Metallographic composite material, preparation method and application thereof

Abstract

This invention relates to the field of materials preparation, and discloses a metallographic replica material, its preparation method, and its applications. The metallographic replica material contains polyvinyl alcohol, a plasticizer, and a dye. The raw materials used in the metallographic replica material, such as polyvinyl alcohol and plasticizer, are all environmentally friendly chemicals, and no organic solvents are used in the preparation process. This makes the preparation process more environmentally friendly and operator-friendly, and it has great potential for industrial applications.

Description

Technical Field

[0001] This invention relates to the field of materials preparation, specifically to a metallographic replica material, its preparation method, and its application. Background Technology

[0002] Metallographic examination is a widely used material testing method, commonly used in fields such as evaluating the safety condition of industrial metal equipment or components. Metallographic examination methods can involve direct observation using a metallographic microscope or sampling using metallographic film techniques followed by microscopic examination.

[0003] On-site metallographic replication technology is a replication technique that involves bonding a pre-made metallographic replica material to the metallographic test sample to obtain the microstructure of the component's metal. As a non-destructive metallographic analysis technique, it is suitable for testing in situations where destructive sampling is not allowed, portable metallographic microscopes are difficult to place and carry, and it is necessary to observe and photograph a local area of ​​the test sample.

[0004] Currently, the commonly used metallographic replica material is AC paper, which is made by dissolving methyl violet, cellulose diacetate, and triphenyl phosphate in acetone. Acetone, the solvent used, is a precursor chemical and is subject to public security control, resulting in long procurement and supply cycles, strict control, and complex procedures. Furthermore, acetone is irritating to human skin and poses a threat to the health of testing personnel. All of these factors significantly complicate on-site metallographic testing and severely impact its progress. Therefore, there is an urgent need to research and develop a new, safe, and environmentally friendly metallographic replica material for on-site metallographic testing. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing metallographic replica materials, such as the use of controlled raw materials in the solvents and the adverse effects of organic solvents on human health and the environment. This invention provides a metallographic replica material, its preparation method, and its application. The raw materials used in the metallographic replica material, such as polyvinyl alcohol and glycerin, are all green and environmentally friendly chemicals. Furthermore, no organic solvents are used in the preparation process, making the preparation process more environmentally friendly and operator-friendly, and it has great potential for industrial application.

[0006] To achieve the above objectives, the present invention provides a metallographic replica material containing polyvinyl alcohol, a plasticizer, and a dye.

[0007] Preferably, the plasticizer is glycerol and / or ethylene glycol.

[0008] Preferably, the staining agent is methyl violet.

[0009] Preferably, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 35-200:2-13:1.

[0010] Preferably, the degree of alcoholysis of the polyvinyl alcohol is 85-90%.

[0011] Preferably, the degree of polymerization of the polyvinyl alcohol is 1600-2000.

[0012] The second aspect of the present invention provides a method for preparing the metallographic replica material, the method comprising: mixing polyvinyl alcohol, plasticizer, dye and water under stirring conditions, followed by heat treatment, cooling and standing, and then spreading and drying.

[0013] Preferably, the temperature of the heat treatment is 80-95°C.

[0014] Preferably, the drying conditions include a temperature of 50-70°C and a time of 4-8 hours.

[0015] Preferably, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 35-200:2-13:1.

[0016] A third aspect of the present invention provides an application of the above-described metallographic replica material or the metallographic replica material obtained by the above preparation method in metallographic inspection.

[0017] The metallographic replica material described in this invention is green and environmentally friendly, causing no pollution to the environment. Furthermore, when the metallographic replica material is used for on-site metallographic film lamination, it does not affect the clarity of the metallographic structure display. The images obtained during subsequent metallographic testing can clearly display the group characteristics.

[0018] Furthermore, the preparation method of the metallographic replica material described in this invention does not use any organic solvents harmful to humans and the environment. The solvent used is water, which is convenient to handle and carry during the preparation process, and poses no risk of leakage, environmental pollution, or fire. It is more environmentally friendly and poses no threat to the health of operators during on-site metallographic testing. Moreover, the polyvinyl alcohol used in this invention is a biodegradable polymer material that can be degraded by bacteria and enzymes in the natural environment, making it even more environmentally friendly and causing no pollution. The plasticizer used in this invention is also a green and environmentally friendly raw material. Neither the raw materials nor the preparation method of the metallographic replica material use any substances harmful to the environment or operators, and the raw materials are simple and readily available. The preparation process is simple and has great potential for industrial application. Attached Figure Description

