A rapid annealing apparatus and method for micro / nano-scale metal samples

Abstract

This invention discloses a rapid annealing apparatus and method for micro / nano-scale metal samples. A metal indenter and a micro / nano-scale metal sample are prepared separately. The micro / nano-scale metal sample is placed at the fixed end of an electromechanical sample rod, while the metal indenter is mounted on the movable end, with the two ends facing each other without contact. Under a transmission electron microscope, the metal indenter is aligned and brought closer to the sample by a piezoelectric ceramic drive. After the indenter and the micro / nano-scale metal sample reach critical contact, several pulsed currents are applied. Then, by controlling the displacement of the piezoelectric ceramic, the cyclic movement of the metal indenter is achieved, thereby applying a constant strain amplitude of pressure-pressure cyclic loading to the micro / nano-scale metal sample. Then, pulsed currents are applied again, and this process is repeated multiple times, thus achieving rapid annealing of the micro / nano-scale metal sample using electromechanical coupling. The micro / nano-scale metal sample annealing method of this invention allows for in-situ observation at the micro / nano scale, with controllable parameters, high success rate, high efficiency, and good stability.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano technology, specifically relating to a device and method for achieving rapid annealing of micro-nano scale metal samples using electromechanical coupling. Background Technology

[0002] Annealing is a widely used heat treatment process. The purpose of annealing is to improve or eliminate various structural defects and residual stresses caused by various processing of metal materials, prevent deformation and cracking, and improve the mechanical properties of metal parts.

[0003] However, traditional macroscopic metal heat treatment annealing processes also lack controllability, real-time performance, and stability. Traditional annealing processes require tens of minutes to several hours, waiting for heavy molds, accessories, and other unrelated components to be uniformly heated to the same temperature. However, due to the structure of the molds and other factors, the thermal environment of the components is uncontrollable and unstable. At the micro-nano scale, the thermal environment between different regions can vary greatly, and it is impossible to observe and adjust it in real time. Therefore, the stability and repeatability of the annealing process are absolutely questionable, posing a challenge to the annealing treatment of micro- and nano-scale materials.

[0004] Meanwhile, in micro- and nano-scale device systems, materials at the micro- and nano-scale need to be controllably processed into designed shapes to meet structural requirements. However, compared to macroscopic materials, even metals like copper and aluminum, which have good plastic deformation capabilities, become unstable at the micro- and nano-scale.

[0005] Meanwhile, during the fabrication of micro- and nanostructures, differences in physicochemical properties such as material composition, orientation, and melting point inevitably introduce localized stresses, leading to an uncontrollable initial state of the prepared sample. These introduced stresses result in excessively high dislocation densities, which significantly impact the sample's mechanical properties. Therefore, annealing is necessary to regulate dislocation density, improve the sample's mechanical properties, and facilitate subsequent characterization, observation, and testing.

[0006] Therefore, there is indeed a lack of a controllable, easy-to-operate, and stable rapid annealing method for micro- and nano-scale metal samples. Summary of the Invention

[0007] To address the problems existing in the background technology, this invention provides a rapid annealing method for micro / nano-scale metal samples using force-electric coupling. During the annealing process, the dislocation density changes of the micro / nano-scale metal sample can be directly observed. This method can quickly and stably remove excessively high dislocation densities in micro / nano-scale metal samples with a high success rate, thereby facilitating the control of the mechanical properties of the micro / nano-scale metal samples. It is energy-efficient, has high annealing efficiency, and is environmentally friendly. The annealing process is continuous and stable, avoiding destructive deformation of the micro / nano-scale metal sample. By rationally setting processing parameters, controllable annealing of micro / nano-scale metal samples of different materials can be achieved.

