of different alloys. The melting of aluminum-silicon alloy is in a temperature range. The melting point temperature range of most alloys is quite large. In this range, the metal is in a semi-solid, semi-liquid, semi-molten state. At this time, it is most likely to absorb gas after being exposed to strong hot furnace gas or flame for a long time. Therefore, for example, the melting temperature in this embodiment is 750-780°C. After all the metal is melted, it should be stirred in time to uniformly distribute the alloy components and temperature in the melt, which will help accelerate the melting of the aluminum alloy.

In some embodiments, a refining agent is added to the smelting furnace for refining. The refining agent is sprayed into the smelting furnace using inert gas, so that the refining agent is fully mixed with the molten metal in the smelting furnace. The refining time of the refining agent is not limited. Until the components and contents in the molten metal are detected: silicon, the content is 7.5%-9%; iron, the content is 0.7%-0.95%; copper, the content is <0.02%; magnesium, the content is <0.02%; manganese , the content is <0.01%; chromium, the content is <0.01%, titanium, the content is <0.01%; vanadium, the content is <0.01%; when the rest is aluminum, the refining time is over.

In order to ensure the thermal conductivity of die-cast aluminum alloys, the elemental composition in the molten metal needs to be strictly controlled during the preparation process. Manganese, chromium, titanium, and vanadium elements in the molten metal will greatly reduce the thermal conductivity of the material and must be strictly controlled; iron within a reasonable range can reduce the tendency of mold sticking; silicon can effectively improve the flow of die-cast aluminum alloys properties, increasing the strength of the material.

In some embodiments, the molten metal in the smelting furnace is allowed to stand and then poured into the transfer bag. The molten metal is transported through the operation package for subsequent die casting and other steps.

When refining molten metal, the slag in the smelting furnace will mix with the molten metal, thus affecting the purity of the molten metal. Therefore, after refining, the molten metal needs to be left standing for a period of time to ensure that the metal melts from the smelting furnace. The purity of the molten metal poured out. Optionally, the standing time is 10-15 minutes. As an example, in this embodiment, the standing time of the molten metal is 10 minutes.

In some embodiments, the aluminum-strontium master alloy is added to the transfer package, and the aluminum-strontium master alloy is melted and mixed with the molten metal to obtain a mixed molten liquid. The content of strontium in the mixed molten liquid is 0.02%-0.04%. After experimental verification, adding aluminum-strontium master alloy to the transfer package and melting it in the molten metal effectively reduces the burning loss of strontium, while controlling the strontium content in the mixed melt to ensure the thermal conductivity of the die-cast aluminum alloy. At the same time, it can also effectively maintain the consistent stability of material components. Compared with the current method of preparing die-cast aluminum alloys, strontium is often added to the smelting furnace. In the high-temperature environment of the smelting furnace, the proportion of strontium in the melt will increase greatly as the smelting time increases. The loss will greatly increase the cost.

To completely melt the aluminum-strontium master alloy and mix it with the molten metal to obtain a mixed molten liquid: use a rotating degassing device to melt the aluminum-strontium master alloy into the molten metal, and stir the mixed molten liquid evenly. The aluminum liquid is further refined using rotating degassing equipment. The working principle of the rotating degassing equipment is that inert gas is ejected into the molten metal through the action of the rotating nozzle, producing a large number of small, high-velocity bubbles that are evenly distributed in the molten metal. . Hydrogen atoms dissolved in the molten metal will be adsorbed into the bubbles, and the bubbles will rise and escape in a spiral shape under the combined effect of rotational force and buoyancy force. At the same time, the aluminum-strontium master alloy can melt quickly during this process, evenly distribute in the aluminum liquid and play a conditioning role, refine the aluminum phase, and inhibit the growth of the silicon phase. Optionally, the rotational degassing should be controlled between 10 minutes and 15 minutes. If the time is too short, the aluminum strontium master alloy may not be fully melted and evenly distributed. If the time is too long, the temperature of the aluminum liquid will drop rapidly, which is not conducive to die casting. .

