Liquid metal constant temperature heat conducting medium and preparation method thereof

Abstract

The present application relates to liquid metal heat conduction technical field, especially to a kind of liquid metal constant-temperature heat conduction medium and preparation method, by weight percentage, heat conduction medium includes: liquid metal 30%-90% and admixture 10%-70%; Liquid metal is selected from one or more of metal gallium, indium, tin, zinc, bismuth, lead, or one or more of the multi-element alloy consisting of gallium, indium, tin, zinc, bismuth;Admixture is selected from one or more of oxide, nitride, sulfide, carbide.The heat conduction medium of the present application has super-wide use temperature zone, can reach room temperature to 900 DEG C or more, heat conduction performance is superior, thermal conductivity is 10W / (m·K)~30W / (m·K), and wettability is good, stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid metal heat conduction, and in particular to a liquid metal constant-temperature heat conduction medium and a preparation method thereof. BACKGROUND

[0002] The constant-temperature bath is an important tool in various scientific research laboratories and production workshops, and can be widely applied in the fields of chemical analysis, petroleum chemical industry, medicine and health, biological culture, geological survey, precision measurement, ocean research, soil analysis, scientific research and teaching, metallurgy, environmental protection, food, etc. The commonly used medium in the constant-temperature bath mainly includes water, oil and molten salt. The boiling point of water is low, and steam is easily generated at high temperature. The oil is oxidized when contacting air above 70℃. The working temperature of the oil bath is below 300℃. The over-temperature oil is decomposed to generate harmful gas, and even fire, and the safety performance is poor. The working temperature of the molten salt is 350℃-500℃. The above three kinds of media are unstable in properties, narrow in working temperature range, and poor in heat transfer performance, and cannot meet the needs of some higher temperature rising and falling or constant-temperature keeping.

[0003] In order to meet some special needs of working temperature above 500℃, the liquid metal can be used as the constant-temperature heat conduction medium. However, the liquid metal has a large density, generally 6g / cm 3 -8g / cm 3 , a large internal pressure, and a strong buoyancy, which easily affects the sample placed therein to make it float out of the liquid metal surface. The fixing, taking out and placing in process of the sample is difficult and time-consuming. SUMMARY

[0004] The present application provides a liquid metal constant-temperature heat conduction medium and a preparation method, to solve the problem that the liquid metal constant-temperature heat conduction medium has a large density, is affected by the factors of large internal pressure and strong buoyancy, and the fixing, taking out and placing in process of the sample is difficult and time-consuming.

[0005] According to a first aspect of the present application, the present application provides a liquid metal constant-temperature heat conduction medium, comprising, by weight percentage: liquid metal 30%-90% and admixture 10%-70%;

[0006] The liquid metal is selected from one or more of metal gallium, indium, tin, zinc, bismuth and lead, or one or more of a multi-element alloy composed of gallium, indium, tin, zinc and bismuth; and the admixture is selected from one or more of oxide, nitride, sulfide and carbide.

[0007] In the above scheme, the application uses oxide or sulfide or nitride or carbide as the admixture to be mixed with the liquid metal. The oxide or sulfide or nitride or carbide has stable properties and high melting point. By selecting the type of liquid metal and the admixture and adjusting the amount ratio between the liquid metal and the admixture, a paste or slurry suspension liquid can be formed. On the one hand, the liquid metal has a wide temperature range and high thermal conductivity, and the influence of the liquid metal buoyancy and pressure on the internal sample is eliminated, without the need to use a customized fixture to fix the sample, and the sample can be conveniently and quickly put in and taken out. On the other hand, the use of the admixture to mix the liquid metal greatly reduces the amount of liquid metal used, significantly reduces the use cost of the thermal conductive medium, and relatively reduces the cost by 20%-50%.

[0008] In a possible design, the liquid metal is selected from one or more of gallium-indium, gallium-tin, gallium-zinc, bismuth-indium binary alloys, or selected from one or more of gallium-indium-tin, gallium-indium-zinc, indium-tin-zinc, bismuth-indium-tin, bismuth-indium-zinc ternary alloys, or selected from one or more of gallium-indium-tin-zinc and / or bismuth-indium-tin-zinc quaternary alloys.

