In-situ microcolumn compression experiment alignment method

Abstract

This application provides an in-situ micropillar compression experiment alignment method, relating to the field of micro / nano mechanical testing instrument technology. The method includes: acquiring a sample; providing a mechanically self-locking alignment device, placing the sample and an in-situ indenter on the mechanically self-locking alignment device to perform macroscopic positioning of the sample, and transferring the sample to the in-situ indenter; removing the in-situ indenter from the mechanically self-locking alignment device and placing it under an electron microscope; controlling a probe to sequentially contact two marks, acquiring coordinate data of the two marks respectively; obtaining the positional deviation of the micropillar relative to the marks in the probe's motion coordinate system based on the coordinate data; controlling the probe to move directly above one of the marks based on the coordinate data; and controlling the probe to move from directly above the mark to directly above the micropillar based on the positional deviation. This application can solve the significant shortcomings of existing sample mounting and alignment technologies in terms of positioning accuracy, operational safety, and engineering reliability.

Description

Technical Field

[0001] This application relates to the field of micro-nano mechanical testing instruments, and in particular to an in-situ micropillar compression experiment alignment method. Background Technology

[0002] In-situ micropillar compression experiments are a crucial method for characterizing the yield strength, work hardening behavior, and deformation mechanisms of materials at the micro- and nano-scale. The core requirement is ensuring that the probe loading axis is highly aligned with the geometric center axis of the micropillar sample. Ideally, the micropillar should withstand pure uniaxial compressive stress. However, since the size of micropillar samples is typically only on the order of micrometers, the alignment tolerance is extremely small (usually less than 500 nm). Once eccentric loading occurs, unexpected additional bending moments will be generated inside the micropillar, leading to stress concentration in the elastic stage of the sample and inducing premature buckling or local shear instability. Ultimately, this results in severely distorted stress-strain curves that fail to accurately reflect the intrinsic mechanical properties of the material.

[0003] Despite the development of in-situ testing technology over the years, existing sample mounting and alignment techniques still have significant shortcomings in terms of positioning accuracy, operational safety, and engineering reliability. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of this application is to provide an in-situ micropillar compression experimental alignment method.

[0005] This application provides the following technical solution: An in-situ micropillar compression experiment alignment method, comprising: A sample is obtained, the sample surface is provided with micropillars and markers, the markers are arranged in pairs on both sides of the micropillars and are symmetrical about the micropillars; A mechanical self-locking alignment device is provided, in which the sample and the in-situ indenter are placed respectively. The mechanical self-locking alignment device is used to perform macroscopic positioning of the sample and transfer the sample to the in-situ indenter, so that the micropillar is located within the preset tolerance range of the theoretical landing point of the probe of the in-situ indenter. The in-situ indenter was removed from the mechanical self-locking alignment device and placed under an electron microscope; The probe is controlled to contact the two marks in sequence, and the coordinate data of the two marks are collected respectively; The positional deviation of the micropillar relative to the mark in the motion coordinate system of the probe is obtained based on the coordinate data. The probe is controlled to move directly above one of the markers based on the coordinate data; The probe is controlled to move from directly above the mark to directly above the micropillar based on the positional deviation.

[0006] As a further optional embodiment of the in-situ micropillar compression experimental alignment method, after the step of controlling the probe to move directly above one of the markers based on the coordinate data, the method further includes: The electron microscope is switched to high-resolution imaging mode, and the high-magnification image of the electron microscope is used to confirm the overlap of the projection of the probe and the mark for the second time.

[0007] As a further optional scheme for the alignment method of the in-situ micropillar compression experiment, the coordinate data of the two markers are A(x1, z1) and B(x2, z2), respectively, and the positional deviation is (∆X, ∆Z), satisfying: ;or, .

[0008] As a further alternative to the in-situ micropillar compression experiment alignment method, both the micropillar and the marker are etched onto the substrate of the sample using a focused ion beam.