Optionally, the aluminum-strontium master alloy has an elongated strip or rod-shaped structure, and the composition range of the aluminum-strontium master alloy is: 10% strontium, <0.3% iron, and <0.01% manganese. The aluminum-strontium master alloy material is not easy to melt in the molten metal if it is larger or thicker. Therefore, in order to ensure that the aluminum-strontium master alloy can be completely melted in the molten metal, the aluminum-strontium master alloy should be made of slender strips. shape or rod-like structure. Since the melting range of aluminum-strontium master alloy containing 10% strontium is between 650°C and 770°C, strontium is easily evaporated or oxidized under high temperature conditions, which greatly weakens the deterioration effect and causes a large loss of strontium.

Optionally, after the refining of the molten metal is completed, the smelting furnace is controlled to maintain a certain temperature, the molten metal is allowed to stand, and then the molten metal is poured from the smelting furnace into the transfer package. As an example, a certain temperature may be a temperature range, such as 740°C-760°C. Optionally, the first temperature is 750 degrees Celsius. By controlling the first temperature to 750 degrees Celsius, the temperature of the molten metal gradually drops from 750 degrees Celsius during the process of pouring it from the smelting furnace into the transfer package. Under this temperature condition, it can meet the requirements for subsequent melting of aluminum strontium master alloy. requirements, and as the temperature drops, strontium is not easy to burn or volatilize. In this embodiment, the aluminum-strontium intermediate alloy is added when the molten metal is poured from the smelting furnace into the transfer bag. At this time, the temperature of the mixed melt is at 750°C and continues to decrease. The rotating device is used to refine and degas while accelerating the aluminum-strontium intermediate alloy. Melting of the alloy, thereby achieving better modification treatment.

In some embodiments, the mixed melt is subjected to a die-casting process to obtain a die-cast aluminum alloy product. For example, the die-casting process includes pouring the mixed melt into a metering furnace of a die-casting machine, and then die-casting the mixed melt in the metering furnace to obtain a die-cast aluminum alloy product. It should be noted that in actual use, the dosing furnace can also be other equipment that can realize mixed melt casting, such as other components used for die casting in the die casting machine. In addition, the die-casting process includes directly alloying the mixed melt to obtain die-cast aluminum alloy products. Optionally, the die-casting process also includes standing, slag removal and die-casting of the mixed melt to ensure the reliability of each component in the mixed melt. The composition and content of die-cast aluminum alloy products are: silicon, content is 7.5%-9%; iron, content is 0.7%-0.95%; copper, content is <0.02%; magnesium, content is <0.02%; manganese, content is <0.01%; chromium, the content is <0.01%; titanium, the content is <0.01%; vanadium, the content is <0.01%; strontium, the content is 0.02%-0.04%; the rest are aluminum and impurity elements; among the impurity elements The content of individual impurity elements is <0.05%, and the total content of impurity elements is <0.15%. The time for the mixed melt to be poured from the smelting furnace to the dosing furnace should not exceed 30 minutes, and the temperature of the mixed melt should be controlled between 660°C and 700°C during this process. The temperature of the die-casting equipment should be controlled at 640°C-660°C, and if the mixed melt is not used for more than 4 hours, the deterioration of strontium will continue to weaken. At this time, the mixed melt should be poured out and re-smelted.

In some embodiments, after the die-cast aluminum alloy product is die-cast, the nozzle material and burrs of the die-cast aluminum alloy product are removed, and the die-cast aluminum alloy products are stacked reasonably. During the stacking process, care should be taken to avoid die-cast aluminum alloy products. The heat dissipation teeth are easily deformed by pressure.

