A metallographic etching clamp
Patent Information
- Application Number
- CN202521883565.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2026-09-04
- Estimated Expiration
- 2035-09-02
AI Technical Summary
[0002]在金相制样过程中，浸蚀作为揭示材料显微组织、晶粒度、多相分布及脱碳层深度等关键特征的核心步骤，传统工艺需将样品完全浸没于化学溶液中，造成显著的技术痛点：首先，该方法导致严重的资源浪费与成本压力，例如常规碳钢硝酸酒精浸蚀单次消耗溶液达40-60ml，而材料的原奥氏体晶粒度使用的专用浸蚀剂成本可高达上千元每250ml，批量检测时含重金属废液(如铬酸盐)的处理费用进一步激增；其次，开放操作环境引发环境污染与健康危害，强挥发性酸液(氢氟酸、王水)逸散率超70％，操作区酸雾浓度达5-15ppm(超过国标限值3-5倍)，长期暴露易损伤呼吸系统，含铅、镉等有毒废液更直接威胁地下水安全；再者，高温浸蚀操作(如50-90℃奥氏体晶粒度检测)危险性突出，硝酸酒精等溶液闪点低至12℃，挥发加剧可能引发爆炸或喷溅灼伤，实验室统计显示此类事故占金相制样事故比例的34％
[0010]有益效果：本实用新型通过精确深度控制与材质适配，在保障浸蚀均匀性的同时，将溶液成本降低60％，彻底解决传统浸蚀的高消耗、高污染及高温爆炸风险问题。
Smart Images
Figure CN224719748U_ABST
Abstract
Description
Technical Field
[0001] This utility model discloses a metallographic etching fixture, belonging to the technical field of metallographic sample preparation equipment, specifically relating to a fixture device for metallographic sample etching treatment. Background Technology
[0002] In metallographic sample preparation, etching is a core step in revealing key characteristics such as the material's microstructure, grain size, multiphase distribution, and decarburized layer depth. Traditional processes require the sample to be completely immersed in a chemical solution, causing significant technical challenges: First, this method leads to severe resource waste and cost pressure. For example, a single etching of carbon steel with nitric acid and alcohol consumes 40-60 ml of solution, while the cost of specialized etching agents for determining the original austenitic grain size can reach thousands of yuan per 250 ml. Furthermore, the cost of treating waste liquids containing heavy metals (such as chromates) further increases during batch testing. Second... Open operating environments pose environmental pollution and health hazards. The evaporation rate of highly volatile acids (hydrofluoric acid, aqua regia) exceeds 70%, with acid mist concentrations in the operating area reaching 5-15 ppm (3-5 times higher than national standards). Long-term exposure can damage the respiratory system, and toxic waste liquids containing lead and cadmium directly threaten groundwater safety. Furthermore, high-temperature etching operations (such as austenite grain size detection at 50-90℃) are particularly dangerous. Solutions like nitric acid and alcohol have flash points as low as 12℃, and accelerated volatilization can lead to explosions or splash burns. Laboratory statistics show that such accidents account for 34% of metallographic sample preparation accidents. Existing improved techniques, such as the simple fixture partial immersion method, still suffer from solutions with evaporation rates exceeding 50% and insufficient depth control accuracy. While closed container solutions reduce evaporation, they make it difficult to adjust the sample position in real time, leading to uneven etching. Moreover, commercial fixtures are mostly made of 304 stainless steel, which has a corrosion weight loss rate exceeding 15 mg / cm³ in hydrofluoric acid or hot alkaline solutions. 2 However, the material compatibility is poor. Therefore, developing a specialized fixture with precise depth control, full enclosure to prevent volatilization, and strong corrosion resistance has become an urgent need to solve the problems of high cost, high pollution, and high risk in metallographic etching. Utility Model Content
[0003] Purpose of the utility model: To provide a metallographic etching fixture to solve the problems mentioned above.
[0004] Technical solution: A metallographic etching fixture, comprising: a beaker, an adjustable bolt, a top cover plate, a square groove, a magnetic material, and a clamping bolt;
[0005] The square groove is located inside the beaker and is connected to the top cover plate by the adjustable bolt. The magnetic material is located inside the square groove and is fixedly installed inside the square groove by the clamping bolt.
[0006] In a further embodiment, the beaker contains a solution.
[0007] In a further embodiment, a sample is provided in the square groove, and the sample is adsorbed onto the lower part of the magnetic material.
[0008] In a further embodiment, the top cover plate is fixedly installed on the beaker and a sealing ring is provided at the connection.
[0009] In a further embodiment, the bottom of the square groove is 2 mm lower than the sample fixing surface so that only the bottom of the sample needs to be exposed to contact the solution.
[0010] Beneficial effects: This utility model, through precise depth control and material matching, reduces solution costs by 60% while ensuring uniform etching, and completely solves the problems of high consumption, high pollution and high temperature explosion risk of traditional etching. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the present invention.
[0012] Figure labels: 1. Beaker; 2. Adjustable bolt; 3. Top cover plate; 4. Square groove; 5. Magnetic material; 6. Clamping bolt; 7. Sample; 8. Solution. Detailed Implementation
[0013] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0014] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0015] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0016] A metallographic etching fixture includes: a beaker 1, an adjustable bolt 2, a top cover plate 3, a square groove 4, a magnetic material 5, a clamping bolt 6, a sample 7, and a solution 8.
