阅读说明：本技术 一种低熔点高潜热相变储能材料及其制备方法 (Low-melting-point high-latent-heat phase change energy storage material and preparation method thereof ) 是由 郭宏 杜世杰 谢忠南 张习敏 黄树晖 米绪军 于 2020-11-19 设计创作，主要内容包括：本发明涉及一种低熔点高潜热相变储能材料及其制备方法,属于相变储能领域。该材料为具有共晶熔化特性的低熔点高潜热合金,按照重量百分比计,包含有：In 10-25％,Sn 10-25％,Ga 0-4％,Zn 0-4％,余量为Bi。制备时,首先按照所述配比称取各组分,将纯度为99.995wt％以上的铟、锡、镓、锌和铋放入真空熔炼炉,然后在真空熔炼炉中隔绝空气控制水、氧含量的条件下进行熔炼、搅拌、浇注和冷却步骤。本发明材料的熔化温度在90～100摄氏度之间,单位体积潜热达到420J/cm～3以上。本发明合金成分体积相变潜热高,合金中不含有有毒有害元素,能广泛应用于电子设备热管理中。(The invention relates to a low-melting-point high-latent-heat phase change energy storage material and a preparation method thereof, belonging to the field of phase change energy storage. The material is a low-melting-point high-latent-heat alloy with eutectic melting property, and comprises the following components in percentage by weight: 10-25% of In, 10-25% of Sn, 0-4% of Ga, 0-4% of Zn and the balance of Bi. When in preparation, the components are weighed according to the mixture ratio, indium, tin, gallium, zinc and bismuth with the purity of more than 99.995 wt% are put into a vacuum smelting furnace, and then the components are put into vacuumAnd smelting, stirring, pouring and cooling are carried out in the smelting furnace under the condition of isolating air and controlling the content of water and oxygen. The melting temperature of the material is between 90 and 100 ℃, and the latent heat per unit volume reaches 420J/cm 3 The above. The alloy of the invention has high volume phase change latent heat, does not contain toxic and harmful elements, and can be widely applied to electronic equipment heat management.)

1. A low-melting-point high-latent-heat phase-change energy storage material is characterized in that: the material is a low-melting-point high-latent-heat alloy with eutectic melting property, and comprises the following components in percentage by weight: 10-25% of In, 10-25% of Sn, 0-4% of Ga, 0-4% of Zn and the balance of Bi.

2. The low-melting-point high latent heat phase change energy storage material of claim 1, wherein: in the alloy, the mass percent of In is 10-20%; the mass percent of Sn is 15-25%; the mass percent of Ga is 0.1-4%; the mass percent of Zn is 0.1-4%.

3. The low-melting-point high latent heat phase change energy storage material of claim 2, wherein: in the alloy, the mass percent of In is 10-15%; the mass percent of Sn is 15-20%; the mass percent of Ga is 0.1-2%; the mass percent of Zn is 0.1-2%.

4. The low-melting-point high latent heat phase change energy storage material according to claim 1, which is characterized in thatCharacterized in that: the melting temperature of the alloy is between 90 and 100 ℃, and the latent heat of phase change of unit volume is more than 420J/cm³。

5. The method for preparing the low-melting-point high latent heat phase change energy storage material according to any one of claims 1 to 3, comprising the steps of: firstly weighing the components according to the mixture ratio, putting indium, tin, gallium, zinc and bismuth with the purity of more than 99.995 wt% into a vacuum smelting furnace, and then smelting, stirring, pouring and cooling under the condition of isolating air and controlling the content of water and oxygen in the vacuum smelting furnace.

6. The method for preparing the low-melting-point high latent heat phase change energy storage material according to claim 5, wherein the method comprises the following steps: the mode of controlling the water and oxygen content by isolating air is as follows: vacuumizing the vacuum smelting furnace to make the vacuum pressure in the vacuum smelting furnace reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

7. The method for preparing the low-melting-point high latent heat phase change energy storage material according to claim 5, wherein the method comprises the following steps: the smelting comprises the following steps: the metal simple substances weighed according to the proportion are placed in a crucible, the crucible is heated to 400-plus-one temperature of 420 ℃ by a heating furnace under the environment of isolating air and controlling the water and oxygen contents, the heating rate is 15-25 ℃/min, the heating is stopped after the temperature is kept for 15-30min, and the casting is carried out when the crucible is cooled to 230-plus-one temperature of 270 ℃ along with the furnace.

8. The method for preparing the low-melting-point high latent heat phase change energy storage material according to claim 5, wherein the method comprises the following steps: the stirring is as follows: after the metal simple substance of the alloy is heated and completely melted, a stirring rod is used for mechanical stirring, and the stirring temperature is not lower than 250 ℃.