In some embodiments, heat treatment of the die-cast aluminum alloy product includes: placing the die-cast aluminum alloy product into an aging furnace, controlling the temperature in the aging furnace to rise to a preset temperature range; and after maintaining the preset time, put the die-cast aluminum alloy product into an aging furnace. The alloy product is removed from the aging furnace and the die-cast aluminum alloy product is cooled. Put the die-cast aluminum alloy product into the aging furnace, heat the aging furnace for a certain period of time, then take the die-cast aluminum alloy product out of the aging furnace and cool it, thereby completing the heat treatment process of the die-cast aluminum alloy product.

Optionally, the preset temperature range is 250 degrees Celsius - 350 degrees Celsius, and the preset time is 2 hours. Optionally, control the aging furnace to uniformly heat up to a preset temperature range. In addition, in the actual production and processing process, technicians can shorten the heat treatment time by increasing the heat treatment temperature, or reduce the heat treatment temperature by extending the heat treatment time, so that die-cast aluminum alloy products are not easy to bulge when the gas content is high. Bubbles can also achieve the purpose of improving thermal conductivity. However, after many experiments with different data, it has been verified that the thermal conductivity of the die-cast aluminum alloy product obtained is the best when the heat treatment temperature is 250 degrees Celsius - 350 degrees Celsius and the heat treatment time is 2 hours.

During the heat treatment process, the temperature in the aging furnace is controlled to be less than 400 degrees Celsius. If die-cast aluminum alloy products heat up too quickly in the aging furnace, the temperature difference between the inside and outside will be too large, resulting in excessive internal stress and small cracks on the interior and surface. For example, the purpose of normalizing is to refine the grains and uniformize the distribution of carbides, remove the internal stress of the material, and reduce the hardness of the material. Generally, after quenching or processing, there is a certain amount of internal stress inside itself, so it is not advisable to heat up too quickly.

Optionally, cooling the die-cast aluminum alloy product includes: controlling the die-cast aluminum alloy product to cool in natural air. Similarly, die-cast aluminum alloy products can also be controlled to be cooled in air cooling. It should be noted that the cooling methods of die-cast aluminum alloy products include but are not limited to the above. As an example, the die-cast aluminum alloy products can also be controlled to be cooled in water cooling. After many experimental verifications, it can be seen that the thermal conductivity of die-cast aluminum alloy products is the same when air-cooled and cooled in natural air. The main difference is the difference in cooling time. When die-cast aluminum alloy products are cooled by water cooling, and the die-cast aluminum alloy products are cooled by water cooling at different temperatures or different times, the thermal conductivity of the die-cast aluminum alloys obtained will be different. Therefore, optional die-cast aluminum alloy products are cooled with natural air.

In some embodiments, the thermal conductivity of the die-cast aluminum alloy product obtained by directly die-casting the mixed melt is compared with whether the aluminum strontium master alloy is added to the transfer package and whether the heat treatment process is performed. The measurement data of tensile strength, yield strength and elongation are shown in Table 1.

Table 1

It can be seen from Table 1 that when no aluminum strontium master alloy is added to the transfer package, the thermal conductivity, tensile strength, yield strength and elongation of the die-cast aluminum alloy products that undergo the heat treatment process are all better than Various properties of thermal conductivity, tensile strength, yield strength and elongation of die-cast aluminum alloy products without heat treatment. When the aluminum strontium master alloy is added to the transfer package, the thermal conductivity, tensile strength, yield strength and elongation of the die-cast aluminum alloy products that undergo the heat treatment process are also better than those of the die-cast aluminum alloy that does not undergo the heat treatment process. The thermal conductivity, tensile strength, yield strength and elongation properties of the product.

Without heat treatment, the thermal conductivity, tensile strength, yield strength and elongation of die-cast aluminum alloy products with aluminum-strontium alloy added to the transfer package are better than those without aluminum-strontium alloy added to the transfer package. Thermal conductivity, tensile strength, yield strength and elongation of die-cast aluminum alloy products; in the case of heat treatment process, the thermal conductivity, The properties of tensile strength, yield strength and elongation are better than the thermal conductivity, tensile strength, yield strength and elongation of die-cast aluminum alloy products without adding aluminum strontium master alloy in the transfer package.

