Method for repairing microcracks in ceramic material

Abstract

The invention relates to the technical field of repairing of microcracks in ceramic materials, and discloses a method for repairing microcracks in a ceramic material, which comprises the following steps: depositing a healing precursor amorphous material in the microcracks of the ceramic material by thin film deposition, and filling the microcracks; in a room temperature environment, a focused electron beam is adopted to irradiate the filled crack, so that the healing precursor material is crystallized into crystals, the crystals epitaxially grow along the two sides of the microcrack, and a repaired ceramic material is obtained; the healing precursor amorphous material is a perovskite type oxide with an ABO3 type crystal structure, A and B are metal cations, and the ion radius of A is larger than that of B. Microcracks are filled by adopting an amorphous material deposition technology, and then the cracks are repaired by adopting a focused electron beam, so that the aim of repairing the cracks of the ceramic material under a room temperature condition is fulfilled.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and in particular to a method for repairing microcracks in ceramic materials. Background Art

[0002] Ceramic materials have excellent properties such as high hardness, high temperature resistance, wear resistance and good insulation, and are widely used in industrial and scientific fields. However, due to the intrinsic brittleness of ceramic materials, they often crack rather than deform under load. Therefore, even tiny cracks can cause catastrophic fatigue failure in ceramic materials, which severely limits their scope of application. In order to improve the fatigue resistance of ceramic materials, traditional solutions mainly rely on toughening by designing special microstructures, such as layered structures, stress-induced phase transitions, and amorphous-crystalline dual-phase structures. Although the optimization of the microstructure can slow down or prevent crack propagation to a certain extent and improve the fatigue resistance of the material, the hidden danger of fatigue failure - cracks - still exists.

[0003] Repairing cracks during crack initiation or propagation, restoring the material to its original state, is a powerful toughening strategy. Due to the strong covalent bonds in ceramics and the low ion mobility at room temperature, crack repair in ceramics is primarily achieved through high-pressure or high-temperature oxidation. However, technologies for crack repair in ceramics at room temperature have yet to be reported.

[0004] Therefore, the existing technology needs to be further improved and enhanced. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for repairing microcracks in ceramic materials, aiming to fill the microcracks by adopting amorphous material deposition technology and then repair the cracks by using a focused electron beam, thereby achieving the purpose of repairing cracks in ceramic materials at room temperature.

[0006] The above object of the present invention is achieved through the following technical solution: A method for repairing microcracks in a ceramic material, comprising the following steps: Using thin film deposition, a healing precursor material is deposited into microcracks of the ceramic material to fill the microcracks; Under room temperature, a focused electron beam is used to irradiate the filled cracks, so that the healing precursor material is crystallized into crystals, and the crystals grow epitaxially along both sides of the microcracks to obtain a repaired ceramic material; the healing precursor amorphous material is a perovskite-type oxide with an ABO3 crystal structure, wherein A and B are metal cations, and the ionic radius of A is greater than the ionic radius of B.

[0007] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0008] As a preferred technical solution, the method for repairing microcracks in ceramic materials is described, wherein the ceramic material is a perovskite-type oxide, preferably a titanate-based ceramic material or a manganate-based ceramic material.

[0009] As a preferred technical solution, in the method for repairing microcracks in ceramic materials, the thin film deposition is selected from one of thin film deposition technologies such as atomic layer deposition, chemical vapor deposition and molecular beam epitaxy.

[0010] As a preferred technical solution, in the method for repairing microcracks in ceramic materials, the width of the microcracks is less than or equal to 10 nm.

[0011] As a preferred technical solution, in the method for repairing microcracks in ceramic materials, the healing precursor material is amorphous BaTiO3, SrTiO3 or LaAlO3.

[0012] As a preferred technical solution, in the method for repairing microcracks in ceramic materials, the temperature of the room temperature environment is 20-25°C.

[0013] As a preferred technical solution, in the method for repairing microcracks in ceramic materials, the focused electron beam is a focused electron beam in a spherical aberration corrected scanning transmission electron microscope.