9. The method for preparing the low-melting-point high latent heat phase change energy storage material according to claim 5, wherein the method comprises the following steps: the pouring and cooling are as follows: pouring the mixture into a copper mold, wherein the cooling mode is water cooling quenching.

10. Use of a low melting point high latent heat phase change energy storage material according to any of claims 1-3 in a phase change material for thermal management of an electronic device.

Technical Field

The invention relates to a low-melting-point high-latent-heat phase-change energy storage material and a preparation method thereof, in particular to a low-melting-point phase-change heat storage alloy with eutectic melting characteristics and a preparation method thereof, and belongs to the field of phase-change energy storage.

Background

With the development of electronic packaging technology towards high frequency, high speed, multiple functions, high performance, small volume and high reliability, device heat dissipation is an important technical bottleneck restricting the performance of electronic products. In the face of complex heat dissipation environment of electronic devices, the high-power assembly cannot complete quick and effective temperature control through active heat dissipation means such as air cooling, water cooling and the like. Under the condition that effective heat dissipation can not be carried out, the phase change material of high heat conduction high latent heat can absorb the waste heat with the means of latent heat storage, accomplishes the temperature control to exothermic assembly, prevents the overheated of chip, can effectual protection chip, the life of extension subassembly.

With the coming of the 5G era, the information transmission speed is quicker, and high information transmission often brings high heating effect. At present, most organic phase-change materials are used as heat storage materials to control and manage heat under the condition of high heat generation caused by high integration. However, the organic phase-change material has three problems which cannot be solved: one is a low volume latent heat, typically less than 200J/cm³The heat stored in unit volume is less; secondly, the heat conductivity is extremely low and is generally 0.5-20W/mK, namely the phase-change material module cannot quickly respond to heat change, and the heat storage performance is greatly influenced; thirdly, the organic materials do not have a fixed melting point, so that the temperature of the device cannot be kept constant after the device generates heat.

In view of the above disadvantages of the organic phase change materials, metallic phase change materials have been developed. The metal phase change material has high volume latent heat, and can store more heat in unit volume; high thermal conductivity, quick response to heat and effective control of device overheating. However, there are still many problems that are difficult to solve when designing a low-melting-point metal phase-change heat storage material.

Cd and Pb contained in the heat storage phase change material with the phase change temperature within 100 ℃ disclosed at present are harmful elements to the environment, and are greatly restricted in the production and use processes. Summarizing the thermophysical properties of the binary low-melting-point alloy, the melting point of the binary alloy system based on elements such as Pb, Sn, Bi, In, Cd and the like is mostly between 100 and 200 ℃. The patent with publication number CN106756418A discloses a phase change energy storage low melting point alloy with high energy storage density and high thermal conductivity and a preparation method thereof. The alloy comprises the following chemical components in percentage by weight: 15.6-16.8% of Sn, 11.9-13.3% of In, 17.8-19.3% of Pb, 6.9-8.2% of Cd, 42.5-45.3% of Bi and 0.3-0.9% of graphene-plated copper powder. The patent with the publication number of CN106282734A discloses a high-thermal-conductivity low-melting-point energy storage alloy, and the melting temperature of the phase-change heat storage material is between 53 and 75 ℃, but the phase-change heat storage material still contains two environmentally harmful elements of Cd and Pb.

The latent heat of the phase-change material with the phase-change temperature of about 100 ℃ disclosed at present is low, and researches show that the high In element addition can greatly reduce the latent heat of phase change of the material. The addition of a large amount of Bi and Sn can increase the phase change latent heat, but can cause the alloy to have the melting characteristics of a plurality of melting points in the melting process, thereby greatly reducing the recycling performance of the material. The patent publication No. CN103146975A discloses a lead-free low-temperature alloy with a melting point of 116 +/-2 ℃ and a preparation method thereof, and the patent publication No. CN103146976A discloses a lead-free low-temperature alloy with a melting point of 100 +/-2 ℃ and a preparation method thereof, wherein the lead-free low-temperature alloy does not contain environmental harmful elements and has a narrow melting range, but has low phase-change latent heat and small heat storage amount in the practical use process.

Therefore, a metal phase change heat storage material with a low melting point and high latent heat, which is environmentally friendly at a melting temperature of 90-100 ℃, and has a eutectic melting characteristic is required. The patent of the present invention is greatly different from the above patent publications by technical comparison.

Disclosure of Invention

The invention aims to develop a phase change heat storage alloy material which has a melting temperature of 90-100 ℃, has latent heat of phase change superior to that of wood alloy, does not contain toxic and harmful elements, and can be widely applied to electronic equipment.

