阅读说明：本技术 航天金属材料耐微重力环境下微生物腐蚀测试方法及装置 (Method and device for testing microbial corrosion of aerospace metal material in microgravity-resistant environment ) 是由 鞠鹏飞 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种航天金属材料耐微重力环境下微生物腐蚀测试方法及装置；本发明装置上的特点是：(1)在旋转壁式反应器的上部增加一个连接装置,(2)连接装置下部和旋转壁式反应器的上部一起运动；连接装置的上部连接电化学工作站,不发生运动,电化学工作站可以实时接收旋转壁式反应器中电极的电化学信号。方法上的特点是：在测试过程中,反应器里的微生物一直处在模拟微重力状态下,待测航天材料处于失重状态下,模拟了空间微重力环境中实际材料和微生物接触的状态,通过电化学工作站研究电化学腐蚀-生物腐蚀交互规律。本发明可解决在地面环境中无法对航天金属材料微重力下耐微生物腐蚀性能进行原位分析问题,旨在更加可靠、便捷、科学地解决该问题。(The invention discloses a method and a device for testing microbial corrosion of an aerospace metal material in a microgravity resistant environment; the device of the invention is characterized in that: (1) adding a connecting device at the upper part of the rotary wall type reactor, (2) moving the lower part of the connecting device and the upper part of the rotary wall type reactor together; the upper part of the connecting device is connected with the electrochemical workstation, and the electrochemical workstation can receive the electrochemical signals of the electrodes in the rotating wall type reactor in real time without movement. The method is characterized in that: in the test process, microorganisms in the reactor are always in a simulated microgravity state, the aerospace material to be tested is in a weightless state, the contact state of actual materials and the microorganisms in a space microgravity environment is simulated, and the electrochemical corrosion-biological corrosion interaction rule is researched through an electrochemical workstation. The invention can solve the problem that the in-situ analysis of the microbial corrosion resistance of the aerospace metal material under microgravity cannot be carried out in the ground environment, and aims to solve the problem more reliably, conveniently and scientifically.)

1. A method for testing microbial corrosion resistance of an aerospace metal material in a microgravity environment is characterized by comprising the following steps:

s1, adding the bacterial suspension into a rotary microorganism culture system;

s2, fixing a test sample of the aerospace metal material to be tested on the upper part of the rotary microorganism culture system, and enabling the surface of one side of the test sample to be in contact with the bacterial suspension; respectively fixing a reference electrode and a counter electrode on the upper part of a rotary microorganism culture system, wherein one side surfaces of the reference electrode and the counter electrode are respectively contacted with a bacterial suspension;

s3, electrically connecting the sample, the reference electrode and the counter electrode with an electrochemical testing system respectively;

s4, starting a rotary microorganism culture system, and adjusting the rotary frequency according to the microorganism species; the sample, the reference electrode and the counter electrode rotate together with the rotating microorganism culture system;

s5, after the bacterial suspension in the rotary microorganism culture system is stabilized, testing the open-circuit potential and the electrochemical impedance of the test sample after the test sample and the microorganism act for different time by using an electrochemical testing system, and evaluating the microbial corrosion resistance of the aerospace metal material.

2. The method for testing the microbial corrosion resistance of the aerospace metal material in the microgravity environment according to claim 1, wherein the aerospace metal material is a metal material with or without a coating; the metal material comprises stainless steel, titanium alloy, aluminum alloy and magnesium alloy; the coating comprises an oxide film, a DLC-based coating, and MoS₂Base coat, CrNBase coating, TiN-based coating, TiO₂And (4) base coating.

3. A test device specially used for the test method of the microgravity environment resistance of the aerospace metal material according to claim 1 or 2, wherein the device comprises:

the device comprises a rotary microorganism culture system, an electrochemical test system and a connecting device; the connecting device consists of a lower connecting device and an upper connecting device;

the upper cover plate of the rotary microorganism culture system is provided with a sample mounting hole, a reference electrode mounting hole and a counter electrode mounting hole;

the lower connecting device comprises a reference electrode, a counter electrode and a sample which are arranged on the upper cover plate, and connecting rods which are respectively fixed above the reference electrode, the counter electrode and the sample;

the upper connecting device is provided with a plurality of circular slideways, one ends of connecting rods connected with the reference electrode, the counter electrode and the sample are respectively clamped in the slideways, the slideways are respectively and electrically connected with the electrochemical testing system, and detection signals on the reference electrode, the counter electrode and the sample are transmitted to the electrochemical testing system;

the reference electrode, the counter electrode, the sample and the connecting rod can rotate along with the rotating microorganism culture system at the same time, and the connecting rods do circular motion in respective slideways.