[0019] Figure 1 These are photographs taken during metallographic testing of the metallographic replica material prepared in Example 1 of this invention;

[0020] Figure 2 These are photographs taken during metallographic testing of the metallographic replica material prepared in Example 2 of this invention;

[0021] Figure 3 These are photographs taken during metallographic testing of the metallographic replica material prepared in Example 3 of this invention;

[0022] Figure 4 These are photographs taken during metallographic testing of the metallographic replica material prepared in Example 4 of this invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] In this invention, the degree of alcoholysis refers to the percentage of hydroxyl groups in the product obtained after the alcoholysis of organic matter; the degree of polymerization refers to the number of consecutive repeating units in the polymer molecular chain, which is used to measure the size of polymer molecules.

[0026] The metallographic replica material of the present invention contains polyvinyl alcohol, plasticizer and dye.

[0027] In existing technologies, the film-forming materials commonly used in metallographic replica materials are mainly cellulose diacetate and triphenyl phosphate, or other polymeric materials that are difficult to degrade. These materials can easily cause further environmental pollution after metallographic testing, and recycling is complex, requiring significant manpower and financial resources. However, the metallographic replica material in this invention is environmentally friendly and harmless to the human body, allowing for effective and safe contact with human skin. Its main film-forming material is polyvinyl alcohol, which can be degraded and removed after subsequent use, without causing environmental pollution. Furthermore, the metallographic replica material, while being environmentally friendly, still provides high testing accuracy, demonstrating significant potential for industrial applications.

[0028] In this invention, polyvinyl alcohol is the main film-forming material of the metallographic replica material. It is a biodegradable polymer material, which is more green and environmentally friendly and will not cause environmental pollution. It will not affect the clarity of the image obtained during subsequent metallographic testing and will not have an adverse effect on metallographic testing.

[0029] In this invention, the plasticizer is used to increase the toughness of the metallographic replica material, improve the film-forming properties of polyvinyl alcohol, and reduce cracks and bubbles generated during the film-forming process. It can be a plasticizer commonly used in the art for plasticizing polyvinyl alcohol.

[0030] In a preferred embodiment, to further ensure the green and environmentally friendly composition of the metallographic replica material, the plasticizer is glycerin and / or ethylene glycol, and more preferably glycerin.

[0031] In this invention, the dye is used to increase the contrast of the metallographic replica material.

[0032] In a preferred embodiment, the staining agent is methyl violet.

[0033] In this invention, by further controlling the amount of polyvinyl alcohol, plasticizer and dye, the metallographic replica material can be better applied to metallographic film technology, thereby further improving the detection accuracy of metallographic detection and making the images obtained by subsequent metallographic detection clearer.

[0034] In a preferred embodiment, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 35-200:2-13:1.

[0035] In a more preferred embodiment, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 50-180:3-10:1.

[0036] In a further preferred embodiment, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 70-170:4-9:1.

[0037] In a further preferred embodiment, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 70-160:4-9:1.

[0038] In this invention, to further enable the metallographic replica material to be better applied to metallographic film technology and improve the accuracy of metallographic detection, the degree of hydrolysis of the polyvinyl alcohol is controlled to be 85-90%. Specifically, the degree of hydrolysis of the polyvinyl alcohol can be 85%, 86%, 87%, 88%, 89%, or 90%.

[0039] In this invention, to further enable the metallographic replica material to be better applied to metallographic film technology and improve the accuracy of metallographic detection, the degree of polymerization of the polyvinyl alcohol is controlled to be 1600-2000, preferably 1700-1900. Specifically, the degree of polymerization of the polyvinyl alcohol can be 1700, 1800, or 1900.

[0040] The present invention further provides a method for preparing the metallographic replica material, the method comprising: mixing polyvinyl alcohol, plasticizer, dye and water under stirring conditions, followed by heat treatment, cooling and standing, and then spreading and drying.

[0041] The raw materials used in the preparation of the metallographic replica material described in this invention are all green and environmentally friendly materials, which can be conveniently and quickly purchased through commercial channels without the need for public security bureau registration. This overcomes the problem of the difficulty in purchasing acetone solvent and other materials used in the prior art. Furthermore, water is used as a solvent in the preparation process of the method described in this invention, and no organic solvents are used. The raw materials are simple and readily available, and there are no safety hazards to the environment or operators, making it easy to carry out large-scale applications.

