阅读说明：本技术 一种原位生成铜包铁热管吸液芯材料的制备方法 (Preparation method for in-situ generation of liquid absorbent core material of copper-clad iron heat pipe ) 是由 张敬国 潘旭 张彬 贺会军 胡强 汪礼敏 李占荣 付东兴 徐景杰 刘祥庆 班丽卿 于 2020-12-14 设计创作，主要内容包括：本发明涉及一种原位生成铜包铁热管吸液芯材料的制备方法,包括：将质量比为1-3:5-7的氧化亚铜粉末和铁粉混合均匀,将得到的混合粉末注入热管模具中,在还原气氛条件下进行烧结,制备得到吸液芯材料。通过该制备方法,实现了铜包覆在铁粉颗粒上,原位生成铜包铁核壳结构的吸液芯,其导热性能与直接烧结铜粉得到的吸液芯相近。本发明提供的制备方法用氧化亚铜和铁粉代替了工业中常用的铜粉,原料价格低,且工艺流程短,大幅降低了热管吸液芯的生产成本,具有广阔的应用前景。(The invention relates to a preparation method for in-situ generation of a copper-clad iron heat pipe liquid absorbent core material, which comprises the following steps: and (2) uniformly mixing cuprous oxide powder and iron powder in a mass ratio of 1-3:5-7, injecting the obtained mixed powder into a heat pipe die, and sintering under a reducing atmosphere condition to prepare the liquid absorbing core material. By the preparation method, copper is coated on iron powder particles, the liquid absorption core with the copper-coated iron core-shell structure is generated in situ, and the heat conduction performance of the liquid absorption core is similar to that of the liquid absorption core obtained by directly sintering copper powder. The preparation method provided by the invention uses cuprous oxide and iron powder to replace copper powder commonly used in industry, has low raw material price and short process flow, greatly reduces the production cost of the heat pipe liquid absorption core, and has wide application prospect.)

1. A preparation method for in-situ generation of a copper-clad iron heat pipe liquid absorption core material is characterized by comprising the following steps: uniformly mixing cuprous oxide powder and iron powder to obtain mixed powder; injecting the mixed powder into a heat pipe die, and sintering under a reducing atmosphere condition to obtain the liquid absorption core material;

wherein the mass ratio of the cuprous oxide powder to the iron powder is 1-3: 5-7.

2. The method of claim 1, wherein the cuprous oxide powder has a particle size of 0.01-2 μm.

3. The method of claim 1, wherein the iron powder has a particle size of 10 to 150 μm.

4. The method of claim 3, wherein the iron powder has a bulk density of 1.8 to 2.5g/cm³。

5. The method of claim 1, wherein the mixing time is from 5 to 10 hours.

6. The method of claim 1, wherein the reducing atmosphere is hydrogen gas or carbon monoxide gas.

7. The method of claim 1, wherein the sintering temperature is 400-790 ℃; the sintering time is 3-8 h.

8. A wicking material obtained by the method of manufacture of any of claims 1-7.

9. A heat pipe comprising the wicking material of claim 8.

Technical Field

The invention relates to the technical field of preparation of heat dissipation materials of devices, in particular to a method for preparing a liquid absorption core material of a copper-clad iron heat pipe in situ.

Background

The heat pipe is used as the most effective heat transfer element, has the advantages of good heat conduction performance, simple structure, reliable work, uniform temperature and the like, has the heat conduction coefficient thousands times of that of copper, does not need to be driven by a power device, and is widely applied to the fields of aviation, aerospace, high-tech electronic devices and the like.

The heat pipe belongs to a closed two-phase heat transfer system, namely in a closed system, heat is transferred by means of phase change of fluid (liquid phase changes into gas phase or gas phase changes into liquid phase), and the heat pipe mainly comprises a capillary liquid absorption core structure, a working medium and a wall shell. When one end of the heat pipe is heated, the working medium can be boiled or evaporated, and latent heat of vaporization is absorbed, so that liquid is changed into steam. The generated steam flows to the cooling section under the action of a certain pressure difference in the pipe, and the steam is condensed into liquid when meeting a cold wall surface, and simultaneously releases latent heat of vaporization and is transferred to an external cold source through the pipe wall. The condensed liquid flows back to the heating section again by gravity or capillary force generated by porous materials on the inner wall of the tube, and the evaporation and heat absorption process is restarted. Therefore, through the continuous phase change of the medium in the pipe and the vaporization by heating again, the circulation is repeated, and the heat is continuously transmitted from one end to the other end, so that the continuous transfer of the heat is completed.

