Magnesium alloy cold plate integrated with titanium alloy runner and preparation method thereof

Abstract

This invention discloses a magnesium alloy cold plate with integrated titanium alloy flow channels and its preparation method. The magnesium alloy cold plate with integrated titanium alloy flow channels includes a first magnesium alloy plate and titanium alloy pipes. A cavity is provided in the upper part of the first magnesium alloy plate. The titanium alloy pipes are embedded in the cavity after being covered with aluminum foil. The external dimensions of the titanium alloy pipes after being covered with aluminum foil match the internal dimensions of the cavity. A second magnesium alloy plate is positioned and covered at the upper end of the first magnesium alloy plate. The first magnesium alloy plate, titanium alloy pipes, aluminum foil, and second magnesium alloy plate are connected by instantaneous liquid phase diffusion welding. This invention uses instantaneous liquid phase diffusion welding and pressure and relatively low temperature as the main driving forces for the connection between magnesium alloy and titanium alloy. The addition of aluminum foil as an intermediate layer adjusts the welding interface reaction and promotes element diffusion, thereby strengthening the microstructure and mechanical properties of the joint. This is beneficial to improving the shear strength of the welding interface, and thus significantly improving the mechanical environmental adaptability and long-term operational reliability of the cold plate.

Description

Technical Field

[0001] This invention belongs to the field of high heat flux density heat dissipation technology, and particularly relates to magnesium alloy cold plates with integrated titanium alloy flow channels and their preparation methods. Background Technology

[0002] As electronic devices develop towards miniaturization, modularization, and high integration, their heat flux density can reach more than 10 times that of traditional air-cooled equipment. Currently, liquid-cooled cold plates with internal flow channels are often used to solve their heat dissipation problems. The principle is to conduct the heat inside the equipment to the continuously flowing coolant in the flow channel of the cold plate and carry it out of the electronic device by the coolant.

[0003] Common liquid-cooled cold plates are functional structural components that integrate the flow channel with the metal substrate. They are typically manufactured by subtractive processing, where the cold plate cavity and cover parts are machined from metal materials such as aluminum alloys, and then welded together and surface-protected. However, with the increasing demands for lightweight and integrated electronic equipment on aerospace platforms, the need for lightweight materials is becoming more urgent. Among these, magnesium alloys, as engineering metals with a density one-third lower than aluminum alloys, have extremely broad application prospects as a base material for liquid-cooled cold plates in electronic devices.

[0004] Patent application CN105268918A discloses a method for preparing a corrosion-resistant liquid-cooled heat dissipation plate. The method involves clamping a titanium alloy fluid pipeline and interface flange assembly between two mold positioning plates using a wax mold, and then casting it into a melting furnace using lost foam casting to form a heat dissipation plate. This method uses aluminum alloy as the base material and forms the heat dissipation plate by casting. However, it is not suitable for magnesium alloys, which have low potential, poor corrosion resistance, and poor compatibility with titanium alloys.

[0005] Patent application CN117715378A discloses a magnesium alloy liquid cooling housing and its preparation method. The housing includes a magnesium alloy cavity, a sealing ring, a magnesium alloy cover plate, and two fluid connectors. The inner surface of the flow channel is protected by micro-arc oxidation and gel sealing. The cavity and cover plate are welded together with a high-energy beam to form a sealed liquid cooling flow channel. Although this preparation method can produce a magnesium alloy liquid cooling flow channel, the magnesium alloy cavity and cover plate need to be differentiated for targeted surface treatment depending on whether they are flow channel areas. The processing flow is complex and the cost of mass production is high. At the same time, the high-energy beam welding is used to seal the flow channel cavity and cover plate, which has low processing efficiency and low reliability for complex structures such as multi-layer flow channels.

[0006] It is evident that current magnesium alloy cold-rolled sheets suffer from problems such as complex forming methods, poor corrosion resistance, and low reliability, necessitating research into structural optimization design and forming processes. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a magnesium alloy cold plate with integrated titanium alloy flow channels and its preparation method, which can improve corrosion resistance and reliability and has a simple forming method.