4. The testing device of claim 3, wherein the rotary microbial cultivation system is a suspended rotating wall reactor; the electrochemical testing system adopts an electrochemical workstation.

5. The test device according to claim 3, wherein the test specimen is a test piece of the aerospace metal material to be tested, which is detachably mounted on the test specimen mounting hole; during testing, the contact area of the test piece and the bacterial suspension in the rotary microorganism culture system is more than or equal to 1cm²。

6. A test device according to claim 3, wherein the circular slideway has at least one contact point for connecting a wire.

7. The testing device of claim 3, wherein adjacent circular ramps are isolated from each other by an insulating material and are electrically non-conductive with respect to each other.

8. A test device according to claim 3, wherein the electrochemical detection is performed during rotation of the rotating microbial cultivation system and the lower connecting means.

9. A testing device according to claim 3, further comprising a rotary drive disposed below the rotary microbial cultivation system.

10. A test device as claimed in claim 3, wherein the connecting rod is an adjustable length connecting rod.

Technical Field

The invention relates to the technical field of material science, microbial science and space environment science, belongs to the field of interdiscipline subjects, and relates to a microbial corrosion testing method and a device for a space metal material under a microgravity resistant environment; the device and the method are used for testing the microbial corrosion resistance of the aerospace metal material under the simulated microgravity environment by using an electrochemical means, and are used for testing the open-circuit potential and the electrochemical impedance change of a coating after the coating and bacteria act for different time by using the electrochemical means so as to further evaluate the microbial corrosion resistance of the coating.

Background

The manned space station creates a good environment for long-term residence of astronauts, and also provides favorable conditions for breeding of microorganisms. In the space environment, microorganisms are influenced by various factors such as microgravity, strong cosmic radiation, high vacuum and the like, and biological properties are obviously changed. Among many factors, the change of the physiological and biochemical properties of bacteria caused by the microgravity environment has the characteristics of wide range, large amplitude, high efficiency and the like. The United states and Russia, etc. have conducted investigations into the plain space station and the international space station and found that microbial contamination is very serious. During sampling, the microorganisms are found to generate obvious visible corrosion phenomena on pipelines, instrument boxes, circulating water meters, heat controllers, air conditioners, oxygen electrolyzers, electric insulation sleeves, switch connectors, view windows and the like in the closed cabins, hidden dangers are brought to reliable service of space stations, and risks such as platform failure and reduced tightness occur.

Therefore, the antibacterial and mildewproof treatment is carried out on the materials selected for the key parts of the space station, the antibacterial and mildewproof performance of the materials is improved, and the growth of microorganisms is slowed down, so that the important functions of guaranteeing the healthy life of astronauts and the long-term reliable service of the key parts of the space station are achieved.

At present, research methods aiming at the influence of microgravity on microbiology can be divided into two types, one type is experimental research carried out in space environment by utilizing facilities such as space vehicles, space stations and the like, and the method has the advantages of being capable of carrying out experimental research in space environmentThe influence of various factors of the space environment on bacteria is reflected truly; another type is a 10-degree simulation using a rotating wall Reactor (RWV) and a High Aspect Ratio Vessel (HARV)^-2g, the microgravity state has the advantage that the experiment is not limited by the space flight time, the carrying weight and the safety of the carrying device. The research on the microbial corrosion resistance of the material in the microgravity environment is mainly carried out in an international space station, 5 months and 5 days in 2020, a Changchang No. 5B carrier rocket flies successfully at an Wenchang space launching field, and the construction of the Chinese space station draws a preface. Therefore, there is an urgent need for a method for evaluating the microbial corrosion resistance of materials in a microgravity environment on the ground.

Disclosure of Invention

The invention aims to provide a method and a device for testing microbial corrosion of an aerospace metal material in a microgravity resistant environment; the method solves the problems that the in-situ analysis of the microbial corrosion resistance of the aerospace metal material in a microgravity state cannot be carried out in a ground environment, and the like, and aims to detect the microbial corrosion resistance of the aerospace metal material in a simulated microgravity environment more reliably, conveniently and scientifically. The invention utilizes the electrochemical workstation to not only carry out in-situ analysis on the microbial corrosion resistance of the aerospace material in the microgravity state, but also carry out visual surface morphology observation on the microbial corrosion resistance of the aerospace material in the microgravity state at different time periods.

