SiBCN-Zr ceramic metal diffusion couple and preparation method thereof

Abstract

The invention provides a SiBCN-Zr ceramic metal diffusion couple and a preparation method thereof, and relates to the technical field of ceramic materials.The preparation method comprises the steps that firstly, SiBCN amorphous powder is prepared through a mechanical alloying method and sintered under the high-pressure condition, so that the powder is heated more evenly in the sintering process, and sample densification can be achieved at the low temperature; and moreover, sintering is carried out under the high-pressure condition, the diffusion driving force can be increased, diffusion of the Zr element in metal end powder can be promoted, good metallurgical bonding is formed between SiBCN and a metal interface, and therefore the bonding strength of SiBCN and the metal interface can be improved. Besides, before hot pressed sintering, the SiBCN amorphous powder and the metal end powder form a sandwich structure through layer laying, so that planarization of the SiBCN and a metal interface can be realized, and reaction and diffusion phenomena of the SiBCN and the metal interface can be observed more visually.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and more particularly, to a SiBCN-Zr ceramic-metal diffusion couple and a preparation method thereof. Background Art

[0002] SiBCN ceramics have excellent high-temperature resistance, oxidation resistance, corrosion resistance, and high-wave penetration properties, and have broad application prospects in the fields of high-temperature structural components, composite materials, and catalyst carriers. In order to improve the performance of SiBCN ceramic materials, metals and metal compounds are usually introduced therein. The introduction of metal phases into SiBCN ceramics is mainly achieved by combining precursor pyrolysis or sol-gel methods with pressure sintering and other methods to prepare SiBCN composite ceramics with more excellent properties. At present, in order to explore the relationship between the properties and structure of SiBCN-metal composite ceramics, the crystallization, structure, and fracture properties of SiBCN-metal composite ceramics under conditions such as oxidation and ablation are mainly analyzed. The diffusion couple method is a method of preparing diffusion couple samples with specific compositions and using the principle of local equilibrium to allow the elements in the samples to diffuse at a certain temperature to reach an equilibrium state, and then measuring and verifying the alloy phase diagram. This method has been widely used in the fields of metal material research, alloy design, and new material development, and is particularly important in exploring alloy phase transformation, high strength and plasticity, and deformation mechanisms. However, at present, there is still a lack of a diffusion couple for studying SiBCN-metal composite ceramics in the related art to achieve a more intuitive observation of the reaction and diffusion phenomena at the SiBCN-metal interface and ensure the bonding strength at the SiBCN-metal interface. Summary of the Invention

[0003] The problem to be solved by the present invention is: how to obtain a diffusion couple for studying SiBCN-metal composite ceramics to achieve a more intuitive observation of the reaction and diffusion phenomena at the SiBCN-metal interface and ensure the bonding strength at the SiBCN-metal interface.

[0004] To solve the above problems, the present invention provides a preparation method for a SiBCN-Zr ceramic-metal diffusion couple, including:

[0005] Step S1: Prepare SiBCN amorphous powder by mechanical alloying method;

[0006] Step S2: Lay the SiBCN amorphous powder and the metal end powder body in layers to form a SiBCN-metal end powder body-SiBCN sandwich structure, and then perform hot pressing sintering to obtain a ceramic-metal diffusion couple; wherein, the pressure of the hot pressing sintering is 25 MPa to 35 MPa; the metal end powder body includes one of Zr powder, ZrB2 powder, and ZrC powder.

[0007] Optionally, in the step S2, the temperature of the hot pressing sintering is 1500 °C to 1800 °C.

[0008] Optionally, in the step S2, the pressure of the hot pressing sintering is 30 MPa.

[0009] Optionally, in the step S2, the time of the hot pressing sintering is 2.5 h to 3.5 h.

[0010] Optionally, in the step S2, the hot pressing sintering is carried out in an inert gas protection atmosphere.

[0011] Optionally, in the step S1, calculated by mole fraction, the raw materials for preparing the SiBCN amorphous powder by mechanical alloying method include: 22 to 30 parts of silicon powder, 0 to 30 parts of boron powder, 15 to 40 parts of graphite powder, and 22.2 to 28.6 parts of boron nitride powder.

