Alloy material and preparation method and application thereof

Abstract

The invention discloses an alloy material and a preparation method and application thereof, and the alloy material comprises the following components in percentage by mass: 30-32% of bismuth; 50-52% of indium; 16-17% of tin; 0.05 to 0.2 percent of gallium; 0-0.5% of magnesium; 0-2.0% of zinc; the content of both magnesium and zinc is not zero. The alloy material is appropriate in melting point, high in heat conductivity coefficient and not prone to brittle rupture in the tabletting process, so that the alloy material solves the problems of normal-temperature transportation and storage and can rapidly respond and achieve efficient heat conduction when the temperature of a thermal assembly rises; in addition, the alloy material can be made into the lamellar phase change material by adopting a simple pressing method.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal interface materials, and in particular relates to an alloy material and a preparation method and application thereof. Background Art

[0002] In electronic devices, some components generate a lot of heat when running. These components are called thermal components, such as central processing units (CPUs) and power integrated circuits (ICs). In order to prevent the temperature of these thermal components from exceeding their safe range, the industry usually uses thermal conductive components (such as heat sinks) to help dissipate heat, and installs fans on the heat sinks to enhance the heat dissipation effect. However, for devices with limited space, such as laptops and personal digital assistants (PDAs), fans cannot be installed due to the thin and light design requirements.

[0003] In order to solve the above problems, the industry has developed a new type of heat dissipation technology, that is, applying a layer of thermal interface material on the contact surface between the thermal conductive component and the thermal component. This material can improve the efficiency of heat conduction and help heat to be better transferred from the thermal component to the heat sink. Commonly used metal thermal interface materials include Field's alloy, Galistan alloy and Wood's metal; however, existing thermal interface materials also have some limitations. For example, Field's alloy is a eutectic alloy composed of 16.5% tin, 51% indium and 32.5% bismuth. Its melting point is 60~62℃ and it is the eutectic point. It is often called phase change metal in this field. When the operating temperature of the chip reaches 70~80℃ or above, it will be liquefied, which can easily fill the gap between the chip and the heat sink fins and reduce thermal resistance; however, not all chips will reach a high temperature of more than 80℃ at any time to liquefy such thermal interface materials. Some chips have an operating temperature of about 60~65℃, that is, the thermal interface material needs to be liquefied, but at this time, Field'salloy is still near the melting point, and the liquefaction efficiency is not good. Galistan alloy is a liquid metal alloy composed of 68.5% gallium, 21.5% indium and 10% tin, with a melting point of about 10~13℃, which is also a eutectic composition. Although its melting point is extremely low, it contains a large amount of Ga. When the content of this element is high, it is easy to react with Al to form a new alloy, which will cause corrosion problems for common aluminum heat sink fins. Therefore, it is only suitable for copper heat sink fins with higher costs. Wood's metal contains 50 bismuth-26.7 lead-13.3 tin-10 cadmium, with a melting point of 50℃, but the current environmental protection regulations make such alloy systems no longer usable.

[0004] In order to solve the limitations of existing thermal interface materials, CN105349866A proposes an alloy material containing 0.67~10% Ga, which reduces the melting point to 40~60°C. Although this type of alloy effectively reduces the melting point, because Ga and Bi are immiscible and it can be found in differential scanning calorimetry (DSC) analysis that the starting temperature of their melting may even be as low as 7°C, this type of alloy has weak structure, is prone to brittle cracking, and has no film-forming properties, and cannot be produced into thin-sheet phase change materials by simple pressing. Furthermore, since the melting point is lower than 50°C, general freight methods are not feasible, especially in summer, when unrefrigerated freight conditions can easily reach above 55°C, so if this type of material is to be transported, it must be transported using refrigerated freight or other low-temperature transportation.

[0005] Therefore, there is an urgent need for an alloy material and a preparation method and application thereof to solve the deficiencies of the existing technical problems. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide an alloy material and a preparation method and application thereof. The alloy material of the present invention has a suitable melting point, high thermal conductivity and is not prone to brittle cracking during the sheeting process. Therefore, the alloy material of the present invention not only solves the problems of transportation and storage at room temperature, but also can respond quickly and achieve efficient heat conduction when the temperature of the thermal component rises, and can also use a simple pressing method to make the alloy material into a thin sheet of phase change material.

[0007] To achieve the above objectives, the present invention provides an alloy material in a first aspect, which comprises the following components in terms of mass percentage: Bismuth 30~32%; Indium 50~52%; Tin 16~17%; Gallium 0.05~0.2%; Magnesium 0~0.5%; Zinc 0~2.0%; Among them, the content of magnesium and zinc is not zero.

