A polishing fixture and sample preparation method for electron backscatter diffraction of a sample

Abstract

The present application relates to the technical field of electron backscatter diffraction characterization, and particularly relates to a polishing clamp for electron backscatter diffraction sample and a sample preparation method. The polishing clamp comprises a base, a recess is arranged on the base, a clamping piece is arranged in the recess, a round hole A and a round hole B are arranged on the clamping piece, a sample containing space is formed between the clamping piece and the side wall of the recess on one side of the clamping piece, a top piece is arranged on the other side of the clamping piece, a round hole C and a round hole D are arranged on the top piece, a first sliding rod passes through the round hole A and the round hole C, a second sliding rod passes through the round hole B and the round hole D, the two ends of the first sliding rod and the second sliding rod are fixedly connected to the base on the two sides of the recess respectively, a top rod is arranged on the side of the top piece away from the clamping piece, and one end of the top rod is threadedly connected to the base. The polishing clamp can be effectively matched with a commercial vibration polishing device, and the application range of sample preparation is improved. Meanwhile, through accurate control of the material, hardness and surface structure of the clamping piece, the clamping stability is ensured, and damage to the sample is avoided.

Description

Technical Field

[0001] This invention relates to the field of electron backscatter diffraction characterization technology, and specifically to a polishing fixture and sample preparation method for electron backscatter diffraction samples. Background Technology

[0002] In the electron backscatter diffraction (EBSD) characterization of coatings, surface modifications, and composite metal materials, sample preparation is a crucial prerequisite for ensuring the accuracy and reliability of the characterization results. Due to the significant heterogeneity of the surfaces to be characterized in these materials—for example, the composition, hardness, and elastic modulus of the coating and the substrate material differ considerably—the thickness of surface modification layers is typically only in the micrometer to submicrometer range, and composite metal materials exhibit interfacial bonding problems between different phase regions, making it extremely difficult to obtain suitable electropolishing parameters. To ensure pattern recognition rates during EBSD detection, the industry currently widely employs a combined sample preparation process of mechanical polishing and vibratory polishing. Mechanical polishing is used to initially remove macroscopic defects and processing traces from the sample surface, while vibratory polishing is used to further remove the surface stress layer generated during mechanical polishing, avoiding interference from the stress layer on crystal orientation information.

[0003] Due to the limitations imposed by coatings, surface modifications, and the unique structural characteristics of composite metal materials, the sampling location and size of EBSD samples are strictly restricted. According to the technical requirements for EBSD characterization, the length and width of the sample must typically be controlled within 10 mm, and the height within 5 mm, to ensure that the sample can fit the sample stage of commercial EBSD testing equipment and that the electron beam can stably act on the characterization area. Compared to ordinary bulk homogeneous metal material samples, these ultra-thin metal samples have smaller characterization areas and more fragile structures, making them unsuitable for direct use with existing commercial vibratory polishing fixtures. They must be fixed using an intermediate medium or a specialized fixture before sample preparation can be carried out.

[0004] Currently, the intermediate media methods for preparing ultrathin metal EBSD samples are mainly divided into two categories: hot mounting and cold mounting. CN 116678905 A discloses a fixture design for vibration polishing using a cold mounting process. This scheme uses cold mounting material to fix the ultrathin aluminum / iron-based alloy sample into shape, and then uses a special fixture for vibration polishing, which to some extent solves the compatibility problem between the sample and the fixture. In CN 119269553 A, a combination of hot and cold mounting methods is used to prepare extremely small metal microwire EBSD samples. First, the metal microwire is initially fixed using hot mounting material, and then a secondary encapsulation is performed using cold mounting material to improve the stability of the sample.

[0005] However, while the hot and cold mounting methods have improved the success rate of preparing ultra-thin metal samples to some extent, they still have significant drawbacks and limitations in practical applications. The advantage of the hot mounting method lies in the good conductivity of the hot-mounted material after curing, which meets the charge conduction requirements of the EBSD detection process. However, the overall size of the hot-mounted sample is usually much larger than the standard size of the EBSD sample, requiring the removal of excess material through cutting or manual breaking to obtain a sample that meets the size requirements. During this process, cutting easily generates mechanical stress, leading to microcracks or damage on the surface to be characterized after vibration polishing. Manual breaking is difficult to control the force, further damaging the surface to be characterized, thus significantly reducing the pattern recognition rate of EBSD, and even causing the sample to be scrapped.