[0008] The technical solution adopted in this invention is as follows:

[0009] I. A device for rapid annealing of micro / nano-scale metal samples using electromechanical coupling

[0010] The system includes an electrochemical etching system, a transmission electron microscope (TEM), a focused ion beam-scanning electron microscope (FSE-SEM) dual-beam system, and an electromechanical single-tilt sample holder and its in-situ control system. The electrochemical etching system is used to process metal wires to obtain metal indenters. The TEM is used to observe the relative position and movement of micro / nano-scale metal samples and metal indenters, as well as the annealing process of micro / nano-scale metal samples under electromechanical coupling conditions. The FSE-SEM dual-beam system is used to process and fix micro / nano-scale metal samples and to etch the end platform of the metal indenter. The electromechanical single-tilt sample holder includes a movable end and a fixed end, which are arranged opposite each other without contact. The micro / nano-scale metal sample and the metal indenter are respectively fixed on the fixed end and the movable end. The in-situ control system includes a mechanical control system, an electrical control system, and a pulse generator.

[0011] In the in-situ control system, the mechanical control system drives the metal indenter on the movable end to achieve three-dimensional movement; the electrical control system applies pulsed current to the micro-nano scale metal sample through a pulse generator.

[0012] The movable end is equipped with a piezoelectric ceramic that is controlled by a mechanical control system to drive the movement of a metal pressure head.

[0013] II. A method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling

[0014] Includes the following steps:

[0015] 1) Micro- and nano-scale metal samples are obtained by etching using a focused ion beam method, and then the micro- and nano-scale metal samples are fixed at the fixed end of an electromechanical single-tilt sample rod.

[0016] 2) The metal wire end is electrochemically etched using an electrochemical etching system to prepare a metal indenter with a sharp head. Then, a focused ion beam-scanning electron microscope dual-beam system is used to etch the tip of the metal indenter into a plane, so that the cross-section of the metal indenter head is trapezoidal.

[0017] The etched metal indenter root is fixed to the movable end, so that the metal indenter head faces the micro-nano scale metal sample at the fixed end.

[0018] In step 2), the diameter of the raw material metal wire is about 0.25 mm, and the diameter of the etched metal indenter is about 50 nm to 200 nm.

[0019] 3) Place the electro-mechanical single-tilt sample rod into the sample chamber of the transmission electron microscope, and use piezoelectric ceramic drive to bring the metal indenter close to and align it with the micro-nano scale metal sample.

[0020] 4) Rapid annealing of micro / nano-scale metal samples is achieved using electromechanical coupling, followed by in-situ observation via transmission electron microscopy. Specifically:

[0021] 4.1) When the metal indenter at the movable end of the electromechanical single-tilt sample rod and the micro / nano-scale metal sample at the fixed end are at the critical contact point, the electrical control system applies several pulse currents (15-20 times) to the micro / nano-scale metal sample through a pulse generator until the boundary line between the high density and low density of dislocations on the surface of the micro / nano-scale metal sample is pushed to the root of the micro / nano-scale metal sample, at which point the application of pulse current is stopped.

[0022] 4.2) After the pulse current is stopped, the displacement of the piezoelectric ceramic is controlled by the mechanical control system to realize the cyclic linear motion of the metal indenter, thereby completing the pressure-pressure cyclic loading of the micro-nano scale metal sample with a constant strain amplitude. After several cycles of loading, it returns to the critical contact point.

[0023] 4.3) Repeat steps 4.1) to 4.2) (generally repeat 2-3 times) until the sample surface reaches the target dislocation density.

[0024] In step 2), the end face diameter of the metal indenter is larger than the diameter of the micro-nano scale metal sample, ranging from 400 nm to 1 μm.

[0025] In step 4.1), the critical contact point is the position where the metal indenter applies pressure to the micro / nano-scale metal sample and the micro / nano-scale metal sample has a strain of about 1%.

[0026] In step 4.2), each time the metal indenter completes a linear motion, it applies stress to the micro / nano-scale metal sample, causing the micro / nano-scale metal sample to produce a strain of 2% to 4%.

[0027] In step 4.2), the pressure is applied 2-5 times.