[0009] As a further optional solution to the in-situ microcolumn compression experiment alignment method, the mechanical self-locking alignment device includes a mounting base, a limiting frame, a protective shell, a guide rail cover, and a sample boat. The limiting frame is embedded in the mounting base, the bottom end of the protective shell is fixedly connected to the limiting frame, the guide rail cover is disposed at the top end of the protective shell, and the sample boat is slidably engaged with the guide rail cover.

[0010] As a further optional approach to the in-situ micropillar compression alignment method, the step of placing the sample in the mechanically self-locking alignment device includes: The sample is placed in the sample boat.

[0011] As a further optional embodiment of the in-situ micropillar compression experiment alignment method, the step of placing the in-situ indenter in the mechanically self-locking alignment device includes: The in-situ indenter is placed inside the protective housing.

[0012] As a further optional approach to the in-situ micropillar compression experiment alignment method, the step of macroscopically positioning the sample using the mechanical self-locking alignment device includes: The sample boat is pushed into the guide rail cover until the sample boat abuts against the guide rail cover along its own sliding direction.

[0013] As a further optional method for the in-situ micropillar compression experiment alignment, the sample is provided with an adhesive layer; The step of transferring the sample to the in-situ indenter includes: Press the sample to bond it to the in-situ indenter through the adhesive layer.

[0014] As a further optional scheme for the alignment method of the in-situ micropillar compression experiment, the preset tolerance is less than 5 μm.

[0015] The embodiments of this application have the following beneficial effects: The above-described in-situ micropillar compression experiment alignment method is used to position the micropillars before conducting the in-situ micropillar compression experiment. First, during sample preparation, in addition to forming micropillars on the sample surface, symmetrical marks about the micropillars are also formed on both sides of the micropillars. Then, the sample and the in-situ indenter are placed in a mechanically self-locking alignment device to macroscopically position the micropillars. The sample is then transferred to the in-situ indenter, ensuring that the micropillars are within the preset tolerance range of the probe's theoretical landing point, i.e., within the effective stroke of the drive mechanism in the in-situ indenter. This ensures that the probe can be precisely aligned with the micropillar through micro-fine-tuning via the drive mechanism. Subsequently, the in-situ indenter, along with the sample, is removed from the mechanically self-locking alignment device and placed under an electron microscope. The probe is controlled to sequentially contact the two marks, and the coordinate data of the two marks are collected. Since the two marks are symmetrically arranged about the micropillars, the positional deviation of the micropillars relative to either mark can be obtained from this coordinate data. Based on this, the probe is first moved to directly above one of the markers according to the coordinate data. Then, based on the positional deviation, the probe is moved from directly above the marker to directly above the micropillar, ultimately achieving precise alignment between the probe and the micropillar. During this process, direct contact between the probe and the marker completely avoids misjudgments caused by parallax effects, resulting in "visual alignment but physical misalignment." Simultaneously, direct contact between the probe and the marker, rather than directly with the micropillar, allows the position of the micropillar to be indirectly determined using the symmetry of the two markers about the micropillar. This avoids scratches on the micropillar surface caused by direct contact without precise alignment, thus preventing interference with subsequent in-situ micropillar compression experiments.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating the steps of the in-situ micropillar compression experiment alignment method in an embodiment of this application is shown. Figure 2 A partial structural schematic diagram of the sample boat in an embodiment of this application is shown; Figure 3 A schematic diagram of the mechanical self-locking alignment device in an embodiment of this application is shown; Figure 4 The diagram shows a comparison of the deformation behavior and mechanical response of in-situ micropillar compression experiments in the embodiments and comparative examples of this application.

[0019] Explanation of key component symbols: 100 - Sample; 110 - Microcolumn; 120 - Marker; 200 - Mounting base; 300 - Limiting frame; 400 - Protective housing; 500 - Guide rail cover; 600 - Sample boat. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] The inventors of this application have discovered that, among existing in-situ testing technologies, sample mounting and alignment technologies mainly fall into the following two categories.