[0009] In the above scheme, by more reasonably selecting the type of liquid metal, the thermal conductive medium can have a wider use temperature range, more superior thermal conductivity, and better wettability and more stable properties.

[0010] In a possible design, the admixture is selected from one or more of lanthanum trioxide, zirconium oxide, tungsten oxide, tantalum pentoxide, nickel oxide, copper oxide, iron oxide, titanium nitride, tantalum nitride, molybdenum sulfide, nickel sulfide, tantalum carbide, tungsten carbide.

[0011] In the above scheme, by more reasonably selecting the type of admixture, the influence of the liquid metal buoyancy and pressure on the internal sample can be more effectively eliminated.

[0012] In a possible design, the density of the admixture is 0.1 g / cm 3 ~ 25 g / cm 3 .

[0013] Alternatively, the density of the admixture can be 0.1 g / cm 3 , 0.5 g / cm 3 , 0.8 g / cm 3 , 1 g / cm 3 , 2 g / cm 3 , 5 g / cm 3 , 8 g / cm 3 , 10 g / cm 3 , 12 g / cm 3 , 14 g / cm 3 , 16 g / cm 318 g / cm 3 20 g / cm 3 22 g / cm 3 23 g / cm 3 24 g / cm 3 or 25 g / cm 3 etc.

[0014] It can be understood that by selecting the reasonable density range value of the admixture, the influence of liquid buoyancy and pressure on the internal sample can be more effectively reduced.

[0015] In a possible design, the powder particle size of the admixture is 1-150 mu m.

[0016] Alternatively, the powder particle size of the admixture can be 1 mu m, 5 mu m, 10 mu m, 20 mu m, 30 mu m, 40 mu m, 50 mu m, 60 mu m, 70 mu m, 80 mu m, 90 mu m, 100 mu m, 110 mu m, 120 mu m, 130 mu m, 140 mu m or 150 mu m, etc.

[0017] It can be understood that by limiting the reasonable particle size range value of the admixture, the admixture can be more evenly dispersed in the liquid metal, and finally form a paste-like or slurry-like suspension liquid.

[0018] In a possible design, the thermal conductivity of the thermal conductive medium is 10-30 W / (m·K).

[0019] It can be understood that the thermal conductive medium with a thermal conductivity of 10-30 W / (m·K) can efficiently heat the heated substance.

[0020] In a possible design, the thermal conductive medium is in a paste-like or slurry-like suspension liquid.

[0021] It can be understood that the thermal conductive medium in a paste-like or slurry-like suspension liquid can more effectively reduce the fluidity of the liquid metal itself, improve the processability, and is not prone to leakage, and can more effectively eliminate the influence of liquid buoyancy and pressure on the internal sample.

[0022] In a possible design, the maximum working temperature of the thermal conductive medium is greater than or equal to 900 DEG C.

[0023] It can be understood that the maximum working temperature of the thermal conductive medium of the present application is greater than or equal to 900 DEG C, which can meet the demand of higher temperature rise and fall or constant temperature, and widen the application scenarios of the thermal conductive medium.

[0024] According to the second aspect of the present application, the present application further provides a preparation method of the above-mentioned thermal conductive medium, comprising the following steps:

[0025] According to the ratio, the liquid metal and the mixture are taken and stirred uniformly;

[0026] The mixture after stirring is uniformly ultrasonically dispersed;

[0027] The mixture after ultrasonic dispersion is subjected to vacuum homogenization treatment, and then after standing, no delamination is observed, and the heat conducting medium is obtained.

[0028] In the above scheme, the mixture has stable properties and high melting and boiling points, the liquid metal is added, fully stirred and mixed, and then subjected to ultrasonic dispersion and vacuum homogenization treatment, so that the liquid metal liquid particles can be fully dispersed, the mixture can be fully dispersed in the liquid metal, and finally a paste-like or slurry-like suspension liquid is formed.

[0029] In a possible design, the stirring is mechanical stirring or magnetic stirring.

[0030] In a possible design, the stirring speed is 200 r / min to 2000 r / min, and the time is 5 min to 30 min.

[0031] Alternatively, the stirring speed can be 200 r / min, 300 r / min, 400 r / min, 500 r / min, 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min, 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min, 1900 r / min, 2000 r / min, etc. The stirring time can be 5 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, 23 min, 25 min, 28 min, or 30 min, etc.