The wick is an important component of the heat pipe. The structural form, material composition and the like of the wick directly influence the heat transfer performance of the heat pipe. The sintered metal liquid absorbing core is an important branch of liquid absorbing core, usually, metal copper powder is directly sintered on the pipe wall by heating to form a capillary structure which is not easy to fall off, and because the metal copper powder is not compact, the air expansion in the sintering process enables the forming structure to have excellent permeability. However, the cost of pure copper powder is expensive, so that the method for preparing the liquid absorbing core by sintering the copper powder has the defect of high cost.

Disclosure of Invention

The invention aims to provide a preparation method for generating a low-cost liquid absorbent core material of a copper-clad iron heat pipe in situ. The preparation method uses cuprous oxide powder and reduced iron powder as raw materials, copper is coated on iron powder particles after high-temperature reduction sintering treatment, a copper-coated iron core-shell structure is formed in situ, the copper-coated iron core-shell structure has good copper heat conduction performance, copper powder commonly used in industry is replaced, the raw materials are low in price, the process flow is short, the production cost of the heat pipe liquid absorption core is greatly reduced, and the application prospect is wide.

To this end, in a first aspect, the present invention provides a method for preparing a wick material for an in-situ generated copper-clad iron heat pipe, comprising: uniformly mixing cuprous oxide powder and iron powder to obtain mixed powder; injecting the mixed powder into a heat pipe die, and sintering under a reducing atmosphere condition to obtain the liquid absorption core material;

wherein the mass ratio of the cuprous oxide powder to the iron powder is 1-3: 5-7; e.g., 1:5, 2:7, 3:7, etc.

The cuprous oxide powder has a particle size of 0.01 to 2 μm, for example, 0.01. mu.m, 0.05. mu.m, 0.1. mu.m, 0.2. mu.m, 0.3. mu.m, 0.4. mu.m, 0.5. mu.m, 0.6. mu.m, 0.7. mu.m, 0.8. mu.m, 0.9. mu.m, 1. mu.m, 1.1. mu.m, 1.2. mu.m, 1.3. mu.m, 1.4. mu.m, 1.5. mu.m, 1.6. mu.m, 1.7. mu.m, 1.8. mu.m, 1.9. mu.m, 2. mu.m, and the like.

Further, the iron powder has a particle size of 10 to 150. mu.m, for example, 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, 150. mu.m, etc.

Further, the bulk density of the iron powder is 1.8-2.5g/cm³E.g. 1.8g/cm³、2.0g/cm³、2.2g/cm³、2.5g/cm³And the like.

Further, the iron powder is one or the combination of two of cast iron powder and reduced iron powder; in the specific embodiment, the reduced iron powder is preferred, and has the advantages of low price, and excellent appearance and performance of the generated wick material.

Further, the mixing time is 5-10 h.

In a preferred embodiment, a double cone mixer is used for mixing; and (3) mixing for 5-10h according to the particle size ratio of the cuprous oxide powder and the iron powder and the apparent density of the iron powder to obtain mixed powder with the optimal mixing effect.

Further, the reducing atmosphere is hydrogen gas or carbon monoxide gas; compared with other reducing gases such as hydrogen-nitrogen mixed gas, the pure hydrogen or carbon monoxide ensures that a complete copper-clad iron core-shell structure is formed in situ.

Further, the sintering temperature is 400-; the sintering time is 3-8h, preferably 5-8h, such as 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h and the like.

According to the invention, the sintering temperature is comprehensively matched according to the particle size ratio and the mass ratio of the cuprous oxide powder and the iron powder so as to obtain the optimal sintering effect and surface appearance. When the particle size of the cuprous oxide powder is 0.1-0.5 μm and the particle size of the iron powder is 45-150 μm, the sintering temperature of 400-530 ℃ is matched; when the grain diameter of the cuprous oxide powder is 0.5-2 μm and the grain diameter of the iron powder is 45-150 μm, the sintering temperature of 530 ℃ and 650 ℃ is matched; when the grain diameter of the cuprous oxide powder is 0.5-2 μm and the grain diameter of the iron powder is 10-45 μm, the sintering temperature of 650-790 ℃ is matched.

