CN202239628U - Device for preparing nonlinear tree-shaped liquid absorption core by selective laser melting - Google Patents

Abstract

The utility model discloses a device for preparing nonlinear tree-like liquid-absorbing core by selective laser melting, comprising a controller, a laser generator, an optical path transmission element, a scanning galvanometer system, an F-θ mirror, a molding chamber, an air inlet, an air outlet, a molding part lifting cylinder, a powder lifting cylinder, and a powder recovery cylinder; the device of the utility model can quickly prepare "tree-like structure" liquid-absorbing cores with arbitrary tube diameter ratios and bifurcation angles, which can be used for scientific research and also meet the needs of the cutting-edge field of high-efficiency heat pipes; the patent also provides a solution for manufacturing two liquid-absorbing cores with different structures at one time by utilizing a spectroscopic system and a dual scanning galvanometer system, which improves efficiency while ensuring quality; this is of great significance to the existing experimental research on liquid-absorbing cores and the preparation of high-quality liquid-absorbing core structures; the utility model has a simple structure, is convenient and quick to operate, has a low production cost, and has positive promotion and application value.

Description

A device for fabricating nonlinear tree-like liquid-absorbing cores by selective laser melting

technical field

The utility model relates to the technical field of electronic manufacturing industry, in particular to a device for preparing a non-linear tree-shaped liquid-absorbing core by selective laser melting. the

Background technique

As the heat flux required for heat dissipation of electronic devices continues to increase, heat pipes have excellent characteristics such as extremely high thermal conductivity, excellent isothermal properties, heat flux variability, and adaptability to constant temperature environments, which can meet the needs of electronic and electrical equipment for heat dissipation. Reliable, flexible control, high heat dissipation efficiency, no need for maintenance and other requirements. Therefore, heat pipe technology has become the preferred technology for heat dissipation of electrical equipment, electronic device cooling, semiconductor components and large-scale integrated circuit board heat dissipation. the

The liquid-absorbing wick is the core part of the heat pipe. In addition to providing capillary force, it can also increase the evaporation and condensation area to enhance the phase change heat transfer process, and also help to maintain a uniform distribution of evaporation temperature. Once the physical size of the micro heat pipe, the type of shell and wick material, and the working fluid are determined, its heat transfer performance is determined by the performance of the wick. According to the channel characteristics of the liquid-absorbent core, it can be divided into three categories: simple uniform type, non-uniform composite type and complex design type. From the process method, the liquid-absorbing core structure includes groove type, wire mesh type, sintered type and so on. the

The development direction of the grooved liquid-absorbing core structure is to further improve the groove aspect ratio and optimize the geometric shape. The study found that under the same test conditions, the heat transfer performance of the thin-walled high-aspect-ratio rough grooved micro-heat pipe can be improved by more than 55% compared with the existing smooth grooved grooved micro-heat pipe. The grooved liquid-absorbing core is made by cutting method, which will produce stress and strain on the metal material and reduce the fatigue life. The cutting method is only suitable for making the shape on the surface of the processed surface and within a limited depth, and considering the need for a tool groove And undercuts are more suitable for processing linear and regular graphic structures, so the structural complexity of the grooved liquid-absorbing core is greatly limited, and it cannot be made into a nonlinear multi-scale liquid-absorbing core structure. For some high-precision fields that have extremely high requirements on the performance of heat pipes, grooved wicks cannot always provide sufficient capillary force while reducing return resistance. the

The liquid-absorbing core of sintered structure is actually a kind of porous material. Taiwan Qihong Technology Co., Ltd. (AVC) explored the gradient sintering capillary liquid-absorbing core of copper powder with different particle sizes, and found that the gradient sintering of copper powder with multiple particle sizes can increase the The contact strength with the wall surface reduces the thermal resistance, and more importantly, it can solve the contradiction that the liquid reflux resistance increases while the capillary suction increases. Although the sintered special molding method has the advantages of low cost and high output, it cannot control the structure and shape at the micro level. With the existing technical means, it is still difficult to greatly improve the scientific structure of the liquid-absorbing core and improve work efficiency. . the

The goal of the structural design of the liquid-absorbent core is to increase the capillary suction, reduce the return resistance and increase the thermal conductivity, which requires increasing the size of the liquid return channel while reducing the micropore radius of the liquid-absorbent core. Although researchers have made a lot of efforts in the design and manufacture of grooved and sintered wicks, they have not yet achieved satisfactory results in solving the contradiction of improving capillary suction while reducing backflow resistance. The reason is: to improve the solid-liquid and solid-vapor interface structure to enhance the boiling (evaporation section) and condensation (condensation section) capabilities, as well as to improve the capillary suction and reduce the reflux resistance, so that the surface microstructure of the ideal heat-absorbing core , Microchannel size and porosity vary nonlinearly in the radial and axial directions, so machining and sintering methods are difficult to accomplish. the