[0022] The first category is the existing, commonly used visual-assisted alignment technology, which is frequently found in commercial in-situ mechanical testing platforms based on open sample stages. This type of approach typically employs a completely open structural design, requiring experimenters to operate a precision displacement mechanism on the outside of the scanning electron microscope (SEM) and rely on visual observation within the two-dimensional projection field of the SEM for alignment.

[0023] This technical solution suffers from significant fundamental flaws. First, SEM images are essentially projections of three-dimensional objects onto a two-dimensional plane, lacking a direct spatial reference in the depth direction (Z-axis). Operators are highly susceptible to parallax effects, leading to misjudgments of "visual alignment but physical misalignment," resulting in highly discrete and difficult-to-reproduce experimental data. Second, this process is extremely dependent on operator experience, belonging to a typical open-loop control mode. Furthermore, due to the lack of physical limits and guidance structures, during blind operation, even minor misoperations can easily cause the expensive diamond probe to rigidly collide with the sample stage, resulting in permanent damage to core components.

[0024] The second category is the active photoelectric alignment technology proposed by the applicant (see patent CN117929109B - An in-situ nanoindentation probe clamping system and sample mounting device). To overcome the instability of manual operation, this active photoelectric alignment technology attempts to introduce a closed-loop automatic alignment system that includes laser feedback and precision electric control.

[0025] However, long-term engineering practice and application have revealed that while this technical solution achieves automation at the theoretical level, its high system integration and lack of necessary mechanical protection for precision components result in severely insufficient engineering robustness in practical applications. The system integrates a laser emitting / receiving module, a retractable electromagnetic adsorption device, and a multi-axis precision rotating mechanism. These highly sensitive precision components are exposed within the confined space of the electron microscope chamber. During the actual operation of probe clamping or sample mounting, the lack of rigid mechanical shielding and guidance makes it extremely easy for even slight operational errors or minor mechanical vibrations to cause micro-displacement of the precision optoelectronic components or even breakage at the probe root. This low fault tolerance characteristic resulting from high precision means that every sample mounting process carries an extremely high risk of equipment damage, placing extremely stringent demands on the operating environment and personnel skills, and leading to a sharp increase in equipment maintenance costs, making it difficult to meet the experimental requirements of high throughput and high stability.

[0026] In summary, the first type of sample installation and alignment technology suffers from insufficient positioning accuracy and high risk of misalignment due to the lack of a guiding reference, while the second type of sample installation and alignment technology suffers from easy damage and difficult maintenance due to the overly precise and fragile system.

[0027] For the above issues, please refer to Figure 1 This embodiment provides an in-situ micropillar compression experiment alignment method, including the following steps: S1, Obtain 100 samples.

[0028] The sample 100 has micropillars 110 and markers 120 on its surface. The markers 120 are arranged in pairs on both sides of the micropillars 110 and are symmetrical about the micropillars 110.

[0029] In some embodiments, both the micropillar 110 and the marker 120 are etched onto the substrate of the sample 100 using a focused ion beam. The focused ion beam has high processing precision, ensuring that the micropillar 110 is located at the midpoint of the line connecting the two markers 120, making the two markers 120 symmetrical about the micropillar 110.

[0030] For example, a circular groove is etched on the substrate of sample 100 using a focused ion beam, with micropillar 110 as the center. Subsequently, a linear groove is etched on the substrate on both sides of micropillar 110 using a focused ion beam. The two linear grooves are located on the same straight line, and the straight line passes through micropillar 110. At this point, the intersection of the circular groove and the two linear grooves is the mark 120.

[0031] S2 provides a mechanical self-locking alignment device, which places the sample 100 and the in-situ indenter in the mechanical self-locking alignment device, macroscopically positions the sample 100 using the mechanical self-locking alignment device, and transfers the sample 100 to the in-situ indenter, so that the micropillar 110 is within the preset tolerance range of the theoretical landing point of the probe of the in-situ indenter.

[0032] Understandably, the mark 120 on sample 100 is located adjacent to micropillar 110, and the mark 120 is also within the preset tolerance range of the probe's theoretical landing point.