[0006] While cold mounting removes the mounting material through specific temperature conditions or chemical reagents, avoiding damage to the sample caused by mechanical cutting or manual breaking, it also faces several limitations in its application. Firstly, the dissolution process of cold mounting typically requires heating or the use of corrosive chemicals. Heating may cause oxidation of the surface of the extremely thin metal sample to be characterized, altering the sample's surface composition and microstructure; corrosive chemicals may corrode the surface, damaging its morphology and crystal structure, thus affecting the accuracy of EBSD characterization results. Secondly, during cold mounting, the mounting material mainly relies on its own gravity and surface tension to bond with the sample, resulting in limited pressure on the extremely thin coating or surface modification layer at the contact interface. During mechanical polishing and vibratory polishing, it is difficult to effectively protect the extremely thin surface to be characterized, easily leading to wear and peeling, and the protective effect is generally limited.

[0007] In fact, various clamp designs and fixing methods have been disclosed in the industry to address the sample clamping problem. However, most of these solutions are only applicable to the preparation of metallographic samples and very few can be directly used in the vibratory polishing process of EBSD samples. For example, CN115078680 A discloses a method for fixing samples using two clamps and bolts. This method clamps the sample with clamps and then adjusts the clamping force with bolts. However, its structural design is relatively simple, and the dimensions of the clamps and bolts cannot be adapted to the clamping holes of commercial vibratory polishing equipment. Furthermore, it cannot adjust the clamping method according to parameters such as the thickness and hardness of the sample. It can only be used to fix larger and more stable metallographic samples. CN 210650184 U discloses a non-embedding clamp including a mating body, a bearing mechanism, a transverse screw, a longitudinal screw, and a second screw. Although this clamp achieves non-embedding fixing, its complex structure, large size, and failure to consider the conductivity and surface stress control requirements of EBSD samples make it unsuitable for the vibratory polishing process of extremely thin metal EBSD samples. It has obvious functional adaptability defects in practical applications.

[0008] In summary, current EBSD sample preparation techniques for ultrathin metallic materials, whether using hot-and-cold mounting methods or existing fixture solutions, suffer from poor compatibility with commercial vibratory polishing equipment, inadequate protection of the surface to be characterized, low sample preparation success rates, and complex and costly operations. Therefore, there is an urgent need to develop a multifunctional EBSD sample preparation method and detachable fixture for ultrathin metallic materials. This method should meet the sample preparation requirements of various ultrathin metallic materials, including coatings, surface modifications, and composite metals, ensuring low-damage and high-precision sample preparation results, while also being economical and easy to operate. This would provide efficient and reliable technical support for the EBSD characterization of ultrathin metallic materials. Summary of the Invention

[0009] To address the poor compatibility between current sample preparation fixtures and commercial vibratory polishing equipment, as well as the technical difficulties in preparing samples for EBSD testing of materials with extremely thin characterization surfaces, such as coated, surface-modified, and composite metals, this invention provides a polishing fixture and sample preparation method for electron backscatter diffraction (EBSD) samples.

[0010] The technical solution of this invention is as follows: In a first aspect, the present invention provides a polishing fixture for electron backscatter diffraction samples, comprising a base, a groove on the upper surface of the base, a clamping piece disposed in the groove, the clamping piece having a circular hole A and a circular hole B, one side of the clamping piece forming a sample receiving space with the sidewall of the groove, and a top plate disposed on the other side of the clamping piece, the top plate having a circular hole C and a circular hole D, a first sliding rod passing through the circular hole A and the circular hole C, and a second sliding rod passing through the circular hole B and the circular hole D, the two ends of the first sliding rod being fixedly connected to the base on both sides of the groove, and the two ends of the second sliding rod being fixedly connected to the base on both sides of the groove, so that the clamping piece and the top plate can slide along the first sliding rod and the second sliding rod in the groove, and a top rod disposed on the side of the top plate away from the clamping piece, the end of the top rod away from the top plate being threadedly connected to the base; The hardness of the clip is determined according to the following formula: When the thickness D of the surface to be characterized of the sample F When the thickness is >100 μm, the hardness H of the clip is... J =(1.4~1.8)H F , When the thickness D of the surface to be characterized of the sample F When the thickness is ≤100 μm, the hardness H of the clip is... J =(1.1~1.4)H F , In the formula, H F This represents the hardness of the surface of the sample to be characterized.

