CN115165498A - Preparation method of Cu-containing antibacterial stainless steel transmission electron microscope sample - Google Patents

Abstract

The invention belongs to the technical field of preparation of transmission electron microscope samples made of stainless steel materials, and designs a preparation method of a Cu-containing antibacterial stainless steel transmission electron microscope sample. The method comprises the following steps: cutting a sheet sample, polishing the sample, preparing a wafer sample, preparing an electrolyte, electrolyzing and double-spraying the wafer sample, and cleaning the wafer sample. The double-spraying electrolyte consists of 800-1200 mL of absolute ethyl alcohol, 60mL-80mL of perchloric acid with the concentration of 70.0-72.0% and 8-12 mL of methyl acetate. The Cu-containing antibacterial stainless steel large-area thin-area transmission electron microscope sample is successfully prepared, the operation is simple, rapid and economical, and the copper-rich phase observed under the transmission electron microscope is clear and complete.

Description

A kind of preparation method of Cu-containing antibacterial stainless steel transmission electron microscope sample

technical field

The invention belongs to the technical field of steel material transmission electron microscope sample preparation, and relates to a method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample, in particular to a high antibacterial rate austenitic antibacterial stainless steel containing copper-rich phases with small size and abundant distribution Sample preparation method for large thin areas.

Background technique

Antibacterial stainless steel is a new type of steel material with wide application prospects. It refers to adding metal elements with bactericidal effect, such as copper (Cu), silver (Ag), etc., to the existing stainless steel matrix, and then after special treatment, in addition to having excellent The mechanical properties of the material can also inhibit the formation of bacterial biofilms on the surface of the material, which is of great significance for creating a clean and healthy living environment.

Cu-containing antibacterial stainless steel is made by adding an appropriate amount of Cu element in the process of smelting stainless steel. After a special heat treatment process, a fine and uniformly dispersed copper-rich phase is precipitated, which inhibits the formation of bacterial biofilm on the surface and plays a bactericidal effect. Therefore, the key to the bactericidal ability of Cu-containing antibacterial stainless steel is the existence of a copper-rich phase. The antibacterial rate of the material is closely related to the size and distribution of the internal copper-rich phase. The study of copper-rich phase has become the key to the successful development of Cu-containing antibacterial stainless steel. . Transmission electron microscopy has the ability to resolve from a few nanometers to sub-nanometers, and is the main characterization method to study the microstructure of materials, especially nanoscale precipitates. In order to observe the details of the copper-rich phase and obtain high-quality copper-rich phase pictures, the preparation of high-resolution TEM samples is the key.

The preparation of TEM samples mainly includes FIB (focused ion beam) technology, ion thinning and electrolytic double jet thinning. Among them, although the FIB technology can prepare samples at fixed points, it takes a long time to complete a sample, and the cost is high; ion thinning requires the sample to be ground below 20 μm or pit treatment in the pre-thinning stage, resulting in sample stress concentration, internal Dislocations increase, and the subsequent thinning process of the sample surface by argon ion bombardment takes a long time, and it even takes several days to complete a sample; although the traditional electrolytic double jet thinning requires grinding to less than 60 μm in the pre-thinning stage, The resulting stress concentration is very small, and the time-consuming process of electrolytic double-spray thinning is short, but due to the small, diffuse and abundant copper-rich phase in the Cu-containing antibacterial stainless steel, and the copper-rich phase will be preferentially corroded, in the electrolytic double-spray thinning process. During the spraying process, the copper-rich phase fell off, leaving dense sieve holes, which caused the program to stop thinning after the light-stop threshold was met. The final sample obtained had many holes, thick edges, and almost no thin area. The thin film sample was successfully prepared. rate is not high. Therefore, it is urgent to develop a convenient, time-saving, economical and high-quality TEM sample method suitable for Cu-containing antibacterial stainless steel.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above problems, and provide a method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample.

