阅读说明：本技术 用超临界二氧化碳对镁及镁合金防腐蚀处理的装置及方法 (The device and method that magnesium and magnesium alloy anticorrosion are handled with supercritical carbon dioxide ) 是由 王悦存 梁倍铭 张利强 李文博 单智伟 于 2019-08-06 设计创作，主要内容包括：本发明公开一种用超临界二氧化碳对镁及镁合金防腐蚀处理的装置及方法,包括密闭容器、第一管道以及第二管道,第一管道的一端通入密闭容器,另一端连接二氧化碳气源,第一管道沿着气体流向依次设置有阀门、流量计、加压泵、加热器和单向阀,第二管道的一端通入密闭容器,第二管道还连接真空泵,密闭容器外侧设置有加热装置；将镁或镁合金在去离子水或碱性溶液中浸泡后,其表面生成氢氧化物膜层,用超临界状态CO<Sub>2</Sub>气体与镁表面的氢氧化物反应生成致密保护膜,提高镁及镁合金的抗腐蚀性能；该方法工艺简单、节能高效、绿色环保,适用于各种镁基金属材料；由于超临界CO<Sub>2</Sub>的扩散性和渗透性好,可以对具有复杂几何外形的工件进行表面处理。(The present invention discloses a kind of device and method handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, including closed container, first pipe and second pipe, one end of first pipe is passed through closed container, the other end connects carbon dioxide air source, first pipe is disposed with valve, flowmeter, force (forcing) pump, heater and check valve along gas flow, one end of second pipe is passed through closed container, and second pipe is also connected with vacuum pump, is provided with heating device on the outside of closed container；After magnesium or magnesium alloy are impregnated in deionized water or alkaline solution, Surface Creation hydroxide film layer, with supercriticality CO 2 Gas reacts the fine and close protective film of generation with the hydroxide of magnesium surface, improves the corrosion resistance of magnesium and magnesium alloy；It is this method simple process, energy-efficient, environmentally protective, it is suitable for various magnesium-base metal materials；Due to supercritical CO 2 Diffusivity and good penetrability, the workpiece with complex geometry shape can be surface-treated.)

1. a kind of device handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, which is characterized in that including closed appearance Device (1), first pipe (10) and second pipe (11), one end of first pipe (10) are passed through closed container (1), and the other end connects Meet CO₂Gas source；First pipe (10) is along CO₂Gas flow is disposed with valve (7), flowmeter (6), force (forcing) pump (5), adds Hot device (4) and check valve (3), one end of second pipe (11) are passed through closed container (1), and second pipe (11) Shanghai is provided with valve Door (7), the thermometer for detecting its internal temperature is provided on closed container (1), and closed container is provided on (1) for examining The pressure gauge of its internal pressure is surveyed, closed container (1) side wall is provided with heating device.

2. the device according to claim 1 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, is disposed with flowmeter (6), valve (7), true from closed container (1) junction to the other end on second pipe (11) Sky pump (8) and CO₂Recyclable device.

3. the device according to claim 1 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, closed container (1) uses autoclave.

4. a kind of method handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, which is characterized in that including following step It is rapid:

Step 1, magnesium and magnesium alloy are impregnated in deionized water or sodium hydroxide solution；

Step 2, the magnesium metal and magnesium alloy that handle by step 1 are dried under vacuum conditions, then in heat-retaining condition Lower and supercritical CO₂Reaction, generates protective film layer on the metallic substrate, and the main component of the protective film layer is magnesium carbonate, institute It states protective film layer magnesium and magnesium alloy are isolated from the outside.

5. the method according to claim 4 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, in step 1, the mass fraction 5%~10% of the sodium hydroxide solution, the vacuum condition is that pressure is lower than 10Pa.

6. the method according to claim 4 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, step 2 gained protective film layer is amorphous state.

7. the method according to claim 4 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, step 2 gained protective film layer is with a thickness of 0.5 μm~3 μm.

8. the method according to claim 4 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, supercritical CO described in step 2₂Temperature be 35 DEG C~60 DEG C, pressure be 8MPa~12MPa；CO₂Purity be not less than 99.9%.

9. the method according to claim 8 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, supercritical CO is used in step 2₂The time of processing is 1~2 hour.

10. the method according to claim 4 handled with supercritical carbon dioxide magnesium and magnesium alloy anticorrosion, feature It is, in step 1, pure magnesium or magnesium alloy in deionized water or sodium hydroxide solution a length of 1 hour~24 hours when impregnating.

Technical field

The invention belongs to corrosions of metal and protection field, and in particular to a kind of to be closed with supercritical carbon dioxide to magnesium and magnesium The device and method of golden anti-corrosion treatment.