[0032] It can be understood that by reasonably limiting the stirring speed and time, the mixture can be more effectively dispersed in the liquid metal to form a paste-like or slurry-like suspension liquid with more stable performance.

[0033] In a possible design, the ultrasonic dispersion frequency is 20 KHz to 30 KHz, and the time is 5 min to 30 min.

[0034] Optionally, the frequency of ultrasonic dispersion can be 20KHz, 21KHz, 22KHz, 23KHz, 24KHz, 25KHz, 26KHz, 27KHz, 28KHz, 29KHz or 30KHz, etc. The time of ultrasonic dispersion can be 5min, 8min, 10min, 12min, 15min, 18min, 20min, 23min, 25min, 28min or 30min, etc.

[0035] It can be understood that by reasonably limiting the frequency and time of ultrasonic dispersion, the admixture can be more effectively dispersed in the liquid metal to form a paste or slurry suspension liquid with more stable performance.

[0036] In a possible design, the vacuum degree of the vacuum homogenization treatment is-60kPa to-100kPa, and the rotating speed is 1000r / min to 2000r / min.

[0037] Optionally, the vacuum degree of the vacuum homogenization treatment can be-60kPa, -70kPa, -80kPa, -90kPa or-100kPa, etc. The rotating speed of the vacuum homogenization treatment can be 1000r / min, 1100r / min, 1200r / min, 1300r / min, 1400r / min, 1500r / min, 1600r / min, 1700r / min, 1800r / min, 1900r / min or 2000r / min, etc.

[0038] It can be understood that by reasonably limiting the vacuum degree and rotating speed of the vacuum homogenization treatment, the admixture can be more effectively dispersed in the liquid metal to form a paste or slurry suspension liquid with more stable performance.

[0039] The beneficial effects of the present application are as follows:

[0040] The liquid metal constant-temperature heat-conducting medium provided by the present application has an ultra-wide use temperature range, can reach room temperature to 900℃ or above, has superior heat-conducting performance, the thermal conductivity is 10W / (m·K) to 30W / (m·K), and has good wettability and stable properties.

[0041] The liquid metal constant-temperature heat-conducting medium provided by the present application uses oxide or nitride or sulfide or carbide to mix liquid metal to form a paste or slurry suspension liquid, eliminates the influence of liquid buoyancy and pressure on the internal sample, does not need to use a customized clamp to fix the sample, and the putting-in and taking-out process is convenient and fast.

[0042] The liquid metal constant temperature heat conducting medium provided by the application utilizes oxide or nitride or carbide to mix liquid metal, reduces the usage amount of liquid metal, and significantly reduces the usage cost of the constant temperature heat conducting medium. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0044] Embodiment 1

[0045] The embodiment provides a liquid metal constant temperature heat conducting medium, and the liquid metal of the heat conducting medium is a binary alloy Ga 75.5 In 24.5 The mass ratio is 35%, and the admixture is zirconium oxide powder (particle size 150 μm), and the mass ratio is 65%.

[0046] The preparation method of the liquid metal constant temperature heat conducting medium includes the following steps.

[0047] The Ga 75.5 In 24.5 The binary alloy 35.00 g and the zirconium oxide powder (particle size 150 μm) 65.00 g are weighed in a beaker, mechanically stirred or magnetically stirred for 5 min to 30 min, the stirring speed is controlled at 200 r / min to 2000 r / min, the admixture is completely mixed with the liquid metal, then ultrasonic dispersion is used, the frequency is 20 KHz to 30 KHz, and the mixture is dispersed for 5 min to 10 min; the dispersed mixture is subjected to vacuum homogenization treatment, the vacuum degree is-60 kPa to-100 kPa, the stirring speed is 1000 r / min to 2000 r / min, and the mixture is static for 24 h at room temperature without delamination, and the heat conducting medium is obtained. The heat conductivity coefficient of the heat conducting medium is 10.9 W / (m·K) through sampling test.

[0048] Embodiment 2

[0049] The embodiment provides a liquid metal constant temperature heat conducting medium, and the liquid metal of the heat conducting medium is a binary alloy Ga 71 In 15 Sn 13 Zn1, the mass ratio is 40%, the admixture is Al2O3 powder (particle size 38 μm), and the mass ratio is 60%.