The purpose of the invention is realized by the following technical scheme:

in a first aspect, the invention relates to a method for testing microbial corrosion resistance of an aerospace metal material in a microgravity environment, which comprises the following steps:

s1, adding the bacterial suspension into a rotary microorganism culture system;

s2, fixing a test sample of the aerospace metal material to be tested on the upper part of the rotary microorganism culture system, and enabling the surface of one side of the test sample to be in contact with the bacterial suspension; respectively fixing a reference electrode and a counter electrode on the upper part of a rotary microorganism culture system, wherein one side surfaces of the reference electrode and the counter electrode are in contact with the bacterial suspension (a sample cannot be directly immersed in the bacterial suspension in a traditional mode, and the sample in the bacterial suspension can shear bacteria in the bacterial suspension in the rotation process to influence the growth of the bacteria in the microgravity environment);

s3, electrically connecting the sample, the reference electrode and the counter electrode with an electrochemical testing system respectively;

s4, starting a rotary microorganism culture system, and adjusting the rotary frequency according to the microorganism species; the sample, the reference electrode and the counter electrode rotate together with the rotating microorganism culture system (the electrochemical test system does not move);

s5, after the bacterial suspension in the rotary microorganism culture system is stabilized, testing the open-circuit potential and the electrochemical impedance of the test sample after the test sample and the microorganism act for different time by using an electrochemical testing system, and further evaluating the microbial corrosion resistance of the aerospace metal material.

As an embodiment of the invention, the aerospace metal material is a metal material with or without a coating.

As an embodiment of the present invention, the metal material includes stainless steel, titanium alloy, aluminum alloy, magnesium alloy.

As an embodiment of the present invention, the coating layer includes an oxide film, a DLC-based coating layer, MoS₂Base coating, CrN base coating, TiN base coating, TiO₂And (4) base coating.

The invention also relates to a testing device special for the testing method of the microbial corrosion resistance of the aerospace metal material in the microgravity resistant environment, which comprises the following steps:

the device comprises a rotary microorganism culture system, an electrochemical test system and a connecting device; the connecting device consists of a lower connecting device and an upper connecting device;

the upper cover plate of the rotary microorganism culture system is provided with a sample mounting hole, a reference electrode mounting hole and a counter electrode mounting hole;

the lower connecting device comprises a reference electrode, a counter electrode and a sample which are arranged on the upper cover plate, and connecting rods which are respectively fixed above the reference electrode, the counter electrode and the sample;

the upper connecting device is provided with a plurality of circular slideways, the other ends of connecting rods connected with the reference electrode, the counter electrode and the sample are respectively clamped in the slideways, the slideways are respectively and electrically connected with an electrochemical testing system, and detection signals on the reference electrode, the counter electrode and the sample are transmitted to the electrochemical testing system; the reference electrode, the counter electrode, the sample and the connecting rod can rotate along with the rotating microorganism culture system at the same time, and the connecting rods do circular motion in respective slideways.

As an embodiment of the invention, the rotating microorganism culture system (optionally a rotating wall reactor) is operated in a sealed state.

In one embodiment of the invention, the test apparatus of the invention is provided with three electrodes in direct contact with the bacterial suspension in the rotating wall reaction vessel, wherein the counter electrode and the reference electrode are secured to the sealing plate by welding, and the working electrode (sample) is secured to the sealing plate by a screw-on gasket, both of which ensure sealing.

As an embodiment of the invention, the rotary microorganism culture system adopts a suspended rotating wall type reactor; the electrochemical testing system adopts an electrochemical workstation. When the device works, the rotating wall type reaction vessel is filled with bacterial suspension, the upper cover plate prevents the solution in the rotating wall type reactor from flying out in the rotating process on one hand, and on the other hand, the three electrodes are fully contacted with the bacterial suspension through special arrangement.

As an embodiment of the invention, the test sample is a test piece of the aerospace metal material to be tested, which is detachably arranged on the test sample mounting hole; during testing, the contact area of the test piece and the bacterial suspension in the rotary microorganism culture system is more than or equal to 1cm²。

In one embodiment of the invention, the circular slideway has at least one contact point for connecting a wire. One end of the lead is connected with the contact point, and the other end of the lead is connected with the corresponding position of the electrochemical testing system. Specifically, a conductive interface is arranged on the slide way corresponding to the sample connecting rod, a reference electrode interface is arranged on the slide way corresponding to the reference electrode connecting rod, and a counter electrode interface is arranged on the slide way corresponding to the counter electrode connecting rod.

