Preparation method of zirconium alloy sample

Abstract

The invention discloses a preparation method of a zirconium alloy sample, which specifically comprises the following steps: acquiring an irradiated zirconium alloy sample; embedding and curing the zirconium alloy sample; grinding and polishing the inlaid and cured zirconium alloy sample; and based on the first etching solution and the second etching solution, the polished zirconium alloy sample is etched, and the zirconium alloy sample is obtained after drying. Different mixed acids are prepared for etching in two steps, a fine structure of a material is subjected to deeper treatment, detail display is enhanced, fine features in crystal grains are exposed, the surface cleanliness and the observable effect are improved, and the display definition of the morphology of the zirconium alloy crystal grains after etching is completed is ensured.

Description

Technical Field

[0001] The present application relates to the field of nuclear fuel technology, and in particular to a method for preparing a zirconium alloy sample. Background Art

[0002] In the research and application of zirconium alloys, it is necessary to etch out the internal organizational structure of the zirconium alloy, observe and analyze its microstructure type, obtain the orientation information between the grains of the sample, and the distribution of various oriented grains in the microstructure. In the related art, electrolytic etching is usually used to obtain zirconium alloy grain morphology samples. However, electrolytic etching requires special equipment and electrolytes, and has high requirements for the control of current, electrolyte concentration and other parameters, which increases the complexity and cost of the experiment. In addition, the degree of electrolytic etching is difficult to control, which is prone to uneven etching, affecting the subsequent observation of grain morphology. Summary of the invention

[0003] In view of this, the present application provides a method for preparing a zirconium alloy sample, the main purpose of which is to solve the technical problems of the electrolytic etching method used in the prior art, which is complicated in experiment, high in cost, difficult to control the degree of electrolytic etching, prone to uneven etching, and affecting the subsequent observation of grain morphology.

[0004] According to the first aspect of the present application, a method for preparing a zirconium alloy sample is provided, the method comprising:

[0005] Obtaining an irradiated zirconium alloy sample;

[0006] The zirconium alloy samples were inlaid and solidified;

[0007] Grinding and polishing the zirconium alloy samples after mounting and solidification;

[0008] The polished zirconium alloy sample is etched based on the first etching solution and the second etching solution, and the zirconium alloy specimen is obtained after drying.

[0009] Optionally, the step of inlaying and curing the zirconium alloy sample specifically includes:

[0010] The zirconium alloy sample is placed in a mold sleeve of preset specifications;

[0011] Epoxy resin was poured into the mold sleeve so that the zirconium alloy sample was immersed in the epoxy resin for curing.

[0012] Optionally, the step of grinding and polishing the embedded and solidified zirconium alloy sample specifically includes:

[0013] The surface of the zirconium alloy sample is ground using a plurality of grinding discs with preset roughness;

[0014] The surface of the ground zirconium alloy sample was polished using a polishing disk.

[0015] Optionally, the step of etching the polished zirconium alloy sample based on the first etching solution and the second etching solution, and obtaining a zirconium alloy sample with a grain morphology after drying, specifically includes:

[0016] The polished zirconium alloy sample is wiped with a first etching solution and etched for a first etching time;

[0017] Rinse the etched zirconium alloy sample with clean water;

[0018] The rinsed zirconium alloy sample is wiped with a second etching solution, and is etched for a second etching time;

[0019] The etched zirconium alloy sample is rinsed with clean water and dried to obtain a zirconium alloy specimen.

[0020] Optionally, the method further comprises:

[0021] Hydrogen fluoride, sulfuric acid, nitric acid and deionized water are mixed according to a first preset volume ratio to prepare a first etching solution.

[0022] Optionally, the method further comprises:

[0023] The hydrogen fluoride, nitric acid and deionized water are mixed according to a second preset volume ratio to prepare a second etching solution.

[0024] Optionally, the first preset volume ratio is 2:3:6:9; the second preset volume ratio is 2:9:9.

[0025] Optionally, the first etching time ranges from 15 seconds to 20 seconds; the second etching time ranges from 15 seconds to 20 seconds.

[0026] Optionally, the mount curing time is 12 hours.

[0027] Optionally, the plurality of preset roughnesses include 220 mesh, 600 mesh and 1200 mesh.

