Preparation method of pure titanium TA2 metallographic specimen for shaped charge liner of shaped charge
Through silicon carbide grinding wheel cutting, cold mounting and multiple polishing and corrosion treatments, the scratch twinning problem in the preparation of pure titanium metallographic samples was solved, and efficient and clear microstructure observation was achieved.
Patent Information
- Application Number
- CN202510654135.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-09-19
AI Technical Summary
In the prior art, it is difficult to effectively remove deformation twins and fine scratches during the preparation of pure titanium metallographic specimens, resulting in unclear microstructure observation.
Silicon carbide grinding wheel cutting and cold mounting are used for mounting, combined with multiple polishing and etching treatments. A etching solution of hydrofluoric acid, nitric acid and distilled water in a specific proportion is used, combined with sandpaper and polishing cloth of different grit sizes to gradually eliminate scratches and twins.
In a short time, pure titanium metallographic specimens without scratches or twins are obtained with clear microstructure, which improves the accuracy of metallographic analysis.
Smart Images
Figure CN120668430A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of metal material microstructure analysis sample preparation, and in particular to a method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner. Background Art
[0002] In recent years, titanium and titanium alloys have been widely used in a wide range of fields, including aerospace, chemical equipment, marine engineering, and medical treatment, due to their excellent properties of high strength, high corrosion resistance, and high heat resistance. To ensure product reliability, titanium and titanium alloys must undergo metallographic examination. During routine metallographic examinations of titanium and titanium alloys, metallographic specimens are prepared by grinding from coarse to fine sandpaper, followed by polishing and etching. Because pure titanium has a single-phase structure and a relatively soft texture, deformation twins and fine scratches produced during metallographic specimen preparation are difficult to eliminate, easily creating artifacts and affecting microstructural observation. Summary of the Invention
[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a simple and efficient method for preparing pure titanium TA2 metallographic specimens for shaped charge liners, aiming to improve the preparation quality of pure titanium TA2 metallographic specimens and thus enhance the accuracy of metallographic analysis.
[0004] In order to achieve the above object, the technical solution adopted in the present invention is: A method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner comprises the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: Mounting the pure titanium TA2 metallographic sample cut in step 1; Step 3: The pure titanium TA2 metallographic specimens inlaid in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine; Step 4: polishing the pure titanium TA2 metallographic sample obtained in step 3, and then corroding it in a corrosive solution for 4-6 seconds; Step 5: Repeat step 4 2-4 times; Step 6: Continue fine polishing and cleaning the pure titanium TA2 metallographic sample surface processed in step 5; Step 7: The pure titanium TA2 metallographic specimen finely polished and cleaned in step 6 is evenly wiped with a cotton ball dipped in a corrosive solution, and then rinsed with running warm water and anhydrous ethanol in sequence and blown dry to obtain a pure titanium TA2 metallographic specimen with a clear structure; The etching solution described in step 4 and step 7 is prepared by mixing hydrofluoric acid solution, nitric acid solution and distilled water in a volume ratio of (1-2): (3-5): (10-20); the mass fraction of the hydrofluoric acid solution is 40%-42%, and the mass fraction of the nitric acid solution is 65%-68%.
[0005] Furthermore, the pure titanium TA2 metallographic sample in step 1 is cut using a silicon carbide cutting wheel, and the cross-sectional area of the sample inspection surface is 100-200 square millimeters.
[0006] As described in step 2, the cut pure titanium TA2 metallographic specimen is mounted using a cold mounting method.
[0007] In step 3, the sandpaper must be kept moist during the process of coarse grinding to fine grinding of the pure titanium TA2 metallographic sample.
[0008] The polishing cloth used in the polishing treatment in step 4 is fine woolen cloth, and the polishing liquid used is diamond spray polishing agent.
[0009] The polishing cloth used in the fine polishing treatment in step six is a fine velvet polishing cloth, and the cleaning liquid used is an alkaline soap solution.
[0010] The wiping time is 5-20 seconds.
[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a silicon carbide grinding wheel cutting blade to cut pure titanium TA2 metallographic specimens, which can reduce the thermal damage and mechanical twins generated during the cutting process that affect the microstructure. (2) The present invention uses a cold embedding method to embed the cut specimens, which can prevent the content and distribution of hydrogen elements in the pure titanium TA2 metallographic specimens from being changed, prevent the specimens from being chamfered, and facilitate grinding. (3) The present invention keeps the sandpaper moist during the coarse grinding and fine grinding processes, which can prevent the grinding surface from generating α-phase deformation twins due to frictional overheating during the polishing process. (4) The present invention reduces the defects such as scratches, low-strain twins, and defects generated in the pure titanium specimens during the grinding process by repeatedly performing polishing and etching operations on the pure titanium specimens, thereby improving the polishing efficiency. (5) The present invention repeatedly polishes and corrodes the pure titanium sample, and then drips alkaline soap solution on a fine velvet cloth to perform fine polishing and cleaning on the sample, thereby reducing the residual scratches, corrosion pits and other defects of the pure titanium sample generated during the polishing process, and obtaining a bright and scratch-free sample surface.
