CN216192852U

CN216192852U - System for be used for passivating aluminium alloy microchannel radiator internal surface runner

Info

Publication number: CN216192852U
Application number: CN202122539844.1U
Authority: CN
Inventors: 边燕飞; 童立超; 李石; 谢明君; 武胜璇; 蔡萌; 王若甫
Original assignee: CETC 54 Research Institute
Current assignee: CETC 54 Research Institute
Priority date: 2021-10-21
Filing date: 2021-10-21
Publication date: 2022-04-05
Anticipated expiration: 2031-10-21

Abstract

The utility model discloses a system for passivating an inner surface flow channel of an aluminum alloy microchannel radiator, and belongs to the technical field of passivation processes. The system comprises an electrolytic cell filled with electrolyte, a corrosion-resistant hose and a programmable direct current power supply; a platinum counter electrode is arranged in the electrolytic cell, the cathode of the direct current power supply is connected with the platinum counter electrode, and the anode of the direct current power supply is connected with the micro-channel radiator; the corrosion-resistant hose is sequentially connected with an electrolyte tank, a filter, a flow channel on the inner surface of the micro-channel radiator, an electrolyte pump and a flow control valve. The utility model can form a uniform and compact anodic aluminum oxide layer on the inner surface of the micro-channel, and can improve the corrosion resistance of the micro-channel in the micro-channel radiator.

Description

System for be used for passivating aluminium alloy microchannel radiator internal surface runner

Technical Field

The utility model relates to the technical field of passivation processes, in particular to a system for passivating an inner surface flow channel of an aluminum alloy micro-channel radiator.

Background

The electronic device is developed towards high frequency, integration, high power and high density, so that the heat productivity and heat flux density of the volume electronic device are greatly increased, and the heat dissipation space is reduced. The heat productivity of the chip is not only related to the energy consumption problem, but also related to the safe and efficient working state of the chip. At present, the traditional heat dissipation mode cannot meet the requirements of the increasing development of electronic technology.

To meet such a challenge, many researchers at home and abroad have proposed various efficient heat dissipation technologies for device level and system level, such as heat pipe technology, micro-channel heat dissipation technology, and the like. The microchannel heat dissipation technology has the characteristics of high heat dissipation capacity and integration with the existing electronic device substrate due to the characteristics of large heat transfer area and short heat diffusion distance, so that the microchannel heat dissipation technology becomes a hot point for the research of the heat dissipation field at home and abroad.

At present, a microchannel radiator usually adopts a vacuum brazing technology, and no corrosion prevention treatment is carried out on a microchannel in a water-cooling substrate after welding. In the using process, the contact surface of the brazing filler metal and the cold plate base material is easy to generate galvanic corrosion in the cooling liquid, and the corrosion of the micro-channel in the water-cooled radiator is accelerated.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a system for passivating an inner surface flow channel of an aluminum alloy microchannel heat sink. The system can form a uniform and compact anodic aluminum oxide layer on the inner surface of the micro-channel, and can improve the corrosion resistance of the micro-channel in the micro-channel radiator.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

a system for passivating an inner surface flow channel of an aluminum alloy microchannel heat sink comprises an electrolytic cell filled with an electrolyte; the corrosion-resistant hose and the programmable direct current power supply are also included; a platinum counter electrode is arranged in the electrolytic cell, the negative electrode of the direct current power supply is connected with the platinum counter electrode, and the positive electrode of the direct current power supply is connected with the micro-channel radiator; the corrosion-resistant hose is sequentially connected with an electrolyte tank, a filter, a flow channel on the inner surface of the micro-channel radiator, an electrolyte pump and a flow control valve.

Further, the electrolyte is 0.3mol/L oxalic acid solution.

Further, the corrosion-resistant hose is a polyvinyl chloride pipe, a rubber pipe or a PV hose.

Furthermore, an acid and alkali resistant plastic clamping and sleeving joint is installed on the flow channel on the inner surface of the micro-channel radiator, and the corrosion resistant hose is connected with the micro-channel radiator through the acid and alkali resistant plastic clamping and sleeving joint.

