A method for rapid high strength microwave bonding of ceramics to cemented carbide

Abstract

This invention discloses a rapid, high-strength microwave bonding method for ceramics and cemented carbide, belonging to the field of ceramic material bonding technology. The method includes the following steps: preparing a metal solder; grinding, polishing, and cleaning the bonding surfaces of the ceramic and cemented carbide respectively; loading the prepared metal solder into a mold and pressing it under uniaxial pressure to obtain a metal solder sheet; placing the ceramic, metal solder sheet, and cemented carbide in a stacked structure in a microwave sintering furnace for microwave sintering to achieve the bonding of the ceramic and cemented carbide. Compared with traditional brazing and diffusion welding, this ceramic-cemented carbide microwave bonding method increases the heating / cooling rate by 6-10 times, improves the single-furnace bonding efficiency by 5-9 times, allows for mass production, and yields ceramic-cemented carbide bonding interfaces with high strength. This invention significantly improves production efficiency, reduces energy consumption, and has widespread application value.

Description

Technical Field

[0001] This invention belongs to the field of ceramic material joining technology, and particularly relates to a rapid high-strength microwave joining method for ceramic-hard alloy. Background Technology

[0002] Ceramic materials, with their excellent wear resistance, chemical stability, and thermal stability, have shown great application potential in key areas of high-end equipment such as aerospace, automotive manufacturing, and engineering machinery, making them advanced structural materials with significant development prospects and core competitiveness. However, the inherent high brittleness of ceramics makes it difficult to directly process them into large-size or complex-structured components, severely restricting their engineering applications. Hard alloys, possessing high strength, high toughness, and high vibration resistance, allow for reliable bonding of ceramics and hard alloys. This fully leverages the performance advantages of both materials, achieving complementary properties and enabling the fabrication of high-performance composite components that combine the excellent service characteristics of ceramics with the structural toughness of hard alloys. This is of great significance for expanding the engineering applications of ceramic materials.

[0003] Currently, the joining technology between ceramics and dissimilar materials mainly relies on traditional methods such as brazing, diffusion welding, and liquid phase bonding. These processes mostly depend on external conduction or radiation heating, and generally suffer from problems such as slow heating rate, wide heat-affected zone, concentrated thermal stress, and large residual stress, which can easily lead to defects such as joint cracking, low strength, and insufficient reliability. At the same time, they also have shortcomings such as long process cycle and low joining efficiency, making it difficult to meet the service reliability and mass production requirements of high-performance composite components for high-end equipment.

[0004] Microwave heating possesses unique advantages such as uniform volume heating, rapid heating rate, low thermal stress, and mild and controllable interfacial reactions. It also features high heating efficiency, short process cycles, and ease of large-scale production, demonstrating significant technological potential in the field of efficient and high-strength ceramic-ceramic alloy bonding. However, there are currently very few publicly available research reports and technical articles on the application of microwave technology to the bonding of ceramic-ceramic alloy dissimilar materials. A mature and stable process scheme and a complete technical system have not yet been formed, and a significant technological gap remains in this field.

[0005] To address the shortcomings of traditional connection technologies, such as slow heating, high stress, poor joint performance, and low efficiency, and to fill the technological gap in the field of ceramic-hard alloy microwave connection, it is urgent to develop a fast, low-stress, and high-strength ceramic-hard alloy microwave connection method to achieve efficient and reliable connection between ceramics and hard alloys. Summary of the Invention

[0006] This invention proposes a rapid, high-strength microwave bonding method for ceramics and cemented carbide to solve the problems existing in the prior art. Based on the advantages of efficient microwave heating, this invention enables high-strength bonding between ceramics and cemented carbide.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for rapid, high-strength microwave bonding of ceramics and cemented carbide includes the following steps: (1) Prepare metal solder; (2) Grind, polish and clean the bonding surfaces of the ceramic and the cemented carbide respectively; (3) The prepared metal solder is loaded into the mold and pressed under uniaxial pressure to obtain metal solder sheet; (4) Place ceramic, metal solder sheet and cemented carbide in a microwave sintering furnace in a stacked structure to achieve the connection between ceramic and cemented carbide.