Background technique

Magnesium is most light structural metallic material, density 1.7g/cm³, it is only the 22% of iron, the 39% of titanium, aluminium 64%.There are many excellent properties, as specific strength and specific stiffness are high, electrical and thermal conductivity is good, bio-compatible after magnesium alloy chemical Property good and good damping shock absorption and electromagnetic shielding performance etc..As " 21 century environmentally protective engineering material " and grand strategy Goods and materials, magnesium and magnesium alloy are in the fields such as automobile, computer, communication and aerospace extensive application.China is magnesium in the world Resource country the most abundant and Yuan Mei big producer, magnesium industry have great development potentiality and wide production in China Product application prospect.

But with most metal phase ratios, magnesium chemical activity itself is high, equilibrium potential is low, have very strong betatopic, The tendency corroded.And the oxide layer compactness of magnesium itself can not enough prevent the erosion of air and water vapour, it cannot be to magnesium Substrate plays a protective role.For magnesium alloy, although the second phase that the alloy element of addition generates facilitates to be promoted strong It spends but since the difference of electrode potential would generally accelerate the corrosion of magnesium alloy.The not corrosion resistant serious shadow of characteristic of magnesium and magnesium alloy The service performance of product and the service life of workpiece are rung, their extensive use is greatly limited.Therefore magnesium and magnesium alloy are improved Resistance to corrosion have and its important meaning.

Currently, the means for magnesium and alloy anticorrosion specifically include that 1) exploitation novel magnesium alloy, or improve alloy structure Structure is to improve corrosion resistance；2) surfacecti proteon is carried out to existing magnesium alloy.Wherein, surfacecti proteon is because its universality is strong and effect The obvious feature of fruit, is widely used.The surface protection technique of several mainstreams includes: anodic oxidation, at chemical conversion Reason, surface coating, the coat of metal, thermal spraying and ion implanting etc..But there is also many deficiencies for current preventive means: anode Oxidation is easy to produce localized hyperthermia during the energization and chemical waste environmental pollution is very big；The film that chemical conversion treatment obtains The layer crisp porous protective of matter is poor and equally exists the reluctant problem of chemical waste fluid；Surface coating layer mechanical performance itself compared with Difference, it is easy to fall off, it will affect the dimensional accuracy of workpiece；Then presence is loosely easy to fall off in conjunction with substrate for the coat of metal, is only applicable to spy Determine the magnesium alloy of ingredient and will form the problems such as galvanic couple accelerates the corrosion of magnesium when coating is defective；Thermal spray process need by Paint heating is to very high temperature, and magnesium is easily oxidized simultaneously because the influence performance of heat can also change during this；Ion note Enter to face implanted layer thickness influenced by workpiece geometries it is very big, and the problems such as complex process, higher cost.In short, in view of The many disadvantages of the prior art need to change thinking, explore a kind of new corrosion protection method.

The fusing point of magnesium lower (~650 DEG C), heat resistance are poor, it is contemplated that finished work-piece be heated geometry easily deform, machine Tool performance also will receive factors, the corrosion-resistant treatments such as influence and should carry out under conditions of nearly room temperature；In addition, magnesium itself is used as one The environmentally protective metal material of kind, improving its corrosion proof method also should energy conservation and environmental protection.Supercritical CO₂(SCF-CO₂) be between A kind of state of matter between gaseous state and liquid has fabulous mobility and permeability, lower critical-temperature (31.1 DEG C) With critical pressure (7.83MPa), and nontoxic, odorless, environmental-friendly, moderate cost and CO₂It can recycle and recycle.It reduces After pressure, carbon dioxide gas can fully volatilize completely, without carrying out any liquid waste processing.

Summary of the invention

The purpose of the invention is to overcome shortcoming and defect of the existing technology, a kind of overcritical titanium dioxide is provided The device and method that carbon handles magnesium and magnesium alloy anticorrosion generates one layer of guarantor based on magnesium carbonate in magnesium and Mg alloy surface Cuticular layer uses supercritical CO₂Environmental protection and energy saving can carry out at a lower temperature, and the method for the invention is to magnesium and magnesium alloy The anticorrosive method being all suitable for.

To achieve the goals above, the technical solution adopted by the present invention is that, it is a kind of with supercritical carbon dioxide to magnesium and magnesium The device of alloy anticorrosion processing, which is characterized in that including closed container, first pipe and second pipe, first pipe One end is passed through closed container, and the other end connects CO₂Gas source；First pipe is along CO₂Gas flow is disposed with valve, flow Meter, force (forcing) pump, heater and check valve, one end of second pipe are passed through closed container, and second pipe is also connected with vacuum pump, closed Outside of containers is provided with heating device.