[0008] The objective of this invention is achieved through the following technical solution: In a first aspect, a magnesium alloy cold plate with integrated titanium alloy flow channels is provided, comprising: The first magnesium alloy plate has a cavity in its upper part. Titanium alloy tubing, which is wrapped with aluminum foil and then embedded in a concave cavity, with the external dimensions of the titanium alloy tubing after being wrapped with aluminum foil matching the internal dimensions of the concave cavity. The second magnesium alloy plate is positioned and covered on the upper end of the first magnesium alloy plate. The first magnesium alloy plate, titanium alloy pipeline, aluminum foil, and second magnesium alloy plate are connected by instantaneous liquid phase diffusion welding.

[0009] Furthermore, the first magnesium alloy plate has a plurality of first pin holes arranged vertically, and the second magnesium alloy plate has a plurality of second pin holes arranged vertically, each matching the horizontal position of the plurality of first pin holes. A positioning pin is interference-fitted into a first pin hole and a second pin hole that match the horizontal position.

[0010] Furthermore, two fluid connectors, respectively connecting the inlet and outlet ends of the titanium alloy pipeline, are detachably connected to the first magnesium alloy plate and / or the second magnesium alloy plate.

[0011] Furthermore, a seal is provided at one end of the fluid connector near the first magnesium alloy plate and / or the second magnesium alloy plate.

[0012] Secondly, a preparation method is provided for preparing a magnesium alloy cold plate with integrated titanium alloy flow channels, comprising the following steps: Fabrication of titanium alloy pipelines and a first magnesium alloy plate with recessed cavities; Mechanical grinding and ultrasonic cleaning were performed on the upper exposed surface of the first magnesium alloy plate, the exposed surface of the titanium alloy pipeline, and the lower exposed surface of the second magnesium alloy plate to remove the oxide layer and oil stains on the upper exposed surface of the first magnesium alloy plate, the exposed surface of the titanium alloy pipeline, and the lower exposed surface of the second magnesium alloy plate. The titanium alloy pipe is wrapped with aluminum foil and then embedded in the cavity; The second magnesium alloy plate is positioned and placed on top of the first magnesium alloy plate to form a cold plate assembly. Instantaneous liquid phase diffusion welding is performed on cold plate assemblies.

[0013] Furthermore, the fabrication of the titanium alloy conduit and the first magnesium alloy plate with the cavity includes: Based on the heat source distribution and heat dissipation requirements of the electronic device, the flow channel shape was optimized using CAE method, and then titanium alloy pipes matching the flow channel were manufactured. A cavity matching the flow channel was also manufactured on the first magnesium alloy plate.

[0014] Furthermore, positioning the second magnesium alloy plate over the upper end of the first magnesium alloy plate includes: Multiple locating pins are vertically inserted into the second magnesium alloy plate and the first magnesium alloy plate, and are interference-fitted with the second magnesium alloy plate and the first magnesium alloy plate.

[0015] Furthermore, the locating pin is made of molybdenum, Invar alloy, or special stainless steel with a coefficient of thermal expansion matching that of magnesium or titanium.

[0016] Furthermore, the instantaneous liquid phase diffusion welding of the cold plate assembly includes: The cold plate assembly is placed in a vacuum diffusion welding process with a protective atmosphere. The temperature is raised to a level higher than the melting point of the aluminum foil but lower than the melting points of the first magnesium alloy plate and the second magnesium alloy, and then vertical pressure is applied to the cold plate assembly. Maintain temperature and vertical pressure to melt the aluminum foil and allow it to undergo a eutectic reaction with the first magnesium alloy plate, the second magnesium alloy plate, and the titanium alloy pipeline to form a transient liquid phase. Magnesium atoms and titanium atoms diffuse into the transient liquid phase and solidify isothermally until metallurgical bonding occurs. It was cooled to room temperature in the vacuum diffusion welding furnace.

[0017] Furthermore, after performing transient liquid phase diffusion welding on the cold plate assembly, the following steps are also included: The two fluid connectors are detachably connected to the first magnesium alloy plate and / or the second magnesium alloy plate so that the two fluid connectors are respectively connected to the inlet and outlet ends of the titanium alloy pipeline.