[0008] Compared with the prior art, the present invention stabilizes the eutectic point of the alloy at 59.5~61.0℃ by precisely controlling the mass ratios of bismuth, indium, and indium to 30~32%, 50~52%, and 16~17%, respectively, which provides the alloy with a stable low melting point characteristic. The introduction of trace gallium (0.05~0.2%) effectively destroys the lattice periodicity and further reduces the melting point; at the same time, it also avoids the problem of brittle cracking of the alloy during the tableting process due to excessive gallium content. The addition of magnesium (0~0.5%) and zinc (0~2.0%) further reduces the melting point, enhances the oxidation resistance of the alloy, and avoids the problem of high melting point slag generation and melting point fluctuations caused by excessive magnesium or zinc content. In addition, the high indium content and uniform eutectic structure significantly improve the thermal conductivity of the alloy. Therefore, the alloy material of the present invention has a suitable melting point, high thermal conductivity, and is not prone to brittle cracking during tableting.

[0009] Furthermore, the initial melting point of the alloy material of the present invention is 52~58°C. The initial melting point is above 52°C, which ensures that the alloy material remains solid during transportation and storage at room temperature, avoiding transportation problems caused by too low a melting point; in addition, because the melting point is controlled at 58°C or below, when the thermal component (such as a chip) begins to heat up, the alloy material will begin to liquefy before the temperature reaches 60~65°C, and the alloy can quickly fill the tiny gap between the thermal component and the heat dissipation component to achieve uniform contact, thereby significantly improving the heat conduction efficiency. The alloy material of the present invention, with its suitable melting point range (52~58°C), not only solves the problem of transportation and storage at room temperature, but also can respond quickly when the thermal component heats up and achieve efficient heat conduction. Furthermore, the thermal conductivity of the alloy material of the present invention is 19~20W / mK. The thermal conductivity of commonly used thermal conductive silicone is usually between 1~12 W / m·K, while the thermal conductivity of the alloy material of the present invention reaches 19~20 W / m·K, which is significantly higher than that of thermal conductive silicone, which means that the alloy material of the present invention can quickly transfer heat from the heat source (such as a chip) to the heat dissipation component to avoid heat accumulation and local overheating.

[0010] Furthermore, the alloy material of the present invention comprises the following components by mass percentage: Bismuth 30.39~31.5%; Indium 50.5~51%; Tin 16.3~16.5%; Gallium 0.05~0.2%; Magnesium 0.3~0.4%; Zinc 0.5~2.0%.

[0011] Further optimizing the content ratio of bismuth, indium, tin, gallium, magnesium and zinc can stabilize the initial melting point of the alloy at 52~56.5℃, while also ensuring that the alloy has good thermal conductivity and exhibits good anti-brittle cracking performance during the tableting process.

[0012] Furthermore, the alloy material of the present invention comprises the following components by mass percentage: Bismuth 30.4~31.45%; Indium 51%; Tin 16.4~16.5%; Gallium 0.1~0.2%; Magnesium 0.31~0.4%; Zinc 0.64~1.5%.

[0013] Further optimizing the content ratio of bismuth, indium, tin, gallium, magnesium and zinc can make the initial melting point of the alloy It is stable at 52.5~56℃, and at the same time ensures that the alloy has better thermal conductivity and better anti-brittle cracking performance during the tableting process.

[0014] Furthermore, the alloy material of the present invention comprises the following components by mass percentage: Bismuth 31.45%; Indium 51%; Tin 16.4%; Gallium 0.2%; Magnesium 0.31%; Zinc 0.64%.

[0015] By precisely setting the content ratios of bismuth, indium, tin, gallium, magnesium and zinc to 31.45%, 51%, 16.4%, 0.2%, 0.31% and 0.64%, the starting melting point of the alloy can be accurately controlled at 52.8 degrees Celsius, while also ensuring that the alloy has excellent thermal conductivity and exhibits excellent anti-brittle cracking properties during the sheeting process.

[0016] Accordingly, a second aspect of the present invention provides a method for preparing an alloy material, comprising the steps of: S1, the formula amount of bismuth, indium, tin, gallium, magnesium, zinc powders are mixed uniformly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 250-300° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3, pouring the mixed alloy liquid into a mold, and obtaining an alloy material by natural cooling.

[0017] Furthermore, in step S1 of the present invention, the purity of the bismuth, indium, tin, gallium, magnesium and zinc powders is above 99.9%.