[0011] Furthermore, the depth of the groove is less than 12 mm.

[0012] Furthermore, the surface of the side of the clip that contacts the sample (i.e. the side of the clip away from the top plate) is provided with a micron-level grid pattern.

[0013] Furthermore, the direction of the micron-level mesh texture forms an angle of 45° to 90° with the direction of vibration polishing, and the texture depth d = (0.05~0.15)D F The texture spacing s = (2.0~5.0)d, where D F The thickness of the surface to be characterized.

[0014] Furthermore, the micron-level mesh texture is processed using laser engraving.

[0015] Furthermore, when the thickness D of the sample S When the thickness is ≤35 μm, the sample is bonded to the clamping roller by conductive adhesive, wherein the thickness D of the conductive adhesive is... E =(0.15~0.28)D S By using a composite fixation method of conductive adhesive and mechanical clamping, the detachment rate of ultrathin samples is reduced, ensuring low-damage and high-precision EBSD sample preparation.

[0016] Furthermore, when the elongation of the surface to be characterized is <2%, the clamping material is silicone, the Shore hardness A of the clamping material is 40~65, and the thickness D of the clamping material is... J =(0.2~0.4)D S In the formula, D S The thickness of the sample is given.

[0017] Furthermore, the diameter of the circular hole A on the clamp is 1.05 to 1.10 times the diameter of the first slide rod; the diameter of the circular hole B on the clamp is 1.05 to 1.10 times the diameter of the second slide rod.

[0018] Furthermore, elastic buffer sleeves are respectively fitted on the outer sides of the first slide rod and the second slide rod, and the surface of the elastic buffer sleeves is provided with anti-slip ridges.

[0019] Furthermore, the height of the anti-slip ridges on the surface of the elastic buffer sleeve is 0.1~0.3 mm, and the ridge spacing is 0.5~1.5 mm.

[0020] Furthermore, the base is cylindrical.

[0021] Furthermore, the outer diameter of the base is adapted to the clamping hole size of commercial vibratory polishing equipment.

[0022] Secondly, the present invention provides a sample preparation method for electron backscatter diffraction samples. The sample preparation method uses the polishing fixture described above, places the sample in the sample receiving space between the clamp and the side wall of the groove, then slides the clamp and the top plate to make the sample fit against the clamp and the side wall of the groove respectively, the top plate fits against the clamp, rotates the top rod to fasten the sample, and then polishes it.

[0023] The beneficial effects of this invention are as follows: The polishing fixture for electron backscatter diffraction (ESD) samples provided by this invention can be effectively matched with commercial vibratory polishing equipment, expanding the application range of sample preparation. It also meets the dynamic matching requirements of the clamps with different samples. Through precise control of the clamp material, hardness, and surface structure, it ensures clamping stability while avoiding damage to the sample, significantly improving the fixture's compatibility and economy. Compared to traditional hot and cold mounting methods, this invention eliminates the need for mounting materials, reducing sample preparation costs and avoiding damage to the sample during mounting material removal. Compared to existing dedicated fixtures, this invention eliminates the need for separately designed fixtures for different samples; flexible combination of components can meet various sample preparation needs, further reducing equipment investment costs. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a top view of the polishing fixture of Embodiment 1 of the present invention.

[0026] Figure 2 This is a left view of the polishing fixture of Embodiment 1 of the present invention.

[0027] Figure 3 This is a schematic diagram of the clip structure of Embodiment 1 of the present invention.

[0028] In the figure, 1-base; 2-groove; 31-first slide rod; 32-second slide rod; 311-blind hole A; 321-blind hole B; 312-through hole A; 322-through hole B; 33-elastic buffer sleeve; 4-clamping piece; 51-top piece; 52-top rod. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0030] The present invention first discloses a polishing fixture for electron backscatter diffraction samples, including a base, clamping plates, sliding components, and fastening components (top plate and top rod).

[0031] The base, as the basic load-bearing component of the fixture, adopts a cylindrical structure design. Its diameter is adapted to the clamping hole size of commercial vibratory polishing equipment, and it can be directly installed into the clamping hole of the vibratory polishing equipment without the need for additional adapter parts, effectively improving the compatibility between the fixture and commercial equipment.