[0008] Further, in step (1), the metal solder, by mass percentage, consists of 90-98% base metal and 2-10% active metal; wherein the base metal is one or a combination of two or more of Ag, Cu, and Ni; and the active metal is one or a combination of two or more of Ti, Zr, Cr, Nb, and V. The base metal selected in this invention possesses excellent ductility, effectively withstanding the thermal stress generated during the dissimilar bonding process of ceramic and cemented carbide; the addition of a small amount of active metal can promote the chemical reaction at the ceramic interface, thereby improving the wettability of the liquid filler metal on the ceramic surface. This enables a reliable connection to be formed between the ceramic and the cemented carbide.

[0009] Further, in step (2), the ceramic includes one of Al2O3, SiAlON, ZrO2, Si3N4, SiC, BN and AlN ceramics.

[0010] Further, in step (2), the cemented carbide includes one of WC cemented carbide, TiC cemented carbide and Ti(C,N) cemented carbide.

[0011] Further, in step (2), the grinding is performed by grinding with B4C grinding powder of specifications W14 and W5 for 5-10 minutes respectively. The polishing is performed by polishing with diamond polishing agent of specifications W1.5-W0.5 on a metallographic sample polishing machine for 5-15 minutes at a speed of 900 r / min. After grinding and polishing, the oil, grease, oxide scale, and rust on the surface of the ceramic and cemented carbide connection are removed, and high friction between the ceramic and cemented carbide connection surfaces is also generated, reducing the surface roughness.

[0012] Furthermore, in step (2), the cleaning is performed by ultrasonic cleaning in anhydrous ethanol for 15 minutes, which can further remove impurities and grease from the surface.

[0013] Furthermore, in step (3), the uniaxial pressure is 50-200 MPa and the duration is 30 s-5 min. Further, in step (3), the thickness of the metal solder sheet is 0.3-0.6 mm. As sintering proceeds, the metal solder sheet shrinks to a certain extent at high temperatures, and the final thickness can reach 0.3-0.6 mm. Within this thickness range, the metal solder sheet can alleviate the residual stress caused by the difference in thermal expansion coefficients during the connection process between ceramics and cemented carbide through certain plastic deformation. If the metal solder sheet is too thin, the interface reaction may not be sufficient, while if it is too thick, the ability to alleviate residual stress will be weakened.

[0014] Further, in step (4), the microwave sintering process is as follows: heating rate 10-80℃ / min, temperature 800-1200℃, holding time 5-60min; SiC powder and / or SiC sheets are used for auxiliary heating during the sintering process. Before the microwave sintering process, the microwave sintering furnace is purged once, evacuated to 200Pa, and then filled with argon protective atmosphere to 0.02MPa. Too low a heating rate will lead to low production efficiency, and too high a heating rate will lead to difficulty in uniform heating, resulting in large thermal stress; when the connection temperature is low, the reaction or diffusion between the metal solder and the ceramic or hard alloy is incomplete, and when the temperature is too high, it may have an adverse effect on the properties of the base material; the effect of the holding time is the same as that of the connection temperature; therefore, the temperature is raised to the connection temperature at a certain heating rate, and then held for a period of time to promote the full chemical reaction or diffusion between the metal solder and the ceramic / hard alloy, thereby achieving a good connection. Microwave sintering, a novel sintering technology that relies on the dielectric loss of materials to achieve rapid overall heating, boasts significant advantages such as high efficiency and energy saving, uniform heating, and low-temperature densification, attracting considerable attention in the field of advanced materials preparation. Currently, research and process solutions for the application of microwave sintering technology in the joining of ceramics and cemented carbides are lacking, with no relevant public reports. This invention utilizes the core characteristics of microwave sintering—volume heating, interface activation, and rapid phase transformation—and introduces them into the ceramic-cemented carbides joining system. This method can significantly enhance the metallurgical reaction at the ceramic-cemented carbides interface, reduce thermal damage to the matrix and thermal deformation of the joint, improve microstructure uniformity and connection strength, while greatly shortening the sintering joining time and increasing production efficiency, providing a new technical path for the efficient joining of ceramic-cemented carbides components. The microwave joining method for ceramics and cemented carbides of this invention has high practical value.