[0012] Optionally, in the step S1, calculated by mole fraction, the raw materials for preparing the SiBCN amorphous powder by mechanical alloying method include: 22 to 30 parts of silicon powder, 15 to 40 parts of graphite powder, and 22.2 to 28.6 parts of boron nitride powder.

[0013] Optionally, the particle sizes of the silicon powder, the boron powder, the graphite powder, and the boron nitride powder are all 6 μm to 45 μm.

[0014] Optionally, in the step S1, the preparation of the SiBCN amorphous powder by mechanical alloying method is carried out under the condition of inert gas protection.

[0015] The present invention also provides a SiBCN-Zr ceramic-metal diffusion couple, which is prepared by the preparation method of the SiBCN-Zr ceramic-metal diffusion couple as described above.

[0016] Compared with the related technology, the present invention first prepares the SiBCN amorphous powder by mechanical alloying method, and then layer-paves the SiBCN amorphous powder and the metal-end powder and then carries out hot pressing sintering, and sintering is carried out under high pressure (25 MPa to 35 MPa), so that the powder is heated more uniformly during the sintering process, and densification of the sample can be achieved at a lower temperature; moreover, sintering under high pressure conditions can increase the diffusion driving force and promote the diffusion of Zr element in the metal-end powder, so that a good metallurgical bond is formed at the SiBCN and metal interface, which is beneficial to improving the bonding strength of the SiBCN and metal interface. In addition, since the SiBCN amorphous powder and the metal-end powder form a SiBCN-metal-end powder-SiBCN sandwich structure by layer-paving before hot pressing sintering, it is beneficial to realize the planarization of the SiBCN and metal interface, and thus can realize a more intuitive observation of the reaction and diffusion phenomena at the SiBCN and metal interface. Description of the Drawings

[0017] Figure 1 It is a schematic flowchart of the preparation method of the SiBCN-Zr ceramic-metal diffusion couple in the embodiment of the present invention;

[0018] Figure 2 It is a scanning electron microscope picture of the SiBCN amorphous powder prepared in Example 1;

[0019] Figure 3 It is one of the scanning electron microscope pictures at the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1;

[0020] Figure 4 It is the second scanning electron microscope picture at the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1;

[0021] Figure 5 It is the XRD pattern at the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1. Detailed Embodiments

[0022] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the present invention in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0024] As used herein, the term "comprising" and its variations are open-ended, that is, "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiment". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or primary-secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0025] As Figure 1 shown, an embodiment of the present invention provides a method for preparing a SiBCN-Zr ceramic-metal diffusion couple, comprising:

[0026] Step S1, preparing SiBCN amorphous powder by mechanical alloying method;

[0027] Step S2, laying the SiBCN amorphous powder and the metal end powder in layers to form a SiBCN-metal end powder-SiBCN sandwich structure, and then performing hot pressing sintering to obtain a ceramic-metal diffusion couple; wherein, the pressure of the hot pressing sintering is 25 MPa to 35 MPa; the metal end powder includes one of Zr powder, ZrB2 powder and ZrC powder.

[0028] In the embodiment of the present invention, first, SiBCN amorphous powder is prepared by mechanical alloying method, and then the SiBCN amorphous powder and the metal end powder are laid in layers and then subjected to hot pressing sintering. Sintering is carried out under high pressure (25 MPa to 35 MPa), so that the powder is heated more uniformly during sintering, and densification of the sample can be achieved at a lower temperature; moreover, sintering under high pressure can increase the diffusion driving force, promote the diffusion of Zr element in the metal end powder, and form a good metallurgical bond at the SiBCN-metal interface, which is beneficial to improving the bonding strength of the SiBCN-metal interface. In addition, since the SiBCN amorphous powder and the metal end powder form a SiBCN-metal end powder-SiBCN sandwich structure by laying in layers before hot pressing sintering, it is beneficial to realize the planarization of the SiBCN-metal interface, and thus the reaction and diffusion phenomena at the SiBCN-metal interface can be observed more intuitively.

[0029] In some embodiments of the present invention, in step S2, the temperature of the hot press sintering is 1500 °C to 1800 °C. Thus, better hot press sintering of the SiBCN-metal end powder-SiBCN sandwich structure is achieved.

[0030] In some embodiments of the present invention, preferably, in step S2, the hot press sintering is carried out under an inert gas protection atmosphere, the pressure of the hot press sintering is 30 MPa, and the time of the hot press sintering is 2.5 h to 3.5 h.