[0028] The beneficial effects of this invention are:

[0029] 1. This invention utilizes electromechanical coupling to achieve rapid annealing of micro- and nano-scale metal samples, which can effectively reduce the dislocation density of micro- and nano-scale metal samples and control the mechanical properties of materials without heat treatment.

[0030] 2. The method of the present invention has high energy utilization efficiency, which can effectively save energy and reduce carbon emissions;

[0031] 3. The method of the present invention can observe the dislocation density changes of micro- and nano-scale metal samples in real time, thereby realizing real-time control of the mechanical properties of the samples;

[0032] 4. The method of the present invention can continuously and stably anneal micro- and nano-scale metal samples, avoiding destructive deformation of micro- and nano-scale metal samples;

[0033] 5. Depending on the different metal materials, the size and shape of the metal indenter, the strain amplitude and loading speed of the metal indenter, the applied pulse current amplitude and frequency, the application time, and other parameters can be directly adjusted to achieve the desired effect. The process is flexible, stable, and reliable. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the device for achieving rapid annealing of micro-nano scale metallic materials using force-electric coupling, as per the present invention.

[0035] Figure 2 These are transmission electron microscope images of the force-electric coupling annealing process of the micro-nano-scale metal sample after the metal indenter and the micro-nano-scale metal sample are brought into close alignment and contact in the embodiment.

[0036] (a) is a transmission electron microscope image of a micro / nano-scale metal sample before the start of annealing;

[0037] (b) is a transmission electron microscope image of a micro / nano-scale metal sample during the annealing process;

[0038] (c) is a transmission electron microscope image of a micro / nano-scale metal sample after annealing.

[0039] Figure 3 These are transmission electron microscope images of a micro / nano-scale metal sample in the embodiment during a pulsed current application process (where the yellow solid line represents the actual position of the dislocation in the current image, and the white dashed line represents the position of the dislocation in the previous image, i.e., before the dislocation moved).

[0040] (a) is a transmission electron microscope image of a micro / nano-scale metal sample before a pulsed current was applied.

[0041] (b) is a transmission electron microscope image of a micro / nano-scale metal sample during a pulsed current application process;

[0042] (c) is a transmission electron microscope image of a micro / nano-scale metal sample after a pulsed current was applied.

[0043] Figure 4 These are transmission electron microscope images of a micro / nano-scale metal sample during a certain cyclic loading process in the embodiment.

[0044] (a) is a transmission electron microscope image of a micro / nano-scale metal sample before a certain cycle of loading;

[0045] (b) is a transmission electron microscope image of a micro / nano-scale metal sample after a certain cyclic loading.

[0046] Figure 5 This is a schematic diagram of the annealing process of micro-nano scale metal samples using electromechanical coupling (where red lines represent dislocations, a single free red line represents a free dislocation, and multiple intersecting red lines represent pinned dislocations).

[0047] (a) Schematic diagram of the micro / nano-scale metal sample and metal indenter before the annealing process begins;

[0048] (b) Schematic diagram of the critical contact point reached after the micro / nano-scale metal sample and the metal indenter are aligned at the same height;

[0049] (c) Schematic diagram after applying a pulsed current to a micro / nano-scale metal sample;

[0050] (d) Schematic diagram of applying cyclic loading to a micro / nano-scale metal sample;

[0051] (e) Schematic diagram after applying cyclic loading to a micro / nano-scale metal sample;

[0052] (f) Schematic diagram of applying a pulsed current after applying cyclic loading to a micro / nano-scale metal sample.

[0053] In the figure: 1. Micro / nano-scale metal sample; 2. Metal indenter; 3. Fixed end of the electro-mechanical single-tilt sample rod; 4. Movable end of the electro-mechanical single-tilt sample rod; 5. Electrical control system of the electro-mechanical single-tilt sample rod; 6. Pulse generator; 7. Mechanical control system of the electro-mechanical single-tilt sample rod. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.