[0018] The beneficial effects of this invention are as follows: The base material of the first and second magnesium alloy plates is magnesium alloy, which can reduce weight and significantly improve the lightweight performance of cold plates used in electronic devices compared to the commonly used aluminum alloy cold plates. The flow channel is formed by titanium alloy piping. Based on the excellent corrosion resistance and environmental adaptability of titanium alloy, the coolant can operate reliably in the flow channel for a long time. The integrated embedded pipe structure has high flow channel forming strength, can withstand high liquid pressure, and is not easy to leak coolant, which helps to improve the reliability and service life of the cold plate. Instantaneous liquid phase diffusion welding is adopted, with pressure and low temperature as the main driving forces for the connection between magnesium alloy and titanium alloy. Aluminum foil is added as an intermediate layer to adjust the welding interface reaction and promote element diffusion, thereby strengthening the microstructure and mechanical properties of the joint. This is beneficial to improving the shear strength of the welding interface, and thus significantly improving the mechanical environmental adaptability and long-term operational reliability of the cold plate. Attached Figure Description

[0019] The invention will now be described in more detail with reference to embodiments and the accompanying drawings. Figure 1 A schematic diagram of the optimized flow channel design in this invention is shown; Figure 2 An exploded view of the magnesium alloy cold plate with integrated titanium alloy flow channels in this invention is shown. Figure 3 An assembly diagram of the magnesium alloy cold plate with integrated titanium alloy flow channels in this invention is shown. Figure 4 A schematic diagram of the installation of the fluid connector in this invention is shown; Figure 5 This shows a cross-sectional view of the fluid connector mounting location in this invention; In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0020] Figure label: 1. Flow channel; 2. Titanium alloy pipeline; 3. Second magnesium alloy plate; 4. First magnesium alloy plate; 5. Aluminum foil; 6. Fluid connector; 7. Locating pin; 8. Screw; 9. Seal. Detailed Implementation

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] Magnesium alloys are excellent cold-rolled steel plate substrates due to their low density, high specific strength, and good ductility. However, their low potential and poor corrosion resistance mean they are prone to corrosion if used as flow channel substrates in prolonged direct contact with liquid cooling media. Titanium alloys, on the other hand, possess advantages such as high specific strength, oxidation resistance, and good corrosion resistance, earning them the title of "deep-sea metal." They are currently widely used in the manufacturing of liquid cooling pipelines for harsh applications. Using magnesium alloys as the main substrate for cold-rolled steel plates with embedded titanium alloy flow channels can achieve a complementary advantage of the two materials, significantly improving the lightweight, mechanical properties, and corrosion resistance of electronic device cold-rolled steel plates. However, magnesium and titanium alloys have significantly different properties, making it impossible to form an alloy phase. Furthermore, they are immiscible in both solid and liquid phases. Existing brazing, fusion welding, and conventional solid-state diffusion welding technologies struggle to achieve reliable welding between magnesium and titanium alloys, severely impacting the structural strength and heat dissipation performance of the cold-rolled steel plate. Therefore, research into structural optimization design and forming processes is necessary.

[0023] Therefore, the present invention provides a magnesium alloy cold plate with integrated titanium alloy flow channels, such as Figure 1-3 As shown, it includes: The first magnesium alloy plate 4 has a cavity in its upper part. Titanium alloy pipe 2, after being covered with aluminum foil 5, is embedded in the cavity. The external dimensions of the titanium alloy pipe 2 after being covered with aluminum foil 5 match the internal dimensions of the cavity. The second magnesium alloy plate 3 is positioned and covered on the upper end of the first magnesium alloy plate 4. The first magnesium alloy plate 4, the titanium alloy pipeline 2, the aluminum foil 5, and the second magnesium alloy plate 3 are connected by instantaneous liquid phase diffusion welding.

[0024] It is understandable that the base material of the first magnesium alloy plate 4 and the second magnesium alloy plate 3 is magnesium alloy, which can reduce weight and significantly improve the lightweight performance of cold plates used in electronic devices compared with the commonly used aluminum alloy cold plates. The flow channel 1 is formed by titanium alloy pipe 2. Based on the excellent corrosion resistance and environmental adaptability of titanium alloy, the coolant can operate reliably in the flow channel 1 for a long time. The integrated embedded pipe structure has high molding strength of the flow channel 1, which can withstand high liquid pressure and is not easy to leak coolant, which helps to improve the reliability and service life of the cold plate.