[0012] The present invention, through repeated polishing and etching with a corrosive solution, can polish a sample to a mirror finish within 10-15 minutes without generating low-strain twins or surface scratches. The present invention is easy to operate and offers high sample preparation efficiency, resolving the technical issue of the difficulty in preparing pure titanium TA2 metallographic specimens and producing pure titanium TA2 metallographic specimens with a clear microstructure. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 1 is a microstructure diagram of a pure titanium TA2 metallographic sample prepared in Example 1 of the present invention; Figure 2 This is a microstructure diagram of the pure titanium TA2 metallographic sample prepared in Comparative Example 1 of the present invention; Figure 3 is a microstructure diagram of a pure titanium TA2 metallographic sample prepared in Example 2 of the present invention; Figure 4 This is a microstructure diagram of the pure titanium TA2 metallographic sample prepared in Example 3 of the present invention. DETAILED DESCRIPTION
[0014] The technical solution of the present invention is described clearly and completely below with reference to the accompanying drawings and specific embodiments.
[0015] The present invention provides a method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner, comprising the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: Mounting the pure titanium TA2 metallographic sample cut in step 1; Step 3: The pure titanium TA2 metallographic specimens inlaid in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine; Step 4: polishing the pure titanium TA2 metallographic sample obtained in step 3, and then corroding it in a corrosive solution for 4-6 seconds; Step 5: Repeat step 4 2-4 times; Step 6: Continue fine polishing and cleaning the pure titanium TA2 metallographic sample surface processed in step 5; Step 7: The pure titanium TA2 metallographic specimen finely polished and cleaned in step 6 is evenly wiped with a cotton ball dipped in a corrosive solution, and then rinsed with running warm water and anhydrous ethanol in sequence and blown dry to obtain a pure titanium TA2 metallographic specimen with a clear structure; The etching solution described in step 4 and step 7 is prepared by mixing hydrofluoric acid solution, nitric acid solution and distilled water in a volume ratio of (1-2): (3-5): (10-20); the mass fraction of the hydrofluoric acid solution is 40%-42%, and the mass fraction of the nitric acid solution is 65%-68%.
[0016] The pure titanium TA2 metallographic specimen described in step 1 is cut using a silicon carbide cutting wheel to reduce thermal damage and mechanical twinning during the cutting process that can affect the microstructure. The cross-sectional area of the specimen inspection surface is 100-200 square millimeters.
[0017] The cut pure titanium TA2 metallographic specimen is mounted using a cold mounting method as described in step 2. The cold mounting method can prevent the content and distribution of hydrogen in the pure titanium TA2 metallographic specimen from being changed, prevent the specimen from being chamfered, and facilitate grinding.
[0018] In step 3, the sandpaper must be kept moist during the rough grinding and fine grinding of the pure titanium TA2 metallographic sample to prevent the generation of α-phase deformation twins due to frictional overheating during the rough and fine grinding process.
[0019] The polishing process described in step 4 is performed using a fine tweed cloth and a diamond spray polishing agent as the polishing liquid. The polishing process involves evenly spraying the diamond spray polishing agent onto the center of a polishing plate covered with fine tweed cloth to polish the pure titanium TA2 metallographic specimen. The fine tweed cloth is soft and less susceptible to polishing scratches, providing an excellent polishing effect on the softer pure titanium specimen. The diamond spray polishing agent has a moderate particle size and is less likely to scratch the polished surface, thus enhancing the polishing effect. In one embodiment, step 4 involves polishing the pure titanium TA2 metallographic specimen for 2-3 minutes and then subjecting it to an etchant solution for 4-6 seconds.
[0020] Step five is to repeat step four 2-4 times until the polishing scratches are removed and the polishing efficiency is improved.
[0021] The polishing cloth used for the fine polishing treatment described in step six is a fine velvet polishing cloth, and the cleaning liquid used is an alkaline soap solution. In this step, the pure titanium TA2 metallographic sample surface is further finely polished and cleaned. In one embodiment, the polishing process is to evenly add 3% alkaline soap solution to the middle position of the polishing plate paved with a fine velvet polishing cloth, and finely polish and clean the sample. The fine velvet polishing cloth has a fine and soft texture and can be used to further finely polish the pure titanium sample surface. The alkaline soap solution can improve the cleanliness of the sample surface, resulting in a bright and scratch-free sample polished surface.
