Preparation method of high-quality surface pure rhenium sample

Abstract

The invention discloses a preparation method of a high-quality surface pure rhenium sample, which comprises the following steps of: cutting and sampling a pure rhenium original material, grinding, polishing and cleaning by ultrasonic vibration, loading the sample on a sample clamping device, then putting the sample into a mixed solution, refrigerating and carrying out electrolytic polishing treatment to obtain the high-quality surface pure rhenium sample. And a pure rhenium sample with a high-quality surface can be obtained. According to the method, the defects of an existing high-quality surface pure rhenium sample preparation method are overcome, single or multiple samples can be prepared at the same time through the method, the quality effect is excellent, the rhenium crystal information analysis rate reaches 99% or above, the urgent requirement of the academic circle for the high-quality surface pure rhenium sample is met, and the method is suitable for popularization and application. And a good technical support and a material preparation basis are provided for macroscopic performance analysis of pure rhenium and deep research work of microscopic deformation mechanism. The method has the advantages of being simple, convenient, efficient, high in safety, low in cost, excellent in technical effect and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material preparation and surface treatment, and particularly provides a preparation method of a high-quality surface pure rhenium sample. BACKGROUND

[0002] Rhenium (Re) is a rare refractory metal of silver-white color, located in group VII B of the periodic table. It is widely used in high-temperature alloys, aerospace, electronic engineering, petrochemical industry, biomedical engineering and other fields due to its high strength, good plasticity, excellent creep resistance, excellent high-temperature resistance, corrosion resistance, heat shock resistance and other excellent properties, and has become one of the important new materials in modern high-tech fields. Generally speaking, the main preparation process of pure rhenium includes powder metallurgy, chemical vapor deposition and electrodeposition. Among them, chemical vapor deposition and electrodeposition are often used to deposit rhenium coating and transition layer, and to prepare rhenium tube thin-wall parts. Rhenium wires, rhenium particles and rhenium sheets that have reached the application state are prepared by powder metallurgy processes such as ball milling, isostatic pressing, sintering and multiple cold rolling forming processes.

[0003] Pure rhenium crystals have a hexagonal close-packed (HCP) structure. During the processing of rhenium products, different processing methods such as rolling deformation and heat treatment are required, which can lead to differences in grain size, preferred orientation, etc. These factors can affect the activation of the crystal slip system and the formation of twins during subsequent deformation, processing or service, and thus affect the performance of the material. When rhenium components are used in super-heat-resistant parts and sub-heat-resistant parts of rockets, space return capsules, satellite attitude adjustment engines and other aerospace fields, they will be subjected to harsh environments such as high temperature, corrosion, oxidation, creep and radiation. The organization, structure, texture and micro-defects of rhenium crystals will further evolve, and thus affect the application of pure rhenium components. When studying these materials, techniques such as metallography, XRD, EBSD and TEM are required for analysis. Due to the high hardness and high wear resistance of pure rhenium, deformation layers are easily generated on the surface during sample preparation, scratches are left on the surface after polishing and etching, and crystal information cannot be analyzed. Therefore, a high-quality surface pure rhenium sample is urgently needed for the study of the deep deformation mechanism, performance anisotropy and in-situ testing of rhenium components. Scholars are also seeking an effective method for preparing a high-quality surface pure rhenium sample.

[0004] Due to the scarcity and special use of rhenium, there are few relevant literatures and patents on the research and development and application of rhenium in various countries. The methods applied to the preparation of pure rhenium samples are few in number and have certain limitations. For example, the researcher Julian E.C. Sabisch proposed in the article Microstructural evolution of rhenium Part I: Compression. Materials Science and Engineering: A, 2018, 732: 251-258 that 5% 2-butoxyethanol, 35% volume ratio 2:1 hydrochloric acid and nitric acid solution, and 60% volume ratio 1:1 methanol and ethanol solution are used as electrolytic polishing solution. The electrolytic polishing solution has complex composition and strong oxidizing and corrosive nitric acid solution, which is not conducive to safe operation. The application number is 202110175782.2. The invention provides a method for preparing a chemical vapor deposition state rhenium EBSD sample. The sample preparation process of the method is complex, the sample needs to be heat-embedded, the polishing time is long, and the prepared metallographic picture has obvious scratches, which will affect the subsequent slip system observation, EBSD analysis, XRD stress analysis and other researches.