[0033] It should be noted that in-situ micropillar compression experiments require the use of an in-situ indenter and an electron microscope. During the experiment, the in-situ indenter is placed inside the electron microscope. The probe of the in-situ indenter presses against the micropillar 110, compressing the micropillar 110, and the in-situ observation is performed through the electron microscope.

[0034] Based on this, when performing step S2 above, the in-situ indenter must first be removed from inside the electron microscope, and then the in-situ indenter must be transferred to an external stage for sample loading.

[0035] Please see Figure 3 In some embodiments, the mechanical self-locking alignment device includes a mounting base 200, a limiting frame 300, a protective housing 400, a guide rail cover 500, and a sample boat 600. The limiting frame 300 is embedded in the mounting base 200, the bottom end of the protective housing 400 is fixedly connected to the limiting frame 300, the guide rail cover 500 is disposed at the top end of the protective housing 400, and the sample boat 100 is slidably engaged with the guide rail cover 500.

[0036] Among them, the mounting base 200 serves as the mechanical load-bearing foundation of the entire system. It is made of high-rigidity material and its bottom is designed with a standard interface that mates with the aforementioned platform. Rigid connection is achieved through positioning pins or threads to eliminate the overall mechanical flexibility of the system.

[0037] The bottom end of the limiting frame 300 is tightly nested above the mounting base 200, and the top end is integrally formed with the protective shell 400. The limiting frame 300 has a U-shaped clamp structure, and its inner surface is precision ground to provide a micron-level lateral (Y-axis) positioning reference for the protective shell 400, effectively preventing lateral micro-movement of the device during experimental stress.

[0038] The protective housing 400 is a hollow cuboid structure, forming a closed safety chamber inside, specifically designed to house the sensors and piezoelectric ceramic components of the in-situ nanoindentation instrument.

[0039] The guide rail cover 500, which covers the top of the protective housing 400, is a key component for achieving precise alignment. Its upper surface is milled with a rectangular guide groove, the central axis of which has been pre-calibrated and aligned with the theoretical loading center axis of the probe during the design and manufacturing stage through precision machining.

[0040] The sample boat 600 is used in conjunction with the guide rail cover 500. This component is used for further precise positioning, and its outer contour forms a precise clearance fit with the guide groove of the guide rail cover 500. The sample boat 600 is engraved with laser reference lines and has only a single degree of freedom for feeding along the guide groove.

[0041] Specifically, in use, the mounting base 200 is rigidly fixed to the platform with bolts to ensure that the mounting base 200 does not wobble. Then, the limiting bracket 300 is inserted into the positioning groove of the mounting base 200. The U-shaped inner wall of the limiting bracket 300 forms the first level of lateral constraint, thus fixing the protective housing 400. Finally, the guide rail cover 500 is fastened to the top of the protective housing 400 and locked.

[0042] Accordingly, in some embodiments, the operation of placing the sample 100 in the mechanical self-locking alignment device in step S2 above is as follows: Place sample 100 in sample boat 600.

[0043] Furthermore, in some embodiments, the operation of placing the in-situ indenter in the mechanical self-locking alignment device in step S2 above is as follows: Place the in-situ indentation instrument into the protective housing 400.

[0044] It should be noted that the protective housing 400 is provided with a window. After the in-situ indenter is placed inside the protective housing 400, the tip of the probe protrudes through the window.

[0045] At this point, the root of the probe, the precision sensor in the in-situ indenter, and the piezoelectric ceramic component that serves as the driving mechanism are all completely enclosed by the protective housing 400. During the alignment process, they are protected by the protective housing 400 and do not collide with other components, effectively preventing accidental bumps during installation. This solves the problem of existing active photoelectric technology being easily damaged due to its precision and fragility, and significantly reduces equipment maintenance costs.

[0046] In some embodiments, the operation of macroscopically positioning the sample 100 using a mechanical self-locking alignment device in step S2 is as follows: Push the sample boat 600 into the guide rail cover 500 until the sample boat 600 abuts against the guide rail cover 500 along its own sliding direction.