The technical solution for realizing the invention is as follows:

a low-melting-point high-latent-heat phase-change energy storage material is a low-melting-point high-latent-heat alloy with eutectic melting characteristics, and the alloy comprises the following components in percentage by weight: 10-25% of In, 10-25% of Sn, 0-4% of Ga, 0-4% of Zn and the balance of Bi.

In the above alloy, the In content is preferably 10 to 20% by mass, more preferably 10 to 15% by mass; the mass percent of Sn is preferably 15-25%, more preferably 15-20%; the mass percent of Ga is preferably 0.1-4%, more preferably 0.1-2%; the mass percentage of Zn is preferably 0.1 to 4%, more preferably 0.1 to 2%.

The melting temperature of the alloy is between 90 and 100 ℃, and the latent heat of phase change of unit volume is more than 420J/cm³。

The second purpose of the invention is to provide a preparation method of the low-melting-point phase-change material. Obtaining the low-melting-point alloy by smelting in a vacuum smelting furnace under the protection of argon.

A preparation method of a low-melting-point high-latent-heat phase-change energy storage material comprises the following steps: firstly, weighing the components according to the proportion, putting indium, tin, gallium, zinc and bismuth into a vacuum smelting furnace, and then carrying out smelting, stirring, pouring and cooling under the condition of isolating air and controlling the content of water and oxygen in the vacuum smelting furnace. The purities of indium, tin, gallium, zinc and bismuth are more than 99.995% (wt%).

The mode of controlling the water and oxygen content by isolating air is as follows: vacuumizing the vacuum smelting furnace to make the vacuum pressure in the vacuum smelting furnace reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

The smelting mode is as follows: the metal simple substance weighed according to the proportion is put into a crucible, the mixture is heated to 400-420 ℃ by a heating furnace under the environment of controlling the water and oxygen contents in the isolated air, the temperature is preferably 400 ℃, the heating rate is 15-25 ℃/min, the preferred temperature is 20 ℃/min, the temperature is kept for 15-30min, the heating is stopped after the preferred time is 20min, and the mixture is cooled to 230-270 ℃ along with the furnace, and the casting is carried out when the temperature is preferably 250 ℃.

The stirring mode is as follows: after the metal simple substance of the alloy is heated and completely melted, a stirring rod is used for mechanical stirring. The stirring temperature is not lower than 250 ℃.

The pouring and cooling mode is as follows: pouring the mixture into a copper mold, wherein the cooling mode is water cooling quenching.

In the alloy, the Bi element is a main element, and the high Bi element content in the alloy can ensure that the alloy has high phase change latent heat. However, since the simple substance melting point of Bi element is 271.6 ℃, when designing a heat storage alloy having a melting point of 100 ℃ or lower, the melting point thereof must be lowered by alloying. Therefore, the melting point of the alloy is reduced to a target range by introducing the Sn element and the In element, wherein the In element can reduce the melting point and improve the thermal conductivity of the alloy, and the Sn element can reduce the melting point and improve the mass latent heat of the material. The pure introduction of In element can lead to the great reduction of phase change latent heat. The melting point cannot be reduced to below 100 ℃ by simply introducing Sn.

In the preparation process, the vacuum melting furnace is used to ensure that the alloy is not oxidized in the preparation process, all components in the alloy can be ensured to be completely melted by keeping the temperature for 15-30min after the alloy is heated to 400-420 ℃, the material can be ensured not to be oxidized in the cooling process by furnace cooling, and the mechanical stirring temperature is higher than 250 ℃ to ensure that no solidified particles exist in the molten metal during stirring.

The low-melting-point phase change energy storage alloy prepared by the preparation process has the advantages that the melting temperature is 90-100 ℃, the volume phase change latent heat is high, and the melting curve has the eutectic composition characteristic of single melting point. The low-melting-point high-latent-heat phase-change energy storage alloy with eutectic melting characteristics can be used as a phase-change material for thermal management of electronic equipment.

The invention has the advantages that: the alloy material obtained by the invention has the melting temperature of 90-100 ℃, and the volume phase change latent heat of 420J/cm³The energy storage requirement for thermal management of a plurality of high-power devices at present is met; the melting curve of the phase-change material is characterized by single-melting-point eutectic composition, so that the phase-change material has good circulation stability, and can still keep stable components after the material absorbs heat and dissipates heat for many times along with the temperature of a device. The preparation method can effectively control the component uniformity of the material and effectively control the oxidation and burning loss of the material.

Drawings

FIGS. 1-5 are melting curves for alloy materials prepared in examples 1-5, respectively.