[0028] By means of the above technical scheme, the present application provides a method for preparing a zirconium alloy sample, specifically, by inlaying and curing the irradiated zirconium alloy sample, mechanical grinding, mechanical polishing, and combining the method of using different etching solutions to perform two chemical etchings, a zirconium alloy grain morphology sample is prepared. The present application prepares different mixed acids for etching in two steps, which processes the fine structure of the material more deeply, strengthens the appearance of details, exposes the subtle features inside the grains, improves the cleanliness and visual effect of the surface, ensures the clarity of the zirconium alloy grain morphology display after etching, and solves the difficulty in displaying the grain size of the zirconium alloy after irradiation. In addition, compared with the preparation method using electrolytic etching in the prior art, it avoids technical problems such as non-conductivity of the zirconium alloy after inlaying and difficulty in electrolytic etching, and is low-cost, simple and fast, and has good economy and practicality.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0031] Figure 1 A schematic flow chart of a method for preparing a zirconium alloy sample provided in an embodiment of the present application is shown;

[0032] Figure 2 A schematic flow chart of another method for preparing a zirconium alloy sample provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0034] The present application embodiment provides a method for preparing a zirconium alloy sample, such as Figure 1 As shown, the method includes:

[0035] S101. Obtain an irradiated zirconium alloy sample.

[0036] The method for preparing the zirconium alloy sample provided in the embodiment of the present application is mainly used in the preparation scenario of the zirconium alloy grain morphology sample after irradiation. Among them, zirconium alloy has excellent nuclear performance, good resistance to high temperature and water vapor corrosion, and is widely used in cladding and grids for nuclear fuel elements. The observation of zirconium alloy grain morphology is an important part of studying the irradiation effect of zirconium alloy, and its results play an important role in studying the performance changes of zirconium alloy in the pile. Therefore, the zirconium alloy after irradiation is cut and sampled to obtain a zirconium alloy sample, which is processed and a sample is prepared to make its grain structure visible, so as to facilitate the subsequent observation of grain morphology.

[0037] S102, inlaying and solidifying the zirconium alloy sample.

[0038] In this step, the sample can be fixed in a supporting material (such as resin) by embedding and curing, which can enhance the mechanical stability of the zirconium alloy sample, making it less likely to break or deform during subsequent processing, and ensuring the integrity and accuracy of the sample. In addition, the cured material can provide a uniform support, so that the sample remains stable during subsequent mechanical processing steps such as grinding. Furthermore, in metallographic microscope analysis, fixing the sample in resin can more clearly observe its structural features and perform more accurate measurements and evaluations.

[0039] S103, grinding and polishing the embedded and solidified zirconium alloy sample.

[0040] In this step, first, a coarse abrasive is used to remove most of the surface unevenness and defects, and secondly, a finer abrasive is used to further smooth the surface and reduce scratches. Finally, an ultra-fine polishing agent and a polishing cloth are used for final polishing to obtain a high-finish surface. During the grinding process, the surface of the zirconium alloy sample can be smoothed to eliminate unevenness and surface irregularities. A flat surface is important for high-precision microscopy observation, surface analysis, and structural research. Furthermore, the zirconium alloy sample is polished to improve the surface finish, thereby improving the surface properties of the material and obtaining a smooth sample surface. The smooth surface can reduce light scattering, making the microscope image clearer, which helps to better analyze the microstructure and characteristics of the material.

[0041] S104, etching the polished zirconium alloy sample based on the first etching solution and the second etching solution, and obtaining a zirconium alloy specimen after drying.

[0042] In this step, the zirconium alloy sample is initially etched using the prepared first etching solution to reveal the main phase and organizational structure of the zirconium alloy, which can reveal the more significant grain boundaries and organizational characteristics in the zirconium alloy. After the initial etching, the zirconium alloy sample is further etched using the prepared second etching solution to further process the fine structure of the material, enhance the appearance of details, expose the fine features inside the grains, and improve the cleanliness and visual effect of the surface. The two etchings can gradually care for the sample through different chemical reactions, increase the selectivity of the grain etching reaction, ensure that the zirconium alloy grain morphology can be clearly observed after etching, and solve the difficulty in displaying the grain size of the zirconium alloy after irradiation.

[0043] The method for preparing a zirconium alloy sample provided in the embodiment of the present application prepares a zirconium alloy grain morphology sample by inlaying and curing, mechanically grinding, and mechanically polishing the irradiated zirconium alloy sample, and combining the method of using different etching solutions to perform two chemical etchings. The present application prepares different mixed acids for etching in two steps, which processes the fine structure of the material more deeply, strengthens the appearance of details, exposes the subtle features inside the grains, improves the cleanliness and visual effect of the surface, ensures the clarity of the zirconium alloy grain morphology display after etching, and solves the difficulty in displaying the grain size of the zirconium alloy after irradiation. In addition, compared with the preparation method using electrolytic etching in the prior art, it avoids technical problems such as non-conductivity of the zirconium alloy after inlaying after irradiation and difficulty in electrolytic etching, and is low-cost, simple and fast, and has good economy and practicality.