As an embodiment of the invention, the adjacent circular slideways are isolated by insulating substances, are not conductive and are in an insulating state.

As an embodiment of the present invention, the electrochemical detection is performed during the rotation of the rotary microorganism culture system and the lower connecting means. The key point of the invention is that the rotation is not stopped during the electrochemical detection, thus ensuring that the bacterial suspension and the test sample are in a weightless state simultaneously in the test process, and obtaining more accurate corrosion resistance of the material in the microorganism under the microgravity environment. The connecting rod is clamped in the slideway and is fully contacted with the slideway; the slideway has the functions of fixing the running track of the connecting rod on one hand and leading out the electric signals on the connecting rod on the other hand for stably transmitting the electric signals on each electrode.

As an embodiment of the present invention, the testing device further comprises a rotation driving device (a rotation motor) provided below the rotary microorganism cultivation system. When the rotating motor below the rotating microorganism culture system is started, the rotating microorganism culture system can rotate, and the electrodes (reference electrode, counter electrode and working electrode) and the connecting rod which are fixedly connected with the rotating microorganism culture system can also rotate at the same angular speed. While the circular slideway of the upper connecting device is not rotatable, and the connecting rod rotates in the slideway.

As an embodiment of the present invention, the connecting rod is an adjustable length connecting rod. The length of the connecting rod and the injection amount of the bacterial suspension are jointly controlled, so that one side surface of the sample is in contact with the bacterial suspension. In the testing process, the bacterial suspension in the rotary microorganism culture system must be filled, and on the basis, the length of the connecting rod is adjusted, so that the bacterial suspension is only in full contact with the surface of one side of the sample.

As an embodiment of the present invention, the sample mounting hole is in a shape of an inverted frustum; the actual shape of sample is round platform form test block, can directly imbed the upper cover plate of rotatory microorganism culture system, and through this kind of mode, the big one side of sample round platform area only contacts with bacterial suspension, and the one side that the area is little is connected fixedly with the connecting rod.

As an embodiment of the invention, the sample mounting holes are a plurality of pairs of mounting holes arranged at symmetrical positions. The test is performed during rotation and the sample should be placed in a symmetrical position.

In conclusion, the invention adds a connecting device on the upper part of the existing rotating wall type reactor, and the other end of the connecting device can be connected with an electrochemical workstation; the added electrochemical workstation is connected in series with the upper part of the rotating wall type reactor and can receive the electrochemical signals of the electrodes in the rotating wall type reactor in real time. Specifically, the invention firstly utilizes a rotating wall type reactor and utilizes centrifugal force to offset gravity, so that microorganisms in a culture container are propagated in a simulated microgravity environment; then putting the test piece into a culture container to make the test piece and the solution contact with each other; then, detecting surface electrochemical signals of the test piece and the microorganism culture solution in different contact time by using an electrochemical workstation through a connecting device; and finally, qualitatively and quantitatively evaluating the microbial corrosion resistance of the aerospace metal material to growth in the microgravity environment through open-circuit potential and electrochemical impedance. Wherein, the higher the open circuit potential and the polarization resistance value of the material are, the stronger the microbial corrosion resistance of the material is.

Compared with the prior art, the invention has the following beneficial effects:

1) in the process of testing the antibacterial performance of the coating, the testing microorganism grows in a simulated microgravity state all the time, and the sample to be tested is in a relatively static state relative to the microorganism culture solution, so that the contact state of an actual material and the microorganism in a space microgravity environment is simulated;

2) according to the device, an electrochemical workstation can monitor the microbial corrosion resistance of the coating in a microgravity environment in real time;

3) the method can solve the problems that the microbial corrosion resistance of the aerospace metal material in a microgravity state cannot be subjected to in-situ analysis in a ground environment, and the like, can more reliably, conveniently and scientifically detect the microbial corrosion resistance of the aerospace metal material in a simulated microgravity environment, and further research the interaction rule of electrochemical corrosion-biological corrosion of a coating in a simulated space service environment and the like;

4) by adopting the set of testing device, the bacterial suspension and the test sample can be in a weightless state at the same time in the ground environment, so that the corrosion resistance of the material in microorganisms in the microgravity environment can be tested, and the beneficial effect of carrying out in-situ analysis on the microorganism corrosion resistance of the aerospace metal material under the microgravity in the ground environment can be realized.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic structural diagram of a microbial corrosion testing device for simulating an aerospace metal material in a microgravity environment;