However, experimental studies have shown that the heat transfer capacity of the wick structures produced by the three traditional processing methods is much lower than that of the "tree-like" wick structure. However, due to the complexity and irregularity of the "tree structure", traditional processing methods cannot be directly prepared, which makes the improvement of the working capacity of the liquid-absorbent core structure very slow, which has become a factor restricting the development of heat dissipation technology. the

Contents of the invention

The purpose of the utility model is to overcome the shortcomings and deficiencies of the prior art, and provide a non-linear tree-shaped liquid-absorbing core device prepared by selective laser melting, which can quickly prepare "tree-like structure" absorbent cores with arbitrary pipe diameter ratios and bifurcation angles. liquid core. the

The utility model is realized through the following technical solutions:

A non-linear tree-shaped liquid-absorbing core device prepared by selective laser melting, including a controller, a laser generator, an optical transmission element, a scanning galvanometer system, an F-θ mirror, a forming chamber, an air inlet, an air outlet, and a lifting of a molded part cylinder, powder lift cylinder, powder recovery cylinder;

The laser generator, the optical path transmission element, the scanning galvanometer system, and the F-θ mirror are sequentially arranged and connected in the optical path;

The F-θ mirror is arranged in the middle of the upper end of the molding chamber, the air inlet is arranged at the upper end of the inner wall on one side of the molding chamber, and the air outlet is arranged at the lower end of the inner wall on the other side of the molding chamber. Equipped with CNC moving brushes;

The molding lifting cylinder is set at the lower end of the molding chamber, the powder lifting cylinder is set on one side of the molding lifting cylinder, and the powder recovery cylinder is set on the other side of the powder lifting cylinder;

The optical transmission element includes an optical fiber transmission line and a collimating beam expander installed on the optical fiber transmission line in sequence; the optical transmission element is composed of an optical isolator and a fiber coupling head. the

The scanning galvanometer system, laser generator, digitally controlled moving brush, powder lifting cylinder, and powder recovery cylinder are respectively connected to the controller. The controller is a computer. the

The device also includes a spectroscopic mirror system composed of a full reflection mirror and a half mirror, the scanning galvanometer system is a double scanning galvanometer system, and the spectroscopic mirror system is arranged between the laser generator and the double scanning galvanometer system in the light path. the

The above-mentioned device specifically includes the following steps for the selective laser melting molding process of the liquid-absorbing core:

(1) Establish a CAD geometric model of the liquid-absorbing core, perform hierarchical discretization, generate scanning path data, and import the scanning path data into the controller 1 . the

(2) In order to ensure that the material is not oxidized during the working process, an inert gas is injected into the molding chamber 7 through the air inlet 8 to control the oxygen concentration in the molding chamber 7 within a certain range. the

(3) The molded piece lifting cylinder 11 is lowered by one level, and the powder lifting cylinder 12 is raised for a certain distance to ensure that there is enough powder overflowed. To the powder recovery cylinder 13. the

(4) The laser scans the Cu powder, focuses through the F-θ mirror 6, forms a focused spot on the processing plane of the metal powder placed on the lifting cylinder 11 of the molded part, melts the Cu powder, and forms a single-layer cross section of the part. system, two liquid-absorbing cores with different structures can be prepared at the same time, and the scanning paths are respectively controlled by the dual-galvanometer scanning system 17. the

(5) The controller 1 determines whether the liquid-absorbing core is formed according to the number of layers scanned. If it has been formed, take out the formed part, otherwise repeat steps (3) and (4) to melt the Cu powder layer by layer until it is accumulated and formed. A formed wick structure is obtained. the

The existing mainstream processing techniques cannot make a nonlinear multi-scale liquid-absorbent core with a tree structure. And adopt the device of the utility model, can manufacture the liquid-absorbing core of tree structure rapidly. The most reasonable structure of the liquid-absorbing core can be achieved, so that it has the largest capillary force and the smallest return resistance. the

The device of the utility model can rapidly prepare liquid-absorbing cores of "tree-like structure" with arbitrary pipe diameter ratios and bifurcation angles, which can be used for scientific research and also meet the needs of the cutting-edge field of high-efficiency heat pipes. This patent also provides a scheme that utilizes a spectroscopic system and a double-scanning galvanometer system to manufacture two liquid-absorbent cores with different structures at one time, which improves efficiency while ensuring quality. This is of great significance to the existing experimental research on liquid-absorbent cores and the preparation of high-quality liquid-absorbent core structures. the