Therefore, the die-cast aluminum alloy product prepared by adding aluminum strontium master alloy to the transfer package and performing a heat treatment process has the highest thermal conductivity, and the tensile strength, yield strength, and elongation are all due to the die-cast aluminum alloy prepared under other conditions. product. It should be noted that the components and contents of the mixed melts of Sample 1, Sample 2, Sample 3 and Sample 4 in the aforementioned Table 1 are all the same, that is, the mixed melts obtained through the same method steps are poured into In the transfer bag, the melt in the transfer bag is divided into four parts and placed to form the aforementioned sample 1, sample 2, sample 3 and sample 4 respectively. In this way, the test conclusions of subsequent related tests are more accurate. It is persuasive and the test results are more reliable.

In addition, in this example, the following comparative tests were also conducted to compare whether the heat treatment process was performed, and to compare the mixed melt obtained by adding aluminum strontium master alloy in the smelting furnace and adding aluminum strontium master alloy in the transfer package at different heat preservation times. The measurement data of thermal conductivity of die-cast aluminum alloy products obtained by die-casting are shown in Table 2.

Table 2

It can be seen from Table 2 that under the same conditions, the thermal conductivity of die-cast aluminum alloy products that undergo heat treatment is significantly higher than that of die-cast aluminum alloy products that do not undergo heat treatment. It can be seen that heat treatment can improve the thermal conductivity of die-cast aluminum alloy products. Rate. In addition, when aluminum-strontium master alloy is added to the smelting furnace, as the holding time increases, the mass proportion of strontium in the material composition of the mixed melt decreases rapidly; while when aluminum-strontium master alloy is added to the transfer package, as the holding time increases, With the increase, the mass proportion of strontium in the material components of the mixed melt slows down significantly. When the molten metal is smelted in the smelting furnace, the temperature is generally above 750°C, while the temperature of the mixed molten metal in the transfer package and die-casting equipment is generally between 650°C and 680°C, which is lower than the temperature in the smelting furnace. It can be seen that strontium element is easily lost under high temperature conditions. At the same time, in actual production, the capacity of molten aluminum in the smelting furnace is generally around 5 tons, and the factory takes longer to consume materials. Because the industry uses forklifts to transport transfer packages, the general capacity is only 0.9 tons, and it can be consumed in less than 2 hours when producing communication radiators. Therefore, the solution of adding aluminum strontium master alloy to the transfer package is more in line with actual production.

It should be noted that the components and contents of the mixed melts of Samples 5 to 10 in the aforementioned Table 2 are all the same, that is, the mixed melts are obtained through the same method steps, and the mixed melts have not yet been poured into the transfer bag. , followed by the relevant experiments described in Table 2. The test conclusions obtained in this way are more convincing and the test results are more reliable.

To sum up, the preparation method of high thermal conductivity die-cast aluminum alloy products provided in this embodiment, compared with the currently commonly used preparation methods of high thermal conductivity die-cast aluminum alloy products, does not require new experimental equipment and process steps during the preparation process. It is simple and reduces the requirements for material purity. It can also have similar performance to die-cast aluminum alloy products prepared by using pure aluminum. It also has higher quality stability during the preparation process, has cost advantages, and is easier to achieve mass production. Similarly, compared with the currently commonly used preparation methods of high thermal conductivity die-cast aluminum alloy products, this preparation method effectively reduces the burning loss of strontium, effectively maintains the consistent stability of the material composition, and reduces costs. In addition, under this heat treatment process condition, taking into account both cost and efficiency, the thermal conductivity of the prepared high thermal conductivity die-cast aluminum alloy product is increased by more than 10%.

