A long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure and preparation method

Abstract

The present application discloses a long-life super-hydrophilic multi-scale stainless steel wire mesh liquid wick structure and preparation method, which belongs to the field of metal surface treatment technology. The processing steps include placing the stainless steel wire mesh liquid wick in a furnace and sintering it in a protective atmosphere, generating a micro-nano composite structure on the surface, providing good comprehensive capillary performance, and using constant current electroplating to plate a dense thin copper film on the surface of the liquid wick, while retaining high capillary performance and improving the service life of the liquid wick in a heat plate with water as the working medium. The present invention uses stainless steel material as the liquid wick, which has the advantage of low cost. At the same time, it uses mature heat treatment and electroplating treatment methods, which are convenient for mass production, further reducing costs and improving competitiveness.

Description

Technical Field

[0001] The present application relates to the technical field of metal surface treatment, and in particular to a long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure and a preparation method thereof. Background Art

[0002] With the rapid development of communication technology, artificial intelligence and other fields, the integration of electronic equipment has become more and more obvious, resulting in the heat flux density exceeding expectations in the small space of electronic products. In order to ensure the reliable operation of electronic equipment, the design and manufacture of ultra-thin heat spreaders are particularly important. The liquid wick, as one of the important components of the heat spreader, plays an irreplaceable role in the long-term stable operation of the heat spreader.

[0003] Traditional heat spreaders rarely use stainless steel to make shell plates and liquid wicks because water vapor and stainless steel cannot coexist stably for a long time. However, considering the high strength and low cost of stainless steel, after treating the surface of stainless steel so that it can coexist stably with water vapor for a long time, stainless steel is gradually being used as one of the materials for ultra-thin heat spreaders. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation method of a long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure, wherein the stainless steel wire mesh liquid-absorbing core is placed in a furnace and sintered in a protective atmosphere to generate a micro-nano composite structure on the surface, providing good comprehensive capillary performance, and a dense thin copper film is plated on the surface of the liquid-absorbing core by constant current electroplating, thereby retaining high capillary performance while improving the service life of the liquid-absorbing core in a heat-absorbing plate with water as the working medium.

[0005] To achieve the above-mentioned purpose, the present invention provides a long-life super-hydrophilic multi-scale stainless steel wire mesh wick structure, comprising a stainless steel wire mesh wick, the surface of which is distributed with nano-scale structures and micro-scale structures, and the outer surface of the nano-scale structure, the micro-scale structure and the stainless steel wire mesh wick is distributed with a thin copper film.

[0006] The present invention provides a method for preparing a long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure, comprising the following steps:

[0007] Step 1, cutting stainless steel, placing it in a furnace for sintering, and obtaining a super hydrophilic stainless steel wire mesh;

[0008] Step 2, dissolving copper sulfate pentahydrate in water, adding concentrated sulfuric acid to obtain an electroplating solution;

[0009] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0010] Step 4, placing the soaked super-hydrophilic stainless steel wire mesh obtained in step 3 in the new electroplating solution of step 2, applying an external power source for electroplating, and obtaining the electroplated super-hydrophilic stainless steel wire mesh;

[0011] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0012] Preferably, in step 1, the sintering atmosphere includes nitrogen or argon, or is in a vacuum state.

[0013] Preferably, in step 1, the sintering temperature is between 400° C. and 1100° C., and the holding time is between 0 and 3 hours.

[0014] Preferably, in step 2, the concentration of copper ions is controlled at 0.1-1 mol / L, and the concentration of hydrogen ions is controlled at 0-0.5 mol / L.

[0015] Preferably, the soaking time in step 3 is 0-1h.

[0016] Preferably, the electroplating in step 4 adopts a constant current electroplating method, the current size is 1-50mA / cm2, and the electroplating time is 0-2h.

[0017] Therefore, the present application provides a long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure and preparation method, which has the following beneficial effects:

[0018] (1) The stainless steel wire mesh wick is placed in a furnace and sintered in a protective atmosphere to generate a micro-nano composite structure on the surface, providing good comprehensive capillary performance. A dense thin copper film is plated on the surface of the wick by constant current electroplating, which retains high capillary performance while improving the service life of the wick in a heat spreader with water as the working medium.