[0050] The preparation method of the liquid metal constant temperature heat conducting medium includes the following steps.

[0051] Accurately weigh Ga 71 In 15 Sn 13 Zn 140.00 g and Al2O3 powder (particle size 38 μm) 60.00.00 g in a beaker; using mechanical stirring or magnetic stirring for 5 min to 30 min, the speed control at 200 r / min to 2000 r / min, so that the mixture and the liquid metal is completely mixed; and then using ultrasonic dispersion dispersion for 5 min to 10 min, the frequency of 20 KHz to 30 KHz; the mixture after dispersion is subjected to vacuum homogenization treatment, the vacuum degree is -60 kPa to -100 kPa, the speed is 1000 r / min to 2000 r / min, at room temperature for 24 h without delamination phenomenon obtained heat conducting medium, the thermal conductivity of the heat conducting medium is 12.8 W / (m·K).

[0052] Example 3

[0053] The embodiment provides a liquid metal constant temperature heat conducting medium, the liquid metal of the heat conducting medium is ternary alloy Ga 69.8 In 17 Sn 12.6 , the mixture is La2O3 powder (particle size 1 μm), and the mass of each accounts for 50%.

[0054] The preparation method of the above-mentioned liquid metal constant temperature heat conducting medium comprises the following steps:

[0055] Accurately weigh Ga 69.8 In 17 Sn 12.6 And La2O3 powder (particle size 1 μm) each 50.00 g in a beaker; using mechanical stirring or magnetic stirring for 5 min to 30 min, the speed control at 200 r / min to 2000 r / min, so that the mixture and the liquid metal is completely mixed; and then using ultrasonic dispersion dispersion for 5 min to 10 min, the frequency of 20 KHz to 30 KHz; the mixture after dispersion is subjected to vacuum homogenization treatment, the vacuum degree is -60 kPa to -100 kPa, the speed is 1000 r / min to 2000 r / min, at room temperature for 24 h without delamination phenomenon obtained heat conducting medium, the thermal conductivity of the heat conducting medium is 13.6 W / (m·K).

[0056] Example 4

[0057] The embodiment provides a liquid metal constant temperature heat conducting medium, the liquid metal of the heat conducting medium is Bi 32.5 In 51 Sn 16.5 , the mass accounts for 90%, and the mixture is WC (tungsten carbide) powder (particle size 1 μm), and the mass accounts for 10%.

[0058] The preparation method of the liquid metal constant temperature heat conducting medium comprises the following steps:

[0059] accurately weigh Bi 32.5 In 51 Sn 16.5 90.00g and WC powder (particle size 1 μm) 10.00g in a beaker; use mechanical stirring or magnetic stirring for 5 min to 30 min, the rotating speed is controlled at 200 r / min to 2000 r / min, so that the mixture is fully mixed with the liquid metal; then use ultrasonic dispersion for 5 min to 10 min, the frequency is 20 KHz to 30 KHz; the dispersed mixture is subjected to vacuum homogenization treatment, the vacuum degree is -60 kPa to -100 kPa, the rotating speed is 1000 r / min to 2000 r / min, and the mixture is static at room temperature for 24 h without delamination, so that the heat conducting medium is obtained, and the heat conductivity of the heat conducting medium is 20.5 W / (m·K).

[0060] Comparative Example 1

[0061] This comparative example is based on Example 1 without mixing the liquid metal, and zirconia powder (particle size 150 μm) is selected as the constant temperature heat conducting medium, and the heat conductivity is 4.8 W / (m·K), which is lower than that of the medium of Example 1.

[0062] Comparative Example 2

[0063] This comparative example is based on Example 1 without mixing the zirconia powder, and liquid metal Ga 75.5 In 24.5 is used as the constant temperature heat conducting medium, and the heat conductivity is 30 W / (m·K).

[0064] Comparative Example 3

[0065] This comparative example is based on Example 2 without mixing the liquid metal, and Al2O3 powder (particle size 38 μm) is selected as the constant temperature heat conducting medium, and the heat conductivity is 7.1 W / (m·K), which is lower than that of the medium of Example 2.