[0005] Therefore, it is extremely important to provide a simple, efficient, safe, low-cost and excellent technical effect method for preparing a high-quality surface pure rhenium sample. SUMMARY

[0006] In view of the deficiencies of the prior art and the urgent needs of the academic circles, the present application provides a simple, safe, easy-to-operate, low-cost and excellent technical effect method for preparing a high-quality surface pure rhenium sample. The method can simultaneously prepare and process single and multiple samples, effectively remove the grinding and polishing marks on the surface of the sample, the sample surface grain boundary, slip and twinning trace is clear and visible, and the rhenium crystal information has a very high resolution.

[0007] The technical scheme of the present application is: a method for preparing a high-quality surface pure rhenium sample, which specifically comprises the following steps: S1) cutting and sampling: cutting and sampling the pure rhenium raw material according to the size of the high-quality surface pure rhenium sample to be prepared, and then grinding and polishing and ultrasonic vibration cleaning to obtain the required sample; S2) electrolytic polishing: fixing the sample obtained in S1) and the clamping device in an acidic electrolytic polishing solution, and then performing refrigeration treatment; S3) connecting the clamping device and the cathode plate to the positive and negative electrodes respectively, connecting the power supply, adjusting the direct current power supply voltage to a certain value, adjusting the initial current density to a certain value, and then performing electrolytic polishing treatment. When the current density rises to a certain value, turn off the power supply, and clean the surface of the sample with water and anhydrous ethanol. A high-quality surface pure rhenium sample is obtained Further, the specific process in S1) is: S1.1) using a wire cut electrical discharge equipment to sample the pure rhenium raw material, the X-axis, Y-axis and Z-axis directions of the sampled pure rhenium sample correspond to the length, width and height directions of the raw material; S1.2) sequentially grinding the sample cut in S1.1) on 280#~5000# silicon carbide sandpaper, then rough polishing the sample on a black damping polishing cloth with W2.0~9.0 diamond polishing paste, and then fine polishing the sample on a silk polishing cloth with W0.5~1.0 diamond polishing paste; S1.3) placing the sample polished in S1.2) in a beaker, adding a cleaning agent to the beaker, and then placing the beaker on an ultrasonic instrument for ultrasonic vibration cleaning treatment, and then blowing dry with anhydrous ethanol for standby.

[0008] Further, the pure rhenium raw sample is in a sintered state, a deformed state or an annealed state; and the shape is cylindrical, plate-shaped or flaky.

[0009] Further, the direction of each treatment in S1.2) is perpendicular to the direction of the previous pass. The cleaning agent is acetone or anhydrous ethanol.

[0010] Further, the material of the fixing clamp in S2) is molybdenum alloy. The electrolytic polishing solution comprises 5~20 Vol.% of perchloric acid, 2~10 Vol.% of methanol and 5~20 Vol.% of 70~93 Vol.% of anhydrous ethanol based on the total volume. The temperature of the refrigeration treatment is ≥-90℃.

[0011] Further, the refrigeration treatment method is using liquid nitrogen refrigeration, subzero temperature water chiller refrigeration or thermoelectric material refrigeration.

[0012] Further, the direct current power supply voltage in S3) is adjusted to 50~60V, and the initial current density is adjusted to 0.2~1.2mA / cm 2 When the current density rises to 6.8~11.5mA / cm 2 , the power is turned off.

[0013] Further, the material of the cathode plate is stainless steel, titanium alloy, zirconium alloy or molybdenum alloy.

[0014] A high-quality surface pure rhenium sample prepared by the preparation method.