The object of the present invention is achieved in this way: a method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample is characterized in that: comprising the following steps: step 1: cutting a thin-shaped Cu-containing antibacterial stainless steel sample; step 2: manually polishing both sides Flake samples, prepared disk samples; Step 3: The electrolyte is prepared from 800~1200mL of absolute ethanol, 60~80mL of perchloric acid with a concentration of 70.0%~72.0% and 8~12 mL of methyl acetate. Step 4: After cleaning the electrolytic cell of the electrolytic double jet thinning apparatus twice with distilled water and anhydrous ethanol respectively, add electrolyte into the electrolytic cell, and align the small holes emitted by the two nozzles of the electrolytic double jet thinning apparatus. The liquid column is connected between the two nozzles; Step 5: Add liquid nitrogen into the electrolytic cell, install the sample to be thinned, adjust the thinning process parameters, and start thinning; Step 6: After the thinning is completed, quickly clean The sample was thinned and placed in a round-bottomed centrifuge tube with a lid containing alcohol to stand. 1 hour before observation, it was taken out and placed on filter paper, and dried with an infrared lamp to obtain a TEM sample containing Cu antibacterial stainless steel.

In the first step, a wire cutting machine is used to cut a square or round thin sample with a thickness of 0.8-1.2 mm, a length and a width of 8-12 mm, or a circular sheet with a diameter of 8-12 mm.

In the second step, firstly, paste the silicon carbide sandpaper with adhesive back on the glass plate, press the 0.8~1.2mm thick sheet sample of Cu-containing antibacterial stainless steel with a rubber stopper, and place the sample at 600# and 1000# in turn. , 1500#, 2000# sandpaper on both sides of the circle, until the thickness of the sample is 50~60μm, then use the wafer punch to punch the 50~60μm thick sample, and finally continue to slowly on the fine silicon carbide sandpaper. Grind both sides to 25~40μm to obtain the sample to be thinned.

The glass plate must be smooth and flat, the rubber stopper is 30-70mm in diameter, and the grinding is to draw "○" on the sandpaper.

The fine silicon carbide sandpaper is 2500-4000 mesh.

In the step 5, the ambient temperature of the electrolysis double spray process is -32~-38°C.

In the fifth step, the thinning process parameters: the electrolysis voltage is 35~40V, the photosensitive stop value is 250~400, and the electrolysis current is 40~56mA during the double jet thinning process.

In the step 6, rapidly cleaning and thinning the sample includes: when the infrared photoelectric automatic sensor alarms, quickly take out the sample clip and put it into a beaker containing absolute ethanol; gently shake the sample clip for 3-5 s, and take out the circle. Then, carefully pick up the sample with tweezers and immerse it in clean absolute ethanol, and gently shake the round sample for 3-5 s; finally, put it in a round-bottomed centrifuge tube with a lid and let it stand.

The beneficial effects of the invention are as follows: the method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample provided by the invention solves the problems that the copper-rich phase falls off a lot, the copper-rich phase is less retained, and the thin area is small, and the transmission electron microscope sample is prepared. The success rate is over 98%. The invention greatly improves the preparation rate of Cu-containing antibacterial stainless steel transmission electron microscope samples, shortens the detection period, the obtained copper-rich phase has clearer appearance and more accurate size, and provides accurate basic experiments for product research and development and process route improvement. data.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1: 304Cu antibacterial stainless steel transmission electron microscope sample prepared by the present invention.

Figure 2: TEM sample of 304Cu antibacterial stainless steel prepared by traditional process.

Figure 3: The 304Cu antibacterial stainless steel copper-rich phase morphology diagram obtained according to the present invention.

Figure 4: 430Cu antibacterial stainless steel transmission electron microscope sample prepared by the present invention.

Figure 5: TEM sample of 430Cu antibacterial stainless steel prepared by traditional process.

Figure 6: The 430Cu antibacterial stainless steel copper-rich phase morphology diagram obtained according to the present invention.

Detailed ways

The invention aims to invent a method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample. Bad question. The method can prepare a transmission sample with a large area and a thin area on the premise of ensuring that the copper-rich phase in the Cu-containing antibacterial stainless steel falls off less, and obtain a high-quality transmission image of the copper-rich phase.