[0014] Beneficial effects: Compared with the existing technology, the present invention uses a focused electron beam to repair microcracks in ceramic materials, realizes crack repair at room temperature, and provides a new repair method for microcracks in ceramic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a schematic flow chart of a method for repairing microcracks in ceramic materials provided by the present invention; Figure 2 is a low-magnification HAADF-STEM image of a free-standing BaTiO3 film with a 2 nm wide microcrack provided by the present invention, including (c) atomic-level HAADF-STEM images before and (d) after repair; (e) elemental mapping of the atomic-level electron energy loss spectrum; Figure 3 This is the HAADF-STEM image of the 10 nm wide crack repair provided by the present invention, where (a) is before repair and (b) is after repair; Figure 4These are HAADF-STEM images of crack repair in the heterogeneous material LaSrMnO3 provided by an embodiment of the present invention, including (a) before repair, (b) after repair, and (c) atomic-level EELS element mapping image after repair. DETAILED DESCRIPTION

[0016] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, When “in summary” is used, it indicates that there are features, steps, operations, devices, components and / or combinations thereof.

[0019] Unless otherwise specified, the relative arrangement of components and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the sake of ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. For the techniques, methods and procedures known to those skilled in the relevant art, The present invention relates to a method and apparatus for use in connection with the present invention and the like. ...

[0020] The present invention provides a method for repairing microcracks in a ceramic material, comprising the following steps: S10, depositing the healing precursor amorphous material into the microcracks of the ceramic material to fill the microcracks.

[0021] Specifically, combined Figure 1 As shown, a ceramic material with microcracks is provided (I in the figure), and a healing precursor amorphous material is deposited into the microcracks of the ceramic material (II in the figure). This can be achieved using techniques such as atomic layer deposition (ALD), chemical vapor deposition (CVD), and molecular beam epitaxy (MBE). The ceramic material can be a perovskite-type oxide, preferably a titanate-based ceramic material or a manganate-based ceramic material. Titanate-based ceramic materials and manganate-based ceramic materials are common and representative. Microcracks generally refer to cracks with a width of less than 10 nm.

[0022] S20. At room temperature, the filled cracks are irradiated with a focused electron beam to crystallize the healing precursor material into crystals, which grow epitaxially along both sides of the microcracks to obtain a repaired ceramic material; the healing precursor amorphous material is a perovskite oxide having an ABO3 crystal structure, wherein A and B are metal cations, and the ionic radius of A is greater than the ionic radius of B, such as A is Ba 2+ 、Sr 2+ 、La 3+ , B is Ti 4+ 、Al 3+ .

[0023] Specifically, the filled ceramic material is placed at room temperature and cracks are repaired using a focused electron beam from a spherical aberration corrected scanning transmission electron microscope (the principle of electron beam crack repair is that electron beam irradiation causes amorphous materials to crystallize into crystals. When the electron beam irradiates the amorphous precursor filling the crack, the amorphous material crystallizes into crystals, and the growth mode is epitaxial growth, that is, the crystals grow epitaxially along both sides of the crack. When all the amorphous precursors in the crack area have completed crystallization, the crack repair is completed). The electron probe gradually scans the crack area to achieve crack repair ( Figure 1 III). The amorphous material used as the healing precursor is a perovskite oxide, which can be well bonded to the ceramic material. The perovskite oxide is BaTiO3, SrTiO3, or LaAlO3.

[0024] The method for repairing microcracks in ceramic materials provided by the present invention is further explained below through specific embodiments.

[0025] Example 1 First, a 20 nm BaTiO3 (BTO) thin film was grown using a pulsed laser deposition (PLD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred onto microgates (with microcracks of different widths).

[0026] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the PLD chamber, and the precursor amorphous BTO was deposited at room temperature to a thickness of about 10 nm.

[0027] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks with a width of about 2 nm). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This solution has been used to repair cracks with a width of about 2 nm in the BTO film (such as Figure 2 shown).

[0028] Example 2 First, a 25 nm BaTiO3 (BTO) thin film was grown using an atomic layer deposition (ALD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0029] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the ALD chamber, and the precursor amorphous BTO was deposited at room temperature to a thickness of about 10 nm.

[0030] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 10 nm wide). Then use a high beam current density to repair the cracks (about 10 8 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This solution has been used to repair cracks with a width of about 10 nm in the BTO film (such as Figure 3 shown).

[0031] Example 3 First, a 20 nm BaTiO3 (BTO) thin film was grown using an atomic layer deposition (ALD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0032] Next, the micro-grid with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the ALD chamber, and the precursor amorphous SrTiO3 was deposited at room temperature to a thickness of about 10 nm.

[0033] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 10 nm wide). Then use a high beam current density to repair the cracks (about 10 8 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as approximately 10 nm in BTO films.