[0015] The method of the present application makes up for the shortcomings of the existing high-quality surface pure rhenium sample preparation method, meets the urgent needs of the academic community for high-quality surface pure rhenium samples, provides technical support for the anisotropy of rhenium components in mechanics, corrosion and irradiation, and provides a good material preparation foundation for the study of slip system of pure rhenium crystals, determination of critical shear stress, and deep-level deformation mechanism of micro defects such as dislocation and twinning. The method has the advantages of being simple, efficient, safe, low in cost, and excellent in technical effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A schematic diagram of a single sample clamping device in Example 1 prepared by the preparation method of the present application; Figure 2 A metallographic microstructure diagram of a pure rhenium sample prepared without using the method; Figure 3 An SEM microstructure diagram of a pure rhenium rolled plate sample in Example 1; Figure 4 A schematic diagram of a multiple sample clamping device in Example 2; Figure 5 A phase distribution diagram of a pure rhenium sheet sample in Example 2; Figure 6 An orientation distribution diagram of a pure rhenium sheet sample in Example 2; Figure 7 A pole figure corresponding to the orientation of a pure rhenium sheet sample in Example 2; Figure 8 An SEM microstructure diagram of a pure rhenium ingot sample in Example 3; Figure 9 An SEM microstructure diagram of a deformed pure rhenium ingot sample in Example 3. DETAILED DESCRIPTION

[0017] The technical solutions of the present application will be further described below in combination with specific embodiments and drawings.

[0018] The present application is a preparation method of a high-quality surface pure rhenium sample, which comprises the following steps: Cutting and sampling: according to the size of the high-quality surface pure rhenium sample to be prepared, an electric spark wire cutting device is used to sample the pure rhenium raw material, and the X-axis, Y-axis and Z-axis directions of the sampled pure rhenium sample correspond to the length, width and height directions of the raw material; Sample grinding and polishing: the pure rhenium sample cut in step (1) is ground in sequence on 280#~5000# silicon carbide sandpaper, then rough polished on black damping polishing cloth with W2.0~9.0 diamond polishing paste, and then fine polished on silk polishing cloth with W0.5~1.0 diamond polishing paste. Ultrasonic cleaning: the pure rhenium sample polished in step (2) is placed in a beaker, cleaning agent is added to the beaker, and then the beaker is placed in an ultrasonic instrument for ultrasonic vibration cleaning treatment, and then dried with anhydrous ethanol for standby. Clamping sample: the pure rhenium sample treated in step (3) is clamped and fixed together with a specific sample clamping device, and the sample clamping device can be selected according to the number and shape of the sample. The materials of the fixing clamp and the cathode plate are conducive to avoiding their rapid corrosion or pollution to the etching solution during the electrolytic polishing process of the sample, and affecting the preparation of high-quality surface pure rhenium sample.

[0019] Electrolytic polishing: the pure rhenium sample and sample clamping device clamped in step (4) are fixed in an electrolytic polishing container, and the sample clamping device, cathode plate and positive and negative electrodes of a direct current power supply are connected by wires, then an appropriate amount of prepared acid electrolytic polishing solution is added to the electrolytic polishing container, and after refrigeration, the power is turned on, the voltage of the direct current power supply is adjusted to 50~60V, and the initial current density is adjusted to 0.2~1.2mA / cm 2 When the current density rises to 6.8~11.5mA / cm 2 , the power is turned off, and the sample surface is cleaned with water and anhydrous ethanol; the use of mixed acid, refrigeration and electrolytic voltage and current density adjustment is conducive to accurately controlling the corrosion rate and surface quality of the pure rhenium sample, and avoiding the problems of corrosion pits caused by too fast initial etching and polishing rate and uneven surface quality of the whole sample in the later stage.

[0020] Observation and testing: the pure rhenium sample after electrolytic polishing in step (5) can be used for surface quality inspection, structure observation under an optical microscope or a scanning electron microscope (SEM), and can also be directly used for X-ray diffraction (XRD) analysis or backscattered electron diffraction (EBSD) analysis, etc. The prepared high-quality surface pure rhenium sample has directionality and representativeness.

[0021] As a preferred technical solution: The pure rhenium original sample in step (1) is in a sintered state, a deformed state or an annealed state, etc., and its shape is cylindrical, plate-shaped or flaky, etc.

[0022] The cut pure rhenium sample in step (2) does not need to be cold-mounted or hot-mounted, and can be directly ground and polished with the aid of a clamp or auxiliary tools such as adhesive tape.

[0023] The granularity of each sandpaper and polishing paste in step (2) is gradually reduced, and the grinding and polishing treatment direction is kept perpendicular to the direction of the previous step.