[0055] like Figure 1As shown, the instruments used in the preparation include an electrochemical etching system, a transmission electron microscope, a focused ion beam-scanning electron microscope (FIB-SEM) dual-beam system, and an electromechanical single-tilt sample rod and its in-situ control system. The electrochemical etching system is used to process the metal wire to obtain the metal indenter 2; the transmission electron microscope is used to observe the relative position and movement of the micro / nano-scale metal sample 1 and the metal indenter 2, as well as the annealing process of the micro / nano-scale metal sample under electromechanical coupling conditions; the focused ion beam-scanning electron microscope dual-beam system is used for processing and fixing the micro / nano-scale metal sample 1 and etching the end platform of the metal indenter 2; the electromechanical single-tilt sample rod and its in-situ control system realize the motion control of the metal indenter 2 and the application of current to the micro / nano-scale metal sample 1.

[0056] The electromechanical single-tilt sample rod consists of two parts: a movable end and a fixed end. The fixed end 3 and the movable end 4 are arranged facing each other without contact. A micro / nano-scale metal sample 1 and a metal indenter 2 are respectively fixed on the fixed end 3 and the movable end 4. In the experiment, the movable end can be driven by the sample rod's mechanical control system to achieve precise control in three-dimensional directions (up, down, left, right, forward, and backward). Alternatively, a pulsed current can be applied by the sample rod's electrical control system and a pulse generator.

[0057] A pulse generator is an electronic device that can be used to generate pulsed current signals with specific amplitude, frequency, and width; a focused ion beam-scanning electron microscope dual-beam system is a micro-nano scale precision processing device that can realize functions such as point etching, deposition, and in-situ analysis.

[0058] The rapid annealing method for micro / nano-scale metal samples includes the following steps:

[0059] 1) A micro-nano-scale metal sample 1 is prepared by etching using a focused ion beam method or other processing and preparation methods. Then, the micro-nano-scale metal sample 1 is fixed at the fixed end 3 of the electro-mechanical single-tilt sample rod, facing the metal pressure head 2 of the movable end 4.

[0060] In step 1), the micro-nano scale metal sample material can be copper, gold, or silver, etc.

[0061] 2) An electrochemical etching system was used to electrochemically etch the end of a metal wire to prepare a sharp-ended metal indenter 2. The diameter of the raw metal wire was approximately 0.25 mm, and the diameter of the etched metal indenter 2 was approximately 50 nm to 200 nm. Then, a focused ion beam-scanning electron microscope dual-beam system was used to etch a platform at the end of the metal indenter 2. The diameter of the platform depends on the size of the micro / nano-scale metal sample, generally ranging from 400 nm to 1 μm. The root of the metal indenter 2 was fixed to the movable end 4, and the metal indenter platform 2 faced the micro / nano-scale metal sample 1.

[0062] In step 2), the metal indenter material can be tungsten, gold, or molybdenum, etc.

[0063] 3) Place the electro-mechanical single-tilt sample rod into the sample chamber of the transmission electron microscope, and use piezoelectric ceramic drive to make the micro-nano scale metal sample 1 and the metal indenter 2 horizontally aligned and close together;

[0064] 4) such as Figure 2 As shown, rapid annealing of micro / nano-scale metal samples is achieved using electromechanical coupling:

[0065] When the two ends of the electromechanical single-tilt sample rod are at the critical contact point, the electrical control system 5 uses the pulse generator 6 to apply several pulse currents (15-20 times) to the micro-nano scale metal sample 1. When the boundary line between the high density and low density of dislocations on the surface is pushed to the root of the micro-nano scale metal sample 1, the application is stopped.

[0066] After the pulsed current is stopped, the displacement of the piezoelectric ceramic is controlled by the mechanical control system 7, and the linear cyclic motion of the metal indenter is realized. Then, a constant strain amplitude (2% to 4%) is applied to the micro-nano scale metal sample 1 for compression-compression cyclic loading. After several cycles (2 to 5 times), it returns to the critical contact point.