[0042] In specific embodiments, the stirring conditions and the stirring apparatus are not limited. For example, the stirring can be any of the following: glass rod stirring, magnetic stirring, or mechanical stirring; the stirring temperature is 25-30°C; and stirring is stopped after all raw materials are completely dissolved.

[0043] In a specific implementation, to ensure complete dissolution of polyvinyl alcohol in water, the mixed materials are subjected to heat treatment. After mixing polyvinyl alcohol, plasticizer, and dye with water, heating is immediately initiated to raise the material temperature to the heat treatment temperature.

[0044] In a preferred embodiment, the heat treatment temperature is 80-95°C. Specifically, the heat treatment temperature can be 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, or 95°C.

[0045] In this invention, the heat treatment time is not limited during the heat treatment process; it is only necessary to ensure that all raw materials are fully dissolved in water through heat treatment.

[0046] In a preferred embodiment, to ensure the complete dissolution of the raw materials, the heat treatment time is limited to 2-4 hours.

[0047] In a specific implementation, the heat-treated material is cooled to room temperature (25°C) and then left to stand until all air bubbles in the material disappear.

[0048] In a preferred embodiment, the settling time is ≥24h, for example, it can be 24-30h.

[0049] In a specific implementation, the flat drying process includes: spreading the solution after the static treatment is completed on a clean, scratch-free glass plate, and then covering the glass plate with a container to allow it to air dry naturally to obtain the metallographic replica material.

[0050] In a preferred embodiment, to further reduce the drying time, the drying temperature is set to 50-70°C, and the drying time is set to 4-8 hours. Specifically, the drying temperature can be 50°C, 55°C, 60°C, 65°C, or 70°C; and the drying time can be 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0051] In this invention, in order to further improve the accuracy of the prepared metallographic replica material in subsequent metallographic testing and to better apply it to metallographic testing, the weight ratio of polyvinyl alcohol, plasticizer and dye is limited to 35-200:2-13:1, preferably 50-180:3-10:1, more preferably 70-170:4-9:1, and even more preferably 70-160:4-9:1.

[0052] In a preferred embodiment, after mixing polyvinyl alcohol, plasticizer, dyeing agent, and water, the concentration of polyvinyl alcohol in the mixture is controlled to be 50-160 g / L, preferably 100-150 g / L. Specifically, the concentration of polyvinyl alcohol can be 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, or 160 g / L.

[0053] In a preferred embodiment, after mixing polyvinyl alcohol, plasticizer, dyeing agent, and water, the concentration of the plasticizer in the mixture is controlled to be 3-10 g / L. Specifically, the concentration of the plasticizer can be 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, or 10 g / L.

[0054] In a preferred embodiment, after mixing polyvinyl alcohol, plasticizer, dye, and water, the concentration of the dye in the mixture is controlled to be 0.8-1.4 g / L. Specifically, the concentration of the dye can be 0.8 g / L, 0.9 g / L, 1 g / L, 1.1 g / L, 1.2 g / L, 1.3 g / L, or 1.4 g / L.

[0055] In a specific implementation, after the dried metallographic replica material is removed from the glass plate, it is cut into rectangular films with a length of 3-4 cm and a width of 1.5-2 cm for later use.

[0056] The present invention also provides an application of the above-mentioned metallographic replica material or the metallographic replica material obtained by the above preparation method in metallographic inspection.

[0057] The present invention further provides a metallographic testing method, the method comprising the following steps:

[0058] (1) The surface of the test component is successively ground, polished, etched, cleaned and dried;

[0059] (2) Wet the treated surface with water, then cover the wetted surface with the metallographic replica material, remove air bubbles, and then dry it;

[0060] (3) Remove the dried metallographic replica material and examine it under a metallographic microscope.

[0061] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0062] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0063] Example 1

[0064] Add 500 mL of purified water to a beaker equipped with a stirrer. While stirring at room temperature (25°C), add 75 g of polyvinyl alcohol (degree of polymerization 1700, degree of hydrolysis 88%), 4 g of glycerol, and 0.5 g of methyl violet. Then, begin heat treatment at 95°C. Stir until the raw materials are completely dissolved, then stop stirring and heat treatment. Cool to room temperature (25°C). Let stand for 24 hours until the bubbles completely disappear. Spread the solution evenly on a clean, scratch-free glass plate. Cover the glass plate with a container and dry at 60°C for 6 hours. After drying, the metallographic replica material is obtained.