[0024] The cleaning agent in step (3) is acetone or anhydrous ethanol.

[0025] The sample clamping device in step (4) includes single and multiple clamping devices, and the multiple clamping device can ensure that each sample is in the same state in the electrolyte. The material used is molybdenum alloy with excellent stability and corrosion resistance in acidic corrosive media, such as Figure 1

[0026] The cathode plate material in step (5) is stainless steel, titanium alloy, zirconium alloy or molybdenum alloy, etc.

[0027] The liquid level of the acidic electrolytic polishing solution added in the electrolytic polishing container in step (5) must be higher than the height of the pure rhenium sample in the container. The electrolytic polishing solution is a mixed solution of 5-20 Vol.% perchloric acid, 2-10 Vol.% methanol and 70-93 Vol.% anhydrous ethanol The refrigeration treatment in step (5) can use liquid nitrogen refrigeration, subzero water chiller refrigeration, thermoelectric material refrigeration, etc., and the minimum refrigeration temperature is -90℃.

[0028] In step (6), the surface scratches, polishing marks and other defects of the high-quality pure rhenium sample are not visible, and the EBSD resolution is excellent, with an average of more than 99%.

[0029] Example 1 A method for preparing a high-quality surface pure rhenium sample for analyzing the microstructure of cold-rolled pure rhenium plate, comprising the following steps: Cutting and sampling: using a wire spark cutting device to sample the middle part of the cold-rolled pure rhenium plate, the size of the pure rhenium sample is 10*8*1mm, and the X, Y and Z axes correspond to the rolling direction, transverse direction and normal direction of the original material, respectively. Sample grinding and polishing: the cuboid pure rhenium sample cut in step (1) is directly ground on 280#, 800#, 1500#, 2000#, 3000# and 5000# silicon carbide sandpaper, at a speed of 300 revolutions / min, then rough polished on black damping polishing cloth with W9.0 and W3.0 diamond polishing paste, and then fine polished on silk polishing cloth with W1.0 and W0.5 diamond polishing paste, at a speed of 600 revolutions / min. The grinding and polishing treatment direction is kept perpendicular to the direction of the previous step.

[0030] ​Ultrasonic cleaning: the pure rhenium sample after polishing in step (2) is placed in a beaker, anhydrous ethanol is added to the beaker, and then the beaker is placed on an ultrasonic instrument for ultrasonic vibration, followed by drying with anhydrous ethanol for standby; Clamping sample: the pure rhenium sample after treatment in step (3) is clamped, and is fixed with a molybdenum alloy sample clamping device of formula (I) Figure 1 Electrolytic polishing: the clamped pure rhenium sample and sample clamping device in step (4) are fixed in an electrolytic polishing container, and the sample clamping device, titanium alloy cathode plate and positive and negative poles of a direct current power supply are connected by wires respectively, then 200mL of acid electrolytic polishing solution of 10Vol.% perchloric acid, 5Vol.% methanol and 85Vol.% anhydrous ethanol is added to a 250mL beaker, liquid nitrogen is used for cooling to-80℃, the power supply is turned on, the voltage of the direct current power supply is adjusted to 50V, and the initial current density is adjusted to 0.4mA / cm 2 When the current density rises to 8.0mA / cm 2 , the power supply is turned off, and the sample surface is cleaned with water and anhydrous ethanol; Observation test: the pure rhenium sample after electrolytic polishing in step (5) is observed by SEM microstructure, and the prepared high-quality surface pure rhenium sample can overcome the surface scratches, polishing marks and other defects shown in Figure 2 , and the SEM morphology of the cold-rolled deformed rhenium plate sample shown in Figure 3 has no obvious visible polishing marks, and the grain size is between 2-200μm.