[0067] Repeat the above operation until the sample surface reaches the target dislocation density; at the same time, perform in-situ observation under a transmission electron microscope;

[0068] As step 4) above is performed, the dislocation density on the surface of the micro / nano-scale metal sample 1 will be significantly reduced: the pulsed current will greatly promote the movement of dislocations, which will escape from the center of the sample to the surface at a very fast speed and thus disappear; throughout the entire electromechanical coupling process, the pulsed current plays a decisive role in the annealing process, while cyclic loading only serves to dislocate depinning. In the next round of electromechanical coupling, the depinned dislocations will escape and disappear more easily under the action of the pulsed current. With multiple rounds of electromechanical coupling annealing, the dislocation density will be greatly reduced, and a "clean" sample surface can finally be obtained, achieving complete annealing of the micro / nano-scale metal sample 1.

[0069] In step 4), a pulse is applied to both ends of the mechanical-electrical single-tilt sample rod using a pulse generator and an electrical control system. This allows for control of the pulse current, pulse amplitude, pulse frequency, and pulse width. For example... Figure 3As shown, the micro / nano-scale metal sample 1 and the metal indenter 2 reach the critical contact point, forming a closed loop in the entire circuit, allowing the application of a pulsed current. The applied pulsed current measurement waveform can be obtained using an oscilloscope. The pulse parameters are (10V, 3ns), pulse amplitude U = 10V, transition time is 2ns (the time interval between the pulse waveform rising from 10% to 90% of its amplitude), pulse width is 2.83ns, defined as the time interval between 50% of the pulse amplitude at the leading and trailing edges, and the total test pulse time (starting point of the leading edge and ending point of the trailing edge) is 4.87ns. The measured waveform matches the preset parameters well, and the error is acceptable.

[0070] Depend on Figure 3 It can be seen that dislocations escape towards both ends of the submicron pillar under the action of pulsed current, thereby reducing the dislocation density on the submicron pillar.

[0071] In step 4), during the cyclic loading process, the cyclic movement of the metal indenter is achieved through a mechanical control system. The load is applied by pressing the micro / nano-scale metal sample with the indenter, and the strain amplitude, movement speed, loading frequency, and number of loading cycles can be controlled. Figure 4 As shown, the metal indenter 2 applies an external force to the micro-nano-scale metal sample 1, causing strain in the micro-nano-scale metal sample 1. Then, the stress is gradually reduced, and the sample returns to the critical contact point. Then, an external force is applied again, causing strain in the micro-nano-scale metal sample 1, which is called cyclic loading.

[0072] like Figure 5 As shown, the force-electric coupling annealing process includes two steps: first, applying a pulsed current, which causes a large number of free dislocations to escape and disappear, while the movement of pinned dislocations is not obvious; second, cyclic loading, which depins the dislocations, and when the pulsed current is applied again, the depinned dislocations will escape, ultimately achieving the purpose of annealing.

[0073] During the application of pulsed current, dislocations in the micro-nano scale metal sample 1 exhibit a significant escape motion towards the edge region. The escape velocity of the dislocations is related to the pulse amplitude, pulse frequency, and pulse width of the pulsed current.

[0074] During cyclic loading, the dislocation density does not decrease significantly; its main function is dispinning, making dislocations easier to escape. The dispinning effect is related to the loading rate, loading frequency, and sample strain.

[0075] During the entire annealing process, dislocations are rapidly reduced, thereby enabling the control of the mechanical properties of the micro-nano scale metal sample 1. Specific implementation examples:

[0077] (1) Preparation of micro / nano-scale metal samples by focused ion beam processing

[0078] A 1*1*0.3cm thin slice was cut from the purchased high-purity block copper (Cu) sample using a wire cutting machine. The surface of the slice was then polished to create a smooth surface, and the sample was immersed in anhydrous ethanol and ultrasonically cleaned for about 20 minutes to remove residual stains from the sample surface.