[0031] In some embodiments of the present invention, in step S1, in terms of molar fractions, the raw materials for preparing the SiBCN amorphous powder by mechanical alloying method include: 22 parts to 30 parts of silicon powder, 0 part to 30 parts of boron powder, 15 parts to 40 parts of graphite powder, and 22.2 parts to 28.6 parts of boron nitride powder. Preferably, in step S1, in terms of molar fractions, the raw materials for preparing the SiBCN amorphous powder by mechanical alloying method include: 22 parts to 30 parts of silicon powder, 15 parts to 40 parts of graphite powder, and 22.2 parts to 28.6 parts of boron nitride powder.

[0032] In some embodiments of the present invention, the particle sizes of the silicon powder, the boron powder, the graphite powder, and the boron nitride powder are all 6 μm to 45 μm. The reason for controlling the particle sizes of the above powders between 6 μm and 45 μm is that when the particle size of the powder is too large, more ball milling time is required in the process of preparing the SiBCN amorphous powder by mechanical alloying method; when the particle size of the powder is too small, agglomeration is likely to occur; too large a difference in the particle sizes of the raw materials will also affect the uniformity of ball milling.

[0033] In some embodiments of the present invention, in step S1, the preparation of the SiBCN amorphous powder by mechanical alloying method is carried out under the condition of inert gas protection.

[0034] The embodiments of the present invention also provide a SiBCN-Zr ceramic-metal diffusion couple, which is prepared by using the preparation method of the SiBCN-Zr ceramic-metal diffusion couple as described above.

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] Example 1

[0037] A1. Preparation of SiBCN amorphous powder by mechanical alloying method: First, silicon powder, boron nitride powder, and graphite powder are placed into a silicon nitride ball milling tank according to a molar ratio of 28.6:28.6:42.8 and subjected to ball milling treatment under argon protection to obtain SiBCN amorphous powder; wherein, during the ball milling treatment process, the main disk rotation speed is 350 rpm, the rotation speed of the ball milling tank is 600 rpm, and the ball milling treatment time is 40 h.

[0038] A2. Layer the SiBCN amorphous powder and the metal end powder in a graphite mold for hot pressing sintering with a diameter of 30 mm to form a SiBCN - metal end powder - SiBCN sandwich structure, and then perform hot pressing sintering under an argon - protected atmosphere to obtain a ceramic - metal diffusion couple. Among them, the pressure of the hot pressing sintering is 30 MPa, the temperature is 1500 °C, and the time is 3 h. The metal end powder is Zr powder.

[0039] Example 2

[0040] A1. Prepare SiBCN amorphous powder by mechanical alloying method: First, place silicon powder, boron powder, boron nitride powder, and graphite powder in a silicon nitride ball - milling tank according to a molar ratio of 22.2:22.2:22.2:33.4, and perform ball - milling treatment under argon protection to obtain SiBCN amorphous powder. Among them, during the ball - milling treatment, the rotation speed of the main disk is 350 rpm, the rotation speed of the ball - milling tank is 600 rpm, and the ball - milling treatment time is 40 h.

[0041] A2. Layer the SiBCN amorphous powder and the metal end powder in a graphite mold for hot pressing sintering with a diameter of 30 mm to form a SiBCN - metal end powder - SiBCN sandwich structure, and then perform hot pressing sintering under an argon - protected atmosphere to obtain a ceramic - metal diffusion couple. Among them, the pressure of the hot pressing sintering is 30 MPa, the temperature is 1500 °C, and the time is 3 h. The metal end powder is ZrB2 powder.

[0042] Example 3

[0043] A1. Prepare SiBCN amorphous powder by mechanical alloying method: First, place silicon powder, boron powder, boron nitride powder, and graphite powder in a silicon nitride ball - milling tank according to a molar ratio of 25.0:12.5:25.0:37.5, and perform ball - milling treatment under argon protection to obtain SiBCN amorphous powder. Among them, during the ball - milling treatment, the rotation speed of the main disk is 350 rpm, the rotation speed of the ball - milling tank is 600 rpm, and the ball - milling treatment time is 40 h.