[0031] Example 2 A method for preparing a high-quality surface pure rhenium sample is used for analyzing the orientation uniformity and texture of an annealed rhenium sheet, and the method comprises the following steps: Cutting and sampling: the edge, middle and 1 / 4 positions of the pure rhenium sheet after annealing treatment are sampled by using an electric spark wire cutting device, the size of the pure rhenium sample is 9*7*0.6mm, and the X axis, Y axis and Z axis directions of all samples correspond to the rolling direction, transverse direction and normal direction of the original rhenium sheet respectively; Sample grinding and polishing: the cuboid pure rhenium sample after cutting in step (1) is directly ground and polished on 320#, 600#, 1200#, 2000#, 3000# and 5000# silicon carbide sandpaper in sequence, the rotation speed is strictly controlled at 320r / min, then W6.0 and W2.5 diamond polishing paste is used for rough polishing on black damping polishing cloth, and then W1.0 and W0.5 diamond polishing paste is used for fine polishing on silk polishing cloth, and the rotation speed is 580r / min; the grinding and polishing directions are perpendicular to the previous direction.

[0032] ​Ultrasonic cleaning: the pure rhenium sample after polishing in step (2) is placed in a beaker, and acetone is added to the beaker, then the beaker is placed on an ultrasonic instrument for ultrasonic vibration, and then the sample is dried with anhydrous ethanol for standby; Clamping sample: the pure rhenium sample after step (3) is clamped, and the sample is fixed with a plurality of molybdenum alloy samples of formula (I) in a sample clamping device; Figure 4 Electrolytic polishing: the pure rhenium sample and the sample clamping device clamped in step (4) are fixed in a beaker, and the sample clamping device, a stainless steel cathode plate and the positive and negative poles of a direct current power supply are connected by wires, respectively, then 500 mL of an acidic electrolytic polishing solution of 15 Vol.% perchloric acid, 3 Vol.% methanol and 82 Vol.% anhydrous ethanol is added to a 20*8*5 cm electrolytic polishing container, liquid nitrogen is used for cooling to-85℃, the power supply is turned on, the voltage of the direct current power supply is adjusted to 60 V, and the initial current density is adjusted to 0.3 mA / cm 2 When the current density rises to 9.5 mA / cm 2 , the power supply is turned off, and the sample surface is cleaned with water and anhydrous ethanol; Observation test: the pure rhenium sample after electrolytic polishing in step (5) is subjected to SEM EBSD analysis, and the EBSD analysis rate is 99.5%, the phase distribution diagram, the orientation distribution diagram and the pole figure are shown in Figures 5-7 , and the results show that the phase structure of the pure rhenium sample is calibrated as HCP-Re, the preferred orientation of the sample is <0001> / / ND, and the pole figure shows a double-peak basal plane texture.

[0033] Example 3 A method for preparing a high-quality surface pure rhenium sample for analyzing the micro indentation loading deformation analysis of an electron beam melted rhenium ingot, which specifically comprises the following steps: Cutting and sampling: the middle position of a pure rhenium button ingot treated by electron beam melting is sampled by using an electric spark wire cutting equipment, the size of the pure rhenium sample is 10*6*1.5 mm, and the X axis, Y axis and Z axis directions of all samples correspond to the radial direction, tangential direction and normal direction of the original rhenium sheet, respectively; Sample grinding and polishing: the cuboid pure rhenium sample after cutting in step (1) is directly ground and polished on 180#, 400#, 1000#, 1500#, 2500# and 5000# silicon carbide sandpaper at a speed of 280 revolutions / min, then rough polishing is performed on black damping polishing cloth with W5.0 and W2.5 diamond polishing paste, and then fine polishing is performed on silk polishing cloth with W1.0 and W0.5 diamond polishing paste at a speed of 590 revolutions / min; the grinding and polishing directions are perpendicular to the previous direction.