[0015] Further, in step (4), the stacked structure is a ceramic-metal solder sheet-hard alloy, and SiC powder and / or SiC sheets are placed around the stacked structure for auxiliary heating.

[0016] The present invention also provides a ceramic-hard alloy composite component, which is prepared by the above-described microwave connection method.

[0017] The present invention also provides an application of ceramic-hard alloy composite components in the fields of aerospace, automotive industry or engineering machinery.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects: (1) The ceramic-hard alloy rapid high-strength microwave connection method of the present invention, compared with brazing and diffusion welding, increases the heating / cooling rate by 6-10 times and significantly shortens the holding time to 1 / 10 to 1 / 20 of the traditional process. The present invention greatly reduces energy consumption and improves production efficiency, and has promotional value.

[0019] (2) The present invention uses metal solder sheet formed under uniaxial pressure as the connecting material, and the resulting ceramic-hard alloy connection interface has high strength, which expands the application of ceramics and has high practical value.

[0020] (3) In this invention, the interface between ceramic and hard alloy is intact and free from defects such as cracks and pores. Good chemical bonding is achieved on the ceramic side. Under the action of microwave field, its non-contact heating mode avoids direct mechanical damage to brittle ceramic materials. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the microwave connection sintering of the present invention; Figure 2 This is a schematic diagram of the shearing test of the present invention; Figure 3 SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 1; Figure 4 SEM image of the Al2O3 ceramic-hard alloy joint prepared in Example 1; Figure 5 SEM image of the cemented carbide side connection interface in the Al2O3 ceramic-ceramic joint prepared in Example 1; Figure 6 SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 2; Figure 7 SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 3; Figure 8 SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 4; Figure 9The image shows a SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 5. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0025] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0026] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0027] This invention provides a method for rapid, high-strength microwave bonding of ceramics and cemented carbide, comprising the following steps: (1) Preparation of metal solder: Prepare metal solder by mass percentage, consisting of 90-98% (e.g., 93%, 95% or 98%) of base metal and 2-10% (e.g., 2%, 5% or 7%) of active metal; the base metal is selected from one or more combinations of Ag, Cu, Ni (e.g., AgCu combination, CuNi combination, Cu), and the active metal is selected from one or more combinations of Ti, Zr, Cr, Nb, V, and mix them evenly to obtain metal solder powder; (2) Pretreatment of the surfaces to be joined: Select the ceramic and cemented carbide surfaces to be joined, and grind, polish and clean them in sequence: grind with B4C grinding powder of specifications W14 and W5 for 5-10 min respectively (e.g., 5 min or 10 min); then polish with diamond polishing agent of specifications W1.5-W0.5 on a metallographic sample polishing machine for 5-15 min (e.g., 5 min, 10 min or 15 min) at a speed of 900 r / min; place the polished ceramic and cemented carbide in anhydrous ethanol for ultrasonic cleaning for 15 min to remove surface impurities and oil stains; Among them, the ceramic is selected from one of Al2O3, SiAlON, ZrO2, Si3N4, SiC, BN and AlN ceramics; the cemented carbide is selected from one of WC cemented carbide (such as YG8, YT15), TiC cemented carbide (such as YN05) and Ti(C,N) cemented carbide (such as TN05); (3) Preparation of metal solder sheet: The metal solder powder is loaded into a cylindrical mold and pressed under a uniaxial pressure of 50-200MPa (e.g., 150MPa) for 30s-5min (e.g., 2min or 3min) to form a metal solder sheet with a thickness of 0.3-0.6mm (e.g., 0.5mm); (4) Loading and atmosphere treatment: Arrange the ceramic-metal solder sheet-hard alloy stack in sequence, and place SiC powder and / or SiC sheets around the stack for auxiliary heating; purge the microwave sintering furnace once, evacuate to below 200Pa (40-100Pa, such as 40Pa or 100Pa), and then fill with argon to a protective atmosphere of 0.02MPa; start microwave sintering, with the following process parameters: heating rate 10-80℃ / min (such as 40℃ / min, 50℃ / min or 60℃ / min), sintering temperature 800-1200℃ (such as 850℃, 900℃, 950℃, 1000℃ or 1200℃), and holding temperature for 5-60min (such as 5min, 10min or 20min, 50min or 60min); continue to use SiC powder and / or SiC sheets for auxiliary heating during the sintering process, and cool with the furnace after the holding temperature is completed to achieve a high-strength connection between the ceramic and the hard alloy.