Flowmeter, valve, vacuum pump and two are disposed with from closed container junction to the other end on second pipe Carbonoxide recyclable device.

Closed container uses autoclave.

A method of magnesium and magnesium alloy anticorrosion are handled with supercritical carbon dioxide, comprising the following steps:

Step 1, magnesium and magnesium alloy are impregnated in deionized water or sodium hydroxide solution；

Step 2, the magnesium metal and magnesium alloy that handle by step 1 are dried under vacuum conditions, are then being kept the temperature Under the conditions of with supercritical CO₂Reaction, generates protective film layer on the metallic substrate, and the main component of the protective film layer is carbonic acid Magnesium and magnesium alloy are isolated from the outside by magnesium, the protective film layer.

In step 1, the mass fraction 5%~10% of the sodium hydroxide solution, the vacuum condition is lower than for pressure 10Pa。

Step 2 gained protective film layer is amorphous state.

Step 2 gained protective film layer is with a thickness of 0.5 μm~3 μm.

Supercritical CO described in step 2₂Temperature be 35 DEG C~60 DEG C, pressure be 8MPa~12MPa；CO₂Purity be not less than 99.9%.

Supercritical CO is used in step 2₂The time of processing is 1~2 hour.

In step 1, a length of 1 hour~24 is small when pure magnesium or magnesium alloy impregnate in deionized water or sodium hydroxide solution When.

Compared with prior art, the present invention at least has the advantages that using force (forcing) pump through first pipe to close The CO for being passed through and heating by heater is closed in container₂, setting check valve makes CO in first pipe₂One direction flows to closed container, makes CO₂Reach supercriticality in closed container, closed container side wall is arranged heating device, is provided on closed container for examining The thermometer of its internal temperature and the pressure gauge for detecting its internal pressure are surveyed, closed container interior reaction temperature can be read in real time With pressure, prevent temperature and pressure in closed container from exceeding scope of design.

Further, flowmeter, valve, vacuum are disposed with from closed container junction to the other end on second pipe Pump and CO₂Recyclable device, after completion of the reaction in time by unreacted CO₂Recycling, and yield can be measured；Vacuum pump was both It can be used to recycle remaining CO₂, can be used for forming vacuum condition to closed container, magnesium to be processed and magnesium alloy can be closed It is dried in container.

Further, closed container uses autoclave, autoclave be commonly use high-pressure sealed reaction vessel, and technology at It is ripe, heating device can be carried.

The present invention is by by CO₂Gas overcriticalization, makes CO₂It at a lower temperature can be with magnesium and Mg alloy surface in water Or the loose hydroxide film generated in alkaline aqueous solution reacts, one layer of generation is fine and close and extremely steady on the metallic substrate Fixed protective layer, comes so that magnesium alloy is isolated from the outside, and the corrosion rate of magnesium and magnesium alloy in the solution can be effectively reduced； Protective film layer is well combined with substrate, is not easy to be destroyed or be fallen off；Protective film layer is grown in by reacting at a lower temperature Metal surface will not cause adverse effect to other of magnesium and magnesium alloy physical and mechanical properties；The present invention is suitable for all Magnesium and magnesium alloy sample are a kind of methods against corrosion of wide spectrum；Simultaneously this method simple process and reaction temperature it is low, magnesium will not be changed And the performance and Product Precision of magnesium alloy itself, can magnesium to any complex geometry shape and magnesium alloy parts carry out at surface Reason；Supercritical CO₂It is a kind of state of matter between gaseous state and liquid, there is fabulous mobility and permeability, lower Critical-temperature (31.1 DEG C) and critical pressure (7.83MPa), and nontoxic, odorless, environmental-friendly, moderate cost and can be anti- Multiple to utilize, after reducing pressure, carbon dioxide gas can fully volatilize completely, without carrying out any liquid waste processing.

Detailed description of the invention

Fig. 1 is schematic device of the present invention

Fig. 2 is the schematic device that sample corrosion resistance test of the present invention generates hydrogen volume；

Fig. 3 a is the scanning electron microscopy picture of the pure magnesium sample after impregnating 2 hours in deionized water,

Fig. 3 b is the pure magnesium sample after immersion 2 hours in deionized water through supercritical CO₂Scanning electricity after processing 1 hour Sub- micro-image,

Fig. 3 c is without supercritical CO₂The a pattern product of processing corrode 24 hours in 3.5wt%NaCl aqueous solution after it is micro- Pattern is seen,

Fig. 3 d is through supercritical CO₂The a pattern product of processing corrode 24 hours in 3.5wt%NaCl aqueous solution after it is microcosmic Pattern；

