阅读说明：本技术 用于制备高氧含量下纯钛ebsd样品的方法 (Method for preparing pure titanium EBSD sample with high oxygen content ) 是由 李玉龙 沈将华 史文迪 师先哲 于 2020-11-26 设计创作，主要内容包括：本发明公开一种用于制备高氧含量下纯钛EBSD样品的方法,其包括：将纯钛切割为形状为立方体的纯钛试样；将高氯酸和无水乙醇进行混合配制电解抛光液；将电解抛光液降温至零下20℃；将直流电源的正极与纯钛试样相连,负极与铝片相连,将直流电源电压调至20V,将铝片与纯钛试样浸入到抛光液中进行抛光处理,纯钛试样与铝片的距离保持在27-30mm。通过本发明能够制得高标定率的纯钛EBSD样品。(The invention discloses a method for preparing a pure titanium EBSD sample with high oxygen content, which comprises the following steps: cutting pure titanium into a pure titanium sample with a cubic shape; mixing perchloric acid and absolute ethyl alcohol to prepare an electrolytic polishing solution; cooling the electrolytic polishing solution to-20 ℃; connecting the positive electrode of a direct current power supply with a pure titanium sample, connecting the negative electrode of the direct current power supply with an aluminum sheet, adjusting the voltage of the direct current power supply to 20V, immersing the aluminum sheet and the pure titanium sample into polishing solution for polishing, and keeping the distance between the pure titanium sample and the aluminum sheet at 27-30 mm. The method can prepare the pure titanium EBSD sample with high calibration rate.)

1. A method for preparing a pure titanium EBSD sample at high oxygen content comprising:

cutting the pure titanium with high oxygen content into a pure titanium sample with a cubic shape;

mixing perchloric acid and absolute ethyl alcohol to prepare an electrolytic polishing solution;

cooling the electrolytic polishing solution to-20 ℃;

connecting the positive electrode of a direct current power supply with a pure titanium sample, connecting the negative electrode of the direct current power supply with an aluminum sheet, adjusting the voltage of the direct current power supply to 20V, immersing the aluminum sheet and the pure titanium sample into polishing solution for polishing, and keeping the distance between the pure titanium sample and the aluminum sheet at 27-30 mm.

2. The method of claim 1, wherein the sides of the pure titanium sample are 1-5 mm.

3. The method of claim 1 or 2, further comprising: pure titanium specimens were cut using a diamond wire cutter.

4. The method of claim 1, wherein the ratio of perchloric acid to absolute ethanol of the electrolytic polishing solution is 1: 9.

5. The method of claim 1, further comprising: the electrolytic polishing solution was stirred using a magnetic stirrer.

6. The method of claim 1, further comprising: and (4) cooling the electrolytic polishing solution by using liquid nitrogen.

7. The method of claim 1, further comprising: cooling the electrolytic polishing solution to minus 50 ℃ and then heating the electrolytic polishing solution to minus 20 ℃.

8. The method of claim 1, further comprising: and shaking the pure titanium sample in the polishing process.

9. The method of claim 1, wherein the polishing time is 6-8 min.

Technical Field

The invention relates to a metal surface treatment technology, in particular to a method for preparing a pure titanium EBSD sample with high oxygen content.

Background

Pure titanium or titanium alloy can form a texture with preferred orientation in the interior after being deformed to a certain degree, and Electron backscattering Diffraction (EBSD) is a powerful technology for researching the orientation of crystal grains, combines a microstructure with crystallography analysis, and realizes texture and orientation difference analysis, grain size and shape analysis, strain and recrystallization analysis, grain boundary, subboundary, twin grain boundary property analysis and the like. However, the technology has high requirements on the quality of sample preparation, and not only the surface of the sample is smooth and has no scratch, but also the surface of the sample has no stress layer, otherwise, the EBSD calibration rate is seriously influenced.

Disclosure of Invention

The invention mainly aims to provide a method for preparing a pure titanium EBSD sample with high oxygen content, so as to solve the problem that the prior art lacks a technology for preparing a high-standard-rate pure titanium EBSD sample.

In order to solve the above problems, a method for preparing a pure titanium EBSD sample with high oxygen content is provided according to an embodiment of the present invention, which includes: cutting pure titanium into a pure titanium sample with a cubic shape; mixing perchloric acid and absolute ethyl alcohol to prepare an electrolytic polishing solution; cooling the electrolytic polishing solution to-20 ℃; connecting the positive electrode of a direct current power supply with a pure titanium sample, connecting the negative electrode of the direct current power supply with an aluminum sheet, adjusting the voltage of the direct current power supply to 20V, immersing the aluminum sheet and the pure titanium sample into polishing solution for polishing, and keeping the distance between the pure titanium sample and the aluminum sheet at 27-30 mm.