[0028] A ceramic-hard alloy composite component can be prepared using the microwave connection method described above.

[0029] The aforementioned ceramic-hard alloy composite components can be applied in the aerospace, automotive, or engineering machinery fields.

[0030] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0031] All raw materials used in this invention were purchased from the market.

[0032] The technical solution of the present invention will be further illustrated by the following embodiments.

[0033] Example 1 A method for rapid, high-strength microwave bonding of ceramics and cemented carbide includes the following steps: (1) Preparation of metal solder: Weigh 93 wt.% of the base metal (66.96 wt.% of Ag powder and 26.04 wt.% of Cu powder) and 7 wt.% of the active metal (Ti powder) and mix them to obtain AgCuTi metal solder powder; (2) Pretreatment of the surfaces to be joined: The Al2O3 ceramic was ground to Φ15.5×4mm using an electrical discharge wire, and the WC cemented carbide (YG8) was cut to Φ15.5×4mm. After grinding the Al2O3 ceramic and WC cemented carbide surfaces to be joined with an angle grinder, they were ground for 5 minutes each with B4C grinding powder of specifications W14 and W5, respectively. Then, they were polished for 10 minutes with diamond polishing agent of specification W1.5 on a metallographic sample polishing machine at a speed of 900 r / min. The treated Al2O3 ceramic and WC cemented carbide were ultrasonically cleaned in anhydrous ethanol for 15 minutes. (3) Preparation of metal solder sheet: The prepared AgCuTi metal solder powder is loaded into a cylindrical stainless steel mold and held under a uniaxial pressure of 150MPa for 2min to obtain a cylindrical metal solder sheet of Φ15.5×0.5mm; (4) Loading and Atmosphere Treatment: Arrange the ceramic-metal solder sheet-hard alloy stack in sequence, and place SiC sheets around the stack for auxiliary heating; purge the microwave sintering furnace once, evacuate to 100 Pa, and then fill with argon to 0.02 MPa protective atmosphere; start microwave sintering (microwave sintering diagram as shown in the figure). Figure 1 As shown in the diagram, the process parameters are: heating rate 40℃ / min, sintering temperature 950℃, holding time 5min; after holding, the furnace is cooled to complete the high-strength connection between the ceramic and the cemented carbide. The Al2O3 ceramic-cemented carbide joint is then ground to a size of 8mm×10mm×10mm and installed into a shearing die. A schematic diagram of the shearing die is shown in the diagram. Figure 2 As shown, a shear test was conducted using a universal testing machine at a speed of 0.1 mm / min. The results show that the shear strength of the prepared Al2O3 ceramic-hard alloy joint is 97.5 MPa.

[0034] Figure 3 The image shows the SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 1. As can be seen from the image, the Al2O3 ceramic and WC hard alloy achieved a good connection under the action of AgCuTi metal solder, without defects such as micro-cracks and incomplete welding.

[0035] Figure 4 The image shows the SEM image of the Al2O3 ceramic side connection interface in the Al2O3 ceramic-hard alloy joint prepared in Example 1. As can be seen from the image, AgCuTi and Al2O3 ceramic underwent a chemical reaction to form a reaction layer of a certain thickness, and the reaction products were distributed relatively evenly.

[0036] Figure 5 The image shows the SEM image of the cemented carbide side connection interface in the Al2O3 ceramic-cemented cemented carbide joint prepared in Example 1. As can be seen from the image, WC cemented carbide and AgCuTi metal solder underwent a certain diffusion and chemical reaction, resulting in a relatively good bond.