[0017] In one embodiment, such as Figure 1 As shown, this utility model provides a metallographic etching fixture. Its innovative design lies in the synergistic effect of the clamping assembly controlled by the adjustable bolt 2 and the sealed top cover to achieve precise local etching of the sample and isolate volatilization. The core structure includes a beaker 1 containing solution 8, a top cover plate 3 with a silicone sealing ring, an adjustable bolt 2 penetrating the top cover, a square groove 4 connecting the ends of the bolt, and a clamping bolt 6. The square groove 4 contains a magnetic material 5 to quickly adsorb the ferromagnetic sample 7, and the bottom of the groove is 2mm lower than the fixing surface of the sample 7 to ensure that only the bottom of the sample 7 needs to be exposed to contact the solution 8. At the same time, the square groove 4 can be replaced with a PTFE-lined corrosion-resistant groove to adapt to strong acid environments. Specific embodiments are as follows—for carbon steel For austenitic grain size testing, a 20×15×15mm polished sample 7 is fixed in an aluminum alloy square groove 4. The clamping bolt 6 is adjusted so that the bottom of the sample 7 is 2mm above the bottom of the groove. LBTK03 solution 8 (liquid level 10ml, saving 70% compared to traditional methods) is poured into beaker 1. The adjustable bolt 2 is rotated so that the bottom of the sample 7 contacts the solution 8, and then the sealing top cover is tightened. The sample is then placed in a 70℃ constant temperature water bath for etching for more than 10 minutes, reducing the acid mist volatilization rate by 90% throughout the process. For austenitic stainless steel aqua regia etching, the square groove 4 is replaced with a polytetrafluoroethylene-lined one, and aqua regia solution 8 (liquid level 9ml) is poured in. The sample is then etched at room temperature in a sealed environment for 1-2 minutes. After disassembly, the inner lining groove is replaced directly to avoid cross-contamination. This fixture, through precise depth control and material matching, ensures etching uniformity while reducing the cost of solution 8 by 60%, completely solving the problems of high consumption, high pollution, and high-temperature explosion risk of traditional etching.
[0018] The specific implementation method of this utility model is as follows: During operation, firstly, select the appropriate fixture assembly based on the material of the sample 7—an aluminum alloy square groove 4 is used when detecting the austenitic grain size of carbon steel, while a polytetrafluoroethylene-lined groove (0.5mm thick lining) is used for processing austenitic stainless steel. Place the pre-polished 20×15×15mm standard sample 7 into the square groove 4, and tighten the clamping bolts 6 to secure the sample 7 firmly, ensuring its bottom surface is precisely 2.0±0.1mm above the bottom of the groove (this dimension is guaranteed by the mechanical limit of the groove's stepped structure). Then, inject the etching solution 8 into a 100ml heat-resistant beaker 1 (10ml of LBTK03 solution 8 for carbon steel / 9ml of aqua regia for stainless steel). The adjustable screw 2 with a spiral lead of 0.5mm precisely controls the downward movement of sample 7, so that the liquid surface of solution 8 only contacts the bottom 1.5-2mm area of sample 7 (the liquid level is marked by the inner scale of beaker 1); immediately press the top cover plate 3 with silicone sealing ring (compression of 1.5mm achieves sealing), at which point the entire device forms a closed system; if high-temperature etching is to be performed (such as 70℃ austenite grain size detection), place beaker 1 in a constant temperature water bath and start heating for more than 10 minutes, then open the lid and take out sample 7. The acid mist emission rate throughout the process is <5%; if room temperature etching is to be performed (such as stainless steel aqua regia treatment), let it stand for 1-2 minutes, then open the lid and directly disassemble the polytetrafluoroethylene liner tank to replace it with a new tank to avoid cross-contamination of residual corrosion liquid. Key operational safeguards include: magnetic material 5 (neodymium iron boron magnet, attraction force > 5N) to achieve ferromagnetic sample fixation in 7 seconds; 316L stainless steel tank with an annual corrosion rate of <0.1mm in a 90℃ nitric acid environment; polytetrafluoroethylene lining with hydrofluoric acid corrosion resistance reaching the highest level of ASTM D543 standard; and micron-level threads (tolerance H7 / g6) of adjustable bolt 2 to ensure immersion depth control accuracy of ±0.05mm. Ultimately, the corrosion uniformity error is <3% (compared to >15% with traditional methods), and the overall cost is reduced by 60%.
[0019] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A metallographic etching fixture, characterized in that, include: Beaker, adjustable bolt, top cover plate, square slot, magnetic material and clamping bolt; The square groove is located inside the beaker and is connected to the top cover plate by the adjustable bolt. The magnetic material is located inside the square groove and is fixedly installed inside the square groove by the clamping bolt.
2. The metallographic etching fixture according to claim 1, characterized in that, The beaker contains a solution.
3. The metallographic etching fixture according to claim 2, characterized in that, The sample is placed in the square groove and is adsorbed onto the lower part of the magnetic material.
4. The metallographic etching fixture according to claim 1, characterized in that, The top cover plate is fixedly installed on the beaker and a sealing ring is provided at the connection.
5. The metallographic etching fixture according to claim 3, characterized in that, The bottom of the square groove is 2 mm lower than the sample fixing surface so that only the bottom of the sample needs to be exposed to contact the solution.