[0047] In other words, when the sample boat 600 is pressed against the guide rail cover 500 and cannot continue to slide, the sample boat 600 reaches the mechanical zero point and completes the self-locking position.

[0048] In some embodiments, the sample 100 is provided with an adhesive layer.

[0049] For example, the lower end of sample 100 is coated with conductive silver paste to form an adhesive layer.

[0050] Accordingly, the operation of transferring sample 100 to the in-situ indenter in step S2 is as follows: Press the sample 100 so that it adheres to the in-situ indenter through the adhesive layer.

[0051] Understandably, after macroscopically positioning the sample 100 using the mechanical self-locking alignment device, the sample 100 is roughly aligned with the probe and close to other parts of the in-situ indenter. At this point, only a slight downward force needs to be applied to the sample 100 to make it adhere to the in-situ indenter and then transfer it to the in-situ indenter.

[0052] Furthermore, in some embodiments, the preset tolerance is less than 5 μm.

[0053] S3. Remove the in-situ indenter from the mechanical self-locking alignment device and place it under the electron microscope.

[0054] As mentioned above, the micropillar 110 is macroscopically positioned using a mechanical self-locking alignment device, and after the sample 100 is transferred to the in-situ indenter, the micropillar 110 is already within the preset tolerance range of the theoretical landing point of the probe of the in-situ indenter.

[0055] Based on this, the in-situ indenter, together with the sample 100, is placed in the electron microscope. The micropillar 110 is also located within the field of view of the electron microscope, allowing the experimenter to quickly and directly capture the micropillar 110 through the electron microscope. This eliminates the need for the experimenter to repeatedly move the sample 100 under the large field of view of the electron microscope to search for the tiny micropillar 110, thus saving a significant amount of time.

[0056] S4, control the probe to contact the two markers 120 in sequence, and collect the coordinate data of the two markers 120 respectively.

[0057] Specifically, the coordinate data of the two markers 120 are A(x1, z1) and B(x2, z2).

[0058] S5, obtain the positional deviation of the micropillar 110 relative to the mark 120 in the motion coordinate system of the probe based on the coordinate data.

[0059] Specifically, the positional deviation is denoted as (∆X, ∆Z).

[0060] The positional deviation of micropillar 110 relative to marker B 120 in the probe's motion coordinate system satisfies: .

[0061] Alternatively, the positional deviation of the micropillar 110 relative to the A mark 120 in the probe's motion coordinate system satisfies: .

[0062] S6, based on the coordinate data, controls the probe to move directly above one of the markers 120.

[0063] Understandably, "directly above" for the mark 120 specifically refers to "directly above" the geometric center of the mark 120.

[0064] S7, based on the positional deviation, control the probe to move from directly above the mark 120 to directly above the micropillar 110.

[0065] Understandably, "directly above" of micropillar 110 specifically refers to "directly above" the geometric center axis of micropillar 110.

[0066] Furthermore, when the probe moves from directly above the marker 120 to directly above the micropillar 110, its actual movement increment in its own motion coordinate system is consistent with the position deviation (∆X, ∆Z).

[0067] If the probe moves from directly above marker B 120 to directly above micropillar 110, then: .

[0068] If the probe moves from directly above marker A 120 to directly above micropillar 110, then: .

[0069] Furthermore, in some embodiments, after step S6, the following step is also included: S6`, switch the electron microscope to high-resolution imaging mode, and use the high-magnification image of the electron microscope to make a secondary confirmation of the overlap between the projection of the probe and the marker 120.

[0070] Secondary confirmation can further improve the alignment accuracy between the probe and the marker 120. Based on the precise alignment of the probe and the marker 120, controlling the probe movement according to the positional deviation is beneficial for the precise alignment of the probe and the micropillar 110.