[0018] Correspondingly, the third aspect of the present invention further provides an application of an alloy material, wherein the alloy material mentioned above or the alloy material prepared by the method for preparing the alloy material mentioned above is placed between the heat dissipation component and the thermal component.

[0019] Compared with the prior art, the alloy material of the present invention has a suitable melting point, which not only solves the problem of room temperature transportation and storage, but also can quickly respond and start to liquefy before the temperature of the thermal component (such as the chip) rises to 60-65°C, thereby achieving efficient heat conduction. At the same time, the high thermal conductivity of the alloy material further improves the heat conduction efficiency between the heat dissipation component and the thermal component, ensuring fast and uniform heat transfer.

[0020] Furthermore, the alloy material of the present invention is a sheet-like structure with a thickness of 0.1 to 1.0 mm. Since the alloy material of the present invention is not prone to brittle fracture during the sheeting process, a thin sheet-like phase change material can be produced by a simple pressing method, and then the alloy material can be used between the heat dissipation component and the thermal component. More specifically, a mechanical roller device can be used to press the alloy material into a sheet-like structure with a thickness of 0.1 to 1.0 mm. DETAILED DESCRIPTION

[0021] In order to better illustrate the purpose, technical scheme and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0022] The purity of the bismuth, indium, tin, gallium, magnesium and zinc powders used in the examples and comparative examples is above 99.9%.

[0023] Example 1 This embodiment provides an alloy material, which includes the following components in terms of mass percentage: Bismuth 30.39%; Indium 50.78%; Tin 16.39%; Gallium 0.05%; Magnesium 0.4%; Zinc 1.99%.

[0024] This embodiment provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium, magnesium, zinc powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0025] Example 2 This embodiment provides an alloy material, which includes the following components in terms of mass percentage: Bismuth 30.5%; Indium 51%; Tin 16.5%; Gallium 0.1%; Magnesium 0.4%; Zinc 1.5%.

[0026] This embodiment provides a method for preparing an alloy material, the steps comprising: S1. Adding the formulated amounts of bismuth, indium, tin, gallium, magnesium and zinc powders into a glass container and mixing them evenly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 290° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0027] Example 3 This embodiment provides an alloy material, which includes the following components in terms of mass percentage: Bismuth 30.4%; Indium 51%; Tin 16.5%; Gallium 0.2%; Magnesium 0.4%; Zinc 1.5%.

[0028] This embodiment provides a method for preparing an alloy material, the steps comprising: S1. Adding the formulated amounts of bismuth, indium, tin, gallium, magnesium and zinc powders into a glass container and mixing them evenly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 295° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0029] Example 4 This embodiment provides an alloy material, which includes the following components in terms of mass percentage: Bismuth 31.45%; Indium 51%; Tin 16.4%; Gallium 0.2%; Magnesium 0.31%; Zinc 0.64%.

[0030] This embodiment provides a method for preparing an alloy material, the steps comprising: S1. Adding the formulated amounts of bismuth, indium, tin, gallium, magnesium and zinc powders into a glass container and mixing them evenly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 300° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0031] Comparative Example 1 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 32.5%; Indium 51%; Tin 16.5%.

[0032] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin powder was added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0033] Comparative Example 2 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 30%; Indium 54%; Tin 15%; Gallium 1%.

[0034] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0035] Comparative Example 3 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 32%; Indium 50%; Tin 16%; Gallium 2%.

[0036] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0037] Comparative Example 4 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 30%; Indium 50%; Tin 14%; Gallium 6%.

[0038] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0039] Comparative Example 5 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 30%; Indium 48%; Tin 14%; Gallium 8%.

[0040] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0041] Comparative Example 6 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 32.17%; Indium 50.50%; Tin 16.34%; Zinc 0.99%.

[0042] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, zinc powder was added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0043] Comparative Example 7 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 29.73%; Indium 51.32%; Tin 15.1%; Gallium 2.94%; Zinc 0.91%.

[0044] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, the formula amount of bismuth, indium, tin, gallium, zinc powder is added to a glass container, mixed to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0045] Comparative Example 8 This comparative example provides an alloy material, which comprises the following components by mass percentage: Bismuth 29.73%; Indium 51.32%; Tin 15.1%; Gallium 2.94%; Magnesium 0.91%.

[0046] This comparative example provides a method for preparing an alloy material, the steps comprising: S1, adding the formulated amounts of bismuth, indium, tin, gallium and magnesium powders into a glass container and mixing them evenly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 280° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3. Pour the mixed alloy liquid into a graphite mold and obtain the alloy material by natural cooling.