[0037] Example 2 Similar to Example 1, the difference is that in step (4), the heating rate during microwave sintering is 40℃ / min, and the temperature is held at 850℃ for 5min. The shear strength of the Al2O3 ceramic-hard alloy joint prepared is 63.07MPa.

[0038] Figure 6 The image shows an SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 2. As can be seen from the SEM image, compared with Example 1, lowering the sintering temperature will suppress the degree of interface reaction, resulting in a significant reduction in the thickness of the reaction layer formed between the intermediate metal solder and the substrates on both sides.

[0039] Example 3 Similar to Example 1, except that in step (4), the heating rate during microwave sintering is 40℃ / min, and the temperature is held at 1000℃ for 5min. The shear strength of the prepared Al2O3 ceramic-hard alloy joint is 68.5MPa.

[0040] Figure 7 The image shows the SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 3. As can be seen from the SEM image, compared with Example 1, although increasing the temperature significantly enhances the atomic diffusion rate and reaction driving force at the interface, it will cause excessive reaction between the solder layer and the substrate, resulting in a decrease in the connection strength.

[0041] Example 4 Similar to Example 1, the difference is that in step (4), the heating rate during microwave sintering is 40℃ / min, and the temperature is held at 950℃ for 10min. The shear strength of the Al2O3 ceramic-hard alloy joint prepared is 33.6MPa.

[0042] Figure 8The image shows a SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 4. As can be seen from the image, the thickness of the reaction layer between the Al2O3 ceramic and the solder layer is significantly reduced. This indicates that the wettability of Ti on the Al2O3 ceramic side has decreased. Excluding the influence of temperature and solder composition, this means that the extended holding time causes a large number of active Ti to remain in the solder layer, generating other phases and significantly reducing the number of titanium atoms available for interfacial reaction. This hinders the growth of the interfacial reaction layer and thus greatly weakens the joint strength.

[0043] Example 5 Similar to Example 1, except that in step (4), the heating rate during microwave sintering is 40℃ / min, and the temperature is held at 950℃ for 20min. The shear strength of the prepared Al2O3 ceramic-hard alloy joint is 68.5MPa.

[0044] Figure 9 The image shows the SEM image of the Al2O3 ceramic-hard alloy interface prepared in Example 5. As can be seen from the SEM image, the further extension of the heat preservation time significantly increases the thickness of the reaction layer between the Al2O3 ceramic and the solder layer. However, the reaction layer grains coarsen, and brittle phases continue to be generated and enriched, which easily leads to stress concentration and defect initiation at the interface, ultimately resulting in a decrease in the mechanical strength of the joint.

[0045] Example 6 Same as Example 1, except that in step (1), 95 wt.% of the base metal (68.4 wt.% of Ag powder and 26.6 wt.% of Cu powder) and 5 wt.% of the active metal (Ti powder) are weighed and mixed to obtain AgCuTi metal solder powder.

[0046] The prepared Al2O3 ceramic-hard alloy joint has a shear strength of 47.6 MPa. It can be found that, compared with Example 1, the reduction of active metal Ti weakens the wetting and activation effect on the ceramic surface, resulting in insufficient driving force for interfacial chemical reaction, making it difficult to form a continuous, dense and well-bonded reaction layer, leading to poor wetting defects, and ultimately causing a significant decrease in the mechanical strength of the joint.

[0047] Example 7 Same as Example 1, except that in step (1), 91 wt.% of the base metal (65.52 wt.% of Ag powder and 25.48 wt.% of Cu powder) and 9 wt.% of the active metal (Ti powder) are weighed and mixed to obtain AgCuTi metal solder powder.

[0048] The prepared Al2O3 ceramic-hard alloy joint has a shear strength of 51.6 MPa. It can be found that an excessively high content of active metal Ti in the solder will significantly enhance the driving force of the interfacial reaction, leading to an excessively vigorous interfacial reaction. This easily generates an excessive amount of continuous and coarse brittle intermetallic compound phase, resulting in an abnormally large reaction layer thickness and ultimately a decrease in the mechanical strength of the joint.