[0044] A2. Layer the SiBCN amorphous powder and the metal end powder in a graphite mold for hot pressing sintering with a diameter of 30 mm to form a SiBCN - metal end powder - SiBCN sandwich structure, and then perform hot pressing sintering under an argon - protected atmosphere to obtain a ceramic - metal diffusion couple. Among them, the pressure of the hot pressing sintering is 30 MPa, the temperature is 1800 °C, and the time is 3 h. The metal end powder is ZrC powder.

[0045] Comparative Example 1

[0046] The difference from Example 1 is that in step A1, the pressure of the hot pressing sintering is 20 MPa.

[0047] Experimental Example

[0048] The SiBCN amorphous powder prepared in Example 1 was characterized by scanning electron microscopy. The results are shown in Figure 2 , and it can be seen from Figure 2 that the SiBCN amorphous powder prepared in Example 1 consists of hard agglomerates composed of nanoscale particles, and the size of the agglomerates is less than 20 μm.

[0049] The morphology at the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1 was characterized by scanning electron microscopy. The results are shown in Figure 3 and Figure 4 , and it can be seen from Figure 3 and Figure 4 that a metallurgical bonding interface in a "meshing" shape is formed between the SiBCN and the metal-end powder in the ceramic-metal diffusion couple prepared in Example 1. Figure 4 The yellow line in Figure 5 is the bonding position between the SiBCN and the metal interface in the ceramic-metal diffusion couple. XRD analysis was carried out on the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1. The results are shown in Figure 5 and it can be seen from

[0050] that phases such as ZrC, BN, and SiC are formed at the SiBCN and metal interface of the ceramic-metal diffusion couple prepared in Example 1. The formation of these phases indicates that the interface compatibility between the SiBCN ceramic and the metal in the ceramic-metal diffusion couple prepared in Example 1 is good. It can also be seen from the above analysis that the diffusion couple of the SiBCN-metal composite ceramic prepared by the method of the present invention can realize more intuitive SEM and EDS observations of the reaction and diffusion phenomena at the SiBCN and metal interfaces.

[0051] Table 1

[0052] Number Shear strength (MPa) Example 1 30 Example 2 31 Example 3 34 Comparative Example 1 22

[0053] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A preparation method of a SiBCN-Zr ceramic-metal diffusion couple, characterized in that Including: Step S1: Prepare SiBCN amorphous powder by mechanical alloying method; Step S2: Lay the SiBCN amorphous powder and the metal end powder in layers to form a SiBCN-metal end powder-SiBCN sandwich structure, and then perform hot pressing sintering to obtain a ceramic-metal diffusion couple; wherein, the pressure of the hot pressing sintering is 25 MPa to 35 MPa; the metal end powder includes one of Zr powder, ZrB2 powder and ZrC powder.

2. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, characterized in that, In step S2, the temperature of the hot pressing sintering is 1500 °C to 1800 °C.

3. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, characterized in that, In step S2, the pressure of the hot pressing sintering is 30 MPa.

4. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, wherein In step S2, the time of the hot pressing sintering is 2.5 h to 3.5 h.

5. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, characterized in that, In step S2, the hot pressing sintering is carried out under an inert gas protection atmosphere.

6. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, characterized in that, In step S1, calculated by mole fraction, the raw materials for preparing SiBCN amorphous powder by mechanical alloying method include: 22 parts to 30 parts of silicon powder, 0 parts to 30 parts of boron powder, 15 parts to 40 parts of graphite powder, and 22.2 parts to 28.6 parts of boron nitride powder.

7. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 6, characterized in that, In step S1, calculated by mole fraction, the raw materials for preparing SiBCN amorphous powder by mechanical alloying method include: 22 parts to 30 parts of silicon powder, 15 parts to 40 parts of graphite powder, and 22.2 parts to 28.6 parts of boron nitride powder.

8. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 6, characterized in that, The particle sizes of the silicon powder, the boron powder, the graphite powder, and the boron nitride powder are all 6 μm to 45 μm.

9. The preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to claim 1, characterized in that, In step S1, the preparation of SiBCN amorphous powder by mechanical alloying method is carried out under the condition of inert gas protection.

10. A SiBCN-Zr ceramic-metal diffusion couple, characterized in that, Prepared by using the preparation method of the SiBCN-Zr ceramic-metal diffusion couple according to any one of claims 1-9.

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