Based on the objective problems of conventional electrolytic double jet thinning in the thinning process of Cu-containing antibacterial stainless steel TEM samples, the present invention provides a preparation method of Cu-containing antibacterial stainless steel TEM samples, which solves the problem that the copper-rich phase falls off a lot, and the thin The problem of small area and low success rate of thin film sample preparation. The transmission sample prepared by this method can realize the characteristics of retained copper-rich phase, less sieve holes, and large area of thin area, and realize information to characterize the size, shape and orientation relationship between copper-rich phase and matrix.

A preparation method of Cu-containing antibacterial stainless steel transmission electron microscope sample, the method comprises the following steps:

(1) On the antibacterial stainless steel sample containing Cu, use a wire cutting machine to cut a sheet sample with a thickness of 0.8~1.2mm;

(2) Manually polish the double-sided sheet-like sample, paste the silicon carbide sandpaper with adhesive back on the glass plate, and press the Φ30~70mm rubber stopper by hand to press the 0.8~1.2mm thick sheet-like sample of Cu-containing antibacterial stainless steel , make the sample turn on 600-mesh, 1000-mesh, 1500-mesh, and 2000-mesh sandpaper and grind both sides in turn until the thickness of the sample is 50~60μm, and use a wafer punch to punch the 50~60μm thick sample to obtain Φ3mm wafer samples;

(3) Continue to grind the wafer sample in step (2) on 2500~4000 mesh silicon carbide sandpaper slowly on both sides to about 25~40μm;

(4) After cleaning the electrolytic cell of the electrolytic double jet thinning instrument twice with distilled water and anhydrous ethanol respectively, add electrolyte into the electrolytic cell, and align the small liquid column ejected from the two nozzles of the electrolytic double jet thinning instrument to make it. Butt between the two nozzles;

(5) Add a part of liquid nitrogen to the electrolytic cell. After the thermometer inside the electrolytic double jet thinning instrument shows a stable display of -30 °C, continue to add liquid nitrogen several times in a small amount until the thermometer shows -32 °C ~ -38 °C Inside.

(6) The electrolyte in step (4) and step (5) is a mixture of 800~1200mL of absolute ethanol, 60mL~80mL of perchloric acid with a concentration of 70.0%~72.0% and 8~12mL of methyl acetate. solution;

(7) Put the sample of about 25~40μm wafer prepared in step (3) into the sample holder of the double jet thinning apparatus, put it into the card slot, close the card slot cover, and insert the sample holder into the middle of the two nozzles, The electrolytic voltage used is 35~40V, the set photosensitive stop value is 250~400, and the electrolytic current is 40~56mA during the double jet thinning process;

(8) When the infrared photoelectric automatic sensor alarms, quickly take out the sample clip and put it into a beaker containing absolute ethanol, shake the sample clip gently for 3~5s (avoid cleaning the thin area), and take out the wafer sample. Carefully pick up the sample with tweezers and immerse it in clean absolute ethanol, gently shake the wafer sample for 3~5s, and finally put it into a round-bottomed centrifuge tube with a lid and let it stand still (to prevent the surface of the wafer sample from being polluted), Take it out 0.5~3.5h before observation, put it on filter paper, and dry it with an infrared lamp.

The specific implementation of the method will be described in detail below with reference to the examples, but the specific implementation of the present invention is not limited to the following examples.

Example 1

Preparation of 304Cu antibacterial stainless steel for transmission electron microscopy and the morphology of copper-rich phase under transmission electron microscopy.