[0049] Example 8 A method for rapid, high-strength microwave bonding of ceramics and cemented carbide includes the following steps: (1) Preparation of metal solder: Weigh 95wt.% of the base metal (Cu powder) and 5wt.% of the active metal (Ti powder) and mix them to obtain CuTi metal solder powder; (2) Pretreatment of the surfaces to be joined: The SiAlON ceramic was ground to Φ15.5×4mm using an electrical discharge wire, and the TiC cemented carbide (YN05) was cut to Φ15.5×4mm. After grinding the SiAlON ceramic and TiC cemented carbide surfaces to be joined with an angle grinder, they were ground for 10min each with B4C grinding powder of specifications W14 and W5, respectively. Then, they were polished for 15min with diamond polishing agent of specification W1.5 on a metallographic sample polishing machine at a speed of 900r / min. The treated SiAlON and TiC cemented carbide were ultrasonically cleaned in anhydrous ethanol for 15min. (3) Preparation of metal solder sheet: The prepared CuTi metal solder powder is loaded into a cylindrical stainless steel mold and held under a uniaxial pressure of 150MPa for 2min to obtain a cylindrical metal solder sheet of Φ15.5×0.5mm; (4) Loading and Atmosphere Treatment: Arrange the ceramic-metal solder sheet-hard alloy stack in sequence, and place SiC sheets around the stack for auxiliary heating; purge the microwave sintering furnace once, evacuate to 40 Pa, and then fill with argon gas to a protective atmosphere of 0.02 MPa; start microwave sintering (microwave sintering diagram as shown in the figure). Figure 1 As shown in the diagram, the process parameters are: heating rate 60℃ / min, sintering temperature 900℃, holding time 10min; after holding, the furnace is cooled to complete the high-strength connection between the ceramic and the cemented carbide. Then, the SiAlON ceramic-cemented carbide joint is ground to a size of 8mm×10mm×10mm and installed into a shearing die. A shearing diagram is shown in the diagram. Figure 2 As shown, a shear test was performed using a universal testing machine at a speed of 0.1 mm / min. The shear strength of the prepared SiAlON ceramic-hard alloy joint was 76.2 MPa.

[0050] Example 9 A method for rapid, high-strength microwave bonding of ceramics and cemented carbide includes the following steps: (1) Preparation of metal solder: Weigh 95wt.% of the base metal (66.5wt.% Cu powder, 28.5wt.% Ni powder) and 5wt.% of the active metal (V powder) and mix them to obtain CuNiV metal solder powder; (2) Pretreatment of the surfaces to be joined: The SiC ceramic was ground to Φ15.5×4mm using an electrical discharge wire, and the Ti(C,N) cemented carbide (TN05) was cut to Φ15.5×4mm. After grinding the SiC ceramic and Ti(C,N) cemented carbide surfaces to be joined with an angle grinder, they were ground for 10min each with B4C grinding powder of specifications W14 and W5, respectively. Then, they were polished for 15min with diamond polishing agent of specification W1.5 on a metallographic sample polishing machine at a speed of 900r / min. The treated SiC ceramic and Ti(C,N) cemented carbide were ultrasonically cleaned in anhydrous ethanol for 15min. (3) Preparation of metal solder sheet: The prepared CuNiV metal solder powder is loaded into a cylindrical stainless steel mold and held under a uniaxial pressure of 150MPa for 3min to obtain a cylindrical metal solder sheet of Φ15.5×0.6mm; (4) Loading and Atmosphere Treatment: Arrange the ceramic-metal solder sheet-hard alloy stack in sequence, and place SiC sheets around the stack for auxiliary heating; purge the microwave sintering furnace once, evacuate to 40 Pa, and then fill with argon gas to a protective atmosphere of 0.02 MPa; start microwave sintering (microwave sintering diagram as shown in the figure). Figure 1 As shown in the diagram, the process parameters are: heating rate 50℃ / min, sintering temperature 1000℃, holding time 60min; after holding, the furnace is cooled to complete the high-strength connection between the ceramic and the cemented carbide. Then, the SiC ceramic-cemented carbide joint is ground to a size of 8mm×10mm×10mm and installed into a shearing die. A shearing diagram is shown in the diagram. Figure 2 As shown, a shear test was performed using a universal testing machine at a speed of 0.1 mm / min. The shear strength of the prepared SiC ceramic-hard alloy joint was 27.3 MPa.

