TWI638068B - Copper alloy porous wick and preparation method thereof - Google Patents

Abstract

The present invention provides a method for preparing a copper alloy porous liquid wick, including the following steps: (a) preparing an electrolyte solution including sulfuric acid having a volumetric molar concentration of 0.5 to 1.8 mol per liter and a volumetric molar concentration of 0.1 per liter To 0.5 mol copper sulfate aqueous solution; (b) using a mixed solution of a surfactant and a basic compound to clean the surface of the copper alloy substrate, then activating it with dilute hydrochloric acid, and then cleaning it; (c) treating the substrate Electrodeposition in an electrolyte to form a porous structure on the substrate; and (d) washing the product obtained in step (c) with water, drying, and sintering. The method of the present invention can directly obtain a porous structure with a specific arrangement and excellent capillary force and permeability on the surface of the substrate, which is beneficial to the transmission of working fluid.

Description

Copper alloy porous liquid wick and preparation method thereof

The invention relates to a liquid wick structure of a soaking plate structure, in particular to a method for preparing a liquid wick of a through hole soaking plate prepared by a soft template method.

With the development of science and technology, electronic products are gradually becoming smaller. As electronic products have more and more functions, their heat dissipation components are increasingly concentrated in a smaller range. Therefore, the heat dissipation of electronic products is an important issue that must be considered in the product design and production assembly process.

Electronic products such as heat pipes and soaking plates, which rely on phase change heat dissipation, have also emerged at the historic moment, and provide good heat dissipation guarantee in product functions. As a result, such radiator components have created a lot of value and profits for manufacturers. The heat dissipation power of heat sinks such as soaking plates also needs to be further improved. The invention patent application CN103542749A discloses a bionic soaking plate liquid wick. The structure of the wick is beneficial to the transfer of working fluid and improves the heat dissipation ability of the soaking plate. And expensive equipment. Invention patent application CN106435665A uses electrochemical deposition to prepare a liquid-absorbent core structure with a natural multi-scale dendritic microneedle-fin copper surface structure as a heat pipe or soaking plate, but this structure is likely to cause the working fluid to be carried by the air stream and reduce heat transfer efficiency . And pass Porous structures prepared by electrochemical deposition methods have problems such as weak bonding with the substrate and poor mechanical strength, which pose great challenges to the reliability and life of the product.

In order to overcome the above shortcomings and deficiencies, an object of the present invention is to provide a method for preparing a copper alloy porous wick, including the following steps: (a) preparing an electrolytic solution to include a volumetric mole concentration of 0.5 to 1.8 moles per liter; An aqueous solution of sulfuric acid and copper sulphate with a volumetric mole concentration of 0.1 to 0.5 mol per liter; (b) using a mixed solution of a surfactant and a basic compound to clean the surface of the copper alloy substrate, then activating it with dilute hydrochloric acid, and then washing Clean; (c) electrodeposit the treated substrate in the electrolyte to form a porous structure on the substrate; and (d) wash and dry the product obtained in step (c), and sinter.

According to an embodiment of the present invention, the electrodeposition is performed by a constant current density method, the constant current density is 0.5 to 5 amperes per square centimeter, and the deposition time is 20 seconds to 10 minutes.

According to another embodiment of the present invention, the current density is 0.8 to 1.5 amps per square centimeter, and the deposition time is 50 to 90 seconds.

According to another embodiment of the present invention, electrodeposition is performed by gradually increasing the current density. The initial current density is 0.01 to 0.1 amperes per square centimeter, the current density growth rate is 0.001 to 0.05 amperes per square centimeter per second, and the deposition time For 10 seconds to 10 minutes.

According to another embodiment of the present invention, the electrodeposition is performed by gradually reducing the current density. The initial current density is 0.5 to 5 amperes per square centimeter, and the current density reduction rate is 0.001 to 0.05 amperes per square centimeter per second. The time is 10 seconds to 10 minutes.

According to another embodiment of the present invention, the substrate is brass, tin brass, lead brass, aluminum brass, nickel brass, or iron brass.

According to another embodiment of the present invention, the sintering is performed in a protective atmosphere, a reducing atmosphere, or a vacuum environment at a temperature of 450 to 750 degrees Celsius.

According to another embodiment of the present invention, the protective atmosphere is at least one selected from nitrogen and argon. The reducing atmosphere is a mixed gas of nitrogen and hydrogen.

The invention further provides a copper alloy porous liquid wick, which is made by the above method.