Fig. 4 a is only sanding and polishing magnesium Sample Scan electron microscopic feature image, and Fig. 4 b is that white frame region is put in Fig. 4 a Big figure, Fig. 4 c are that Fig. 4 b corresponds to zone X ray detecting power spectrum (EDX) analysis result；

Fig. 5 a. is the MAG block shape Sample Scan electron microscopic feature image through deionized water immersion treatment, and Fig. 5 b is Fig. 5 a The enlarged drawing in region in middle white box, Fig. 5 c are that Fig. 5 b corresponds to zone X ray detecting power spectrum (EDX) analysis result；

Fig. 6 a is after deionized water is impregnated, and in overcritical supercritical CO₂Treated MAG block shape Sample Scan electronics Microstructure image, Fig. 6 b are the enlarged drawing in region in white box in Fig. 6 a, and Fig. 6 c is that Fig. 6 b corresponds to zone X ray detecting power spectrum (EDX) result is analyzed；

Fig. 7 be pure magnesium sample after only impregnating 12 hours in deionized water with impregnate 12 hours in deionized water after simultaneously Through supercritical CO₂The X-ray diffraction spectrum (XRD) of pure magnesium sample after processing 2 hours analyzes result；

Fig. 8 is after impregnating 12 hours in deionized water and through supercritical CO₂Magnesium and magnesium alloy after processing 2 hours exist In the NaCl aqueous solution of 3.5wt% by 24 hours test after hydrogen generating quantity comparison diagram；

Fig. 9 is the pure magnesium of 4N5 and four kinds of different magnesium alloy hydrogen generating quantity comparison diagrams in the embodiment of the present invention.

In attached drawing, 1- closed container, 2- sample, 3- check valve, 4- heater, 5- force (forcing) pump, 6- flowmeter, 7- valve, 8- vacuum pump, 9-CO₂Gas tank, 10- first pipe, 11- second pipe.

Specific embodiment

The present invention is described further by the following example: according to following embodiments, the present invention may be better understood. However, as it will be easily appreciated by one skilled in the art that specific material ratio, process conditions and its result described in embodiment are only used In illustrating the present invention, without the present invention described in detail in claims should will not be limited.

A kind of device carrying out anti-corrosion treatment to magnesium and magnesium alloy with supercritical carbon dioxide, including closed container 1, One pipeline 10 and second pipe 11, one end of first pipe 10 are passed through closed container 1, and the other end connects CO₂Gas source, the first pipe Road 10 is disposed with valve 7, flowmeter 6, force (forcing) pump 5, heater 4 and check valve 3 along gas flow, and check valve 3 makes CO₂ It is flowed into closed container 1, first pipe 10 will not be flowed to from closed container；One end of second pipe 11 is passed through closed container 1, Second pipe 11 is also connected with vacuum pump 8, and pipe hole is offered on the lid of closed container 1, and closed container 1 passes through pipeline and the external world Connection；It is provided with the thermometer for detecting its internal temperature on closed container 1, is provided on closed container 1 for detecting it The pressure gauge of internal pressure, 1 side wall of closed container are provided with heating device, and the heating device uses heater strip.

Flowmeter 6, valve 7 and CO are disposed with from closed container junction to the other end on second pipe 11₂It returns Receiving apparatus；CO₂Gas source uses CO₂Gas tank 9；Vacuum pump 8 is arranged in valve 7 and CO₂Between recyclable device, the outlet of vacuum pump 8 connects Meet CO₂The entrance of recyclable device, CO₂The pipeline and CO of recyclable device inlet₂Recyclable device is detachably connected.

When carrying out anti-corrosion treatment to magnesium or magnesium alloy using device of the present invention, deionized water or hydroxide will be passed through Sodium solution impregnate and dry after magnesium and magnesium alloy be put into closed container 1, the valve 7, heater 4 on second pipe 11 with And force (forcing) pump 5 is in closed state, opens vacuum pump and takes the air in closed container 1 away, closes on second pipe 11 Valve 7；The valve 7 in first pipe 10 is opened, CO is opened₂Gas tank 9, force (forcing) pump 5 and heater 4, CO₂It is overpressurized and is added Heat enter closed container 1 in, from closed container 1 thermometer and pressure gauge monitor its internal pressure temperature and reach CO₂It is super to face After boundary's condition, pressure-maintaining and heat-preservation is carried out, so that CO₂It is reacted with magnesium and magnesium alloy, generation main component is magnesium carbonate (MgCO₃) guarantor Cuticular layer.

This part is served only for that invention is further explained, should not be understood as the restriction to invention protection scope, should The technician in field can make some nonessential modifications and adaptations to the present invention according to the content of foregoing invention；Below Illustrate particular content of the present invention by specific embodiment: