A heat dissipation block and a manufacturing method thereof

Abstract

The application discloses a heat dissipation block and a manufacturing method thereof. The manufacturing method comprises the following steps: drying alloy powder raw materials, and laying the dried alloy powder raw materials on a substrate layer by layer to form an alloy powder layer, and heating and sintering the alloy powder layer by emitting a laser beam on the upper surface of the alloy powder layer by using a laser sintering device after laying each alloy powder layer. In the sintering of the same alloy powder layer, the scanning track of the laser probe moves along a straight line, and the adjacent two scanning tracks are overlapped on one side. The scanning tracks of the laser probe of the adjacent two alloy powder layers are crossed during sintering. Thus, the heat dissipation block can reserve sufficient time for heat loss during the formation of each alloy powder layer, and the next layer of forming processing is carried out, so that the heat dissipation block is not prone to internal cracking caused by thermal stress concentration.

Description

Technical Field

[0001] This invention belongs to the field of laser sintering technology, and particularly relates to a heat sink and its manufacturing method. Background Technology

[0002] 3D printing technology is highly favored due to its unique manufacturing process. However, when manufacturing large parts, existing 3D printing technology can create huge thermal stress between layers due to the accumulation of internal heat. During the subsequent slow release of thermal stress, the parts are prone to cracking and deformation, which affects the quality of the product. Taking the production of high-speed train brake pads as an example, because 3D printing technology creates high thermal stress inside the brake pads and at the contact points between the brake pads and the substrate, there is a risk of cracking at the locations with high internal thermal stress, resulting in defective products. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a method for manufacturing a heat sink that is simple to manufacture and can avoid heat accumulation inside the heat sink.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A method for manufacturing a heat sink, comprising the following steps: drying alloy powder raw materials, and then laying them layer by layer on a substrate to form an alloy powder layer; after each layer of the alloy powder layer is laid, a laser sintering device is used to emit a laser beam to scan the upper surface of the alloy powder layer for heating and sintering; wherein, during the sintering of the same alloy powder layer, the scanning trajectory of the laser probe moves along a straight strip, and the sides of adjacent two scanning trajectories that are close to each other overlap, until all alloy powder layers are sintered; during the sintering of two adjacent alloy powder layers, the scanning trajector trajector intersects with each other.

[0005] The beneficial effect of the above technical solution is that: when the heat sink is processed, each layer of alloy powder is formed, sufficient time is reserved for heat dissipation before the next layer is formed, until the heat sink is formed. The heat accumulation inside is low, and cracks inside the heat sink will not occur due to thermal stress concentration.

[0006] The alloy powder mentioned in the above technical solution is TNZT-Si powder with a particle size of 15-53μm.

[0007] The beneficial effects of the above technical solution are: it is wear-resistant, has high strength, and has good thermal conductivity.

[0008] The alloy powder described in the above technical solution is dried in a vacuum drying oven at 50°C for 2 hours.

[0009] The beneficial effect of the above technical solution is that it can remove moisture from the alloy powder in advance.

[0010] The laser head of the laser sintering equipment described in the above technical solution is a continuous fiber laser.

[0011] The beneficial effects of the above technical solution are: it has good processing effect and makes the melting of alloy powder layers more uniform in all places.

[0012] The laser power of the laser sintering equipment described in the above technical solution is 210W, the scanning speed v is 700mm / s, the scanning spacing h is 0.1μm, and the scanning strategy is to rotate 67° per layer.

[0013] The beneficial effects of the above technical solution are that its heat sink has good wear resistance, high strength, and good thermal conductivity.

[0014] The alloy powder layer described in the above technical solution has a thickness of 30 μm.

[0015] The beneficial effect of the above technical solution is that its structure is simple.

[0016] The alloy powder layer described in the above technical solution is sintered in an argon atmosphere.

[0017] The beneficial effects of the above technical solution are: it can avoid material oxidation, and at the same time, argon purging makes the porous structure inside the alloy powder layer form airflow channels to accelerate heat dissipation.

[0018] The substrate preheating temperature described in the above technical solution is 180°C.

[0019] The beneficial effect of the above technical solution is that: by preheating the substrate, the large temperature difference between the substrate and the heat sink can be avoided, which could lead to cracking of the heat sink.

[0020] The second objective of this invention is to provide a heat sink with a simple structure and a porous internal structure.

[0021] To achieve the above objectives, another technical solution of the present invention is as follows: a heat sink, manufactured by the method described above.