[0019] (3) Stainless steel is used as the material of the liquid-absorbing core, which greatly reduces the material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a process flow chart of the manufacturing process of the present invention;

[0022] Figure 3 is a graph of electrochemical test results of Example 2-5;

[0023] In the figure, H is 800°, heat treatment for 2h, immersion for 0h, and electroplating for 0h; HE1 is heat treatment at 800° for 2h, immersion for 0.5h, and electroplating for 0.5h; HE2 is heat treatment at 800° for 2h, immersion for 0.5h, and electroplating for 1h; HE3 is heat treatment at 800° for 2h, immersion for 0.5h, and electroplating for 1.5h; HE4 is heat treatment at 800° for 2h, immersion for 0.5h, and electroplating for 2h.

[0024] Figure 4 is a comparison diagram of the self-corrosion current of Examples 2-5;

[0025] Figure 5 is a comparison chart of the capillary properties of Examples 2-5;

[0026] Figure 6 Result diagrams of Comparative Example 1 and Example 2, wherein a is the result diagram of Comparative Example 1, and b is the result diagram of Example 2.

[0027] Reference numerals

[0028] 1. Stainless steel wick screen; 2. Electroplated copper film; 11. Nano-scale structure; 12. Micro-scale structure. DETAILED DESCRIPTION

[0029] Example 1

[0030] like Figure 1 As shown, the stainless steel wire mesh liquid absorbent core structure includes a stainless steel wire mesh liquid absorbent core 1, and the surface of the stainless steel wire mesh liquid absorbent core is distributed with a nano-scale structure 11 and a micro-scale structure 12, and the outer surface of the nano-scale structure 11 and the micro-scale structure 12 and the stainless steel wire mesh liquid absorbent core 1 is distributed with a thin copper film 2. The stainless steel wire mesh 1 is heat-treated to obtain the nano-scale structure 11 and the micro-scale structure 12, and the nano-scale structure 11 and the micro-scale structure 12 can be controlled by changing the temperature and time of the heat treatment process to ensure that the wire mesh liquid absorbent core has good capillary properties. At this time, the surface of the stainless steel wire mesh is covered with iron and chromium oxides. In order to further ensure that the stainless steel liquid absorbent core maintains a long life and stable operation in a heat plate with water as the working medium, a constant current electroplating treatment method is used to plate a thin copper film 2 on the surface of the stainless steel liquid absorbent core, so that the liquid absorbent core still has a long life under the premise of ensuring that the liquid absorbent core has a high capillary property.

[0031] Example 2

[0032] The preparation method of the stainless steel wire mesh liquid absorbent core is as follows:

[0033] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 800℃, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0034] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.5 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 0.1 mol / L, to obtain an electroplating solution;

[0035] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0036] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 30 mA / cm 2 , the electroplating time is 0.5h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0037] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0038] Example 3

[0039] The preparation method of the stainless steel wire mesh liquid absorbent core is as follows:

[0040] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 800℃, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0041] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.5 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 0.1 mol / L, to obtain an electroplating solution;

[0042] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0043] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 30 mA / cm 2 , the electroplating time is 1h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0044] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0045] Example 4

[0046] The preparation method of the stainless steel wire mesh liquid absorbent core is as follows:

[0047] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 800℃, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0048] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.5 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 0.1 mol / L, to obtain an electroplating solution;

[0049] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0050] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 30 mA / cm 2 , the electroplating time is 1.5h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0051] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0052] Example 5

[0053] The preparation method of the stainless steel wire mesh liquid absorbent core is as follows:

[0054] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 800℃, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0055] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.5 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 0.1 mol / L, to obtain an electroplating solution;

[0056] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0057] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 30 mA / cm 2 , the electroplating time is 2h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0058] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0059] Example 6

[0060] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 400°C, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0061] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.1 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 0.1 mol / L, to obtain an electroplating solution;

[0062] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0063] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 10 mA / cm 2 , the electroplating time is 0.5h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0064] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0065] Example 7

[0066] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 1100°C, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0067] Step 2, dissolving copper sulfate pentahydrate in water, controlling the concentration of copper ions at 0.5 mol / L, and adding concentrated sulfuric acid dropwise to dilute the sulfuric acid concentration in the solution to 1 mol / L, to obtain an electroplating solution;

[0068] Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 for 0.5 h to obtain a soaked super-hydrophilic stainless steel wire mesh;

[0069] Step 4: Place the soaked super-hydrophilic stainless steel mesh obtained in step 3 in the new electroplating solution of step 2 and electroplate with an external power supply at a current of 50 mA / cm 2, the electroplating time is 0.5h, and the super hydrophilic stainless steel wire mesh after electroplating is obtained;

[0070] Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh, thereby obtaining a stainless steel wire mesh liquid-absorbing core structure.