[0032] A groove is provided on the upper part of the base to accommodate and install the sliding and fastening components, providing a stable space for clamping the sample. To ensure that the components installed inside the groove do not interfere with the movement of the equipment during the vibratory polishing process, and to meet the size requirements of the EBSD sample, the depth of the groove is designed to be less than 12 mm. This provides sufficient installation space for the sliding, fastening, and sample components, while also preventing the components from protruding too much from the base and colliding with the polishing equipment.

[0033] Both the sliding assembly and the fastening assembly are arranged inside the groove on the upper part of the base. The clamping piece is arranged on the sliding assembly, with one side of the clamping piece attached to the fastening assembly and the other side facing the surface of the sample to be characterized. Through the clamping force applied by the fastening assembly, the clamping piece forms a stable clamping effect on the sample.

[0034] The clamping piece has two circular holes, A and B, which are preferably symmetrically designed. One side of the clamping piece forms a sample receiving space with the sidewall of the groove, and a top plate is provided on the other side of the clamping piece. The fastening assembly includes a top plate and a top rod. The top plate has two circular holes, C and D. The sliding assembly includes a first slide rod and a second slide rod. The first slide rod passes through circular holes A and C, and the second slide rod passes through circular holes B and D. The two ends of the first slide rod are fixedly connected to the bases on both sides of the groove, and the two ends of the second slide rod are fixedly connected to the bases on both sides of the groove, so that the clamping piece and the top plate can slide along the first slide rod and the second slide rod in the groove. A top rod is provided on the side of the top plate away from the clamping piece, and the end of the top rod away from the top plate is connected to the base by a thread.

[0035] The diameter of the circular hole A is set to be 1.05 to 1.10 times the diameter of the first slide rod, and the diameter of the circular hole B is set to be 1.05 to 1.10 times the diameter of the second slide rod. This hole diameter design can ensure that the clamp can be smoothly fitted onto the slide rod, and can also prevent the clamp from shaking due to excessive hole diameter.

[0036] Meanwhile, elastic buffer sleeves are respectively fitted on the outer sides of the first and second slide rods. These elastic buffer sleeves can be made of rubber with good elasticity, and their outer surface has anti-slip ridges with a ridge height of 0.1~0.3 mm and a ridge spacing of 0.5~1.5 mm. The elastic buffer sleeves create a buffer between the clamping plate and the sliding assembly, reducing the impact of equipment vibration on the clamping plate during vibratory polishing. At the same time, the anti-slip ridges increase the friction between the clamping plate and the elastic buffer sleeve, preventing the clamping plate from rotating or shifting during polishing, further ensuring the stability of the sample clamping.

[0037] In some embodiments of the present invention, the hardness parameters of the clips are designed differently for cases where the thickness of the surface to be characterized varies. Specifically, when the thickness D of the surface to be characterized is... F When the thickness is >100 μm, the surface to be characterized is relatively thick and has a certain structural strength. At this time, the hardness H of the clip is... J Set to H J =(1.4~1.8)H F H F This is the hardness of the surface of the sample to be characterized. By setting the hardness slightly higher than that of the surface to be characterized, it is ensured that the clamps can stably hold the sample, preventing the sample from slipping or shifting during polishing.

[0038] When the thickness D of the surface to be characterized F When the thickness is ≤100 μm, the surface to be characterized is thin and the structure is fragile, making it more sensitive to clamping force and clamp hardness. At this point, the hardness H of the clamp is... J Adjust to H J =(1.1~1.4)H F H F This represents the hardness of the surface of the sample to be characterized.

[0039] In other embodiments of the present invention, in order to further improve the contact stability between the clamp and the sample and avoid the sample from sliding during the polishing process, a micron-level grid pattern is processed on the surface of the clamp facing the sample. This pattern can increase the friction between the clamp and the sample, while dispersing the clamping force and preventing excessive local pressure.