FIG. 2 is a schematic view of a lower-middle connecting device of a microbial corrosion testing device for simulating an aerospace metal material in a microgravity environment;

FIG. 3 is a schematic view of an upper connection device in a microbial corrosion test device for simulating an aerospace metal material in a microgravity environment;

FIG. 4 is a graph of open circuit potential versus immersion time for 2A12 aluminum alloy in microorganisms under simulated microgravity conditions;

FIG. 5 is a graph of electrochemical impedance of 2A12 aluminum alloy in microorganisms under simulated microgravity conditions as a function of immersion time;

FIG. 6 is a graph of open circuit potential versus immersion time for 2219 aluminum alloy in microorganisms under simulated microgravity conditions;

FIG. 7 is a graph of electrochemical impedance of 2219 aluminum alloy in microorganisms under simulated microgravity environment as a function of immersion time;

FIG. 8 is a graph of open circuit potential versus soak time for 2195 aluminum alloy in microorganisms under a simulated microgravity environment;

FIG. 9 is a graph of electrochemical impedance of 2195 aluminum alloy in microorganisms under simulated microgravity conditions as a function of immersion time;

wherein, 1-connecting device, 2-upper connecting device, 3-first sample connecting rod, 4-air inlet, 5-lower connecting device, 6-reference electrode connecting rod, 7-counter electrode connecting rod, 8-second sample connecting rod, 9-air outlet, 10-rotary microorganism culture system, No. 11-1 sample, 12-counter electrode, No. 13-2 sample, No. 14-3 sample, No. 15-4 sample, 16-reference electrode, No. 17-5 sample, No. 18-6 sample, 19-sample conducting interface, 20-counter electrode conducting interface, 21-reference electrode conducting interface, 22-sample connecting rod slide way, 23-counter electrode connecting rod slide way, 24-reference electrode connecting rod slide way, 25-sample conducting wire, 26-counter electrode conducting wire, 27-reference electrode conducting wire, 28-reference electrode interface, 29-counter electrode interface, 30-working electrode interface and 31-electrochemical workstation.

Detailed Description

The present invention will be described in detail with reference to examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be apparent to those skilled in the art that several modifications and improvements can be made without departing from the inventive concept. All falling within the scope of the present invention.

A testing device for testing the microbial corrosion resistance of an aerospace metal material in a microgravity environment is disclosed in figures 1, 2 and 3, and comprises: a rotary microbial cultivation system 10 (using a suspended rotating wall reactor), an electrochemical workstation 31 and a connection device 1; the connecting device 1 consists of a lower connecting device 5 and an upper connecting device 2;

the upper cover plate of the rotary microorganism culture system 10 is provided with a sample mounting hole, a reference electrode mounting hole and a counter electrode mounting hole; an air inlet 4 and an air outlet 9 are also arranged; the bacterial suspension is also injected into the microorganism culture vessel of the rotary microorganism culture system 10 through the air inlet 4 and/or the air outlet 9.

The lower connecting device 5 includes a reference electrode 16, a counter electrode 12, a sample (the sample may be a plurality of symmetrically arranged samples) mounted on the upper cover plate, and a plurality of connecting rods respectively fixed above the reference electrode 16, the counter electrode 12, and the sample, and includes: a reference electrode connecting rod 6, a counter electrode connecting rod 7, a first sample connecting rod 3, a second sample connecting rod 8 and the like;

be equipped with a plurality of circular slides on upper portion connecting device 2, include: a sample connecting rod slide 22, a counter electrode connecting rod slide 23 and a reference electrode connecting rod slide 24; the other end of the reference electrode connecting rod 6 is clamped in the reference electrode connecting rod slide way 24, the other end of the counter electrode connecting rod 7 is clamped in the counter electrode connecting rod slide way 23, and the other ends of the first sample connecting rod 3 and the second sample connecting rod 8 are clamped in the sample connecting rod slide way 22; a sample conductive interface 19 is arranged on the sample connecting rod slide way 22, a counter electrode conductive interface 20 is arranged on the counter electrode connecting rod slide way 23, and a reference electrode conductive interface 21 is arranged on the reference electrode connecting rod slide way 24; one end of a sample conducting wire 25 is connected with the sample conducting interface 19, the other end of the sample conducting wire is connected with a working electrode interface 30 of an electrochemical workstation 31, one end of a counter electrode conducting wire 26 is connected with a counter electrode conducting interface 20, the other end of the counter electrode conducting wire is connected with a counter electrode interface 29 of the electrochemical workstation 31, one end of a reference electrode conducting wire 27 is connected with a reference electrode conducting interface 21, and the other end of the reference electrode conducting wire 27 is connected with a reference electrode interface 28 of the electrochemical workstation. The detection signals on the reference electrode 16, the counter electrode 12 and the sample are transmitted to the electrochemical workstation 31.