(1) Cut a 10mm×10mm square, 1.0mm thick flake 304Cu antibacterial stainless steel sample;

(2) Hold the rubber stopper of Φ50mm in hand, press the sample obtained in step (1), and grind it on both sides on 600-mesh, 1000-mesh, 1500-mesh, and 2000-mesh sandpaper in turn, until the thickness is about 56μm, punch a Φ3mm disc, Then continue to grind on both sides slowly on 3000-grit sandpaper, and the final sample thickness is about 38μm;

(3) Clean the electrolytic cell and wash it twice with distilled water and absolute ethanol respectively;

(4) Preparation of electrolyte: put the electrolytic cell in a well-ventilated fume hood, add 1000 mL of absolute ethanol to the electrolytic cell, and measure 65 mL of 70.0%~72.0% perchloric acid and 10 mL of methyl acetate with a graduated cylinder. , while stirring with a glass rod, slowly add it to anhydrous ethanol;

(5) Align the small liquid column ejected from the two nozzles of the electrolytic double-jet thinning instrument, so that it is connected in the middle of the two nozzles, and add liquid nitrogen into the electrolytic cell to make the electrolysis temperature -33℃~-35℃;

(6) Put the 304Cu antibacterial stainless steel Φ3mm, about 38μm thick disc into the sample holder, put it into the card slot, close the card slot cover, insert the sample holder between the two nozzles, adjust the electrolytic voltage to 38V, and set the photosensitive The stop value is 300, press the start button, the thinning starts, and the current during the thinning process is 46mA;

(7) "DiDiDi" sensor alarms, thinning is over, quickly take out the sample holder and put it into a beaker containing absolute ethanol, gently shake the sample holder for 5s, open the sample holder, take out the wafer sample, use tweezers Carefully pick up the sample and immerse it in clean absolute ethanol, gently shake the wafer sample for 5s, and finally put it into a round-bottom centrifuge tube with a lid containing alcohol and let it stand to obtain a 304Cu antibacterial stainless steel TEM sample;

(8) Take out the 304Cu antibacterial stainless steel TEM sample of step (7) 1 hour before the observation, put it on the filter paper, dry it with an infrared lamp for 3 minutes, put it into the TEM sample holder and then enter the TEM for observation. The observation results are shown in Figure 1 and Figure 1. 2 is a transmission electron microscope sample of 304Cu antibacterial stainless steel prepared by traditional electrolytic double-spraying, and FIG. 3 is a morphological map of the copper-rich phase of 304Cu antibacterial stainless steel obtained in Example 1.

Embodiment 2

Preparation of 430Cu antibacterial stainless steel for transmission electron microscopy and the morphology of copper-rich phase under transmission electron microscopy.

(1) Cut a 10mm×10mm square, 1.0mm thick sheet-like 430Cu antibacterial stainless steel sample;

(2) Hold the rubber stopper of Φ50mm in hand, press the sample obtained in step (1), and grind it on both sides on 600-mesh, 1000-mesh, 1500-mesh, and 2000-mesh sandpaper in turn, until the thickness is about 52μm, punch a Φ3mm disc, Then continue to grind on 4000-grit sandpaper slowly on both sides, and the final sample thickness is about 39μm;

(3) Clean the electrolytic cell and wash it twice with distilled water and absolute ethanol respectively;

(4) Preparation of electrolyte: put the electrolytic cell in a well-ventilated fume hood, add 1000 mL of absolute ethanol to the electrolytic cell, and measure 65 mL of 70.0%~72.0% perchloric acid and 10 mL of methyl acetate with a graduated cylinder. , while stirring with a glass rod, slowly add it to anhydrous ethanol;

(5) Align the small liquid column ejected from the two nozzles of the electrolytic double jet thinning instrument, so that it is docked in the middle of the two nozzles, and add liquid nitrogen into the electrolytic tank to make the electrolysis temperature -33 °C ~ -36 °C;

(6) Put the 430Cu antibacterial stainless steel Φ3mm, about 39μm thick disc into the sample holder, put it into the card slot, close the card slot cover, insert the sample holder between the two nozzles, adjust the electrolytic voltage to 35V, and set the photosensitive The stop value is 300, press the start button, the thinning starts, and the current during the thinning process is 40mA;

(7) "DiDiDi" sensor alarms, thinning is over, quickly take out the sample holder and put it into a beaker containing absolute ethanol, gently shake the sample holder for 5s, open the sample holder, take out the wafer sample, use tweezers Carefully pick up the sample and immerse it in clean absolute ethanol, gently shake the wafer sample for 5s, and finally put it into a round-bottomed centrifuge tube containing alcohol and let it stand to obtain a 430Cu antibacterial stainless steel TEM sample;

(8) Take out the 430Cu antibacterial stainless steel TEM sample of step (7) 1 hour before the observation, put it on the filter paper, dry it with an infrared lamp for 3 minutes, put it into the TEM sample holder and then enter the TEM for observation. The observation results are shown in Figure 4 and Figure 4. 5 is a transmission electron microscope sample of 430Cu antibacterial stainless steel prepared by traditional electrolytic double-spraying, and FIG.