[0040] The micron-level mesh texture is fabricated using laser engraving, a process that offers advantages such as high precision and excellent texture consistency, allowing for precise control over the texture's size and shape. To ensure the mesh texture maximizes its anti-slip and stress-dispersing effects, the texture direction forms a 45°–90° angle with the direction of vibration polishing. This angle design effectively prevents sample displacement along the polishing direction, enhancing the anti-slip effect. Simultaneously, the texture depth d and the thickness D of the surface to be characterized are... F Related, specifically set to d=(0.05~0.15)D F By designing the relationship between the texture and the thickness of the surface to be characterized, we can avoid the problem that the texture is too deep, which would reduce the structural strength of the clip itself, or that the texture is too shallow, which would not be able to play an effective anti-slip role. The texture spacing s is set to s=(2.0~5.0)d. The reasonable spacing design can ensure the anti-slip effect while avoiding the problem that the texture is too dense, which would reduce the flatness of the clip surface and affect the fit with the sample.

[0041] In other embodiments of the invention, for samples with extremely thin thickness (sample thickness D) S For samples with a thickness ≤35 μm, such as metal foils and ultra-thin coated samples, the structural strength of these samples is extremely low. Relying solely on mechanical clamping with clips can easily lead to sample detachment, wrinkling, or breakage. A composite fixing method combining conductive adhesive and mechanical clamping can be used. Specifically, before placing the clips onto the sliding assembly, the clips and samples are first rolled and bonded using conductive adhesive. This rolling operation ensures that the conductive adhesive is evenly distributed between the clips and the sample, forming a stable bonding interface while preventing air bubbles. The thickness D of the conductive adhesive... E Set to D E =(0.15~0.28)D S This thickness design ensures that the conductive adhesive has sufficient bonding strength to firmly fix the sample to the clip, while also preventing the conductive adhesive from being too thick, which would result in an excessive distance between the sample and the clip and affect the stability of subsequent mechanical clamping. At the same time, the conductivity of the conductive adhesive can also meet the charge conduction requirements in the EBSD detection process, avoiding charge accumulation that could affect the characterization results.

[0042] In other embodiments of the present invention, for brittle samples with an elongation of less than 2% on the surface to be characterized, such as ceramic coating samples and high-hardness surface-modified layer samples, these samples are extremely sensitive to pressure during clamping. Even slight uneven pressure can cause cracks or even breakage of the surface to be characterized. In this case, it is preferable to use a clamping pad made of silicone. Silicone has good elasticity and flexibility, which can act as a buffer during clamping and reduce local pressure concentration. At the same time, the Shore hardness A of the silicone should be controlled within the range of 40 to 65. This hardness range can ensure that the clamping pad has a certain structural strength to achieve stable clamping of the sample, while avoiding damage to the sample caused by excessive hardness. In addition, the thickness D of the clamping pad... J Set to D J =(0.2~0.4)D S By designing the clamps in relation to the sample thickness, it is ensured that the clamps can provide uniform support for the sample, further improving the stability and safety during the clamping process.

[0043] In other embodiments of the present invention, the components of the polishing fixture are designed to be detachable, so that the polishing fixture can be flexibly adjusted according to the specific parameters of the sample to adapt to different types of ultra-thin metal samples.

[0044] In terms of the design of the fastening assembly, to meet the clamping requirements of samples with different thicknesses, the fastening assembly is designed as a T-shaped structure. This structure includes two parts: a top plate and a top rod. The top plate is used to contact the clamping plates and evenly transmit the clamping force to the clamping plates, while the top rod is used to adjust the clamping position and force. The top rod is available in two length specifications to accommodate samples of different thicknesses: when the sample thickness D... S When the diameter is ≤5.0 mm, a long rod should be used for the clamp; when 5.0 mm <D S For thicknesses ≤10.0 mm, a short rod is used in the clamp. This length design ensures that the rod does not extend too far beyond the base after installation, avoiding interference with the movement of the vibratory polishing equipment, while also ensuring that the rod can stably apply clamping force to the clamping plate to prevent the sample from loosening.

[0045] The sliding assembly uses set screws for both the first and second slide bars. Specifically, a through hole is provided on one side of the base groove, and a blind hole is provided on the other side. The set screw passes through the through hole, the top plate, and the clamping plate, and is then screwed into the blind hole for fixation. This structural design simplifies the installation and removal of the set screws and facilitates adjusting the position of the clamping plate according to the size of the sample. The two sets of set screws are preferably arranged symmetrically to ensure uniform force on the clamping plate and prevent tilting that could lead to unstable sample clamping.