[0044] Further, as a refinement and expansion of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, the embodiment of this application provides another method for preparing a zirconium alloy sample, such as Figure 2 As shown, the method includes:

[0045] S201. Obtain an irradiated zirconium alloy sample.

[0046] This step and Figure 1 The method of step S101 shown is the same and will not be repeated here.

[0047] S202, placing the zirconium alloy sample into a mold sleeve of preset specifications.

[0048] S203, pouring epoxy resin into the mold sleeve, so that the zirconium alloy sample is immersed in the epoxy resin for curing.

[0049] In steps S202 and S203, a mold sleeve of suitable specifications is pre-selected, and the zirconium alloy sample is placed in the mold sleeve, ensuring that the surface of the sample is kept at a certain distance from the inner wall of the mold sleeve so that the epoxy resin can be completely covered. Thereafter, the epoxy resin is slowly poured into the mold sleeve along the wall of the mold sleeve to ensure that the epoxy resin can completely cover the zirconium alloy sample. The mold sleeve containing the epoxy resin and the zirconium alloy sample is left to cure. When the curing time is reached, it is checked whether the epoxy resin is completely cured. After confirming that the epoxy resin is completely cured, the encapsulation of the zirconium alloy sample is completed.

[0050] Optionally, the preset specifications of the mold sleeve can be determined according to the size of the grinder and polisher, so that the cured sample can be stably fixed in the grinder and polisher to ensure the processing quality. Further, multiple mold sleeves can be prepared in advance, and numbers can be engraved on the outer surface or inner surface of each mold sleeve, and then during the preparation process, multiple samples can be cut at the same time, and each sample can be placed in a numbered mold sleeve for easy observation.

[0051] Optionally, the inlay curing time is 12 hours. Sufficient curing time can ensure that the resin is completely cured, and help to achieve good adhesion between the resin and the zirconium alloy, thereby enhancing the bonding strength, reducing bubbles or unevenness generated during the curing process, and ensuring a smooth surface.

[0052] S204, grinding the surface of the zirconium alloy sample using a plurality of grinding discs with preset roughness.

[0053] S205. Polish the surface of the ground zirconium alloy sample using a polishing disc.

[0054] In steps S204 and S205, grinding discs, polishing discs and polishing agents of different coarseness are prepared in advance, the zirconium alloy sample is fixed on the workbench of the grinding and polishing machine, and a coarser grinding disc (such as 220 mesh) is selected to grind the sample to remove significant defects and irregularities on the surface of the zirconium alloy sample; a finer grinding disc (such as 600 mesh) is selected to further grind the sample to smooth the sample surface and remove the marks left in the rough grinding stage; a finer grinding disc (such as 1200 mesh) is selected to grind to remove fine scratches in the medium grinding stage and further improve the surface finish.

[0055] Further, after grinding is completed, the polishing agent is evenly applied on the polishing disc, and the sample is brought into contact with the polishing disc for uniform polishing to obtain a mirror effect. The surface of the sample is checked. After ensuring that the surface is smooth and uniform without any scratches or flaws, the grinding and polishing operations are completed.

[0056] Optionally, during the step-by-step grinding process, set the grinding parameters (such as grinding and polishing machine speed, pressure and grinding time) corresponding to the coarse, medium and fine grinding steps according to the requirements of the sample, and check the sample surface regularly during the grinding process to ensure the uniformity and fineness of the surface treatment. The clean water needs to be turned on 30 seconds before each polishing, so that the polishing agent of the sample and the polishing disc can be completed by the rotation of the automatic grinding and polishing machine in the last 30 seconds. After polishing, use clean water to thoroughly clean the sample surface to remove the residual polishing agent.

[0057] Optionally, multiple preset roughnesses include 220 mesh, 600 mesh, and 1200 mesh. By setting coarse, medium, and fine grains and preparing grinding discs with different roughnesses, the smoothness and uniformity of the sample surface can be improved layer by layer, the risk of sample damage during the grinding process can be reduced, and the final surface quality of the sample can be ensured.

[0058] In the above manner, the zirconium alloy sample is gradually ground using multiple grinding discs with preset roughness, and then finally polished using a polishing disc, which can effectively remove defects and unevenness on the sample surface and achieve an ideal surface finish.