[0071] In summary, the above-mentioned in-situ microcolumn compression experiment alignment method is used to position the microcolumn 110 before conducting the in-situ microcolumn compression experiment. First, when preparing the sample 100, in addition to forming the microcolumn 110 on the surface of the sample 100, symmetrical markings 120 about the microcolumn 110 are also formed on both sides of the microcolumn 110. Subsequently, sample 100 and the in-situ indenter were placed in a mechanically self-locking alignment device. The device was used to macroscopically position the micropillar 110. Sample 100 was then transferred to the in-situ indenter, ensuring the micropillar 110 was within the preset tolerance range of the probe's theoretical landing point. This meant the micropillar 110 was within the effective stroke of the drive mechanism in the in-situ indenter, allowing for precise micro-adjustment of the probe to the micropillar 110. Simultaneously, this ensured the micropillar 110 remained within the electron microscope's field of view during subsequent fine-tuning, enabling researchers to quickly and directly locate it without repeatedly moving the sample boat 600 to search for the tiny micropillar 110 within the electron microscope's large field of view, significantly saving time. The in-situ indenter, along with sample 100, was then removed from the mechanically self-locking alignment device and placed under the electron microscope. The control probe was then sequentially contacted with two markers 120, and their coordinate data were collected. Since the two markers 120 are symmetrically positioned about the micropillar 110, the positional deviation of the micropillar 110 relative to any one of the markers 120 can be obtained based on this coordinate data. Based on this, the probe is first moved to be directly above one of the markers 120 according to the coordinate data, and then moved from directly above the marker 120 to directly above the micropillar 110 according to the positional deviation. This achieves precise alignment between the probe and the micropillar 110, with a positioning accuracy of 10 nm, a significant improvement over the previous 20 nm accuracy. During this process, direct contact between the probe and the marker 120 completely avoids misjudgments caused by parallax effects, resulting in "visual alignment but physical misalignment." Simultaneously, direct contact between the probe and the marker 120, rather than directly with the micropillar 110, allows the position of the micropillar 110 to be indirectly determined by the symmetry of the two markers 120 about the micropillar 110. This avoids scratches on the surface of the micropillar 110 caused by direct contact without precise alignment, thus preventing interference with subsequent in-situ micropillar compression experiments.

[0072] It should be noted that after step S3, steps S4, S5, S6, S6', and S7 are all performed inside the electron microscope. In particular, whether it is controlling the probe to contact the mark 120 in step S4, or performing a secondary confirmation of the overlap between the projection of the probe and the mark 120 in step S6', the operator can directly observe the probe through the electron microscope, making full use of the high resolution of the electron microscope to achieve high-precision positioning of the probe.

[0073] In contrast, the applicant's proposed active photoelectric alignment technology performs the alignment operation outside the scanning electron microscope (SEM). The sample and probe are only placed inside the SEM for nanomechanical property testing after the sample and probe are installed. In other words, the SEM does not participate in the alignment process, and its high resolution is not fully utilized.

[0074] The above-described in-situ micropillar compression alignment method combines external and internal electron microscope operations. First, the sample 100 is macroscopically positioned externally using a mechanical self-locking alignment device, so that the micropillar 110 is within the 5μm tolerance range of the theoretical landing point of the in-situ indenter probe. Then, the micropillar 110 is precisely positioned internally using the specific positional relationship between the two markers 120 and the micropillar 110 (the two markers 120 are symmetrical about the micropillar 110). This achieves the synergy of the micropillar 110, the mechanical self-locking alignment device, and the internal electron microscope operation, ultimately achieving a positioning accuracy of 10nm between the probe and the micropillar 110.

[0075] TiN ceramic micropillars 110 (approximately 2 μm in diameter) prepared in the same batch were selected for both example and comparative experiments, as follows: Example The sample boat 600, carrying sample 100, slides into the guide groove on the guide rail cover 500 until it reaches the limiting position. Utilizing the mechanical self-locking function of the mechanical self-locking alignment device, the micropillar 110 is quickly and physically locked within the preset tolerance range of the electron microscope's field of view and the theoretical landing point of the probe. This process simplifies the originally complex three-dimensional search process into a unidirectional mechanical sliding, taking only a few seconds, significantly improving alignment efficiency and greatly reducing reliance on the experimenter's experience. Simultaneously, this mechanical limiting mechanism physically locks the minimum safe distance between the probe and the micropillar 110 in the Z-axis direction, providing rigid anti-collision protection for subsequent nanoscale operations.