In the device, the reference electrode, the counter electrode, the sample and the connecting rod can rotate along with the rotating microorganism culture system at the same time, and the connecting rods make circular motion in respective slideways.

As an embodiment of the invention, the test sample is a test piece of the aerospace metal material to be tested, which is detachably arranged on the test sample mounting hole; during testing, the contact area of the test piece and the bacterial suspension in the rotary microorganism culture system is more than or equal to 1cm²。

As an embodiment of the present invention, the connecting rod is an adjustable length connecting rod. The length of the connecting rod and the injection amount of the bacterial suspension are jointly controlled, so that one side surface of the sample is contacted with the liquid bacterial suspension. In the testing process, the bacterial suspension in the rotary microorganism culture system must be filled, and on the basis, the length of the connecting rod is adjusted, so that the bacterial suspension is fully contacted with the surface of one side of the sample.

As an embodiment of the present invention, the sample mounting hole is in a shape of an inverted frustum; the actual shape of sample is round platform form test block, can directly imbed the upper cover plate of rotatory microorganism culture system, and through this kind of mode, the big one side of sample round platform area only contacts with bacterial suspension, and the one side that the area is little is connected fixedly with the connecting rod.

In the apparatus of the present invention, the rotary microorganism culture system (rotary wall type reaction vessel) is operated in a sealed state. In one embodiment of the invention, the test apparatus of the invention is provided with three electrodes in direct contact with the bacterial suspension in the rotating wall reaction vessel, wherein the counter electrode and the reference electrode are secured to the sealing plate by welding, and the working electrode (sample) is secured to the sealing plate by a screw-on gasket, both of which ensure sealing.

When the device is used for testing, electrochemical detection is carried out in the rotating process of the rotating microorganism culture system and the lower connecting device. The key point of the invention is that the rotation is not stopped during the electrochemical detection, thus ensuring that the bacterial suspension and the test sample are in a weightless state simultaneously in the test process, and obtaining more accurate corrosion resistance of the material in the microorganism under the microgravity environment. The connecting rod is clamped in the slideway and is fully contacted with the slideway; the slideway has the functions of fixing the running track of the connecting rod on one hand and leading out the electric signals on the connecting rod on the other hand for stably transmitting the electric signals on each electrode.

Second, testing method

1. Sample preparation

The test material was processed into a cylindrical specimen of phi 10mm x 5 mm. All test pieces were sequentially polished with 400#, 800#, 1200# and 2000# metallographic abrasive paper, and then degreased. Then, the sample is added into 75% ethanol/water solution for sterilization for 15min, placed into a sterile disposable culture dish, air-dried in a sterile operating platform, and subjected to ultraviolet sterilization for 30min for later use.

2. Preparation of the bacterial suspension

Preparing a bacterial suspension.

3. Action of aerospace metal material and microorganism

The samples can be placed at the positions (figure 2) corresponding to the No. 1 sample 11, the No. 2 sample 13, the No. 3 sample 14, the No. 4 sample 15, the No. 5 sample 17 and the No. 6 sample 18 at the bottom of the lower part of the connecting device, the prepared bacterial suspension is added into a microorganism culture container (figure 1) of the rotary microorganism culture system 10, so that the bacterial suspension is fully contacted with the surface of one side of the sample, a rotator is started, and the rotating speed is adjusted, so that the bacterial suspension is in a simulated microgravity state in the microorganism culture container. Controlling the temperature in the microbial culture container to be 35-37 ℃, and testing the corrosion resistance of the microbial culture container in the bacterial suspension for 2 days, 7 days and 14 days by using an electrochemical workstation. In the electrochemical test, a three-electrode system is adopted, a calomel electrode is used as a reference electrode, a platinum electrode is used as a counter electrode, a sample is used as a working electrode, and bacterial suspension is used as a test medium. The reference electrode, the counter electrode and the working electrode are all in contact with the bacterial suspension at one side.

4. Open circuit potential after application

A traditional three-electrode system is selected to carry out open-circuit potential test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The testing time is 0.5-3 h.