[0066] Comparative Example 4

[0067] This comparative example is based on Example 2 without mixing the Al2O3 powder, and liquid metal Ga 71 In 15 Sn 13 Zn1 is used as the constant temperature heat conducting medium, and the heat conductivity is 28 W / (m·K).

[0068] Comparative Example 5

[0069] The comparative example is based on Example 3, and La2O3 powder (particle size 1 μm) is selected as the constant temperature heat transfer medium without mixing liquid metal. The tested thermal conductivity is 6.3 W / (m·K), which is lower than that of the medium of Example 3.

[0070] Comparative Example 6

[0071] The comparative example is based on Example 3, and La2O3 powder (particle size 1 μm) is selected as the constant temperature heat transfer medium without mixing liquid metal. The tested thermal conductivity is 6.3 W / (m·K), which is lower than that of the medium of Example 3. 69.8 In 17 Sn 12.6 As the constant temperature heat transfer medium, the tested thermal conductivity is 34 W / (m·K).

[0072] Comparative Example 7

[0073] The comparative example is based on Example 4, and Al2O3 powder is not mixed, and quaternary alloy liquid metal Bi 32.5 In 51 Sn 16.5 As the constant temperature heat transfer medium, the tested thermal conductivity is 26 W / (m·K).

[0074] Comparative Example 8

[0075] The comparative example is based on Example 4, and WC powder (particle size 1 μm) is selected as the constant temperature heat transfer medium without mixing liquid metal. The tested thermal conductivity is 10.1 W / (m·K), which is lower than that of the heat transfer medium of Example 4.

[0076] Comparative Example 9

[0077] The comparative example is based on Example 3, and the liquid metal for forming the heat transfer medium is ternary alloy Ga 69.8 In 17 Sn 12.6 , and the admixture is non-metallic oxide SiO2 powder (particle size 1 μm), and the mass of each is 50%. The heat transfer medium is obtained by mixing according to the same steps, and the tested thermal conductivity is 6.4 W / (m·K), which is lower than that of the heat transfer medium of Example 3.

[0078] Based on the above comparative examples and comparative examples, the thermal conductivities of the constant temperature heat transfer media are compared as shown in Table 1 below:

[0079] Table 1

[0080] No. Thermal conductivity W / (m K) Maximum operating temperature °C Example 1 10.9 1500 Example 2 12.8 900 Example 3 13.6 1300 Example 4 20.5 1400 Comparative Example 1 4.8 1500 Comparative Example 2 30 1600 Comparative Example 3 7.1 1700 Comparative Example 4 28 1000 Comparative Example 5 6.3 1300 Comparative Example 6 34 1600 Comparative Example 7 26 1300 Comparative Example 8 10.1 1000 Comparative Example 9 6.4 900

[0081] As can be seen from the experimental results of Table 1, the liquid metal constant-temperature heat-conducting medium of the present application has an ultra-wide use temperature range, the highest working temperature can reach above 900℃, and has superior heat-conducting performance, the thermal conductivity is 10W / (m·K)~30W / (m·K), and has good wettability and stable properties. In addition, the present application uses oxides or sulfides or nitrides or carbides as the admixture to be mixed with the liquid metal, the oxides or sulfides or nitrides or carbides have stable properties and high melting points, by selecting the types of the liquid metal and the admixture and adjusting the dosage ratio between the liquid metal and the admixture, a paste or slurry suspension liquid can be formed, which on the one hand maintains the wide temperature range and high heat-conducting performance of the liquid metal, and at the same time eliminates the influence of the liquid metal buoyancy and pressure on the internal sample, without the need to use a customized fixture to fix the sample, the process of putting in and taking out is convenient and fast, on the other hand, the use amount of the liquid metal is greatly reduced by mixing the liquid metal with the admixture, and the use cost of the heat-conducting medium is significantly reduced.