[0059] In the actual application scenario, a remote-controlled cutting device is used to cut the irradiated zirconium alloy, and the cut samples are transferred to the mounting hot chamber in the hot chamber. In the mounting hot chamber, epoxy resin is used to form samples of fixed size. After the samples are fixed, mechanical grinding and mechanical polishing are carried out in sequence.

[0060] S206, wiping the polished zirconium alloy sample with a first etching solution, and etching for a first etching time.

[0061] S207, rinsing the etched zirconium alloy sample with clean water.

[0062] S208, wiping the rinsed zirconium alloy sample with a second etching solution, and etching for a second etching time.

[0063] S209, rinsing the etched zirconium alloy sample with clean water, and obtaining a zirconium alloy sample after drying.

[0064] In steps S206 to S209, during the irradiation process, due to the influence of irradiation, corrosion, high temperature, etc., the microstructure of the zirconium alloy changes, resulting in changes in performance, and its grains are difficult to display clearly, and there are a large number of corrosion pits. In order to make the zirconium alloy grain morphology clearly displayed and facilitate the subsequent in-depth study of the relationship between the zirconium alloy grain morphology and irradiation performance, the present application proposes a method for step-by-step chemical etching of the zirconium alloy sample using a mixed acid etching solution. Specifically, the first etching solution and the second etching solution are prepared in advance, and the polished zirconium alloy sample is wiped with the first etching solution. To ensure that the sample is etched evenly, the manipulator clamps the medical cotton wool full of etching solution and wipes the sample back and forth in one direction, and etches according to the specified first etching time. After the first etching time is over, the sample is taken out, the etched sample is thoroughly rinsed with clean water, and after removing the etching solution residue on the surface, the zirconium alloy sample is wiped with the second etching solution. To ensure that the sample is etched evenly, the manipulator clamps the medical cotton wool full of etching solution and wipes the sample back and forth in one direction, and etches according to the specified second etching time. After the second etching time is over, take out the sample, rinse the etched sample thoroughly with clean water, remove the etching liquid residue on the surface, dry the sample to ensure that the sample is completely dry, carefully check the surface of the dried zirconium alloy sample to confirm whether the etching effect meets the requirements, whether there are defects or uneven etching areas, and finally obtain the zirconium alloy grain morphology sample.

[0065] Optionally, hydrogen fluoride, sulfuric acid, nitric acid and deionized water are mixed according to a first preset volume ratio to prepare a first etching solution. A composite etching solution with strong etching ability can be formed by mixing hydrogen fluoride (HF), sulfuric acid (HSO) and nitric acid (HNO). In the first step of etching, H2SO4 is added as an etching component to remove rough impurities on the surface, stabilize the acidity of the solution, maintain the chemical stability of the etching solution, avoid the instability of the etching effect caused by the change of acidity, reduce the excessive etching of other acids on specific materials, and improve the processing quality of the sample surface. Further, hydrogen fluoride, nitric acid and deionized water are mixed according to a second preset volume ratio to prepare a second etching solution. Only hydrogen fluoride, nitric acid and deionized water are used to prepare a composite etching solution for secondary etching, and hydrogen fluoride and nitric acid can further refine the etching process. According to the different properties and processing requirements of the materials, the ratio of the two etching solutions is adjusted to make the processing process more adaptable and meet different etching tasks.

[0066] Optionally, the first preset volume ratio is 2:3:6:9, and hydrogen fluoride, sulfuric acid, nitric acid and deionized water are prepared in a volume ratio of 2:3:6:9 to prepare a first etching solution. This can combine the strong corrosiveness of hydrogen fluoride, the removal ability of sulfuric acid and the dissolving ability of nitric acid. At an appropriate dilution level, the ratio of the three acids can accelerate the etching process and improve processing efficiency. At the same time, the relatively low hydrogen fluoride concentration helps to reduce excessive etching of the metal substrate and ensure the selectivity and precision of etching.

[0067] Furthermore, the second preset volume ratio is 2:9:9. The second etching solution is prepared by mixing hydrogen fluoride, nitric acid and deionized water in a volume ratio of 2:9:9. The hydrogen fluoride concentration is relatively high, which is helpful for processing and removing fine surface features, while the proportion of nitric acid helps to further dissolve the metal and reduce damage to the substrate. By finely adjusting the ratio of hydrogen fluoride and nitric acid, a more uniform etching effect can be achieved, and the smoothness of the final surface is improved, thereby improving the overall surface quality of the sample.