5. Post-operative electrochemical impedance

A traditional three-electrode system is selected to carry out Electrochemical Impedance (EIS) test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The amplitude of the alternating current signal of the EIS test is 5mV, and the frequency change is 100mHz to 10 kHz.

The specific application is shown in the following examples:

example 1

The staphylococcus aureus ATCC6538 is selected as a representative strain, 2A12 aluminum alloy in southwest aluminum industry is selected as a material, and sulfuric acid anodic oxidation treatment is carried out on the surface of the aluminum alloy.

1. Sample preparation

The test material was 2A12 aluminum alloy, which was processed into a cylindrical test piece of phi 10mm by 5 mm. All test pieces are sequentially polished by metallographic abrasive paper of No. 400, No. 800, No. 1200 and No. 2000 respectively, then deoiled and subjected to sulfuric acid anodic oxidation treatment. Then, the sample is added into 75% ethanol/water solution for sterilization for 15min, placed into a sterile disposable culture dish, air-dried in a sterile operating platform, and subjected to ultraviolet sterilization for 30min for later use.

2. Preparation of the bacterial suspension

The preparation of the bacterial suspension is carried out according to the method mentioned in GB/T21510-2008 & ltmethod for detecting antibacterial property of nano inorganic material & gt, the test bacteria is staphylococcus aureus, and the colony count is 3 multiplied by 105 cfu/mL.

3. Action of aerospace metal material and microorganism

Placing the 2A12 aluminum alloy sample after anodic oxidation treatment at the bottom of the position (figure 2) of the No. 1 sample and the No. 6 sample 18 at the lower part of the connecting device, adding the prepared bacterial suspension into a culture container (figure 1) to ensure that the bacterial suspension is fully contacted with one side surface of the sample, starting a rotator, and adjusting the rotating speed to ensure that the bacterial suspension is in a simulated microgravity state in the culture container. Controlling the temperature in the incubator to be 35-37 ℃, and testing the corrosion resistance of the original sample, 2 days, 7 days and 14 days in the microbial solution by using an electrochemical workstation.

4. Open circuit potential after application

A traditional three-electrode system is selected to carry out open-circuit potential test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The testing time is 0.5-3 h. Fig. 4 shows the open circuit potential, and the higher the open circuit potential, the more stable the surface of the material is, the better the corrosion resistance is. From the level of the open circuit potential, the corrosion resistance of the material surface decreases with time.

5. Post-operative electrochemical impedance

Selecting traditional three electrode bodiesThe Electrochemical Impedance (EIS) test is carried out on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is an auxiliary electrode, a saturated calomel electrode is a reference electrode, the sample is a working electrode, and the effective area of the sample is 1.0cm². The amplitude of the alternating current signal of the EIS test is 5mV, and the frequency change is 100mHz to 10 kHz. Fig. 5 is a Nyquist diagram, generally, the magnitude of the capacitive arc radius reflects the magnitude of the charge transfer resistance in the electrochemical corrosion process, and the larger the capacitive arc radius is, the larger the charge transfer resistance is, the better the corrosion resistance of the material is. The increase of time can be judged by the size of the capacitive arc radius, and the microbial corrosion resistance of the material is weakened.

Example 2

The staphylococcus aureus ATCC6538 is selected as a representative strain, 2219 aluminum alloy in southwest aluminum industry is selected as a material, and sulfuric acid anodic oxidation treatment is carried out on the surface of the aluminum alloy.

1. Sample preparation

The test material was 2219 aluminum alloy, which was processed into a cylindrical test piece of Φ 10mm × 5 mm. All test pieces are sequentially polished by metallographic abrasive paper of No. 400, No. 800, No. 1200 and No. 2000 respectively, then deoiled and subjected to sulfuric acid anodic oxidation treatment. Then, the sample is added into 75% ethanol/water solution for sterilization for 15min, placed into a sterile disposable culture dish, air-dried in a sterile operating platform, and subjected to ultraviolet sterilization for 30min for later use.

2. Preparation of the bacterial suspension

The preparation of the bacterial suspension is carried out according to the method mentioned in GB/T21510-2008 & ltmethod for detecting antibacterial property of nano inorganic material & gt, the test bacteria is staphylococcus aureus, and the colony count is 3 multiplied by 105 cfu/mL.