[0082] As can be seen from the experimental results of Example 1 and Comparative Example 1, Example 2 and Comparative Example 3, Example 3 and Comparative Example 5, Example 4 and Comparative Example 8, only the admixture of the present application is used without adding the liquid metal, the heat-conducting coefficient of the obtained heat-conducting medium is low, in addition, the powder-like substance is used as the heat-conducting medium, there are gaps between the particles, the air in the gaps further increases the medium thermal resistance, and there is the problem of uneven heat conduction, which is not suitable for use as a constant-temperature bath heat-conducting medium. As can be seen from the experimental results of Example 1 and Comparative Example 2, Example 2 and Comparative Example 4, Example 3 and Comparative Example 6, Example 4 and Comparative Example 7, only the liquid metal is used as the heat-conducting medium, although the heat-conducting coefficient is high and the highest working temperature is high, the liquid metal buoyancy and pressure will affect the internal sample, a customized fixture is needed to fix the sample, and the cost is high.

[0083] As can be seen from the experimental results of Example 3 and Comparative Example 9, by selecting the appropriate type of liquid metal and the appropriate type of admixture, the admixture can be uniformly dispersed in the liquid metal, which significantly improves the heat transfer efficiency of the medium and ensures the uniformity of the temperature, so as to effectively improve the heat-conducting coefficient of the heat-conducting medium and increase the highest working temperature of the heat-conducting medium.

[0084] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A liquid metal thermostatic heat conducting medium, characterized in that, By weight percentage, including: liquid metal 30%-90% and admixture 10%-70%; The liquid metal is selected from one or more of gallium, indium, tin, zinc, bismuth, lead, or one or more of a multi-element alloy consisting of gallium, indium, tin, zinc, bismuth; the admixture is selected from one or more of oxide, nitride, sulfide, carbide; The mixture is selected from one or more of lanthanum trioxide, zirconium oxide, tungsten oxide, tantalum pentoxide, nickel oxide, copper oxide, iron oxide, titanium nitride, tantalum nitride, molybdenum sulfide, nickel sulfide, tantalum sulfide, tungsten carbide; the powder particle size of the mixture is 1-150 μm; the density of the mixture is 0.1-25 g / cm 3 . 3 ​ The thermal conductivity of the thermal conductive medium is 10 W / (m·K)~30 W / (m·K); the thermal conductive medium is a paste or slurry suspension liquid; the maximum working temperature of the thermal conductive medium is ≥900℃; The preparation method of the thermal conductive medium comprises the following steps: The liquid metal and the admixture are weighed according to the proportion, and stirred uniformly; The mixture after stirring uniformly is ultrasonically dispersed; The mixture after ultrasonic dispersion is subjected to vacuum homogenization treatment; then, after standing, no delamination phenomenon is observed, and the thermal conductive medium is obtained; The stirring adopts mechanical stirring or magnetic stirring; the stirring speed is 200 r / min~2000 r / min, and the time is 5 min~30 min; the ultrasonic dispersion frequency is 20 KHz~30 KHz, and the time is 5 min~30 min; the vacuum degree of the vacuum homogenization treatment is -60 kPa~-100 kPa, and the rotation speed is 1000 r / min~2000 r / min.

2. The thermally conductive medium of claim 1, wherein, The liquid metal is selected from one or more of gallium-indium, gallium-tin, gallium-zinc, bismuth-indium binary alloy, or one or more of gallium-indium-tin, gallium-indium-zinc, indium-tin-zinc, bismuth-indium-tin, bismuth-indium-zinc ternary alloy, or one or more of gallium-indium-tin-zinc and / or bismuth-indium-tin-zinc quaternary alloy.

3. The method for producing a thermally conductive medium according to claim 1 or 2, characterized by, Comprising the following steps: The liquid metal and the admixture are weighed according to the proportion, and stirred uniformly; The mixture after stirring uniformly is ultrasonically dispersed; The mixture after ultrasonic dispersion is subjected to vacuum homogenization treatment; then, after standing, no delamination phenomenon is observed, and the thermal conductive medium is obtained.

4. The production method according to claim 3, characterized by, The stirring adopts mechanical stirring or magnetic stirring.

5. The preparation method according to claim 3, characterized in that, The stirring speed is 200 r / min~2000 r / min, and the time is 5 min~30 min.

6. The preparation method according to claim 3, characterized in that, The ultrasonic dispersion frequency is 20 KHz~30 KHz, and the time is 5 min~30 min.

7. The preparation method according to claim 3, characterized in that, The vacuum degree of the vacuum homogenization treatment is -60 kPa~-100 kPa, and the rotation speed is 1000 r / min~2000 r / min.