[0068] Furthermore, the first etching time ranges from 15 seconds to 20 seconds; the second etching time ranges from 15 seconds to 20 seconds. By setting the time of the initial etching to 15s to 20s, such as 15s, 16s, 18s, etc., it helps to quickly remove the main impurities and oxide layers on the surface without over-etching, thereby preventing unnecessary corrosion to the substrate. Secondly, the time of the second etching is set to 15s to 20s, such as 15s, 16s, 18s, etc., to perform fine processing, ensure further fine cleaning of the surface after the initial etching, avoid over-etching, ensure a more uniform etching process, and avoid uneven etching caused by improper time.

[0069] In the above manner, the sample prepared by the two-step etching method has a smooth surface and no obvious corrosion pits. The grain morphology is clearly visible when observed under the C-DIC circular polarization mode of a metallographic microscope placed in a hot chamber, which can meet the observation requirements of the zirconium alloy grain morphology.

[0070] In actual application scenarios, since the irradiated zirconium alloy has strong radioactivity, all operations of the method for preparing the grain morphology sample of the irradiated zirconium alloy provided in this application are completed by remote control of a manipulator in a hot chamber. The hot chamber operability and grain morphology effect of this method can meet the experimental requirements of observing the grain morphology of zirconium alloys after irradiation. In addition, the entire process is completed in the hot chamber by a manipulator, and the staff does not need to come into close contact with the irradiated zirconium alloy sample, which greatly reduces the exposure dose of the staff. In addition, the manipulator can perform precise positioning and operation, especially when dealing with complex or small samples, to reduce errors caused by human factors and ensure the quality and accuracy of sample preparation.

[0071] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present application.

[0072] The above application serial numbers are for description only and do not represent the advantages or disadvantages of the implementation scenarios.

[0073] The above disclosure only discloses several specific implementation scenarios of the present application. However, the present application is not limited thereto, and any changes that can be conceived by technicians in this field should fall within the scope of protection of the present application.

Claims

1. A method for preparing a zirconium alloy sample, characterized in that: include: Obtaining an irradiated zirconium alloy sample; Performing inlay curing on the zirconium alloy sample; Grinding and polishing the zirconium alloy samples after mounting and solidification; The polished zirconium alloy sample is etched based on the first etching solution and the second etching solution, and the zirconium alloy specimen is obtained after drying.

2. The method according to claim 1, characterized in that The step of inlaying and curing the zirconium alloy sample specifically includes: placing the zirconium alloy sample into a mold sleeve of preset specifications; Epoxy resin is poured into the mold sleeve so that the zirconium alloy sample is immersed in the epoxy resin for curing.

3. The method according to claim 1, characterized in that: The step of grinding and polishing the embedded and solidified zirconium alloy sample specifically includes: Grinding the surface of the zirconium alloy sample using a plurality of grinding discs with preset roughness; The ground surface of the zirconium alloy sample is polished using a polishing disk.

4. The method according to claim 1, characterized in that: The step of etching the polished zirconium alloy sample based on the first etching solution and the second etching solution, and obtaining the zirconium alloy sample with grain morphology after drying, specifically comprises: The polished zirconium alloy sample is wiped with the first etching solution and etched for a first etching time; Rinse the etched zirconium alloy sample with clean water; Wiping the rinsed zirconium alloy sample with the second etching solution, and etching for a second etching time; The etched zirconium alloy sample is rinsed with clean water and dried to obtain the zirconium alloy test sample.

5. The method according to any one of claims 1 to 4, characterized in that Also includes: Hydrogen fluoride, sulfuric acid, nitric acid and deionized water are mixed according to a first preset volume ratio to prepare a first etching solution.

6. The method according to any one of claims 1 to 4, characterized in that Also includes: The hydrogen fluoride, nitric acid and deionized water are mixed according to a second preset volume ratio to prepare a second etching solution.

7. The method according to any one of claims 1 to 4, characterized in that The first preset volume ratio is 2:3:6:9; The second preset volume ratio is 2:9:

9.

8. The method according to any one of claims 1 to 4, characterized in that The first etching time ranges from 15 seconds to 20 seconds; The second etching time ranges from 15 seconds to 20 seconds.

9. The method according to any one of claims 1 to 4, characterized in that The setting time for the mount is 12 hours.

10. The method according to any one of claims 1 to 4, characterized in that Multiple preset roughnesses include 220 mesh, 600 mesh, and 1200 mesh.

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