[0076] Subsequently, based on mechanical positioning, contact coordinate correction is performed. In the X-axis direction, the control probe makes light contact with two markers 120 in sequence with low load (usually ≤5μN), and collects the coordinate data of the two markers 120 respectively, thereby obtaining the positional deviation of the micropillar 110 relative to any one of the markers 120.

[0077] Finally, based on the coordinate data, the probe is first moved to be directly above one of the markers 120, and the electron microscope is switched to high-resolution imaging mode. The high-magnification image of the electron microscope is used to confirm the projection overlap between the probe and the marker 120 for the second time. Then, based on the aforementioned positional deviation, the probe is moved from directly above the marker 120 to directly above the micropillar 110, ultimately achieving sub-micron level precise overlap between the probe loading axis and the geometric center axis of the micropillar 110 in three-dimensional space.

[0078] Through the synergistic effect of the aforementioned mechanical self-locking alignment device and the in-situ micropillar compression experiment alignment method, the entire alignment process (including mechanical installation and microscopic correction) is shortened to less than 5 minutes. Experimental results are as follows: Figure 4 As shown in (b), (c), and (d), throughout the compression process, the three micropillars 110 maintained perfect axisymmetric deformation without any bending or tilting, proving that the load was always applied along the geometric central axis. The corresponding data are as follows: Figure 4 As shown in the colored curves (TiN-2 / 3 / 4) in (e), the three curves are highly overlapping, the measured yield strength is stable at around 11 GPa, the linearity in the elastic stage is excellent, and the micro-pillar 110 maintains axisymmetric uniform drum-shaped deformation throughout the loading process, indicating that ideal uniaxial compression has been achieved.

[0079] Comparative Example Using existing, commonly used open-stage technology, the entire experiment relied on manual visual searching and alignment by the operator under a scanning electron microscope. The experiment revealed three significant drawbacks of the existing technology: (1) The alignment time is extremely high and inefficient. Due to the lack of physical limiting reference, the experimenter needs to repeatedly move the sample stage under the large field of view of the SEM to find the tiny micropillar 110, and then perform reciprocating trial approximation in the X, Y and Z axes. The average time for searching and aligning a single micropillar 110 is more than 30 minutes, which seriously restricts the efficiency of acquiring high-throughput mechanical data.

[0080] (2) The operation is cumbersome and the risk of damage to the micropillar 110 and the equipment is extremely high. In the open space lacking guidance constraints, the relative position of the probe and the micropillar 110 depends entirely on visual judgment, which is prone to misjudgment due to parallax effect. In this comparative experiment, an accident occurred where the probe accidentally scratched the side wall of the micropillar 110 due to a misjudgment of the Z-axis depth, causing damage to the surface of the micropillar 110. The experimental results are as follows: Figure 4 (a) and Figure 4 As shown by the black curve (TiN-1) in (e), the damaged and misaligned micropillar 110 underwent non-uniform deformation in the early stage of compression (when the strain was less than 2%), resulting in premature initiation of local shear bands. The measured yield strength was only about 9 GPa, and the elastic modulus was too low, indicating serious data distortion.

[0081] (3) The process requires highly skilled operators and is difficult to promote. The process requires operators to have excellent hand-eye coordination and extensive experience in electron microscopy. Ordinary experimental personnel cannot master it in a short period of time, which leads to a high degree of personnel dependence and randomness in the success rate of the experiment.