[0051] Example 10 A method for rapid, high-strength microwave bonding of ceramics and cemented carbide includes the following steps: (1) Preparation of metal solder: Weigh 93 wt.% of the base metal (80 wt.% Cu powder, 13 wt.% Ni powder) and 7 wt.% of the active metal (Ti powder) and mix them evenly to obtain CuNiTi metal solder powder; (2) Pretreatment of the surfaces to be joined: The Si3N4 ceramic was ground to Φ15.5×4mm using an electrical discharge wire, and the WC cemented carbide (YT15) was cut to Φ15.5×4mm. After grinding the Si3N4 ceramic and WC cemented carbide surfaces to be joined with an angle grinder, they were ground for 5 minutes each with B4C grinding powder of specifications W14 and W5, respectively. Then, they were polished for 10 minutes with diamond polishing agent of specification W0.5 on a metallographic sample polishing machine at a speed of 900r / min. The treated Si3N4 and WC cemented carbide were ultrasonically cleaned in anhydrous ethanol for 15 minutes. (3) Preparation of metal solder sheet: The prepared CuNiTi metal solder powder is loaded into a cylindrical stainless steel mold and held under a uniaxial pressure of 150MPa for 3min to obtain a cylindrical metal solder sheet of Φ15.5×0.6mm; (4) Loading and Atmosphere Treatment: Arrange the ceramic-metal solder sheet-hard alloy stack in sequence, and place SiC sheets around the stack for auxiliary heating; purge the microwave sintering furnace once, evacuate to 40 Pa, and then fill with argon gas to a protective atmosphere of 0.02 MPa; start microwave sintering (microwave sintering diagram as shown in the figure). Figure 1 As shown in the diagram, the process parameters are: heating rate 50℃ / min, sintering temperature 1000℃, holding time 5min; after holding, the furnace is cooled to complete the high-strength connection between the ceramic and the cemented carbide. Then, the Si3N4 ceramic-cemented carbide joint is ground to a size of 8mm×10mm×10mm and installed into a shearing die. A shearing diagram is shown in the diagram. Figure 2 As shown, a shear test was performed using a universal testing machine at a speed of 0.1 mm / min. The shear strength of the prepared Si3N4 ceramic-hard alloy joint was 70.6 MPa.

[0052] Example 11 Similar to Example 1, the difference is that in step (1), 95 wt.% of the base metal (70 wt.% Ag powder, 25 wt.% Cu powder) and 5 wt.% of the active metal (Zr powder) are weighed and mixed to obtain AgCuZr metal solder powder; in step (2), the ceramic is ZrO2 ceramic. The shear strength of the prepared ZrO2 ceramic-hard alloy joint is 51.2 MPa.

[0053] Example 12 Similar to Example 1, the difference is that in step (1), 98 wt.% of the base metal (70 wt.% Ag powder, 28 wt.% Cu powder) and 2 wt.% of the active metal (Cr powder) are weighed and mixed to obtain AgCuCr metal solder powder; in step (2), the ceramic is AlN ceramic. The shear strength of the prepared AlN ceramic-hard alloy joint is 49.3 MPa.

[0054] Example 13 Same as Example 1, except that in step (2), the ceramic is BN ceramic. The shear strength of the prepared BN ceramic-hard alloy joint is 59.0 MPa.

[0055] Comparative Example 1 Similar to Example 1, the difference is that in step (4), the heating rate during microwave sintering is 40℃ / min, and the temperature is held at 800℃ for 30min.

[0056] The Al2O3 ceramic-hard alloy joint prepared in this comparative example separated during subsequent grinding, indicating low joint strength. The low joint strength was caused by a low connection temperature setting, resulting in insufficient solder melting, significantly reduced fluidity and spreading ability, and an inability to uniformly fill the weld gap. Simultaneously, the reactive Ti element lacked sufficient reaction kinetic energy, making it difficult to form a continuous and dense metallurgical reaction layer with the Al2O3 ceramic. The interface was only simply adhered, resulting in extremely weak bonding. This indicates that at this connection temperature of 800℃, the diffusion and reaction between the solder and the base material to be joined were insufficient, leading to weak adhesion and easy peeling of the joint.