In a second aspect of the present invention, a core material is provided, which is obtained by the method of making described herein.

In a third aspect of the invention, a heat pipe is provided that includes a wicking material as described herein.

Compared with the prior art, the technical scheme of the invention has the following remarkable progress: the invention utilizes cuprous oxide and reduced iron powder as raw materials, the raw materials are uniformly mixed according to a certain proportion and then are injected into a heat pipe mould, and the copper is coated on iron powder particles through high-temperature reduction sintering, a copper-coated iron core-shell structure is generated in situ, the copper has good heat conduction performance, and the heat conduction performance is similar to that of a liquid absorption core obtained by directly sintering copper powder. The preparation method provided by the invention uses cuprous oxide and iron powder to replace copper powder commonly used in industry, has low raw material price and short process flow, greatly reduces the production cost of the heat pipe liquid absorption core, and has wide application prospect.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. In the drawings:

FIG. 1 is a schematic flow chart of a method for producing a liquid absorbent core material for copper-clad iron heat pipes in situ according to the present invention;

FIG. 2 is a scanning electron micrograph of the wick material prepared in example 1;

FIG. 3 is the results of the spectroscopic analysis of the core material prepared in example 1.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Example 1

The embodiment provides a preparation method for generating a low-cost liquid absorbent core material of a copper-clad iron heat pipe in situ, which comprises the following steps:

(1) selecting cuprous oxide powder with the particle size range of 0.01-0.5 mu m;

(2) the cuprous oxide powder selected in the step (1) and the copper oxide powder with the particle size range of 45-150 mu m and the apparent density of 1.8g/cm³Uniformly mixing the reduced iron powder according to the mass ratio of 1:5, and mixing for 5 hours by using a double-cone mixer;

(3) and (3) injecting the mixed powder obtained in the step (2) into a heat pipe die, and carrying out high-temperature reduction sintering treatment under the pure hydrogen atmosphere, wherein the sintering temperature is 400 ℃, and the sintering time is 7.5 hours, so as to prepare the liquid absorption core material.

Scanning electron microscope imaging and energy spectrum analysis are carried out on the surface of the prepared liquid absorbing core material, the scanning electron microscope imaging result is shown in figure 2, the energy spectrum analysis result is shown in tables 1 and 3, and according to the electron microscope imaging and energy spectrum analysis result, the liquid absorbing core material prepared by the method has a copper-clad iron core-shell structure and forms excellent surface appearance.

TABLE 1

Element	Wt％	At％
			FeK	08.06	09.06
CuK	91.94	90.94
			Matrix	Correction	ZAF

Example 2

The embodiment provides a preparation method for generating a low-cost liquid absorbent core material of a copper-clad iron heat pipe in situ, which comprises the following steps:

(1) selecting cuprous oxide powder with the particle size range of 0.5-2 μm;

(2) the cuprous oxide powder selected in the step (1) and the copper oxide powder with the particle size range of 45-150 mu m and the apparent density of 2.0g/cm³Uniformly mixing the reduced iron powder according to the mass ratio of 2:7, and mixing for 8 hours by using a double-cone mixer;

(3) and (3) injecting the mixed powder obtained in the step (2) into a heat pipe die, and carrying out high-temperature reduction sintering treatment under pure hydrogen atmosphere, wherein the sintering temperature is 600 ℃, and the sintering time is 6h, so as to prepare the liquid absorbing core material.

Example 3

The embodiment provides a preparation method for generating a low-cost liquid absorbent core material of a copper-clad iron heat pipe in situ, which comprises the following steps:

(1) selecting cuprous oxide powder with the particle size range of 0.5-2 μm;

(2) oxygen selected in the step (1)Cuprous oxide powder, and has particle size of 10-45 μm and apparent density of 2.2g/cm³Uniformly mixing the reduced iron powder according to the mass ratio of 3:7, and mixing for 10 hours by using a double-cone mixer;

(3) and (3) injecting the mixed powder obtained in the step (2) into a heat pipe die, and carrying out high-temperature reduction sintering treatment under the pure hydrogen atmosphere, wherein the sintering temperature is 790 ℃, and the sintering time is 8h, so as to prepare the liquid absorption core material.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.