Referring to Figure 1, an embodiment of the present disclosure also provides a high thermal conductivity die-cast aluminum alloy product, which is prepared by the preparation method of the high thermal conductivity die-cast aluminum alloy product of the previous embodiment. The composition and content of the aluminum alloy material are: silicon , content is 7.5%-9%; iron, content is 0.7%-0.95%; copper, content is <0.02%; magnesium, content is <0.02%; manganese, content is <0.01%; chromium, content is <0.01% ; Titanium, the content is <0.01%; Vanadium, the content is <0.01%; Strontium, the content is 0.02%-0.04%; The rest are aluminum and impurity elements, among which, the content of a single impurity element in the impurity element is <0.05%, and the impurity element The total content is less than 0.15%.

Example 1

A high thermal conductivity die-cast aluminum alloy product, made of raw materials with the following mass parts: silicon content is 7.5%, iron content is 0.8%; copper content is 0.01%; magnesium content is 0.015%; manganese content The content of chromium is 0.009%; the content of titanium is 0.007%; the content of vanadium is 0.002%; the content of strontium is 0.02%; the rest is aluminum and impurity elements, among which the content of a single impurity element in the impurity elements is < 0.05%, the total content of impurity elements is 0.14%.

Example 2

A high thermal conductivity die-cast aluminum alloy product, made of the following raw materials in parts by mass: silicon content is 9%, iron content is 0.7%; copper content is 0.017%; magnesium content is 0.01%; manganese content The content of chromium is 0.009%; the content of chromium is 0.005%; the content of titanium is 0.004%; the content of vanadium is 0.009%; the content of strontium is 0.02%; the rest is aluminum and impurity elements, among which the content of a single impurity element in the impurity elements is < 0.05%, the total content of impurity elements is 0.1%.

Example 3

A high thermal conductivity die-cast aluminum alloy product, made of the following raw materials in parts by mass: silicon content is 8%, iron content is 0.95%; copper content is 0.013%; magnesium content is 0.005%; manganese content The content of chromium is 0.03%; the content of titanium is 0.008%; the content of vanadium is 0.005%; the content of strontium is 0.04%; the rest are aluminum and impurity elements, among which the content of a single impurity element in the impurity elements is < 0.05%, the total content of impurity elements is 0.12%.

Example 4

A high thermal conductivity die-cast aluminum alloy product, made of the following raw materials in parts by mass: silicon content is 9%, iron content is 0.7%; copper content is 0.012%; magnesium content is 0.011%; manganese content The content of chromium is 0.007%; the content of titanium is 0.009%; the content of vanadium is 0.004%; the content of strontium is 0.03%; the rest is aluminum and impurity elements, among which the content of a single impurity element in the impurity elements is < 0.05%, the total content of impurity elements is 0.14%.

Example 5

A high thermal conductivity die-cast aluminum alloy product, made of raw materials with the following mass parts: silicon content is 8.7%, iron content is 0.77%; copper content is 0.009%; magnesium content is 0.018%; manganese content The content of chromium is 0.002%; the content of chromium is 0.005%; the content of titanium is 0.008%; the content of vanadium is 0.003%; the content of strontium is 0.036%; the rest is aluminum and impurity elements, among which the content of a single impurity element in the impurity elements is < 0.05%, the total content of impurity elements is 0.136%.

The thermal conductivity test was conducted on the high thermal conductivity die-cast aluminum alloy products of Examples 1 to 5. The test results showed that the thermal conductivity of each high thermal conductivity die-cast aluminum alloy product exceeded 180W/(m·K). Due to the high thermal conductivity die-cast aluminum Alloy products have high thermal conductivity and can be used in the field of communication technology. They can also be widely used in photovoltaics, new energy vehicles and other fields that require efficient heat dissipation.

Referring to FIG. 1 , an embodiment of the present disclosure also provides a radiator, which is made of the aforementioned high thermal conductivity die-cast aluminum alloy product.

The high thermal conductivity die-cast aluminum alloy product in this embodiment not only has high thermal conductivity, but also has excellent processing performance, so that it can use various molding processes to process radiators of various complex shapes.