[0034] Example 4 First, a 20 nm BaTiO3 (BTO) thin film was grown using a pulsed laser deposition (PLD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0035] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the PLD chamber, and the precursor amorphous LaAlO3 was deposited at room temperature to a thickness of about 10 nm.

[0036] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 2 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as 2 nm in BTO films.

[0037] Example 5 First, a 20 nm LaSrMnO3 (LSMO) thin film was grown using a pulsed laser deposition (PLD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0038] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the PLD chamber, and the precursor amorphous LaAlO3 was deposited at room temperature to a thickness of about 10 nm.

[0039] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 2 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as 2 nm in LSMO films.

[0040] Example 6 First, a 25 nm LaSrMnO3 (LSMO) thin film was grown using a pulsed laser deposition (PLD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0041] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed into the PLD chamber, and the precursor amorphous BaTiO3 was deposited at room temperature to a thickness of about 10 nm.

[0042] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 5 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as 5 nm in LSMO films.

[0043] Example 7 First, a 25 nm LaSrMnO3 (LSMO) thin film was grown using a pulsed laser deposition (PLD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0044] Next, the micro-gate with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the PLD chamber, and the precursor amorphous SrTiO3 was deposited at room temperature to a thickness of about 10 nm.

[0045] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 5 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as 5 nm in LSMO films.

[0046] Example 8 First, a 25 nm LaSrMnO3 (LSMO) thin film was grown using a chemical vapor deposition (CVD) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0047] Next, use double-sided tape to stick the micro-grid with the self-supporting film to the sample drag, and then place the sample drag into the CVD chamber to deposit the precursor amorphous SrTiO3 at room temperature, with a thickness of about 10 nm.

[0048] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 5 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as 5 nm in LSMO films.

[0049] Example 9 First, a 25 nm LaSrMnO3 (LSMO) thin film was grown using a molecular beam epitaxy (MBE) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0050] Next, the micro-grid with the self-supporting film was adhered to the sample drag using double-sided tape. The sample drag was then placed in the MBE chamber, and the precursor amorphous SrTiO3 was deposited at room temperature to a thickness of about 10 nm.

[0051] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 10 nm wide). Then use a high beam current density to repair the cracks (about 10 9 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as approximately 10 nm in LSMO films.

[0052] Example 10 First, a 25 nm LaSrMnO3 (LSMO) thin film was grown using a molecular beam epitaxy (MBE) system. The film was then dissolved from the substrate to obtain a free-standing film, which was then transferred to the microgate.

[0053] Next, the micro-grating with the self-supporting film was adhered to the sample drag using double-sided tape, and the sample drag was placed in the MBE chamber to deposit the precursor amorphous LaAlO3 at room temperature to a thickness of about 10 nm.

[0054] Finally, the obtained sample was placed in a spherical aberration corrected scanning transmission electron microscope. First, a low beam density current imaging (about 10 7 eA -2 .s -1 ), find the region of interest with cracks (select cracks about 10 nm wide). Then use a high beam current density to repair the cracks (about 10 8 eA -2 .s -1 ), the electron probe gradually scans the crack area to achieve crack repair. This scheme has been used to repair cracks as wide as approximately 10 nm in LSMO films.

[0055] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for repairing microcracks in ceramic materials, characterized in that: The steps include: Using thin film deposition, a healing precursor material is deposited into microcracks of the ceramic material to fill the microcracks; Under room temperature, a focused electron beam is used to irradiate the filled cracks, so that the healing precursor material is crystallized into crystals, and the crystals grow epitaxially along both sides of the microcracks to obtain a repaired ceramic material; the healing precursor amorphous material is a perovskite-type oxide with an ABO3 crystal structure, wherein A and B are metal cations, and the ionic radius of A is greater than the ionic radius of B.

2. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The ceramic material is a titanate-based ceramic material or a manganate-based ceramic material.

3. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The thin film deposition is selected from one of atomic layer deposition, chemical vapor deposition and molecular beam epitaxy.

4. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The width of the microcracks is less than or equal to 10 nm.

5. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The healing precursor material is amorphous BaTiO3 or SrTiO3 or LaAlO3.

6. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The temperature of the room temperature environment is 20-25°C.

7. The method for repairing microcracks in ceramic materials according to claim 1, characterized in that: The focused electron beam is a focused electron beam in a spherical aberration correction scanning transmission electron microscope.

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