[0022] The advantages of the above technical solution are that it has a simple structure and good wear resistance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the heat sink according to an embodiment of the present invention.

[0024] In the figure: 1. Alloy powder layer, 2. Substrate. Detailed Implementation

[0025] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0026] Example 1

[0027] like Figure 1 As shown, this embodiment provides a method for manufacturing a heat sink, with the following steps: Alloy powder raw materials are dried, and then layered onto a substrate to form an alloy powder layer. After each layer of the alloy powder is laid, a laser sintering device is used to emit a laser beam to scan the upper surface of the alloy powder layer for heating and sintering. During sintering of the same alloy powder layer, the scanning trajectory of the laser probe moves along a straight line, and adjacent scanning trajectories overlap on their closest sides until all alloy powder layers are sintered. When two adjacent alloy powder layers are sintered, the scanning trajector of the laser probe intersects with each other. This allows sufficient time for heat dissipation after each alloy powder layer is formed before proceeding to the next layer, until the heat sink is fully formed. This results in low internal heat accumulation and prevents internal cracking due to thermal stress concentration.

[0028] The alloy powder mentioned in the above technical solution is TNZT-Si powder with a particle size of 15-53μm, which is wear-resistant, has high strength, and good thermal conductivity.

[0029] The alloy powder described in the above technical solution is dried in a vacuum drying oven at 50°C for 2 hours, which removes moisture from the alloy powder in advance.

[0030] The laser head of the laser sintering equipment described in the above technical solution is a continuous fiber laser, which has good processing effect and makes the melting of the alloy powder layer more uniform in all places.

[0031] The laser power of the laser sintering equipment described in the above technical solution is 210W, the scanning speed v is 700mm / s, the scanning spacing h is 0.1μm, and the scanning strategy is to rotate 67° per layer (that is, after processing each layer, the laser scanning trajectory rotates 67° clockwise or counterclockwise, and during the processing, it either always rotates clockwise or always rotates counterclockwise). Its heat sink has good wear resistance, high strength, and good thermal conductivity.

[0032] The alloy powder layer described in the above technical solution has a thickness of 30 μm and a simple structure.

[0033] The alloy powder layer described in the above technical solution is sintered in an argon atmosphere, which can prevent material oxidation. At the same time, argon purging causes the porous structure inside the alloy powder layer to form airflow channels to accelerate heat dissipation.

[0034] The substrate preheating temperature described in the above technical solution is 180°C. This preheating of the substrate avoids large temperature differences between the substrate and the heat sink, which could lead to cracking of the heat sink.

[0035] When the surface of the alloy powder layer is laser scanned, a groove line is formed at the overlap of two adjacent scanning trajectories, such as... Figure 1 As shown in the figure, the grooves of the two adjacent alloy powder layers are staggered.

[0036] After the heat sink is manufactured in this embodiment, high-speed train brake pads can be directly processed on the heat sink using 3D molding technology or laser molding technology. The heat sink can then be ground off on the high-speed train brake pads later.

[0037] Example 2

[0038] This embodiment provides a heat sink, which is manufactured by the method described above. It has a simple structure and good wear resistance.

[0039] It should be noted that the above detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0041] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0042] Furthermore, when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is described as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0043] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0044] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., may be used here to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figure. It should be understood that spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the figure.

[0045] For example, if a device in the accompanying drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method of making a heat spreader, comprising: The steps are as follows: The alloy powder raw material is dried, and then layered onto a substrate to form an alloy powder layer. After each layer is laid, a laser sintering device emits a laser beam to scan the upper surface of the alloy powder layer for heating and sintering. During sintering of the same alloy powder layer, the laser head's scanning trajectory moves along a straight line, and adjacent scanning trajectories overlap on their closest sides until all alloy powder layers are sintered. During sintering of adjacent alloy powder layers, the laser head's scanning trajectories intersect. The laser head of the laser sintering device is a continuous fiber laser. The alloy powder is TNZT-Si powder with a particle size of 15-53 μm. The laser power of the laser sintering device is 210 W, the scanning speed v is 700 mm / s, the scanning spacing h is 0.1 μm, and the scanning strategy is a 67° rotation per layer.

2. The method of claim 1, wherein The alloy powder was dried in a vacuum drying oven at 50°C for 2 hours.

3. The method of claim 1, wherein The thickness of the alloy powder layer is 30 μm.

4. The method of claim 1-3, wherein The alloy powder layer is sintered in an argon atmosphere.

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