Through the present disclosure, since the aluminum strontium master alloy is added during the turnover process of the molten metal, and a heat treatment process is adopted after die-casting, the problems of easy mold sticking, poor molding, and significant decline in mechanical properties of castings during die-casting can be solved, achieving The thermal conductivity of aluminum alloy products exceeds 180W/(m·K). The body of the radiator made of this material has good heat dissipation effect and can be used in wireless communication base station radiators.

The above are only optional embodiments of the present disclosure, and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the principles of this disclosure shall be included in the protection scope of this disclosure.

Claims

A method for preparing high thermal conductivity die-cast aluminum alloy products, including:

Put the aluminum-silicon alloy into the smelting furnace and raise the temperature to melt the aluminum-silicon alloy;

Add refining agent into the smelting furnace for refining;

Let the molten metal in the smelting furnace stand and then pour it into the transfer bag;

Adding an aluminum-strontium master alloy to the transfer package, melting the aluminum-strontium master alloy and mixing it with the molten metal to obtain a mixed melt, the content of strontium in the mixed melt is 0.02%-0.04%;

The mixed melt is subjected to die-casting processing to obtain a die-cast aluminum alloy product. The components and contents of the die-cast aluminum alloy product are: silicon, with a content of 7.5%-9%; iron, with a content of 0.7%-0.95%; copper, The content is <0.02%; Magnesium, the content is <0.02%; Manganese, the content is <0.01%; Chromium, the content is <0.01%; Titanium, the content is <0.01%; Vanadium, the content is <0.01%; Strontium, the content is 0.02%-0.04%; the rest is aluminum and impurity elements, the content of a single impurity element in the impurity elements is <0.05%, and the total content of the impurity elements is <0.15%; and

The die-cast aluminum alloy product is heat treated.
The preparation method according to claim 1, wherein said melting the aluminum strontium master alloy and mixing it with the molten metal to obtain a mixed molten liquid is:

The aluminum strontium master alloy is melted using a rotating degassing device and mixed with the molten metal to obtain a mixed molten liquid, and the mixed molten liquid is evenly stirred.
The preparation method according to claim 2, wherein the working time of the rotating degassing equipment is 10 minutes to 15 minutes.
The preparation method according to claim 1, wherein the heat treatment of the die-cast aluminum alloy product includes:

Put the die-cast aluminum alloy product into an aging furnace, and control the temperature in the aging furnace to rise to a preset temperature range; and

After maintaining for a preset time, the die-cast aluminum alloy product is taken out of the aging furnace and cooled.
The preparation method according to claim 4, wherein the preset temperature range is 250 degrees Celsius to 350 degrees Celsius, and the preset time is 2 hours.
The preparation method according to claim 4, wherein said cooling the die-cast aluminum alloy product includes: controlling the die-cast aluminum alloy product to be cooled in natural air.
The preparation method according to claim 1, wherein the aluminum-strontium master alloy is in the form of an elongated strip or rod-shaped structure.
The preparation method according to claim 1, wherein said pouring the molten metal in the smelting furnace into a transfer bag after it is allowed to stand includes:

Control the temperature in the smelting furnace to 740 degrees Celsius to 760 degrees Celsius, and then pour the molten metal in the smelting furnace into the transfer bag after letting it stand for 10 minutes.
A high thermal conductivity die-cast aluminum alloy product prepared by the preparation method of a high thermal conductivity die-cast aluminum alloy product as described in any one of claims 1 to 8. The composition and content of the die-cast aluminum alloy product are:

Silicon, content is 7.5%-9%; Iron, content is 0.7%-0.95%; Copper, content is <0.02%; Magnesium, content is <0.02%; Manganese, content is <0.01%; Chromium, content is <0.01 %; titanium, content is <0.01%; vanadium, content is <0.01%; strontium, content is 0.02%-0.04%;

The rest are aluminum and impurity elements, wherein the content of a single impurity element in the impurity elements is <0.05%, and the total content of the impurity elements is <0.15%.
A radiator made of the high thermal conductivity die-cast aluminum alloy product described in claim 9.