In the present invention, a porous wick prepared by a composite method of electrodeposition and sintering is used. The pure copper porous structure prepared by electrodeposition is subjected to high temperature treatment, and the nanostructure is rearranged by using the nano effect, thereby enhancing its structural strength. The method of the present invention can be applied to various shapes of heat pipes and soaking plates. The thickness of the porous structure can be arbitrarily adjusted above 10 microns (μm), which provides a new direction for the personalized design of the product. The method of the present invention can directly obtain a porous structure with a specific arrangement and excellent capillary force and permeability on the surface of the substrate, which is beneficial to the transmission of working fluid.

FIG. 1 (a), FIG. 1 (b), FIG. 1 (c), and FIG. 1 (d) are scanning electron microscope photos and element distribution diagrams of a porous wick inlay section prepared in Example 1 of the present invention.

2 (a) and 2 (b) are scanning electron microscope photographs of the surface of the porous wick prepared in Example 1 of the present invention.

The present invention is described in detail below with reference to specific embodiments. However, the protection scope of the present invention is not limited to the following embodiments.

Example 1

Weigh a certain amount of copper sulfate, dissolve the copper sulfate in deionized water to form a copper sulfate solution, and then add an appropriate amount of concentrated sulfuric acid to the copper sulfate solution to obtain a volume mole concentration of 0.5 moles per liter (mol / L) Electrolyte having a sulfuric acid and volume mol concentration of 0.1 mol / L copper sulfate per liter.

H70 brass was used as the substrate, and the substrate was washed with a mixed solution of a surfactant and an alkaline compound, then activated with dilute hydrochloric acid, and then cleaned with deionized water.

The treated substrate was electrodeposited in a prepared solution using a constant current density method to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the current density was 0.5 amps per square centimeter (A / cm ² ) For 10 minutes.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Example 2

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 1.8 moles (mol / L) per liter, and the concentration of copper sulfate was 0.5 moles (mol / L) per liter.

Using iron brass as a substrate, the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in a prepared solution using a constant current density method to form a porous structure on the substrate. The electrodeposition temperature was room temperature and the current density was 0.8 amperes per square centimeter (A / cm ² ). The time is 90 seconds.

The substrate and the porous structure thereon were washed with water and dried, and then sintered in a vacuum sintering furnace at 500 degrees Celsius.

Example 3

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 1.0 mole (mol / L) per liter, and the concentration of copper sulfate was 0.2 mole (mol / L) per liter.

Using lead brass as a substrate, the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in a prepared solution using a constant current density method to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the current density was 1.5 amperes per square centimeter (A / cm ² ) For 50 seconds.

The substrate and the porous structure thereon are washed with water and dried, and then sintered in a vacuum sintering furnace at a temperature of 600 degrees Celsius.

Example 4

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.8 moles (mol / L) per liter, and the concentration of copper sulfate was 0.2 moles (mol / L) per liter.

Using aluminum brass as a substrate, the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in a prepared solution using a constant current density method to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the current density was 5 amperes per square centimeter (A / cm ² ) For 20 seconds.

The substrate and the porous structure thereon are washed with water and dried, and then sintered in a vacuum sintering furnace at a temperature of 750 degrees Celsius.

Example 5

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.7 moles (mol / L) per liter, and the concentration of copper sulfate was 0.3 moles (mol / L) per liter.

H68 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in a prepared solution using a constant current density method to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the current density was 1 amp per square centimeter (A / cm ² ) For 1 minute.

The substrate and the porous structure thereon were washed with water and dried, and then sintered in a vacuum sintering furnace at 700 degrees Celsius.

Example 6

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually decreasing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 0.5 amps per square centimeter. (A / cm ² ), the current density is decelerated to 0.05 amps per square centimeter per second (A / cm ² .s), and the time is 10 seconds.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Example 7

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually reducing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 2 amps per square centimeter. (A / cm ² ), the current density is decelerated to 0.002 amps per square centimeter per second (A / cm ² .s), and the time is 5 minutes.

The substrate and the porous structure thereon are washed with water and dried, and then sintered in a vacuum sintering furnace at a temperature of 600 degrees Celsius.

Example 8

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually reducing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 5 amps per square centimeter. (A / cm ² ), the current density is decelerated to 0.001 amps per square centimeter per second (A / cm ² .s), and the time is 10 minutes.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Example 9

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually increasing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 0.01 amps per square centimeter. (A / cm ² ), the current density increase rate is 0.05 amps per square centimeter second (A / cm ^{2 ·} s), and the time is 10 seconds.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Example 10

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually increasing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 0.1 amps per square centimeter. (A / cm ² ), the current density increased at a rate of 0.001 amps per square centimeter per second (A / cm ² .s), and the time was 10 minutes.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Example 11

An electrolytic solution was prepared in the same manner as in Example 1, except that the concentration of sulfuric acid was 0.5 moles (mol / L) per liter, and the concentration of copper sulfate was 0.1 moles (mol / L) per liter.