Furthermore, a data recorder for measuring the voltage or current of the electrolyte in real time is also arranged in the electrolytic cell; the multifunctional data acquisition unit of the data recorder is electrically connected with the electrolyte pump; when the anodic oxidation current reaches a specified low threshold, the multifunctional data acquisition unit of the data recorder opens the electrolyte pump, so that ions in the flow channel of the microchannel radiator are supplemented.

The utility model adopts the technical scheme to produce the beneficial effects that:

the utility model changes the traditional passivation process method that the microchannel radiator is integrally placed in the electrolytic cell at present, but places the microchannel radiator outside the electrolytic cell, thereby avoiding the complex steps of protecting the outer surface of the radiator in the traditional passivation process and reducing the labor cost; in addition, the use of the utility model can form a uniform and compact anodic aluminum oxide layer on the inner surface of the micro-channel, and can improve the corrosion resistance of the flow channel on the inner surface of the micro-channel radiator; and the implementation mode is simple.

Drawings

FIG. 1 is a schematic illustration of a passivation process equipment installation according to an embodiment of the present invention.

In the figure: 1. programmable direct current power supply, 2, lead, 3, platinum counter electrode, 4, electrolyte, 5, electrolytic cell, 6, corrosion-resistant hose, 7, filter, 8, flow control valve, 9, quick-operation joint, 10, microchannel radiator, 11, electrolyte pump.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Further, the electrolyte is 0.3mol/L oxalic acid solution.

The utility model changes the traditional passivation process method of integrally placing the microchannel radiator into the electrolytic cell, but places the microchannel radiator outside the electrolytic cell, and forms a closed loop system for flowing electrolyte with an electrolyte pump, a flow control valve, the electrolytic cell, a filter, a corrosion-resistant hose and a quick connector in sequence. In this system, a platinum counter electrode is inserted into the electrolytic cell and a programmable dc power supply is used to apply a voltage between the aluminum microchannel heat sink and the platinum counter electrode. In addition, a data logger is employed in the system to measure the voltage and current in the cell at a fixed frequency and when the anodization current reaches a specified low threshold, the electrolyte pump is turned on using a multi-functional data acquisition unit to replenish the ions in the internal channels of the microchannel heat sink.

The anodization is performed under a constant electrolyte flow or a pulsed electrolyte flow, the internal volume of the microchannel heat sink is small, and the microchannel heat sink is placed outside the electrolyte bath, so that the electrolyte may be exhausted as the anodization reaction proceeds. Based on these considerations, pulsed electrolyte flow conditions are employed to avoid possible mass transport problems. In pulsed electrolyte flow anodization, when the current in the electrochemical cell drops to a specified threshold, the electrolyte pump is turned on using the data logger device, forcing fresh electrolyte to flow into the interior of the microchannel heat sink. After forcing the new electrolyte to flow through the entire microchannel heat sink interior, the pump is turned off and the anodization proceeds again with the fixed electrolyte present inside the microchannel heat sink.

Referring to fig. 1, the present embodiment forms a closed loop system for electrolyte flow by an electrolytic cell 5, a filter 7, an aluminum alloy microchannel radiator 9, an electrolyte pump 11, and a flow control valve 8 through a corrosion-resistant hose 6 and a quick coupling 9. In this system, a platinum counter electrode 3 is inserted into an electrolytic cell 5 and a programmable dc power supply 1 is used to apply a voltage between an aluminum microchannel heat sink 9 and the platinum counter electrode 3. In addition, a data recorder is used in the system to measure the voltage and current in the electrochemical cell 5 at a fixed frequency, and when the current value is lower than a certain threshold value, the electrolyte pump 11 is automatically controlled to start working, so that the fresh electrolyte 4 is forced to flow into the microchannel radiator 9. When new electrolyte 4 flows through the entire inside of the microchannel heat sink 9, the electrolyte pump 11 is automatically turned off and the anodization proceeds again with a fixed electrolyte inside the microchannel heat sink 9. The process is carried out circularly all the time. Until the passivation process is finished. The method can form a uniform and compact anodic aluminum oxide layer on the inner surface of the micro-channel, and can improve the corrosion resistance of the micro-channel in the micro-channel radiator.