[0046] Secondly, the present invention also discloses a sample preparation method for electron backscatter diffraction (EBSD) samples. This method, in conjunction with the aforementioned polishing fixture, performs vibration polishing on the ultrathin metal sample to be prepared in order to obtain a sample that meets the requirements for EBSD characterization.

[0047] In some embodiments of the present invention, the specific sample preparation method is as follows: Place the sample in the sample receiving space between the clamp and the side wall of the groove, then slide the clamp and the top plate to make the sample fit against the clamp and the side wall of the groove respectively, and the top plate fit against the clamp. Rotate the top rod to tighten the sample, and then polish it.

[0048] In summary, the polishing fixture and sample preparation method for electron backscatter diffraction (EBSD) samples provided by this invention effectively solves the problems of poor equipment compatibility, high sample preparation difficulty, high damage rate, high cost, and complex operation in the current ultrathin metal EBSD sample preparation process through reasonable structural design and process parameter optimization. It achieves low-damage and high-precision preparation of EBSD samples, and provides an efficient and reliable sample preparation scheme for the microstructure characterization of various ultrathin metal materials such as metal foils, coatings, surface modification layers, and composite metals. It has important engineering application value and promotion prospects.

[0049] Example 1 like Figures 1 to 3 As shown, a polishing fixture for electron backscatter diffraction samples includes a base 1 made of martensitic stainless steel. Martensitic stainless steel has high strength, high hardness, and good corrosion resistance, ensuring that the base is not easily deformed or rusted during long-term use, thus guaranteeing the structural stability and service life of the fixture. The base 1 is a cylinder with a diameter of 30.0 mm. This size is determined based on the clamping hole size of most commercial vibratory polishing equipment on the market. The clamping hole diameter of mainstream commercial vibratory polishing equipment is usually around 30 mm. Therefore, the 30.0 mm base diameter can be directly adapted to such equipment without additional adapter parts, significantly improving the versatility of the fixture. At the same time, a groove 2 is opened on the upper part of the base 1 for installing the sliding component and fastening component for clamping the sample. The groove 2 is located in the central area of ​​the base 1 to ensure the overall center of gravity is stable after the components are installed, preventing the fixture from shifting during polishing.

[0050] Since the standard size requirement for EBSD specimens is less than 10 mm × 10 mm × 5 mm (length × width × height), in order to ensure that the interior of groove 2 can accommodate the specimen, sliding components and fastening components, and to avoid excessive protrusion of components from the base that would interfere with the movement of the equipment, the depth of the groove is designed to be less than 12 mm.

[0051] The sliding assembly includes a first slide rod 31 and a second slide rod 32. Both the first slide rod 31 and the second slide rod 32 are set screws, preferably slotted conical set screws. These set screws have a conical head with a slot at the top, facilitating installation and removal with a flathead screwdriver. The conical head design also minimizes the space occupied by the head after installation, preventing excessive head protrusion from affecting the installation of other components or interfering with equipment movement. To ensure compatibility with the clamping holes of the vibratory polishing equipment, the lengths of the first slide rod 31 and the second slide rod 32 after assembly should not exceed the base's range. Therefore, a blind hole is provided on one side of the base in the groove 2, and a through hole is provided on the other side of the base in the groove 2. Blind holes A311 and B321 are provided on one side of the base. Both blind holes A311 and B321 are threaded holes. Blind hole A311 is used for screwing in and fixing the first slide rod 31, and blind hole B321 is used for screwing in and fixing the second slide rod 32. On the other side of the base, through holes A312 and B322 are provided to facilitate the installation and removal of the first slide rod 31 and the second slide rod 32. The depths of blind holes A311 and B321 are determined according to the lengths of the first slide rod 31 and the second slide rod 32, ensuring that the ends of the first slide rod 31 and the second slide rod 32 do not penetrate the base after being screwed in, thus avoiding affecting the structural integrity of the base. The diameter of through hole A312 matches the nominal diameter of the first slide rod 31, and the diameter of through hole B322 matches the nominal diameter of the second slide rod 32, ensuring that the first slide rod 31 and the second slide rod 32 can pass through smoothly, while avoiding wobbling caused by excessively large hole diameters.

[0052] The fixture is equipped with multiple clamping plates 4 of different materials, hardness and thickness to meet the clamping requirements of different types of ultra-thin metal samples.