[0025] It should be noted that the titanium alloy pipe 2 can be a TC4 titanium alloy pipe with an outer diameter of 5mm and a wall thickness of 1mm, which can be bent into the corresponding shape by tooling; the first magnesium alloy plate 4 and the second magnesium alloy plate 3 can be made of AZ31B magnesium alloy.

[0026] In one embodiment, a plurality of first pin holes are vertically provided on the first magnesium alloy plate 4, and a plurality of second pin holes are vertically provided on the second magnesium alloy plate 3, which are respectively matched with the horizontal positions of the plurality of first pin holes. A positioning pin 7 is interference-fitted into a first pin hole and a second pin hole that are matched with the horizontal position.

[0027] Understandably, this setup is intended to improve the assembly precision of the cold plate.

[0028] In one embodiment, such as Figure 1-5 As shown, two fluid connectors 6, which are respectively connected to the inlet and outlet ends of the titanium alloy pipeline 2, are connected to the first magnesium alloy plate 4 and the second magnesium alloy plate 3 by screws 8.

[0029] Understandably, this setup is intended to allow for quick disconnection and reconnection of external liquid cooling supply equipment using the fluid connector 6.

[0030] It should be noted that the first magnesium alloy plate 4 and the second magnesium alloy plate 3 have threaded holes that match the mounting flange on the fluid connector 6, and the fluid connector 6 can be quickly installed and removed by screws 8.

[0031] In one embodiment, such as Figure 4 and Figure 5 As shown, a sealing element 9 is provided at one end of the fluid connector 6 near the first magnesium alloy plate 4 and the second magnesium alloy plate 3. That is, the sealing element 9 is provided on the mounting end face of the fluid connector 6 with the first magnesium alloy plate 4 and the second magnesium alloy plate 3 to prevent the coolant from leaking inside the flow channel 1 of the titanium alloy pipeline 2. Specifically, an annular groove is provided at one end of the fluid connector 6 near the first magnesium alloy plate 4 and the second magnesium alloy plate 3. The sealing element 9 can be a sealing ring installed in the annular groove. After the fluid connector 6 is installed with the first magnesium alloy plate 4 and the second magnesium alloy plate 3, the sealing ring is pre-tightened, thereby preventing the coolant from leaking at the inlet and outlet ends of the flow channel 1.

[0032] This invention also provides a preparation method for preparing magnesium alloy cold plates with integrated titanium alloy flow channels, such as... Figure 1-5 As shown, it includes the following steps: Fabricate titanium alloy pipe 2 and first magnesium alloy plate 4 with concave cavity; Mechanical grinding and ultrasonic cleaning are performed on the upper exposed surface of the first magnesium alloy plate 4, the exposed surface of the titanium alloy pipe 2, and the lower exposed surface of the second magnesium alloy plate 3 to remove the oxide layer and oil stains on the upper exposed surface of the first magnesium alloy plate 4, the exposed surface of the titanium alloy pipe 2, and the lower exposed surface of the second magnesium alloy plate 3. The titanium alloy pipe 2 is wrapped with aluminum foil 5 and then embedded in the cavity; The second magnesium alloy plate 3 is positioned and covered on the upper end of the first magnesium alloy plate 4 to form a cold plate assembly. Instantaneous liquid phase diffusion welding is performed on cold plate assemblies.

[0033] It is understandable that the use of instantaneous liquid phase diffusion welding with pressure and low temperature as the main driving force for the connection between magnesium alloy and titanium alloy, and the addition of aluminum foil 5 as an intermediate layer to adjust the welding interface reaction and promote element diffusion, so as to strengthen the microstructure and mechanical properties of the joint, thereby improving the shear strength of the welding interface, and thus greatly improving the mechanical environment adaptability and long-term operational reliability of the cold plate. In addition, the cold plate after welding can be further machined and surface treated according to actual needs to adapt to the mechanical interface requirements of different electronic device internal functional modules for assembly and interconnection. It can be used as a common part or standard part, with excellent scalability and wide applicability.