Before passivation, the micro-channel radiator is placed into an electrolyte circulating system through a rubber pipe joint. Starting an electrolyte pump, introducing a 1M NaOH solution into the aluminum microchannel radiator, and polishing at a flow rate of 50ml/min for 1.5 min. Then, the mixture was rinsed with deionized water at a flow rate of 50ml/min for 1.5min and dried with 0.34MPa of compressed air for 1 min.

An electrochemical system with 2 electrodes is adopted, a platinum counter electrode 3 is connected with the cathode of a programmable direct current power supply 1 through a lead 2, a metal micro-channel radiator is connected with the anode of the programmable direct current power supply 1, the voltage is adjusted from 0V to 30V at the rate of 4V/min, and the electrolyte 4 in an electrolytic cell 5 is 0.3mol/L oxalic acid solution.

The filter 7 is used for filtering out impurities in the electrolyte to prevent the micro-channel from being blocked.

The flow control valve 8 is used to control the flow of the electrolyte, and a needle valve is used in this embodiment.

The electrolyte pump 11 drives the circulation of the electrolyte, the flow rate of the electrolyte being 50 ml/min.

The quick connector 9 is connected with the metal micro-channel radiator and the corrosion-resistant hose 6, the quick connector is an acid and alkali resistant plastic clamping and sleeving connector, and the corrosion-resistant hose is a PV hose;

the corrosion resistant hoses are tightly fitted at each end of the microchannel heat sink, forming a closed electrolyte flow path inside the microchannel heat sink. The voltage and current in the cell 5 are measured at a fixed frequency using a data logger and when the current level falls below a certain threshold, the electrolyte pump 11 is automatically controlled to start working forcing fresh electrolyte 4 into the microchannel heat sink 9. When new electrolyte 4 flows through the entire inside of the microchannel heat sink 9, the electrolyte pump 11 is automatically turned off and the anodization proceeds again with a fixed electrolyte inside the microchannel heat sink 9. The process is carried out circularly all the time. Until the passivation process is finished.

In this example, the data logger used Agilent 34970A to measure voltage and current in an electrochemical cell at a sampling rate of 1 Hz. When the anodization current reached a specified low threshold, the electrolyte pump was turned on using the multi-functional data acquisition unit of Agilent 34970a to replenish the ions within the microchannel heat exchanger channels.

The passivation time of the micro-channel radiator 10 is 3 hours, the micro-channel heat exchanger is taken out of the electrolyte circulating system after passivation, deionized water is used for washing for 1.5min at the flow rate of 50ml/min, and then compressed air is used for drying for 1 min.

And (3) immersing the microchannel radiator into deionized water at the temperature of 95-98 ℃ for 30min for hole sealing treatment. After sealing, the microchannel heat exchanger was dried with compressed air for 1 min.

Claims

1. A system for passivating an inner surface flow channel of an aluminum alloy microchannel heat sink comprises an electrolytic cell filled with an electrolyte; the device is characterized by also comprising a corrosion-resistant hose and a programmable direct current power supply; a platinum counter electrode is arranged in the electrolytic cell, the negative electrode of the direct current power supply is connected with the platinum counter electrode, and the positive electrode of the direct current power supply is connected with the micro-channel radiator; the corrosion-resistant hose is sequentially connected with an electrolyte tank, a filter, a flow channel on the inner surface of the micro-channel radiator, an electrolyte pump and a flow control valve.

2. The system of claim 1, wherein the electrolyte is 0.3mol/L oxalic acid solution.

3. The system of claim 1, wherein the corrosion resistant hose is a polyvinyl chloride, rubber, or PV hose.

4. The system of claim 1, wherein the flow channel on the inner surface of the microchannel heat sink is provided with an acid and alkali resistant plastic clamp joint, and the corrosion resistant hose is connected with the microchannel heat sink through the acid and alkali resistant plastic clamp joint.

5. The system for passivating an inner surface flow channel of an aluminum alloy microchannel heat sink as recited in claim 1, wherein a data recorder for measuring voltage or current of the electrolyte in real time is further provided in the electrolytic cell; the multifunctional data acquisition unit of the data recorder is electrically connected with the electrolyte pump; when the anodic oxidation current reaches a specified low threshold, the multifunctional data acquisition unit of the data recorder opens the electrolyte pump, so that ions in the flow channel of the microchannel radiator are supplemented.