The utility model has the advantages of simple structure, convenient and quick operation, low production cost, and has positive popularization and application value. the

Description of drawings

Fig. 1 is a structural schematic diagram of a device for preparing a nonlinear tree-shaped liquid-absorbent core by selective laser melting of the present invention. the

Fig. 2 is another schematic diagram of the structure of the non-linear dendritic liquid-absorbing core device prepared by selective laser melting of the present invention. the

Fig. 3 is a schematic diagram of the structure of the tree-shaped liquid-absorbent core. the

In the figure above: controller 1; laser generator 2; optical transmission element 3; scanning galvanometer system 4; processing plane 5; F-θ mirror 6; molding chamber 7; air inlet 8; air outlet 9; CNC moving brush sheet 10; molded piece lifting cylinder 11; powder lifting cylinder 12; powder recovery cylinder 13; transparent dust cover 14; half mirror 15; full mirror 16; double scanning galvanometer system 17. the

Detailed ways

The specific implementation manner of the present utility model will be further described in detail below, but the implementation manner of the present utility model is not limited thereto. the

Example

As shown in Figure 1, the non-linear tree-shaped liquid-absorbing core device prepared by selective laser melting of the utility model includes a controller 1, a laser generator 2, an optical transmission element 3, a scanning galvanometer system 4, an F-θ mirror 6, and a molding chamber 7 , air inlet 8, air outlet 9, numerical control moving brush piece 10, molded piece lifting cylinder 11, powder lifting cylinder 12, powder recovery cylinder 13; the laser generator 2, optical path transmission element 3, scanning galvanometer system 4, The F-θ mirror 6 is connected to the optical path in turn;

The F-θ mirror 6 is arranged in the middle of the upper end of the molding chamber 7, the air inlet 8 is arranged at the upper end of the inner wall on one side of the molding chamber 7, and the gas outlet 9 is arranged at the lower end of the inner wall on the other side of the molding chamber 7, A numerically controlled moving brush 10 is also provided in the molding chamber 7;

The molding lifting cylinder 11 is arranged at the lower end of the molding chamber 7, the powder lifting cylinder 12 is arranged on one side of the molding lifting cylinder 11, and the powder recovery cylinder 13 is arranged on the other side of the powder lifting cylinder 12;

The scanning galvanometer system 4 , the laser generator 2 , the digitally controlled moving brush 10 , the molded part lifting cylinder 11 , and the powder lifting cylinder 12 are respectively connected to the controller 1 . The controller 1 is a computer. the

The device also includes a beam splitter system made up of a full mirror 16 and a half mirror 15, the scanning galvanometer system 4 is a double scan galvanometer system 17, and the beam splitter system is arranged between the laser generator 2 and the double scan galvanometer. In the optical path between the mirror system 17. the

A transparent dustproof cover 14 is provided between the molding chamber 7 and the F-θ mirror 6 . the

The controller 1 controls the laser generator 2, the scanning galvanometer system 4, the molded part lifting cylinder 11, the powder recovery cylinder 13 and the digitally controlled moving brush 10, and is connected to the laser generator 2 and the scanning galvanometer system of the controller through a USB interface. 4 control cards. For laser generator 2, a fiber laser generator with a power of 50 to 400W is preferred, the beam quality is less than 1.1, and the power of the fiber laser can meet the requirements of the focused spot. The optical path transmission element 3 includes an optical fiber transmission line and a collimating beam expander (not shown in the figure) installed on the optical fiber transmission line in turn. The optical path transmission element 3 adopts an optical isolator and a fiber coupling head (not shown in the figure). A water cooling mechanism is provided on the jacket of the optical fiber transmission line. The scanning galvanometer system 4 is provided with an air-cooling mechanism, and the air outlet 9 of the molding chamber 7 is provided with an oxygen content detector. The Cu powder is ball milled for a certain period of time, so that the particle size is roughly 500-1000nm, to avoid dust from being too small, and at the same time reduce the melting energy of the particles, and scan at a faster speed, thereby improving the surface quality of the workpiece. Due to the small size of the particles, in order to prevent the dust from rising during the powder pushing process of the digitally controlled mobile brush 10, it covers the surface of the F-θ mirror 6, reducing the transmittance of the F-θ mirror 6 and thus affecting the quality of the working laser, because F- The θ mirror 6 has a precise surface and is not suitable for cleaning, so a transparent dust cover 14 that is convenient for regular disassembly and cleaning is specially added. the

The laser beam emitted by the laser generator 2 is transmitted through the optical path transmission element 3, and the scanning is controlled by the galvanometer system 4. The scanning path is generated by the layered discrete CAD geometric model of the controller 1 and focused by the F-θ mirror 6. The uppermost layer of powder in the lifting cylinder 11 of the molded part is that the processing plane 5 is on the focal plane of the F-θ mirror 6 . The air inlet 8 and the air outlet 9 are controlled by the controller 1 to inject inert gas into the molding chamber 7 and discharge air. the