Wherein the side length of the pure titanium sample is 2 mm.

Wherein the method further comprises: pure titanium specimens were cut using a diamond wire cutter.

Wherein the ratio of perchloric acid to absolute ethyl alcohol in the electrolytic polishing solution is 1: 9.

Wherein the method further comprises: the electrolytic polishing solution was stirred using a magnetic stirrer.

Wherein the method further comprises: and (4) cooling the electrolytic polishing solution by using liquid nitrogen.

Wherein the method further comprises: cooling the electrolytic polishing solution to minus 50 ℃ and then heating the electrolytic polishing solution to minus 20 ℃.

Wherein the method further comprises: and shaking the pure titanium sample in the polishing process.

Wherein the polishing time is 6-8 min.

According to the technical scheme of the invention, the pure titanium EBSD sample with high standard rate can be prepared by preparing the electrolytic polishing solution comprising perchloric acid and absolute ethyl alcohol and immersing the cubic pure titanium sample into the polishing solution with the temperature of minus 20 ℃ for polishing treatment.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a flow chart of a method for preparing a pure titanium EBSD sample at high oxygen content in accordance with an embodiment of the present invention;

FIG. 2 is a graph of experimental results for samples of pure titanium EBSD prepared according to embodiments of the present invention and having an oxygen content of 0.48 at%;

FIG. 3 is a graph of experimental results for samples of pure titanium EBSD prepared according to embodiments of the present invention and having an oxygen content of 2.5 at%.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The method for preparing the pure titanium EBSD sample mainly comprises mechanical polishing, argon ion polishing and electrolytic polishing. Conventional mechanical polishing can also produce a very good EBSD pattern, but not all areas produce a calibratable pattern, since the EBSD calibration rate is affected by the creation of an excess stress layer during mechanical polishing. Better surfaces can be obtained by argon ion polishing technology, and mechanical damage can not be caused to a sample, but experimental parameters are not well mastered, and the cost of experimental instruments is too high, so that the method cannot be popularized at present. The electrolytic polishing is a common means for preparing pure titanium EBSD samples, the whole experimental process is simple, materials and instruments required by the experiment are convenient to purchase, and finally prepared samples are bright in surface and high in calibration rate. However, improper setting of any parameter during the experiment process can cause sample preparation failure, so that it is necessary to find a method for preparing pure titanium EBSD samples with different oxygen contents.

The technical solutions provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

FIG. 1 is a flow chart of a method for preparing a pure titanium EBSD sample at high oxygen content, as shown in FIG. 1, comprising the steps of:

step S102, cutting the pure titanium into pure titanium samples with cubic shapes.

Firstly, providing a pure titanium sample with high oxygen content, and cutting out the pure titanium sample with high oxygen content in a cubic shape by using a diamond wire cutting machine, wherein the side length of the sample can be between 1 and 5 mm. The diamond wire cutting machine is used for cutting a sample, so that high cutting precision can be guaranteed, and the flatness of a cutting surface is good; the size of the pure titanium sample is kept between 1 and 5mm, so that the subsequent polishing process is facilitated. And then cleaning the surface with alcohol, and polishing the surface of the sample with 2000# waterproof abrasive paper, so that the polishing effect can be ensured while the polishing time is shortened.

And step S104, mixing perchloric acid and absolute ethyl alcohol to prepare the electrolytic polishing solution.

In this embodiment, perchloric acid and absolute ethyl alcohol are mixed to prepare an electrolytic polishing solution, and the proportion of the electrolytic polishing solution can be HCLO₄:C₂H₅And OH is 1:9, pouring the electrolytic polishing solution into a clean beaker, putting a rotor into the beaker, and stirring the polishing solution by using a magnetic stirrer, so that the components of the polishing solution can be uniformly mixed and the heat dissipation is faster.

Step S106, cooling the electrolytic polishing solution to 20 ℃ below zero.