[0065] Example 2

[0066] Add 500 mL of purified water to a beaker equipped with a stirrer. While stirring at room temperature (25°C), add 80 g of polyvinyl alcohol (degree of polymerization 1700, degree of hydrolysis 88%), 5 g of glycerol, and 0.6 g of methyl violet. Then, begin heat treatment at 90°C. Stir until the raw materials are completely dissolved, then stop stirring and heat treatment. Cool to room temperature (25°C). Let stand for 24 hours until the bubbles completely disappear. Spread the solution evenly on a clean, scratch-free glass plate. Cover the glass plate with a container and dry at 60°C for 6 hours. After drying, the metallographic replica material is obtained.

[0067] Example 3

[0068] Add 500 mL of purified water to a beaker equipped with a stirrer. While stirring at room temperature (25°C), add 50 g of polyvinyl alcohol (degree of polymerization 1700, degree of hydrolysis 88%), 3 g of glycerol, and 0.7 g of methyl violet. Then, begin heat treatment at 85°C. Stir until the raw materials are completely dissolved, then stop stirring and heat treatment. Cool to room temperature (25°C). Let stand for 24 hours until the bubbles completely disappear. Spread the solution evenly on a clean, scratch-free glass plate. Cover the glass plate with a container and dry at 60°C for 6 hours. After drying, the metallographic replica material is obtained.

[0069] Example 4

[0070] Add 500 mL of purified water to a beaker equipped with a stirrer. While stirring at 25 °C, add 15 g of polyvinyl alcohol (degree of polymerization 1700, degree of hydrolysis 88%), 4 g of glycerol, and 0.5 g of methyl violet. Then, begin heat treatment at 95 °C. Stir until the raw materials are completely dissolved, then stop stirring and heat treatment, and cool to 25 °C. Let stand for 24 hours until the bubbles completely disappear. Spread the solution evenly on a clean, scratch-free glass plate, then cover the glass plate with a container and dry at 60 °C for 6 hours. After drying, the metallographic replica material is obtained.

[0071] Test case

[0072] The metallographic replica materials prepared in Examples 1-4 were cut into rectangular films with a length of 3cm and a width of 2cm. Metallographic film technology was used to conduct metallographic inspection on local parts of the heat-resistant steel (12Cr1MoVG) pipe.

[0073] Test method: The surface of the test component is successively ground, polished, etched with a 4% nitric acid alcohol solution, cleaned and dried; the treated surface of the test component is moistened with water, and then the metallographic replica is used to cover the moistened surface to remove air bubbles in the metallographic replica material, and then allowed to dry naturally; after drying, the metallographic replica material is peeled off with tweezers and then observed and photographed under a metallographic microscope.

[0074] Figure 1 The images are metallographic images obtained from the metallographic replica material prepared in Example 1. Figure 2 The images are metallographic images obtained from the metallographic replica material prepared in Example 2. Figure 3 The images shown are metallographic images obtained from the metallographic replica material prepared in Example 3. Figure 4 The image shown is a metallographic image obtained from the metallographic replica material prepared in Example 4. It contains many white spots, which affects the image clarity.

[0075] pass Figure 1-3The results show that the metallographic replica material described in this invention can be well applied to metallographic testing, and the obtained images are clear. Moreover, the raw materials used in the preparation process are green and environmentally friendly. Water is used as a solvent in the preparation process, and no organic solvents are used, which has a very broad application prospect.

[0076] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A metallographic replica material, characterized in that, The metallographic replica material contains polyvinyl alcohol, plasticizer, and dye; the plasticizer is glycerol and / or ethylene glycol, the weight ratio of polyvinyl alcohol, plasticizer, and dye is 35-200:2-13:1, the degree of alcoholysis of polyvinyl alcohol is 85-90%, and the degree of polymerization of polyvinyl alcohol is 1600-1800. The preparation method of the metallographic replica material includes: mixing polyvinyl alcohol, plasticizer, dye and water under stirring conditions, then heat treatment, cooling and standing, and then flat drying. In the mixture obtained by mixing polyvinyl alcohol, plasticizer, dye and water, the concentration of polyvinyl alcohol is 100-160 g / L.

2. The metallographic replica material according to claim 1, characterized in that, The staining agent is methyl violet.

3. The metallographic replica material according to claim 1, characterized in that, The heat treatment temperature is 80-95℃.

4. The metallographic replica material according to claim 1, characterized in that, The drying conditions include: a drying temperature of 50-70℃ and a drying time of 4-8 hours.

5. The application of the metallographic replica material according to any one of claims 1-4 in metallographic inspection.

Images