[0022] The wiping time in step 7 is 5-20 seconds. The color of the sample surface changes from blue to gray, indicating that the etching is in place. This etching time can fully corrode the pure titanium TA2 metallographic sample without causing insufficient or excessive corrosion, and can obtain a pure titanium TA2 metallographic sample with a clear microstructure. Example 1:
[0023] The preparation method of the pure titanium TA2 metallographic specimen in this embodiment includes the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: cold-mounting the pure titanium TA2 metallographic specimen cut in step 1; Step 3: The pure titanium TA2 metallographic specimens processed by cold mounting in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine, keeping the sandpaper moist during the coarse and fine grinding process; Step 4: Polish the pure titanium TA2 metallographic sample obtained in step 3 using a fine woolen cloth and a diamond spray polishing agent. The sample is then placed in a corrosive solution for 5 seconds. Step 5: Repeat step 4 3 times; Step 6: Finely polish and clean the pure titanium TA2 metallographic specimen surface treated in step 5 with a fine velvet cloth and alkaline soap solution; In step seven, the pure titanium TA2 metallographic specimen, finely polished and cleaned in step six, was evenly rubbed with a cotton ball dipped in a corrosion solution for 10 seconds, causing the corroded surface to turn from blue to gray. The specimen was then rinsed with running warm water and then anhydrous ethanol and dried, yielding a pure titanium TA2 metallographic specimen with a clear microstructure. The corrosion solution consisted of a mixture of hydrofluoric acid solution, nitric acid solution, and distilled water in a ratio of 2:5:15, with a mass fraction of 40% hydrofluoric acid and 66% nitric acid.
[0024] Figure 1 This is the microstructure of the pure titanium TA2 metallographic sample prepared in Example 1. Figure 1 It can be seen that the pure titanium TA2 metallographic sample has a clear microstructure and is basically free of scratches, twins, and corrosion pit defects, indicating that the present invention can conveniently obtain a pure titanium TA2 metallographic sample with a clear microstructure.
[0025] Comparative Example 1: The preparation method of the pure titanium TA2 metallographic specimen of this comparative example comprises the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: cold-mounting the pure titanium TA2 metallographic specimen cut in step 1; Step 3: The pure titanium TA2 metallographic specimens processed by cold mounting in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine, keeping the sandpaper moist during the coarse and fine grinding process; Step 4: polishing the pure titanium TA2 metallographic sample ground in step 3, using a fine woolen cloth as the polishing cloth and a diamond spray polishing agent as the polishing liquid; Step 5: Evenly wipe the surface of the pure titanium sample polished in step 4 with a cotton ball dipped in a corrosion solution for 10 seconds, and the corrosion surface turns from blue to gray, and then rinse with warm water and anhydrous ethanol in sequence and blow dry to obtain a pure titanium TA2 metallographic sample; the metallographic etching solution is prepared by mixing hydrofluoric acid solution, nitric acid solution, and distilled water in a ratio of (2:5:15), the mass fraction of the hydrofluoric acid solution is 40%, and the mass fraction of the nitric acid solution is 66%.
[0026] Figure 2 The microstructure of the pure titanium TA2 metallographic sample prepared in this comparative example is shown in FIG. Figure 2 It can be seen that the microstructure of the pure titanium TA2 metallographic specimen has defects such as scratch residues and twins caused by improper polishing, and the microstructure display is not clear enough.
[0027] from Figure 1 and Figure 2 From the comparison of the microstructures of the pure titanium TA2 metallographic specimens, it can be seen that the microstructure of the pure titanium TA2 metallographic specimens after repeated polishing and corrosion treatments and fine polishing and cleaning treatments is clearer, with basically no defects such as scratch residues and twins. This shows that this embodiment uses repeated polishing and corrosion operations to remove scratches and twins generated during the coarse grinding and fine grinding processes, and then uses fine polishing and cleaning treatments on the specimen surface, which can effectively remove scratch residues and defects caused by the polishing process, and can obtain a pure titanium TA2 metallographic specimen with a clear microstructure. Example 2:
[0028] The preparation method of the pure titanium TA2 metallographic specimen in this embodiment includes the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: cold-mounting the pure titanium TA2 metallographic specimen cut in step 1; Step 3: The pure titanium TA2 metallographic specimens processed by cold mounting in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine, keeping the sandpaper moist during the coarse and fine grinding process; Step 4: Polish the pure titanium TA2 metallographic sample obtained in step 3 using a fine woolen cloth and a diamond spray polishing agent. The sample is then placed in a corrosive solution for 5 seconds. Step 5: Repeat step 4 4 times; Step 6: Finely polish and clean the pure titanium TA2 metallographic specimen surface treated in step 5 with a fine velvet cloth and alkaline soap solution; In step seven, the pure titanium TA2 metallographic specimen, finely polished and cleaned in step six, was evenly rubbed with a cotton ball dipped in a corrosion solution for 17 seconds, causing the corroded surface to turn from blue to gray. The specimen was then rinsed with running warm water and then anhydrous ethanol and dried, yielding a pure titanium TA2 metallographic specimen with a clear microstructure. The corrosion solution consisted of a mixture of hydrofluoric acid solution, nitric acid solution, and distilled water in a ratio of 1:3:15, with the mass fraction of hydrofluoric acid being 40% and the mass fraction of nitric acid being 67%.