[0034] It should be noted that since the upper exposed surface of the first magnesium alloy plate 4, the exposed surface of the titanium alloy pipe 2, and the lower exposed surface of the second magnesium alloy plate 3 are all surfaces to be welded, mechanical grinding and ultrasonic cleaning are required for the upper exposed surface of the first magnesium alloy plate 4, the exposed surface of the titanium alloy pipe 2, and the lower exposed surface of the second magnesium alloy plate 3.

[0035] It should be noted that, in order to achieve a reliable connection between the first and second magnesium alloy cold plates and the titanium alloy pipeline 2, aluminum foil 5 with a thickness of 20~50um is added between the titanium alloy pipeline 2 and the first magnesium alloy cold plate, and between the titanium alloy pipeline 2 and the second magnesium alloy cold plate, in order to adjust the interface reaction and promote the diffusion and solubility of magnesium-titanium dissimilar metals; wherein, the material of aluminum foil 5 can be pure aluminum or Al-Si alloy, preferably Al-12Si (wt%) foil, and the thickness is preferably 30um.

[0036] It should also be noted that 800# sandpaper is preferred for mechanical grinding, and acetone is preferred for ultrasonic cleaning for 15 minutes followed by drying.

[0037] In one embodiment, fabricating the titanium alloy conduit 2 and the first magnesium alloy plate 4 with the cavity includes: Based on the overall heat source distribution and heat dissipation requirements of electronic devices, CAE methods are used to optimize the design as follows: Figure 1 The flow channel 1 shown is then machined and bent to form a titanium alloy pipe 2 that matches the flow channel 1. A cavity matching the flow channel 1 is also machined on the first magnesium alloy plate 4, with a mechanical interface for assembly with the fluid connector 6.

[0038] Understandably, this setup is intended to target heat sources and meet the overall heat dissipation requirements of devices with intelligent processing capabilities.

[0039] In one embodiment, positioning the second magnesium alloy plate 3 over the upper end of the first magnesium alloy plate 4 includes: Multiple locating pins 7 are vertically inserted into the second pin holes of the second magnesium alloy plate 3 and the first pin holes of the first magnesium alloy plate 4, and are interference-fitted with the second pin holes of the second magnesium alloy plate 3 and the first pin holes of the first magnesium alloy plate 4.

[0040] In one embodiment, the locating pin 7 is made of molybdenum, Invar alloy, or a special stainless steel with a coefficient of thermal expansion matching that of magnesium or titanium, so that the locating pin 7 can still provide a positioning effect between the first magnesium alloy plate 4 and the second magnesium alloy plate 3 when the cold plate assembly is subjected to instantaneous liquid phase diffusion welding; wherein, the diameter of the locating pin 7 is 0.01~0.05mm smaller than the diameter of the first pin hole and the second pin hole; in addition, the head of the locating pin 7 has a guide cone angle so that the locating pin 7 can be inserted into the second pin hole and the first pin hole.

[0041] In one embodiment, transient liquid phase diffusion welding of a cold plate assembly includes: The cold-plate assembly is placed in a vacuum diffusion welding furnace using welding fixtures, and a vacuum of 5×10⁻⁶ is applied. - ³ Pa; The temperature is increased at a rate of 5~20℃ / min to a temperature higher than the melting point of aluminum foil 5 and lower than the melting points of the first magnesium alloy plate 4 and the second magnesium alloy, specifically to 480~520℃ (this temperature is between the eutectic point of aluminum or Al-Si and the solidus line of magnesium alloy). After reaching the set temperature, a vertical pressure of 0.5~5MPa is applied to the cold plate assembly through the pressure loading mechanism integrated in the welding fixture or the external mechanical pressurization device. Maintain the temperature and vertical pressure for 10~120 minutes to allow the aluminum foil 5 to melt and undergo a eutectic reaction with the first magnesium alloy plate 4, the second magnesium alloy plate 3 and the titanium alloy pipeline 2 to form a transient liquid phase. Magnesium atoms and titanium atoms diffuse into the transient liquid phase and solidify isothermally until metallurgical bonding is achieved and the overall connection of the cold plate is completed. After cooling to below 100°C in the vacuum diffusion welding furnace, high-purity argon gas is introduced to break the airflow and obtain a one-piece molded cold plate. The two fluid connectors 6 are connected to the first magnesium alloy plate 4 and the second magnesium alloy plate 3 by screws 8, so that the two fluid connectors 6 are respectively connected to the inlet end and the outlet end of the titanium alloy pipeline 2.