[0082] Comparative analysis shows that the aforementioned in-situ microcolumn compression experiment alignment method, through the precise fit between the guide groove and the sample boat, eliminates parallax errors and hand tremors inherent in manual operation, fundamentally preventing pressure deviation and significantly improving the accuracy and repeatability of in-situ microcolumn compression experimental data. Furthermore, this method, by using a fully enclosed protective shell and an embedded limiting frame, physically isolates the sensitive sensor and probe root, effectively preventing accidental bumps during installation. This solves the problem of existing active photoelectric technologies being fragile and easily damaged, significantly reducing equipment maintenance costs. Finally, this method utilizes a "plug-and-play" single-degree-of-freedom sliding installation method, reducing the installation and alignment time for a single sample 100 from tens of minutes to less than one minute, without requiring cumbersome calibration and debugging, thus greatly improving experimental efficiency.

[0083] In summary, the above-mentioned in-situ microcolumn compression test alignment method effectively ensures the high robustness of in-situ mechanical testing and the extremely high reliability of data while significantly reducing the operational threshold and time cost.

[0084] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A method for in-situ micropillar compression experiment alignment, characterized in that, include: A sample is obtained, the sample surface is provided with micropillars and markers, the markers are arranged in pairs on both sides of the micropillars and are symmetrical about the micropillars; A mechanical self-locking alignment device is provided, in which the sample and the in-situ indenter are placed respectively. The mechanical self-locking alignment device is used to perform macroscopic positioning of the sample and transfer the sample to the in-situ indenter, so that the micropillar is located within the preset tolerance range of the theoretical landing point of the probe of the in-situ indenter. The in-situ indenter was removed from the mechanical self-locking alignment device and placed under an electron microscope; The probe is controlled to contact the two marks in sequence, and the coordinate data of the two marks are collected respectively; The positional deviation of the micropillar relative to the mark in the motion coordinate system of the probe is obtained based on the coordinate data. The probe is controlled to move directly above one of the markers based on the coordinate data; The probe is controlled to move from directly above the mark to directly above the micropillar based on the positional deviation.

2. The in-situ micropillar compression experiment alignment method according to claim 1, characterized in that, Following the step of controlling the probe to move directly above one of the markers based on the coordinate data, the method further includes: The electron microscope is switched to high-resolution imaging mode, and the high-magnification image of the electron microscope is used to confirm the overlap of the projection of the probe and the mark for the second time.

3. The in-situ micropillar compression experiment alignment method according to claim 1, characterized in that, The coordinate data of the two markers are A(x1, z1) and B(x2, z2), respectively, and the positional deviation is (∆X, ∆Z), satisfying: ;or, 。 4. The in-situ micropillar compression experiment alignment method according to claim 1, characterized in that, Both the micropillars and the markers were etched onto the substrate of the sample using a focused ion beam.

5. The in-situ micropillar compression experiment alignment method according to claim 1, characterized in that, The mechanical self-locking alignment device includes a mounting base, a limiting frame, a protective housing, a guide rail cover, and a sample boat. The limiting frame is embedded in the mounting base, the bottom end of the protective housing is fixedly connected to the limiting frame, the guide rail cover is disposed at the top end of the protective housing, and the sample boat is slidably engaged with the guide rail cover.

6. The in-situ micropillar compression experiment alignment method according to claim 5, characterized in that, The step of placing the sample in the mechanically self-locking alignment device includes: The sample is placed in the sample boat.

7. The in-situ micropillar compression experiment alignment method according to claim 5, characterized in that, The step of placing the in-situ indenter in the mechanical self-locking alignment device includes: The in-situ indenter is placed inside the protective housing.

8. The in-situ micropillar compression experiment alignment method according to claim 5, characterized in that, The step of macroscopically positioning the sample using the mechanical self-locking alignment device includes: The sample boat is pushed into the guide rail cover until the sample boat abuts against the guide rail cover along its own sliding direction.

9. The in-situ micropillar compression experiment alignment method according to claim 5, characterized in that, The sample has an adhesive layer; The step of transferring the sample to the in-situ indenter includes: Press the sample to bond it to the in-situ indenter through the adhesive layer.

10. The in-situ micropillar compression experimental alignment method according to any one of claims 1 to 9, characterized in that, The preset tolerance is less than 5μm.

Images