[0053] When the thickness D of the surface to be characterized of the sample F When the thickness is >100 μm, the hardness H of the clip is... J =(1.4~1.8)H F H F The hardness of the surface of the sample to be characterized; When the thickness D of the surface to be characterized of the sample F When the thickness is ≤100 μm, the hardness H of the clip is... J =(1.1~1.4)H F H F The hardness of the surface of the sample to be characterized; When the thickness D of the sample S When the thickness is ≤35 μm, the sample is bonded to the clamping roller by conductive adhesive, and the thickness D of the conductive adhesive is... E =(0.15~0.28)D S ; When the elongation of the surface to be characterized is <2%, the clamping material is silicone, the Shore hardness A of the clamping is 40~65, and the thickness D of the clamping is... J=(0.2~0.4)D S D S The thickness of the sample is given.

[0054] The surface of the side of the clip that contacts the sample (i.e., the side of the clip away from the top plate) is laser-engraved with a micron-level mesh pattern. The direction of the micron-level mesh pattern forms an angle of 45° to 90° with the direction of the vibratory polishing motion, and the pattern depth d = (0.05~0.15)D. F The texture spacing s = (2.0~5.0)d, where D F The thickness of the surface to be characterized.

[0055] In use, select a suitable clip and fix it in the groove 2. The clip has two symmetrical circular holes (circular hole A and circular hole B). Through these two symmetrical circular holes, the clip 4 can be fitted onto the sliding component, making the operation simple and quick. To facilitate the disassembly and position adjustment of the clip, the diameter of circular hole A is set to 1.05 to 1.10 times the diameter of the first slide rod 31, and the diameter of circular hole B is set to 1.05 to 1.10 times the diameter of the second slide rod 32. This diameter ensures that the clip can be smoothly fitted onto the sliding component, while also preventing the clip from wobbling significantly on the sliding component due to an excessively large diameter, thus ensuring clamping stability.

[0056] The fastening assembly includes a top plate 51 and a top rod 52. The top plate 51 is also placed in the groove 2 and works in conjunction with the clamping plate 4. The top plate 51 has two symmetrical circular holes (circular hole C and circular hole D), through which the top plate 51 can be fitted onto the sliding assembly, making operation simple and quick. Due to the limitations of the EBSD sample size and the clamping holes of the vibratory polishing equipment, to expand the application range of the fixture, the top rod 52 is available in two length specifications: when the sample thickness D... S When the thickness is ≤5.0 mm, a long rod should be used for the top rod 52; when 5.0 mm < thickness D S For thicknesses ≤10.0 mm, a short rod is used for the push rod 52. The design of these two length specifications ensures that, within each thickness range, when the sample thickness is at its maximum, the end of the push rod 52 extends no more than 1.5 mm beyond the base, without affecting the polishing motion.

[0057] The push rod 52 and the top plate 51 can be connected by abutment or by threads. The end of the push rod 52 away from the top plate 51 is provided with threads. As a fit, the base is provided with a through hole C on the side with through holes A312 and B322. Through hole C is a threaded hole. By rotating the push rod 52, the axial position of the push rod 52 can be adjusted, thereby adjusting the pressure of the top plate 51 on the clamping plate 4, that is, the clamping force.

[0058] Furthermore, considering the sliding engagement between the clamping piece 4 and the top piece 51 on the first slide bar 31 and the second slide bar 32 during the clamping process, an elastic buffer sleeve 33 is provided in the slidable area of ​​the first slide bar 31 and the second slide bar 32. The outer surface of the elastic buffer sleeve 33 is provided with anti-slip ridges, the height of which is designed to be 0.1~0.3 mm and the ridge spacing to be designed to be 0.5~1.5 mm.

[0059] The assembly method of the polishing fixture in this embodiment 1 is as follows: First, select a suitable clamping piece 4, then place the clamping piece 4 and the top piece 51 in the groove 2 of the base 1 respectively. The first sliding rod 31 passes through the through hole A312 on the base 1, the round hole C of the top piece 51, and the round hole A of the clamping piece 4 in sequence, and extends into the blind hole A311 of the base 1 and is rotated and fixed. The second sliding rod 32 passes through the through hole B322 on the base 1, the round hole D of the top piece 51, and the round hole B of the clamping piece 4 in sequence, and extends into the blind hole B321 of the base 1 and is rotated and fixed. Then, place the sample in the sample receiving space formed between the clamping piece 4 and the groove 2, slide the clamping piece 4 and the top piece 51 to make the clamping piece 4 contact the sample, and then pass the top rod 52 through the through hole C on the base 1 to contact and fit with the top piece 51. Rotate the top rod 52, and its tail threadedly locks itself in the through hole C, thus completing the clamping of the sample.