[0047] The initial melting point of the alloy materials of Examples 1 to 4 and Comparative Examples 1 to 8 was tested by differential scanning calorimetry (DSC). The test conditions were: under nitrogen protection, the temperature was raised at a heating rate of 10°C / min, and the starting point of the endothermic peak was recorded as the initial melting point. The test results are shown in Table 1.

[0048] According to ISO22007-2 standard, the thermal conductivity of the alloy materials of Examples 1 to 4 and Comparative Examples 1 to 8 was tested using a transient method using a HotDisk TPS500S instrument. The test conditions were: at room temperature (25°C), using a sample with a thickness of 2 mm, measuring the heat flux density and temperature gradient, and calculating the thermal conductivity. The test results are shown in Table 1.

[0049] The alloy materials of Examples 1 to 4 and Comparative Examples 1 to 8 were pressed into thin sheets with a thickness of 0.1 mm using a mechanical roller device to observe whether brittle cracks appeared on the surface of the thin sheets. The experimental conditions were: the pressing pressure was 50 MPa and the pressing speed was 5 mm / s. The experimental results are shown in Table 1.

[0050] Table 1

[0051] As shown in Table 1, the initial melting point range of the alloy materials of Examples 1 to 4 is 52°C to 58°C, the thermal conductivity is close to 19.80 W / m·K, and no brittle cracking occurs on the surface of the sheets, which indicates that the alloy material of the present invention has a suitable melting point, a high thermal conductivity and is not prone to brittle cracking during the sheeting process.

[0052] By comparing Comparative Examples 1 to 5, it can be seen that the addition of Ga significantly reduces the initial melting point of the alloy, but the excessively high gallium content causes the alloy to be prone to brittle cracking during the tableting process.

[0053] By comparing Comparative Example 1 with Comparative Example 6, it can be seen that the addition of zinc further reduces the melting point and is less prone to brittle cracking.

[0054] By comparing Comparative Example 1 with Comparative Example 7, it can be seen that relying solely on the combination of bismuth, indium, excess gallium and zinc will result in the alloy having a too low melting point and being brittle.

[0055] Comparing Comparative Example 1 with Comparative Example 8, it can be seen that the alloy only relying on the combination of bismuth, indium, excess gallium and magnesium also makes the alloy melting point too low and brittle.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An alloy material, characterized in that: In terms of mass percentage, it includes the following components: Bismuth 30~32%; Indium 50~52%; Tin 16~17%; Gallium 0.05~0.2%; Magnesium 0~0.5%; Zinc 0~2.0%; Wherein, the contents of magnesium and zinc are not zero.

2. The alloy material according to claim 1, characterized in that The initial melting point of the alloy material is 52-58°C.

3. The alloy material according to claim 1, characterized in that: The thermal conductivity of the alloy material is 19-20 W / mK.

4. The alloy material according to claim 1, characterized in that: In terms of mass percentage, it includes the following components: Bismuth 30.39~31.5%; Indium 50.5~51%; Tin 16.3~16.5%; Gallium 0.05~0.2%; Magnesium 0.3~0.4%; Zinc 0.5~2.0%.

5. The alloy material according to claim 4, characterized in that: In terms of mass percentage, it includes the following components: Bismuth 30.4~31.45%; Indium 51%; Tin 16.4~16.5%; Gallium 0.1~0.2%; Magnesium 0.31~0.4%; Zinc 0.64~1.5%.

6. The alloy material according to claim 5, characterized in that: In terms of mass percentage, it includes the following components: Bismuth 31.45%; Indium 51%; Tin 16.4%; Gallium 0.2%; Magnesium 0.31%; Zinc 0.64%.

7. A method for preparing the alloy material according to any one of claims 1 to 6, characterized in that the steps include: S1, the formula amount of bismuth, indium, tin, gallium, magnesium, zinc powders are mixed uniformly to obtain a first mixture; S2, placing the first mixture into an electric heating furnace, heating it to 250-300° C. and then maintaining the temperature until the first mixture is completely melted to obtain a mixed alloy liquid; S3, pouring the mixed alloy liquid into a mold, and obtaining an alloy material by natural cooling.

8. An application of an alloy material, characterized in that: The alloy material as claimed in any one of claims 1 to 6 or the alloy material prepared by the method for preparing the alloy material as claimed in claim 7 is placed between the heat dissipation component and the thermal component.

9. Use of the alloy material according to claim 8, characterized in that: The alloy material is in a sheet structure and has a thickness of 0.1-1.0 mm.

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