[0034] ​Ultrasonic cleaning: the pure rhenium sample after polishing in step (2) is placed in a beaker, and acetone is added into the beaker, and then the beaker is placed on an ultrasonic instrument for ultrasonic vibration, and then the sample is dried with anhydrous ethanol for standby; Clamping sample: the pure rhenium sample after treatment in step (3) is clamped, and the sample is fixed with the single type molybdenum alloy sample clamping device; Electrolytic polishing: the pure rhenium sample and the sample clamping device clamped in step (4) are fixed in a beaker, and the sample clamping device, the zirconium alloy cathode plate and the positive and negative poles of the direct current power supply are connected by wires, then 220 mL of the prepared 10 Vol.% perchloric acid, 2 Vol.% methanol and 88 Vol.% anhydrous ethanol acid electrolytic polishing solution is added into a 300 mL beaker, the temperature is lowered to-78℃ by using liquid nitrogen, the power supply is turned on, the voltage of the direct current power supply is adjusted to 52 V, the initial current density is adjusted to 0.25 mA / cm 2 , and electrolytic polishing is carried out, and when the current density rises to 7.8 mA / cm 2 , the power supply is turned off, and the sample surface is cleaned with water and anhydrous ethanol; Observation test: the pure rhenium sample after electrolytic polishing in step (5) is subjected to micro indentation loading test, and the sample before and after deformation is analyzed by SEM, as shown in Figures 8-9 , it can be observed from the figure that the surface quality of the rhenium ingot after electrolytic polishing is excellent without visible polishing marks, and the sliding and twinning system interaction traces in the deformed sample grain are clearly visible.

[0035] The above examples are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A method for producing a high-quality surface pure rhenium sample, characterized by, The preparation method specifically comprises the following steps: S1) cutting and sampling: cutting and sampling the pure rhenium raw material according to the size of the pure rhenium sample required to prepare a high-quality surface, grinding and polishing and ultrasonic vibration cleaning, thereby obtaining the required sample; S2) electrolytic polishing: fixing the sample obtained in S1) with a clamping device, placing it in an acidic electrolytic polishing solution, and performing refrigeration treatment; S3) connecting the positive and negative electrodes, connecting the power supply, and performing electrolytic polishing treatment when the direct current power supply voltage is adjusted to a certain value and the initial current density is adjusted to a certain value, and then closing the power supply and cleaning the sample surface with water and anhydrous ethanol. Thus, a high-quality surface pure rhenium sample is obtained.

2. The preparation method of claim 1, wherein the specific process in S1) is: S1.1) using an electric spark wire cutting device to sample the pure rhenium raw material, and the X-axis, Y-axis and Z-axis directions of the sampled pure rhenium sample correspond to the length, width and height directions of the raw material; S1.2) sequentially grinding the sample cut in S1.1) on 280#-5000# silicon carbide sandpaper, then performing rough polishing treatment on the black damping polishing cloth with W2.0-9.0 diamond polishing paste, and then performing fine polishing treatment on the silk velvet polishing cloth with W0.5-1.0 diamond polishing paste; S1.3) placing the polished sample in S1.2) in a beaker, adding a cleaning agent to the beaker, and then placing the beaker in an ultrasonic instrument for ultrasonic vibration cleaning treatment, and then blowing dry with anhydrous ethanol for standby.

3. The preparation method according to claim 1, characterized in that, The pure rhenium raw sample is in a sintered state, a deformed state or an annealed state; and the shape is cylindrical, plate-shaped or flaky.

4. The production method according to claim 2, characterized by, The direction of each treatment in S1.2) is perpendicular to the direction of the previous pass. The cleaning agent is acetone or anhydrous ethanol.

5. The preparation method according to claim 1, characterized in that, The material of the fixing clamp in S2) is molybdenum alloy; The electrolytic polishing solution comprises 5-20 Vol.% of perchloric acid, 2-10 Vol.% of methanol and 5-20 Vol.% of 70-93 Vol.% of anhydrous ethanol based on the total volume; The temperature of the refrigeration treatment is ≥-90℃.

6. The production method according to claim 5, wherein The refrigeration treatment is performed using liquid nitrogen, a subzero water-cooled refrigerator or a thermoelectric material.

7. The preparation method according to claim 1, characterized in that, The direct current power voltage in the S3) is adjusted to 50-60V, and the initial current density is adjusted to 0.2-1.2mA / cm 2 The electrolytic polishing treatment is performed, and when the current density rises to 6.8-11.5mA / cm 2 , the power is turned off.

8. The method of claim 1, wherein, The material of the cathode plate in S3) is stainless steel, titanium alloy, zirconium alloy or molybdenum alloy.

9. The method of claim 1, wherein, The EBSD analysis rate of the high-quality surface pure rhenium sample obtained by the preparation method is averagely above 99%.

10. A high-quality surface pure rhenium sample, characterized by, The high-quality surface pure rhenium sample is prepared by the preparation method of any one of claims 1-9.

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