H70 brass was used as the substrate, and the substrate was pretreated in the same manner as in Example 1.

The treated substrate was electrodeposited in the prepared solution by gradually increasing the current density to form a porous structure on the substrate. The electrodeposition temperature was 20 degrees Celsius and the initial current density was 0.2 amps per square centimeter. (A / cm ² ), the current density increase rate is 0.005 amps per square centimeter second (A / cm ^{2 ·} s), and the time is 5 minutes.

The substrate and the porous structure thereon were washed with water and dried, and then sintered at 450 ° C in a vacuum sintering furnace.

Figure 1 (a) is a scanning electron microscope photograph of a porous wick prepared in Example 1 of the present invention. It can be seen from the figure that the light gray part is the main structure of the wick; Figure 1 (b) shows elemental zinc The distribution state of the element, the white spots represent the distribution and existence of the element; Figure 1 (c) is the distribution state of the element copper, and the gray spots represent the distribution and existence of the element; Figure 1 (b) and Figure 1 (c) illustrate the porous liquid absorption The core is in the form of a copper-zinc alloy; Figure 1 (d) is the composition content of the structure, which can further prove the existence of the copper-zinc alloy. The above results proved that the zinc element in the substrate diffused into the porous structure to form a copper-zinc alloy after sintering. Fig. 2 (a) and Fig. 2 (b) are scanning electron microscope photographs of different magnifications on the surface of the porous wick prepared in Example 1. Fig. 2 (a) shows the porous structure of the wick; Fig. 2 ( b) The prism structure is seen on the surface, which proves that the diffusion of zinc element in the substrate after sintering is caused. Since the zinc element in the substrate diffuses into the porous structure to form a copper-zinc alloy during the sintering process, the surface hydrophilicity of the porous structure is increased, which facilitates the transmission of the working fluid in the porous structure, thereby improving the heat dissipation efficiency.

For other embodiments provided by the present invention, the obtained product results are the same as or similar to those in Embodiment 1, and will not be described in detail here.

Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding Changes and modifications should all fall within the protection scope of the patent application attached to the present invention.

Claims (6)

A method for preparing a copper alloy porous wick includes the following steps: (a) preparing an electrolyte solution including sulfuric acid having a volumetric molar concentration of 0.5 to 1.8 mol per liter and a volumetric molar concentration of 0.1 to 0.5 mol per liter Aqueous copper sulfate aqueous solution; (b) using a mixed solution of a surfactant and an alkaline compound to clean the surface of a copper alloy substrate, then activating it with dilute hydrochloric acid, and then cleaning it; (c) treating the treated substrate in the electrolytic solution Electrodeposition in liquid to form a porous structure on the substrate; and (d) washing and drying the product obtained in step (c), and sintering; wherein, a constant current density method, a method of gradually increasing the current density, or Electrodeposition with gradually decreasing current density; when using constant current density for electrodeposition, the constant current density is 0.5 to 5 amps per square centimeter, and the deposition time is 20 seconds to 10 minutes; when using a gradually increasing current density Electrodeposition method, the initial current density is 0.01 to 0.1 amps per square centimeter, the current density growth rate is 0.001 to 0.05 amperes per square centimeter per second, and the deposition time is 10 seconds to 10 minutes Clock; when the electrodeposition is performed by gradually decreasing the current density, the initial current density is 0.5 to 5 amps per square centimeter, the current density is reduced at a rate of 0.001 to 0.05 amperes per square centisecond and the deposition time is 10 seconds to 10 minute. The method for preparing a copper alloy porous wick according to item 1 of the scope of the patent application, wherein when electrodeposition is performed using a constant current density method, the constant current density is 0.8 to 1.5 amperes per square centimeter, and the deposition time is 50 to 90 second. The method for preparing a copper alloy porous wick according to item 1 of the scope of the patent application, wherein the substrate is brass, tin brass, lead brass, aluminum brass, nickel brass or iron brass. The method for preparing a copper alloy porous wick according to item 1 of the scope of the patent application, wherein the sintering is performed in a protective atmosphere, a reducing atmosphere, or a vacuum environment at a temperature of 450 to 750 degrees Celsius. The method for preparing a copper alloy porous liquid wick as described in item 4 of the scope of the patent application, wherein the protective atmosphere is at least one selected from nitrogen and argon; and the reducing atmosphere is a mixed gas of nitrogen and hydrogen. A copper alloy porous liquid wick is made by any one of the methods described in claims 1 to 5 of the scope of patent application.