As shown in Figure 2, in order to improve work efficiency, a spectroscopic mirror system composed of full reflection mirror 16 and half reflection mirror 15 is added to divide the light beam generated by laser generator 2 into two beams. Through the double-scanning galvanometer system 17 controlled by the controller 1, two graphics can be scanned simultaneously, and two different liquid-absorbing core structures can be processed at one time. the

The laser melting process of the above-mentioned device on the liquid-absorbing core can be realized through the following steps:

(1) Establish a CAD geometric model of the liquid-absorbing core, perform hierarchical discretization, generate scanning path data, and import the scanning path data into the controller 1 . the

(2) In order to ensure that the material is not oxidized during the working process, an inert gas is injected into the molding chamber 7 through the air inlet 8 to control the oxygen concentration in the molding chamber 7 within a certain range. the

(3) The molded piece lifting cylinder 11 is lowered by one level, and the powder lifting cylinder 12 is raised for a certain distance to ensure that there is enough powder overflowed. To the powder recovery cylinder 13. the

(4) The laser scans the Cu powder, focuses through the F-θ mirror 6, forms a focused spot on the processing plane of the metal powder placed on the lifting cylinder 11 of the molded part, melts the Cu powder, and forms a single-layer cross section of the part. system, two liquid-absorbing cores with different structures can be prepared at the same time, and the scanning paths are respectively controlled by the dual-galvanometer scanning system 17. the

(5) The controller 1 determines whether the liquid-absorbing core is formed according to the number of layers scanned. If it has been formed, take out the formed part, otherwise repeat steps (3) and (4) to melt the Cu powder layer by layer until it is accumulated and formed. A formed wick structure is obtained. the

As shown in Figure 3, the structural parameters of the non-linear tree-shaped liquid-absorbing core formed in this patent have the following characteristics: the pipe diameter ratio is about 1.3, and the bifurcation angle is about 55°. However, the structural size of the liquid-absorbent core formed by this method is not limited to the above parameters. the

Just can realize the utility model preferably as mentioned above. the

The above-described embodiment is a preferred embodiment of the present utility model, but the implementation of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications, and substitutions made without departing from the spirit and principles of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model. the

Claims (6)

1. A non-linear tree-shaped liquid-absorbing core device prepared by selective laser melting, characterized in that it includes a controller, a laser generator, an optical path transmission element, a scanning galvanometer system, an F-θ mirror, a molding chamber, an air inlet, Air outlet, molded parts lift cylinder, powder lift cylinder, powder recovery cylinder; The laser generator, the optical path transmission element, the scanning galvanometer system, and the F-θ mirror are sequentially arranged and connected in the optical path; The F-θ mirror is arranged in the middle of the upper end of the molding chamber, the air inlet is arranged at the upper end of the inner wall on one side of the molding chamber, the air outlet is arranged at the lower end of the inner wall on the other side of the molding chamber, and the molding chamber is also provided with There are CNC mobile brushes; The molding lifting cylinder is arranged at the lower end of the molding chamber, the powder lifting cylinder is arranged on one side of the molding lifting cylinder, and the powder recovery cylinder is arranged on the other side of the powder lifting cylinder; The scanning galvanometer system, laser generator, digitally controlled moving brush, powder lifting cylinder, and powder recovery cylinder are respectively connected to the controller. 2. The non-linear dendritic liquid-absorbing core device prepared by selective laser melting according to claim 1, is characterized in that the device also includes a spectroscopic mirror system composed of a full reflection mirror and a half reflection mirror, and the scanning galvanometer system It is a double-scanning galvanometer system, and the spectroscopic mirror system is arranged in the optical path between the laser generator and the double-scanning galvanometer system. 3 . The device for preparing nonlinear tree-shaped liquid-absorbent cores by selective laser melting according to claim 2 , wherein the optical path transmission components include optical fiber transmission lines and collimating beam expanders sequentially installed on the optical fiber transmission lines. 4 . 4 . The non-linear dendritic liquid-absorbing core device prepared by selective laser melting according to claim 3 , wherein the optical path transmission element is composed of an optical isolator and a fiber coupling head. 5 . The non-linear dendritic liquid-absorbing core device prepared by selective laser melting according to claim 4 , wherein a transparent dust-proof cover is arranged on the top of the forming chamber. 6 . The non-linear dendritic liquid-absorbing core device prepared by selective laser melting according to claim 5 , wherein the controller is a computer. 7 . the

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