The above are only specific embodiments of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the field of the present invention are all covered by the present invention. within the scope of the patent.

Claims (8)

1. A preparation method of a Cu-containing antibacterial stainless steel transmission electron microscope sample is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: cutting a sheet-shaped Cu-containing antibacterial stainless steel sample;

step two: manually polishing a double-sided sheet-like sample to prepare a wafer sample;

step three: the electrolyte is a mixed solution prepared from 800-1200 mL of absolute ethyl alcohol, 60-80mL of perchloric acid with the concentration of 70.0-72.0% and 8-12 mL of methyl acetate;

step four: cleaning an electrolytic cell of the twice-electrolysis double-spraying thinning instrument by using distilled water and absolute ethyl alcohol respectively, adding electrolyte into the electrolytic cell, and aligning small liquid columns ejected by two nozzles of the twice-electrolysis double-spraying thinning instrument to enable the small liquid columns to be butted between the two nozzles;

step five: adding liquid nitrogen into the electrolytic bath, filling a sample to be thinned, adjusting thinning process parameters, and starting thinning;

step six: and after the thinning is finished, quickly cleaning the thinned sample, putting the sample into a cover-connected round-bottom centrifuge tube containing alcohol, standing, taking out the sample 1 hour before observation, putting the sample on filter paper, and drying the filter paper by using an infrared lamp to obtain the transmission electron microscope sample containing the Cu antibacterial stainless steel.

2. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: in the first step, a square sheet sample with the thickness of 0.8 to 1.2mm and the length and width of 8 to 12mm or a circular sheet sample with the diameter of 8 to 12mm is cut by a wire cutting machine.

3. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: in the second step, firstly, silicon carbide abrasive paper with back adhesive is adhered to a glass plate, a rubber plug is used for pressing a sheet-shaped sample containing Cu antibacterial stainless steel with the thickness of 0.8 to 1.2mm, the two sides of the sample are sequentially ground on 600#, 1000#, 1500# and 2000# abrasive paper in a rotating ring mode until the thickness of the sample is 50 to 60 mu m, then a wafer punching device is used for punching a wafer on the sample with the thickness of 50 to 60 mu m, and finally the two sides of the sample are continuously ground on the fine silicon carbide abrasive paper slowly to 25 to 40 mu m to obtain a sample to be thinned.

4. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: the glass plate is required to be smooth and flat, the diameter of the rubber plug is 30-70mm, and the grinding is to draw a circle on sand paper.

5. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: the fine silicon carbide sand paper is 2500 to 4000 meshes.

6. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: in the fifth step, the environmental temperature in the electrolytic double-spraying process is-32 to-38 ℃.

7. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: in the fifth step, thinning process parameters are as follows: the electrolytic voltage is 35 to 40V, the light sensing stop value is 250 to 400, and the electrolytic current is 40 to 56mA in the double-spraying thinning process.

8. The method for preparing a Cu-containing antibacterial stainless steel transmission electron microscope sample according to claim 1, characterized in that: in the sixth step, rapidly cleaning and thinning the sample comprises: when the infrared photoelectric automatic sensor gives an alarm, quickly taking out the sample clamp and putting the sample clamp into a beaker containing absolute ethyl alcohol; gently shaking the sample for 3 to 5 seconds, and taking out a wafer sample; carefully clamping the sample with a forceps, soaking the sample in clean absolute ethyl alcohol, and gently shaking the wafer sample for 3 to 5 seconds; and finally, placing the mixture into a centrifugal tube with a circular bottom and a cover for containing alcohol and standing.

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