[0071] Comparative Example 1

[0072] The preparation method of the stainless steel wire mesh liquid absorbent core is as follows:

[0073] Step 1, cut the stainless steel into a size of 100mm*20mm, place it in a furnace and sinter it in an argon atmosphere with a flow rate of 0.7L / min, the sintering temperature is 800℃, and keep it warm for 2h after sintering to obtain a super hydrophilic stainless steel wire mesh;

[0074] Step 2: The super-hydrophilic stainless steel wire mesh obtained in step 1 is cleaned and dried to obtain a stainless steel wire mesh liquid-absorbing core structure.

[0075] Figure 3-Figure 5 The electrochemical test result diagram and capillary performance test result diagram of the liquid absorbent core prepared according to the above steps are shown in the results. It can be seen from the results that compared with the hydrophobic surface of normal stainless steel, the surface can have a multi-scale structure after heat treatment, which can provide good capillary performance. On this basis, the electroplating process is further added to cover the multi-scale structure surface with a thin copper film to improve the compatibility of stainless steel with water vapor. Short or long electroplating time is not favorable. When the time is short, a dense surface film cannot be formed and a good isolation effect cannot be achieved; if the time is too long, larger copper particles will be formed at the intersection of the stainless steel wire mesh, reducing the porosity of the wire mesh and easily falling off, thereby destroying the integrity of the surface film.

[0076] Therefore, the present application provides a long-life super-hydrophilic multi-scale stainless steel wire mesh wick structure and preparation method, which retains high capillary performance while improving the service life of the wick in a heat spreader with water as the working medium. The present invention uses stainless steel material as the wick, which has the advantage of low cost, and uses mature heat treatment and electroplating treatment methods to facilitate mass production, further reduce costs, and improve competitiveness.

[0077] In the description of this specification, the description with reference to the terms "an experimental example", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the experimental example or example are included in at least one experimental example or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0078] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A long-life super-hydrophilic multi-scale stainless steel wire mesh wick structure, characterized in that: It comprises a stainless steel wire mesh liquid absorbent core, the surface of the stainless steel wire mesh liquid absorbent core is distributed with a nano-scale structure and a micro-scale structure, and the outer surface of the nano-scale structure, the micro-scale structure and the stainless steel wire mesh liquid absorbent core is distributed with a thin copper film; The method for preparing the long-life super-hydrophilic multi-scale stainless steel wire mesh liquid-absorbing core structure comprises the following steps: Step 1, cutting stainless steel, placing it in a furnace for sintering, and obtaining a super hydrophilic stainless steel wire mesh; Step 2, dissolving copper sulfate pentahydrate in water, adding concentrated sulfuric acid to obtain an electroplating solution; Step 3, soaking the super-hydrophilic stainless steel wire mesh obtained in step 1 in the electroplating solution in step 2 to obtain a soaked super-hydrophilic stainless steel wire mesh; Step 4, placing the soaked super-hydrophilic stainless steel wire mesh obtained in step 3 in the new electroplating solution of step 2, applying an external power source for electroplating, and obtaining the electroplated super-hydrophilic stainless steel wire mesh; Step 5: The electroplated stainless steel wire mesh obtained in step 4 is cleaned and dried to complete the long-life super-hydrophilic multi-scale surface treatment of the stainless steel wire mesh to obtain a stainless steel wire mesh liquid wick structure; In step 1, the sintering atmosphere includes nitrogen and argon, or is in a vacuum state; In step 1, the sintering temperature is between 400°C and 1100°C, and the holding time is between 0 and 3 hours; In step 2, the concentration of copper ions is controlled at 0.1-1 mol / L, and the concentration of hydrogen ions is controlled at 0-0.5 mol / L; in step 3, the soaking time is 0-1 h; In step 4, the electroplating method is constant current electroplating, and the current size is 1-50mA / cm 2 , the plating time is 0-2h.

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