And after stirring, cooling the electrolytic polishing solution to 20 ℃ below zero, cooling by adopting liquid nitrogen, and measuring the temperature by using a temperature tester. In one embodiment, the temperature may be decreased to-50 ℃ and then increased to-20 ℃. Liquid nitrogen is added to ensure that the temperature of the electrolytic polishing solution reaches more than 50 ℃ below zero, the polishing is started when the temperature of the electrolytic polishing solution rises to 20 ℃ below zero, so that the electrolytic polishing solution does not have temperature gradient and higher experimental precision, and the whole sample is cleaned by alcohol before polishing to ensure that the surface of the sample is clean and more impurities are not brought into the electrolytic polishing solution.

And S108, connecting the positive electrode of the direct current power supply with the pure titanium sample, connecting the negative electrode of the direct current power supply with the aluminum sheet, adjusting the voltage of the direct current power supply to 20V, immersing the aluminum sheet and the pure titanium sample into polishing solution for polishing, and keeping the distance between the pure titanium sample and the aluminum sheet between 27mm and 30 mm.

The sample needs to be slightly shaken in the polishing process, and after polishing is finished, the sample is washed by water and dried. The test equipment can be simplified and the operation is simple by using a direct current power supply and clamping the pure titanium sample by a clamp. The small sample and the low temperature can ensure that the current is stabilized at 0.01-0.05A in the polishing process, the small current enables the solution to be heated slowly, the sample is ensured to be continuously polished in the low-temperature environment, and finally the pure titanium EBSD sample with high standard rate is obtained.

An embodiment is described below in conjunction with fig. 2 and 3.

Example 1

1. Obtaining a pure titanium sample with the oxygen content of 0.48 at%, cutting out a cubic pure titanium sample with the side length of 2mm by using a diamond wire cutting machine, cleaning the surface of the sample by using alcohol, polishing the surface of the sample by using 2000# water sand paper, cleaning the polished sample by using alcohol, and then putting the cleaned sample into alcohol for storage.

2. Cleaning the measuring cylinder with alcohol, drying, adding 90ml of absolute ethyl alcohol and 10ml of perchloric acid solution into the measuring cylinder in sequence, mixing, pouring into a beaker, and stirring by using a magnetic stirrer. And after stirring, adding liquid nitrogen into the polishing solution, and measuring the temperature by using a temperature tester to ensure that the temperature is firstly reduced to minus 50 ℃ and then increased to minus 20 ℃.

3. And connecting the positive pole of the power supply with a clamp for clamping the sample by using a power supply clamping wire, connecting the negative pole of the power supply with an aluminum sheet, adjusting the direct-current voltage to 20V, immersing the sample and the aluminum sheet into a polishing solution, wherein the distance between the sample and the aluminum sheet is 27mm, and slightly shaking the sample in the polishing process.

4. And (4) taking out the sample after polishing for 6min, washing away the surface polishing solution by using clean water, drying by using a blower, and then putting the sample into alcohol for storage. The calibration rate reaches 92.5 percent after the EBSD test is carried out. The results of the experiment are shown in FIG. 2.

Example 2

1. Obtaining a pure titanium sample with the oxygen content of 2.5 at%, cutting out a cubic pure titanium sample with the side length of 2mm by using a diamond wire cutting machine, cleaning the surface of the sample by using alcohol, polishing the surface of the sample by using 2000# water sand paper, cleaning the polished sample by using alcohol, and then putting the cleaned sample into alcohol for storage.

2. Cleaning the measuring cylinder with alcohol, drying, adding 90ml of absolute ethyl alcohol and 10ml of perchloric acid solution into the measuring cylinder in sequence, mixing, pouring into a beaker, and stirring by using a magnetic stirrer. And after stirring, adding liquid nitrogen into the polishing solution, and measuring the temperature by using a temperature tester to ensure that the temperature is firstly reduced to minus 50 ℃ and then increased to minus 20 ℃.

3. And connecting the positive pole of the power supply with a clamp for clamping the sample by using a power supply clamping wire, connecting the negative pole of the power supply with an aluminum sheet, adjusting the direct-current voltage to 20V, immersing the sample and the aluminum sheet into a polishing solution, wherein the distance between the sample and the aluminum sheet is 27mm, and slightly shaking the sample in the polishing process.

4. And (4) taking out the sample after polishing for 7min, washing away the surface polishing solution by using clean water, drying by using a blower, and then putting the sample into alcohol for storage. The calibration rate reaches 94.8 percent after the EBSD test is carried out. The results of the experiment are shown in FIG. 3.

According to the electrolytic polishing method disclosed by the invention, the polishing process is simple, the surface of the polished pure titanium sample presents a mirror surface, and the pure titanium EBSD sample with a high calibration rate can be obtained.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.