Detailed Description

The invention relates to a low-melting-point high-latent-heat phase change energy storage alloy with eutectic melting characteristics, which comprises the following components in percentage by weight: 10% -25% of indium In; 10 to 25 percent of Sn; 0% -4% of gallium Ga; 0 to 4 percent of zinc Zn; the balance being Bi. Preferably, In is 10 to 15 percent; sn is 10 to 15 percent. When in preparation, firstly, the components are weighed according to the mixture ratio, indium, tin, gallium, zinc and bismuth with the purity of the weighed metal simple substance being more than 99.995 percent (wt%) are put into a vacuum smelting furnace, and then the steps of smelting, stirring, pouring and cooling are carried out under the condition that the vacuum smelting furnace is isolated from air and the water and oxygen content are controlled.

The invention accurately designs the proportion of each element by carrying out phase diagram calculation and solidification process simulation on an In-Bi-Sn ternary alloy system, and has the core of controlling the content of the element In. Wherein, too much In content can reduce the phase transformation latent heat of the alloy, and too little In content can make the melting point of the alloy too high. Finally, Ga and Zn elements are added in combination with thermodynamic design to further adjust the phase change latent heat and the phase change temperature of the alloy, and meanwhile, the heat conductivity of the alloy can be improved and the density of the alloy can be adjusted by adding the Ga and the Zn.

Example 1

A method of high latent heat phase change energy storage material, comprising the steps of:

(1) the alloy with the eutectic melting characteristic and the low melting point and the high latent heat of the embodiment comprises the following components in parts by weight: 10% of Sn, 10% of In and 80% of Bi.

(2) According to the mixture ratio, taking Sn, In and Bi elementary substance metal blocks with the corresponding mass purity of 99.995%, ultrasonically cleaning In 95% alcohol solution for 5min, and drying In a drying oven. And putting the dried metal simple substance into a vacuum smelting furnace, closing the vacuum smelting furnace, vacuumizing to enable the vacuum pressure in the vacuum smelting furnace to reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

(3) Placing the metal simple substance into a crucible, heating to 400 ℃ by a heating furnace at a heating rate of 20 ℃/min under the environment of isolating water and oxygen, preserving heat for 20min, and stopping heating. Cooling to 250 ℃ along with the furnace. And mechanically stirring by using a stirring rod in the heat preservation and cooling processes.

(4) When the temperature of the molten liquid is reduced to 250 ℃, the molten liquid is poured into a copper mold for water cooling and temperature reduction, and after the alloy molten liquid is solidified, water cooling quenching treatment is carried out.

Example 2

A method of high latent heat phase change energy storage material, comprising the steps of:

(1) the alloy with the eutectic melting characteristic and the low melting point and the high latent heat of the embodiment comprises the following components in parts by weight: 20% of Sn, 20% of In and 60% of Bi.

(2) According to the mixture ratio, taking Sn, In and Bi elementary substance metal blocks with the corresponding mass purity of 99.995%, ultrasonically cleaning In 95% alcohol solution for 5min, and drying In a drying oven. And putting the dried metal simple substance into a vacuum smelting furnace, closing the vacuum smelting furnace, vacuumizing to enable the vacuum pressure in the vacuum smelting furnace to reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

(3) Placing the metal simple substance into a crucible, heating to 400 ℃ by a heating furnace at a heating rate of 20 ℃/min under the environment of isolating water and oxygen, preserving heat for 20min, and stopping heating. Cooling to 250 ℃ along with the furnace. And mechanically stirring by using a stirring rod in the heat preservation and cooling processes.

(4) When the temperature of the molten liquid is reduced to 250 ℃, the molten liquid is poured into a copper mold for water cooling and temperature reduction, and after the alloy molten liquid is solidified, water cooling quenching treatment is carried out.

Example 3

A method of high latent heat phase change energy storage material, comprising the steps of:

(1) the alloy with the eutectic melting characteristic and the low melting point and the high latent heat of the embodiment comprises the following components in parts by weight: 20% of Sn, 10% of In and 70% of Bi.

(2) According to the mixture ratio, taking Sn, In and Bi elementary substance metal blocks with the corresponding mass purity of 99.995%, ultrasonically cleaning In 95% alcohol solution for 5min, and drying In a drying oven. And putting the dried metal simple substance into a vacuum smelting furnace, closing the vacuum smelting furnace, vacuumizing to enable the vacuum pressure in the vacuum smelting furnace to reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

(3) Placing the metal simple substance into a crucible, heating to 400 ℃ by a heating furnace at a heating rate of 20 ℃/min under the environment of isolating water and oxygen, preserving heat for 20min, and stopping heating. Cooling to 250 ℃ along with the furnace. And mechanically stirring by using a stirring rod in the heat preservation and cooling processes.