[0079] The polished sample was fixed on the SEM (Scanning Electron Microscope) stage, and a 10*4*1.5μm cross-sectional thin slice was extracted from the sample using a focused ion beam-SEM dual-beam system. This slice was then fixed onto a special TEM (Transmission Electron Microscope) grid. The grid was then attached to a 45° SEM stage, and the extracted slice was thinned and processed using an ion beam. This resulted in a submicron-scale rectangular slice with dimensions controlled at approximately 200*640nm and a thickness of about 200nm, yielding the desired micro / nano-scale metal sample 1—a submicron column.

[0080] The micro / nano-scale metal sample 1 is fixed at the fixed end 3 of the electromechanical single-tilt sample rod, facing the movable end 4.

[0081] (2) Preparation of metal indenter 2

[0082] Specifically, a 0.25 mm diameter tungsten (W) wire is used. Before use, the oxide layer is removed by sanding with sandpaper, followed by ultrasonic cleaning in an ethanol solution. A 1 mol / L sodium hydroxide solution is prepared and, combined with an electrochemical etching system, a certain voltage is applied for etching to obtain a tungsten metal needle tip 2 with a front diameter of approximately 50 nm to 200 nm. After completion, the power is quickly cut off. The etched tungsten needle is fed into a focused ion beam-scanning electron microscope dual-beam system. Using the ion beam etching, a platform is machined at the end of the tungsten needle tip 2, with the platform diameter controlled at approximately 800 nm. The root of the metal indenter 2 is fixed to the movable end 4, with the sharp part of the metal indenter 2 facing the fixed end 3.

[0083] (3) Bring the movable end close to the fixed end inside the transmission electron microscope.

[0084] By directly observing with a transmission electron microscope, the positions of the submicron column 1 and the metal indenter 2 were located. The movable end of the metal indenter 2 was continuously adjusted in the vertical direction until the metal indenter 2 and the submicron column 1 were at the same horizontal height within the sample chamber of the transmission electron microscope and were in the same plane. Then, the displacement of the movable metal indenter 2 in the front-back and left-right directions was controlled. Figure 2 This causes the submicron column 1 and the metal indenter 2 to approach each other and reach a critical contact position.

[0085] (4) Apply pulsed current

[0086] When the submicron column 1 and the metal indenter 2 approach each other and reach the critical contact position, a closed loop can be formed in the system.

[0087] Using the electrical control system 5 and the pulse generator 6, several pulse currents are applied to the submicron column 1, with pulse parameters of (10V, 3ns).

[0088] like Figure 3 As shown, during the application of pulsed current, free dislocations escape quickly, while pinned dislocations show little change.

[0089] (5) Loop loading

[0090] After the pulse current is stopped, the metal pressure head 2 is used to squeeze the submicron column 1 by the mechanical control system 7, so as to realize the cyclic movement of the metal pressure head 2, and then apply a constant strain amplitude pressure-pressure cyclic loading to the submicron column 1. The strain is about 2%, the single cycle time is about 17s, the rate is about 1.1nm / s, the loading direction is Cu

[111] orientation, the cyclic loading is performed 5 times, and finally it returns to the critical contact point.

[0091] like Figure 4 As shown, after cyclic loading, dislocations will unpinnage and become free dislocations, which facilitates the escape of subsequent dislocations.

[0092] (6) Repeat steps (4) and (5) 2-3 times. The dislocations on the surface of the submicron pillar 1 will be reduced rapidly, thus achieving the purpose of rapid annealing.