3. Action of aerospace metal material and microorganism

Placing the 2219 aluminum alloy sample after the anodic oxidation treatment at the bottom of the position (figure 2) corresponding to the No. 2 sample and the No. 5 sample 17 at the lower part of the connecting device, adding the prepared bacterial suspension into a culture container (figure 1) to ensure that the bacterial suspension is fully contacted with the surface of one side of the sample, starting a rotator, and adjusting the rotating speed to ensure that the bacterial suspension is in a simulated microgravity state in the culture container. Controlling the temperature in the incubator to be 35-37 ℃, and testing the corrosion resistance of the original sample, 2 days, 7 days and 14 days in the microbial solution by using an electrochemical workstation.

4. Open circuit potential after application

A traditional three-electrode system is selected to carry out open-circuit potential test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The testing time is 0.5-3 h. Fig. 6 shows the open circuit potential, and the higher the open circuit potential, the more stable the surface of the material is, the better the corrosion resistance is. From the level of the open circuit potential, the corrosion resistance of the material surface decreases with time.

5. Post-operative electrochemical impedance

A traditional three-electrode system is selected to carry out Electrochemical Impedance (EIS) test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The amplitude of the alternating current signal of the EIS test is 5mV, and the frequency change is 100mHz to 10 kHz. Fig. 7 is a Nyquist diagram, generally, the magnitude of the capacitive arc radius reflects the magnitude of the charge transfer resistance in the electrochemical corrosion process, and the larger the capacitive arc radius is, the larger the charge transfer resistance is, the better the corrosion resistance of the material is. The increase of time can be judged by the size of the capacitive arc radius, and the microbial corrosion resistance of the material is weakened.

Example 3

The staphylococcus aureus ATCC6538 is selected as a representative strain, 2195 aluminum alloy in southwest aluminum industry is selected as a material, and sulfuric acid anodic oxidation treatment is carried out on the surface of the aluminum alloy.

1. Sample preparation

The test material was 2195 aluminum alloy, which was processed into a cylindrical test piece of Φ 10mm × 5 mm. All test pieces are sequentially polished by metallographic abrasive paper of No. 400, No. 800, No. 1200 and No. 2000 respectively, then deoiled and subjected to sulfuric acid anodic oxidation treatment. Then, the sample is added into 75% ethanol/water solution for sterilization for 15min, placed into a sterile disposable culture dish, air-dried in a sterile operating platform, and subjected to ultraviolet sterilization for 30min for later use.

2. Preparation of the bacterial suspension

The preparation of the bacterial suspension is carried out according to the method mentioned in GB/T21510-2008 & ltmethod for detecting antibacterial property of nano inorganic material & gt, the test bacteria is staphylococcus aureus, and the colony count is 3 multiplied by 105 cfu/mL.

3. Action of aerospace metal material and microorganism

Placing the 2219 aluminum alloy sample after the anodic oxidation treatment at the bottom of the position (figure 2) corresponding to the No. 3 sample and the No. 4 sample at the lower part of the connecting device, adding the prepared bacterial suspension into a culture container (figure 1), enabling the bacterial suspension to be fully contacted with the surface of one side of the sample, starting a rotator, and adjusting the rotating speed to enable the bacterial suspension to be in a simulated microgravity state in the culture container. Controlling the temperature in the incubator to be 35-37 ℃, and testing the corrosion resistance of the original sample, 2 days, 7 days and 14 days in the microbial solution by using an electrochemical workstation.

4. Open circuit potential after application

A traditional three-electrode system is selected to carry out open-circuit potential test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The testing time is 0.5-3 h. Fig. 8 shows the open circuit potential, and the higher the open circuit potential, the more stable the material surface and the better the corrosion resistance. From the level of the open circuit potential, the corrosion resistance of the material surface decreases with time.

5. Post-operative electrochemical impedance

A traditional three-electrode system is selected to carry out Electrochemical Impedance (EIS) test on a sample at a Princeton P4000A electrochemical station, wherein a platinum sheet is used as an auxiliary electrode, a saturated calomel electrode is used as a reference electrode, the sample is used as a working electrode, and the effective area of the sample is 1.0cm². The amplitude of the alternating current signal of the EIS test is 5mV, and the frequency change is 100mHz to 10 kHz. FIG. 9 is a Nyquist plot showing that the magnitude of the arc radius of capacitive reactance generally reflects the magnitude of the charge transfer resistance during electrochemical corrosion, the larger the arc radius of capacitive reactance, the larger the charge transfer resistance, and the materialThe better the corrosion resistance. The increase of time can be judged by the size of the capacitive arc radius, and the microbial corrosion resistance of the material is weakened.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.