[0060] Example 2 Electron backscattering diffraction (EBSD) samples were prepared using the polishing fixture described in Example 1. Four different types of ultrathin metal samples were selected and subjected to fixture assembly, mechanical polishing, and vibration polishing, respectively. The samples were then characterized using an EBSD detection device, and the pattern recognition rate was statistically analyzed. Specific experimental parameters and results are shown in Table 1 below. In Table 1, D... F The symbol “——” indicates the thickness D of the surface to be characterized. F With the sample thickness D S equal.

[0061] Table 1. EBSD sample preparation matching parameters for different specimens

[0062] It is evident that when using the polishing fixture of this invention for sample preparation, the EBSD recognition rate is above 85%, which can meet the actual use requirements.

[0063] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A polishing fixture for electron backscatter diffraction samples, comprising a base, characterized in that, The upper surface of the base is provided with a groove, and a clamping piece is provided in the groove. The clamping piece has a circular hole A and a circular hole B. One side of the clamping piece and the side wall of the groove form a sample receiving space. A top piece is provided on the other side of the clamping piece. The top piece has a circular hole C and a circular hole D. A first sliding rod passes through the circular holes A and C, and a second sliding rod passes through the circular holes B and D. The two ends of the first sliding rod are fixedly connected to the base on both sides of the groove, and the two ends of the second sliding rod are fixedly connected to the base on both sides of the groove, so that the clamping piece and the top piece can slide along the first sliding rod and the second sliding rod in the groove. A top rod is provided on the side of the top piece away from the clamping piece. The end of the top rod away from the top piece is connected to the base by a thread. The hardness of the clip is determined according to the following formula: When the thickness D of the surface to be characterized of the sample F When the thickness is >100 μm, the hardness H of the clip is... J =(1.4~1.8)H F , When the thickness D of the surface to be characterized of the sample F When the thickness is ≤100 μm, the hardness H of the clip is... J =(1.1~1.4)H F , In the formula, H F The hardness of the surface of the sample to be characterized; The surface of the clip that contacts the sample is provided with a micron-level grid pattern; The micron-level mesh texture has an angle of 45° to 90° with the direction of vibration polishing, and the texture depth d = (0.05~0.15)D. F The texture spacing s = (2.0~5.0)d, where D F The thickness of the surface to be characterized.

2. A polishing fixture for electron backscatter diffraction samples as described in claim 1, characterized in that, When the thickness D of the sample S When the thickness is ≤35 μm, the sample is bonded to the clamping roller by conductive adhesive, wherein the thickness D of the conductive adhesive is... E =(0.15~0.28)D S .

3. A polishing fixture for electron backscatter diffraction samples as described in claim 1, characterized in that, When the elongation of the surface to be characterized is <2%, the clamping material is silicone, the Shore hardness A of the clamping is 40~65, and the thickness D of the clamping is... J =(0.2~0.4)D S In the formula, D S The thickness of the sample is given.

4. A polishing fixture for electron backscatter diffraction samples as described in claim 1, characterized in that, The diameter of the circular hole A on the clamp is 1.05 to 1.10 times the diameter of the first sliding rod; the diameter of the circular hole B on the clamp is 1.05 to 1.10 times the diameter of the second sliding rod.

5. A polishing fixture for electron backscatter diffraction samples as described in claim 1, characterized in that, Elastic buffer sleeves are fitted on the outer sides of the first slide rod and the second slide rod, respectively, and the surface of the elastic buffer sleeves is provided with anti-slip embossing.

6. A polishing fixture for electron backscatter diffraction samples as described in claim 5, characterized in that, The height of the anti-slip ridges on the surface of the elastic buffer sleeve is 0.1~0.3 mm, and the ridge spacing is 0.5~1.5 mm.

7. A polishing fixture for electron backscatter diffraction samples as described in claim 1, characterized in that, The outer diameter of the base is compatible with the clamping hole size of commercial vibratory polishing equipment.

Images