Claims

1. A method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling, the apparatus used in the method comprising an electrochemical etching system, a transmission electron microscope, a focused ion beam-scanning electron microscope dual-beam system, and an electromechanical single-tilt sample rod and its in-situ control system; The electrochemical etching system is used to process the metal wire to obtain the metal indenter (2); the transmission electron microscope is used to observe the relative position and movement of the micro / nano-scale metal sample (1) and the metal indenter (2), as well as the annealing process of the micro / nano-scale metal sample (1) under electromechanical coupling conditions; the focused ion beam-scanning electron microscope dual-beam system is used to process and fix the micro / nano-scale metal sample (1) and to etch the end platform of the metal indenter (2); the electromechanical single-tilt sample rod includes a movable end (4) and a fixed end (3), the fixed end (3) and the movable end (4) are arranged facing each other without contact, and the micro / nano-scale metal sample (1) and the metal indenter (2) are fixed on the fixed end (3) and the movable end (4) respectively; the in-situ control system includes a mechanical control system (7), an electrical control system (5) and a pulse generator (6). In the in-situ control system, the mechanical control system (7) drives the metal indenter (2) on the movable end (4) to achieve three-dimensional movement; the electrical control system (5) applies pulse current to the micro-nano scale metal sample (1) through the pulse generator (6); The movable end (4) is equipped with a piezoelectric ceramic that is controlled by the mechanical control system (7) and drives the metal pressure head (2) to move; Its features are, Includes the following steps: 1) Micro-nano scale metal samples (1) were obtained by etching using focused ion beam method, and then the micro-nano scale metal samples (1) were fixed at the fixed end (3) of the electromechanical single tilt sample rod. 2) The metal wire end is electrochemically etched using an electrochemical etching system to prepare a metal indenter (2) with a sharp head. Then, a focused ion beam-scanning electron microscope dual-beam system is used to etch the tip of the metal indenter (2) into a plane, so that the cross section of the metal indenter (2) is trapezoidal. The root of the etched metal indenter (2) is fixed to the movable end (4), so that the head of the metal indenter (2) faces the micro-nano scale metal sample (1) at the fixed end (3). 3) Place the electro-mechanical single-tilt sample rod into the sample chamber of the transmission electron microscope, and use the piezoelectric ceramic drive to bring the metal indenter (2) close to and align it with the micro-nano scale metal sample (1). 4) Rapid annealing of micro / nano-scale metal samples is achieved using electromechanical coupling, followed by in-situ observation via transmission electron microscopy. Specifically: 4.1) When the metal indenter (2) at the movable end of the electromechanical single-tilt sample rod and the micro / nano-scale metal sample (1) at the fixed end are at the critical contact point, the electrical control system (5) applies several pulse currents to the micro / nano-scale metal sample (1) through the pulse generator (6) until the boundary line between the high density and low density of dislocations on the surface of the micro / nano-scale metal sample (1) is pushed to the root of the micro / nano-scale metal sample (1), and then the pulse current is stopped. 4.2) After the pulse current is stopped, the displacement of the piezoelectric ceramic is controlled by the mechanical control system (7) to realize the cyclic linear motion of the metal indenter (2), thereby completing the constant strain amplitude pressure-pressure cyclic loading on the micro-nano scale metal sample (1). After several cycles of loading, it returns to the critical contact point. 4.3) Repeat steps 4.1) to 4.2) until the sample surface reaches the target dislocation density.

2. The method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling according to claim 1, characterized in that, In step 2), the end face diameter of the metal indenter (2) is larger than the diameter of the micro-nano scale metal sample (1), which is 400 nm to 1 μm.

3. The method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling according to claim 1, characterized in that, In step 4.1), the critical contact point is the position where the metal indenter (2) applies pressure to the micro-nano scale metal sample (1) and the micro-nano scale metal sample (1) has a strain of 1%.

4. The method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling according to claim 1, characterized in that, In step 4.2), each time the metal indenter (2) completes a linear motion, the metal indenter (2) applies stress to the micro-nano scale metal sample (1), and the micro-nano scale metal sample (1) generates a strain of 2% to 4%.

5. The method for rapid annealing of micro / nano-scale metal samples using electromechanical coupling according to claim 1, characterized in that, In step 4.2), the pressure is applied 2-5 times.

Images