(4) When the temperature of the molten liquid is reduced to 250 ℃, the molten liquid is poured into a copper mold for water cooling and temperature reduction, and after the alloy molten liquid is solidified, water cooling quenching treatment is carried out.

Example 4

A method of high latent heat phase change energy storage material, comprising the steps of:

(1) the alloy with the eutectic melting characteristic and the low melting point and the high latent heat of the embodiment comprises the following components in parts by weight: 15% of Sn, 15% of In and 70% of Bi.

(2) According to the mixture ratio, taking Sn, In and Bi elementary substance metal blocks with the corresponding mass purity of 99.995%, ultrasonically cleaning In 95% alcohol solution for 5min, and drying In a drying oven. And putting the dried metal simple substance into a vacuum smelting furnace, closing the vacuum smelting furnace, vacuumizing to enable the vacuum pressure in the vacuum smelting furnace to reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

(3) Placing the metal simple substance into a crucible, heating to 400 ℃ by a heating furnace at a heating rate of 20 ℃/min under the environment of isolating water and oxygen, preserving heat for 20min, and stopping heating. Cooling to 250 ℃ along with the furnace. And mechanically stirring by using a stirring rod in the heat preservation and cooling processes.

(4) When the temperature of the molten liquid is reduced to 250 ℃, the molten liquid is poured into a copper mold for water cooling and temperature reduction, and after the alloy molten liquid is solidified, water cooling quenching treatment is carried out.

Example 5

A method of high latent heat phase change energy storage material, comprising the steps of:

(1) the alloy with the eutectic melting characteristic and the low melting point and the high latent heat of the embodiment comprises the following components in parts by weight: 10% of Sn, 16% of In, 70% of Bi, 3% of Zn and 1% of Ga.

(2) According to the mixture ratio, taking Sn, In, Bi, Zn and Ga elementary metal blocks with the corresponding mass purity of 99.995%, ultrasonically cleaning for 5min In 95% alcohol solution, and drying In a drying oven. And putting the dried metal simple substance into a vacuum smelting furnace, closing the vacuum smelting furnace, vacuumizing to enable the vacuum pressure in the vacuum smelting furnace to reach-0.1 MPa, and then filling argon into the vacuum smelting furnace to normal pressure.

(3) Placing the metal simple substance into a crucible, heating to 400 ℃ by a heating furnace at a heating rate of 20 ℃/min under the environment of isolating water and oxygen, preserving heat for 20min, and stopping heating. Cooling to 250 ℃ along with the furnace. And mechanically stirring by using a stirring rod in the heat preservation and cooling processes.

(4) When the temperature of the molten liquid is reduced to 250 ℃, the molten liquid is poured into a copper mold for water cooling and temperature reduction, and after the alloy molten liquid is solidified, water cooling quenching treatment is carried out.

The alloy obtained in the above examples was tested for various performance parameters, and the data is shown in table 1.

Table 1 results of performance testing of examples 1-4

Examples	Peak temperature of phase transition	Enthalpy of phase change J/g	Volume latent heat J/cm3
				1	94.4	48.07	446.426
2	91	53.5	497.55
				3	92.5	49.43	445.117
4	93.2	50.68	463.621
				5	90.4	46.58	423.4

Fig. 1 to 5 are melting curves of alloy materials prepared in examples 1 to 5, respectively, and it can be seen from the graphs that the alloy materials prepared in examples 1 to 5 have eutectic melting characteristics, the eutectic melting point of the alloy material prepared in example 1 is 94.4 ℃, the eutectic melting point of the alloy material prepared in example 2 is 91 ℃, the eutectic melting point of the alloy material prepared in example 3 is 92.5 ℃, the eutectic melting point of the alloy material prepared in example 4 is 93.2 ℃ and the eutectic melting point of the alloy material prepared in example 5 is 90.4 ℃.

The alloy with low melting point, high latent heat and eutectic melting property has the melting temperature of 90-100 ℃, and the latent heat per unit volume reaches 420J/cm³The above. The alloy of the invention has high volume phase change latent heat, does not contain toxic and harmful elements, and can be widely applied to electronic equipment heat management.

In the above embodiments, only some embodiments of the preparation method of the low-melting-point high latent heat phase change energy storage material of the present invention are shown, in the above technical solution of the present invention: the components can be freely selected within the limited scope, and are not listed any more, so the technical scheme included in the above description is regarded as illustrative and is not used for limiting the protection scope of the patent application.