[0057] Comparative Example 2 Similar to Example 1, the difference is that in step (4), the process parameters during microwave sintering are: heating rate 40℃ / min, sintering temperature increased to 1200℃, and holding for 10min.

[0058] The Al2O3 ceramic-hard alloy joint prepared in this comparative example suffers from excessive melting of the solder due to the microwave sintering temperature being much higher than the melting point of the intermediate solder metal layer (770-810℃). Under the action of surface tension, the molten solder agglomerates and shrinks to form droplets, which cannot be fully spread and filled at the interface. This easily leads to weld voids, material shortages, and large-area unbonded defects, ultimately resulting in poor joint density, a significant decrease in bonding strength, and a shear strength of only 11 MPa.

[0059] Comparative Example 3 Same as Example 1, except that in step (2), the Al2O3 ceramic and cemented carbide were not polished after grinding.

[0060] The shear strength of the Al2O3 ceramic-hard alloy joint prepared in this comparative example is 21 MPa. Because the Al2O3 ceramic and hard alloy were not polished after grinding, the surfaces to be joined were relatively rough. During the joining process, they failed to adhere tightly to the metal welding layer, resulting in small holes and a significant decrease in strength.

[0061] Comparative Example 4 Similar to Example 1, the difference is that no metal welding powder is prepared, that is, no metal welding layer is added between Al2O3 ceramic and cemented carbide, and the two are directly microwave connected.

[0062] The Al2O3 ceramic-hard alloy prepared in this comparative example failed to achieve bonding because, without the addition of metal welding powder, both Al2O3 ceramic and hard alloy are chemically stable, making it difficult for them to undergo a chemical reaction, thus preventing bonding.

[0063] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for rapid, high-strength microwave bonding of ceramics and cemented carbide, characterized in that, Includes the following steps: (1) Prepare metal solder; (2) Grind, polish and clean the bonding surfaces of the ceramic and the cemented carbide respectively; (3) The prepared metal solder is loaded into the mold and pressed under uniaxial pressure to obtain metal solder sheet; (4) Place ceramic, metal solder sheet and cemented carbide in a microwave sintering furnace in a stacked structure to achieve the connection between ceramic and cemented carbide.

2. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (1), the metal solder consists of 90-98% base metal and 2-10% active metal by mass percentage; The base metal is one or more of Ag, Cu and Ni; the active metal is one or more of Ti, Zr, Cr, Nb and V.

3. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (2), the ceramic includes one of Al2O3, SiAlON, ZrO2, Si3N4, SiC, BN and AlN ceramics.

4. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (2), the cemented carbide includes one of WC cemented carbide, TiC cemented carbide and Ti(C,N) cemented carbide.

5. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (2), the grinding is performed by grinding with B4C grinding powder of specifications W14 and W5 for 5-10 minutes respectively; The polishing process involves polishing with a diamond polishing compound of specification W1.5-W0.5 for 5-15 minutes at a rotation speed of 900 r / min.

6. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (3), the uniaxial pressure is 50-200 MPa and the duration is 30s-5min; The thickness of the metal solder sheet is 0.3-0.6 mm.

7. The ceramic-hard alloy rapid high-strength microwave connection method according to claim 1, characterized in that, In step (4), the microwave sintering process is as follows: heating rate 10-80℃ / min, temperature 800-1200℃, holding time 5-60min; SiC powder and / or SiC sheets are used for auxiliary heating during the sintering process.

8. The method for rapid high-strength microwave connection of ceramic-hard alloy according to claim 1, characterized in that, In step (4), the stacked structure is ceramic-metal solder sheet-hard alloy.

9. A ceramic-hard alloy composite component, characterized in that, It is prepared by the microwave connection method according to any one of claims 1-8.

10. The application of the ceramic-hard alloy composite component as described in claim 9 in the fields of aerospace, automotive industry or engineering machinery.

Images