[0042] Understandably, the fluid connector 6 connected to the cold plate allows for quick disassembly and interconnection of external liquid cooling supply equipment; in addition, the fluid connector is installed after instantaneous liquid phase diffusion soldering, which avoids the instantaneous liquid phase diffusion soldering affecting or damaging the fluid connector.

[0043] It should be noted that the preferred process parameters for instantaneous liquid phase diffusion welding are a heating rate of 10℃ / min, a set temperature of 495±5℃, a vertical pressure of 2MPa, a corresponding external mechanical pressurization device to increase the total pressure to about 650N, and a holding time of 60min.

[0044] In summary, the present invention has the following advantages over the prior art: The base material of the first magnesium alloy plate 4 and the second magnesium alloy plate 3 is magnesium alloy. Compared with the commonly used aluminum alloy cold plate, the present invention can reduce weight and significantly improve the lightweight performance of cold plates used in electronic devices. Traditional aluminum alloy welded cold plates cannot be specifically surface protected on the inner flow channel wall after welding. The aluminum alloy substrate itself has poor corrosion resistance, and the flow channel is easily damaged by coolant corrosion after long-term use. This invention uses titanium alloy pipes 2 to form the flow channel 1. Based on the excellent corrosion resistance and environmental adaptability of titanium alloy, the coolant can be reliably operated in the flow channel 1 for a long time. Traditional welding of cold-rolled steel plates is prone to cracking, leading to coolant leakage. This invention adopts an integrated embedded pipe structure, with high forming strength of the flow channel 1, which can withstand high liquid pressure and is not easy to leak coolant, which helps to improve the reliability and service life of the cold-rolled steel plate. Magnesium alloys and titanium alloys are difficult to simultaneously exist in a molten state due to their different properties. They are essentially immiscible and do not undergo metallurgical reactions in the liquid state, making it difficult to achieve reliable welding using traditional fusion welding processes. This invention employs instantaneous liquid phase diffusion welding, using pressure and relatively low temperature as the main driving forces for the connection between magnesium and titanium alloys. Furthermore, the addition of aluminum foil 5 as an intermediate layer adjusts the welding interface reaction and promotes element diffusion, thereby strengthening the microstructure and mechanical properties of the joint. This improves the shear strength of the welding interface, significantly enhancing the mechanical environmental adaptability and long-term operational reliability of the cold-rolled plate. Additionally, this invention eliminates the need for cumbersome pre- and post-weld treatments. The cold plate formed by welding according to the present invention can be subjected to secondary machining and surface treatment according to actual needs to adapt to the mechanical interface requirements of the internal functional modules of different electronic devices for assembly and interconnection. It can be used as a common part or standard part, and has excellent scalability and wide applicability.

[0045] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A magnesium alloy cold plate with integrated titanium alloy flow channels, characterized in that, include: The first magnesium alloy plate (4) has a cavity on its upper part; Titanium alloy pipe (2), the titanium alloy pipe (2) is wrapped with aluminum foil (5) and then embedded in the cavity, the external dimensions of the titanium alloy pipe (2) after being wrapped with aluminum foil (5) match the internal dimensions of the cavity; The second magnesium alloy plate (3) is positioned and covered on the upper end of the first magnesium alloy plate (4); The first magnesium alloy plate (4), the titanium alloy pipeline (2), the aluminum foil (5) and the second magnesium alloy plate (3) are connected by instantaneous liquid phase diffusion welding.