[0029] Figure 3 This is the microstructure of the pure titanium TA2 metallographic sample prepared in Example 2. Figure 3 It can be seen that the pure titanium metallographic sample has a clear microstructure and is substantially free of scratches, twins, and corrosion pit defects, indicating that the present invention can conveniently obtain a pure titanium metallographic sample with a clear microstructure. Example 3:
[0030] The preparation method of the pure titanium TA2 metallographic specimen in this embodiment includes the following steps: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: cold-mounting the pure titanium TA2 metallographic specimen cut in step 1; Step 3: The pure titanium TA2 metallographic specimens processed by cold mounting in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine, keeping the sandpaper moist during the coarse and fine grinding process; Step 4: Polish the pure titanium TA2 metallographic sample obtained in step 3 using a fine woolen cloth and a diamond spray polishing agent. The sample is then placed in a corrosive solution for 4 seconds. Step 5: Repeat step 4 3 times; Step 6: Finely polish and clean the pure titanium TA2 metallographic specimen surface treated in step 5 with a fine velvet cloth and alkaline soap solution; In step seven, the pure titanium TA2 metallographic specimen, finely polished and cleaned in step six, was evenly rubbed with a cotton ball dipped in a corrosion solution for 13 seconds, causing the corroded surface to turn from blue to gray. The specimen was then rinsed with running warm water and then anhydrous ethanol and dried, yielding a pure titanium TA2 metallographic specimen with a clear microstructure. The corrosion solution consisted of a mixture of hydrofluoric acid solution, nitric acid solution, and distilled water in a ratio of 2:5:20, with the mass fraction of hydrofluoric acid being 40% and the mass fraction of nitric acid being 65%.
[0031] Figure 4 This is the microstructure of the pure titanium TA2 metallographic sample prepared in Example 3. Figure 4 It can be seen that the pure titanium metallographic sample has a clear microstructure and is substantially free of scratches, twins, and corrosion pit defects, indicating that the present invention can conveniently obtain a pure titanium metallographic sample with a clear microstructure.
[0032] While the embodiments of the present invention have been shown and described above, they are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner, characterized in that: The following steps are involved: Step 1: Cut the sample from the annealed pure titanium TA2 workpiece using a silicon carbide cutting wheel; Step 2: Mounting the pure titanium TA2 metallographic sample cut in step 1; Step 3: The pure titanium TA2 metallographic specimens inlaid in step 2 were respectively # , 600 # , 1000 # , 1500 # , 2000 # Silica sandpaper, grinding from coarse to fine; Step 4: polishing the pure titanium TA2 metallographic sample obtained in step 3, and then corroding it in a corrosive solution for 4-6 seconds; Step 5: Repeat step 4 2-4 times; Step 6: Continue fine polishing and cleaning the pure titanium TA2 metallographic sample surface processed in step 5; Step 7: The pure titanium TA2 metallographic specimen finely polished and cleaned in step 6 is evenly wiped with a cotton ball dipped in a corrosive solution, and then rinsed with running warm water and anhydrous ethanol in sequence and blown dry to obtain a pure titanium TA2 metallographic specimen with a clear structure; The etching solution described in step 4 and step 7 is prepared by mixing hydrofluoric acid solution, nitric acid solution and distilled water in a volume ratio of (1-2): (3-5): (10-20); the mass fraction of the hydrofluoric acid solution is 40%-42%, and the mass fraction of the nitric acid solution is 65%-68%.
2. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: The pure titanium TA2 metallographic sample described in step 1 is cut using a silicon carbide cutting wheel, and the cross-sectional area of the sample inspection surface is 100-200 square millimeters.
3. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: As described in step 2, the cut pure titanium TA2 metallographic specimen is mounted using a cold mounting method.
4. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: In step 3, the sandpaper must be kept moist during the process of coarse grinding to fine grinding of the pure titanium TA2 metallographic sample.
5. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: The polishing cloth used in the polishing treatment in step 4 is fine woolen cloth, and the polishing liquid used is diamond spray polishing agent.
6. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: The polishing cloth used in the fine polishing treatment in step six is a fine velvet polishing cloth, and the cleaning liquid used is an alkaline soap solution.
7. The method for preparing a pure titanium TA2 metallographic sample for a shaped charge liner according to claim 1, characterized in that: The wiping time is 5-20 seconds.