2. The magnesium alloy cold plate with integrated titanium alloy flow channels according to claim 1, characterized in that, The first magnesium alloy plate (4) is provided with a plurality of first pin holes vertically, and the second magnesium alloy plate (3) is provided with a plurality of second pin holes that are respectively matched with the horizontal positions of the plurality of first pin holes. A positioning pin (7) is connected to a first pin hole and a second pin hole that are matched with the horizontal position by interference fit.

3. The magnesium alloy cold plate with integrated titanium alloy flow channels according to claim 1, characterized in that, Two fluid connectors (6) are detachably connected to the first magnesium alloy plate (4) and / or the second magnesium alloy plate (3), respectively connecting the inlet end and the outlet end of the titanium alloy pipeline (2).

4. The magnesium alloy cold plate with integrated titanium alloy flow channels according to claim 3, characterized in that, The fluid connector (6) is provided with a seal (9) at one end near the first magnesium alloy plate (4) and / or the second magnesium alloy plate (3).

5. A preparation method for preparing a magnesium alloy cold plate with integrated titanium alloy flow channels as described in any one of claims 1-4, characterized in that, Includes the following steps: A titanium alloy pipeline (2) and a first magnesium alloy plate (4) with a cavity are fabricated. Mechanical grinding and ultrasonic cleaning were performed on the upper exposed surface of the first magnesium alloy plate (4), the exposed surface of the titanium alloy pipe (2), and the lower exposed surface of the second magnesium alloy plate (3) to remove the oxide layer and oil stains on the upper exposed surface of the first magnesium alloy plate (4), the exposed surface of the titanium alloy pipe (2), and the lower exposed surface of the second magnesium alloy plate (3). The titanium alloy pipe (2) is wrapped with aluminum foil (5) and then embedded in the cavity; The second magnesium alloy plate (3) is positioned and covered on the upper end of the first magnesium alloy plate (4) to form a cold plate assembly; Instantaneous liquid phase diffusion welding was performed on the cold plate assembly.

6. The preparation method according to claim 5, characterized in that, The fabrication of the titanium alloy pipeline (2) and the first magnesium alloy plate (4) with a cavity includes: Based on the heat source distribution and heat dissipation requirements of the electronic device, the shape of the flow channel (1) is optimized using the CAE method, and then a titanium alloy pipeline (2) matching the flow channel (1) is manufactured. A cavity matching the flow channel (1) is also manufactured on the first magnesium alloy plate (4).

7. The preparation method according to claim 5, characterized in that, The step of positioning the second magnesium alloy plate (3) over the upper end of the first magnesium alloy plate (4) includes: Multiple locating pins (7) are vertically inserted into the second magnesium alloy plate (3) and the first magnesium alloy plate (4) and are interference-fitted with the second magnesium alloy plate (3) and the first magnesium alloy plate (4).

8. The preparation method according to claim 7, characterized in that, The locating pin (7) is made of molybdenum, Invar alloy or special stainless steel with a thermal expansion coefficient matching that of magnesium or titanium.

9. The preparation method according to claim 5, characterized in that, The instantaneous liquid phase diffusion welding of the cold plate assembly includes: The cold plate assembly is placed in a vacuum diffusion welding furnace with a protective atmosphere. The temperature is raised to a level higher than the melting point of the aluminum foil (5) and lower than the melting points of the first magnesium alloy plate (4) and the second magnesium alloy, and then vertical pressure is applied to the cold plate assembly. Maintain temperature and vertical pressure to melt aluminum foil (5) and react with the first magnesium alloy plate (4), the second magnesium alloy plate (3) and the titanium alloy pipe (2) to form a transient liquid phase. Magnesium atoms and titanium atoms diffuse into the transient liquid phase and solidify isothermally until metallurgical bonding occurs. It was cooled to room temperature in the vacuum diffusion welding furnace.

10. The preparation method according to claim 5 or 9, characterized in that, After performing instantaneous liquid phase diffusion welding on the cold plate assembly, the following steps are also included: The two fluid connectors (6) are detachably connected to the first magnesium alloy plate (4) and / or the second magnesium alloy plate (3) so that the two fluid connectors (6) are respectively connected to the inlet and outlet of the titanium alloy pipeline (2).

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