Active brazing filler metal and preparation method and application thereof

Abstract

The invention belongs to the technical field of metal and nonmetal heterogeneous welding, and particularly relates to active brazing filler metal and a preparation method and application thereof.The active brazing filler metal comprises, by mass, 10%-45% of Mg element and the balance metal elements similar to metal to be welded and inevitable impurities; wherein the metal element similar to the metal to be welded comprises at least one of Al element and Sn element. The active brazing filler metal provided by the invention is magnesium-containing active brazing filler metal, is relatively high in activity, can be applied to heterogeneous welding of metal materials and non-metal materials, does not need to be pressurized, realizes welding of parts in complex shapes, and forms a good welding interface.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of heterogeneous welding of metal and non-metal, and particularly relates to an active filler metal as well as a preparation method and application thereof. BACKGROUND

[0002] The connection methods of graphite, ceramic, glass and other materials and metal include mechanical connection, adhesion, brazing, diffusion welding and the like, wherein the most researched and most widely applied welding method is diffusion welding and brazing. In particular, since the brazing heating temperature is low, the influence on the structure and performance of the base material is small, the welding deformation of the base material is small, and batch production can be realized, so the brazing method becomes a relatively practical connection method of graphite, ceramic, glass and other materials and metal.

[0003] Graphite, glass, ceramic and other materials are quite different from metal in crystal structure, and are difficult to be wetted by metal filler metal containing metal bonds. Most filler metals only form beads on the surface, rarely or not at all wet, resulting in certain difficulty in direct brazing. At present, there are two main methods for brazing non-metallic materials: one is to metalize the surface of the non-metallic material, and then use conventional filler metal for brazing. This method is complex, which to some extent limits its development. The other is to use filler metal containing active elements such as Ti, Zr, Hf and Pd to directly braze non-metallic materials in vacuum. At present, this method is studied more. However, using this method, the welding process needs to be pressurized to ensure the welding quality, which greatly increases the process difficulty and cost, and it is also difficult to weld complex-shaped parts that are difficult to pressurize.

[0004] Therefore, the existing filler metal and brazing method still needs to be improved. SUMMARY

[0005] The present application aims to provide an active filler metal as well as a preparation method and application thereof. The active filler metal provided by the present application is a magnesium-containing active filler metal, which has high activity and can be applied to the heterogeneous welding of metal and non-metallic materials, does not need to be pressurized, and can realize the welding of complex-shaped parts, forming a good welding interface.

[0006] The present application provides an active filler metal in a first aspect, which includes the following components in mass percentage: 10% to 45% of Mg element, and the rest is a metal element of the same kind as the metal to be welded and unavoidable impurities; wherein the metal element of the same kind as the metal to be welded contains at least one of Al element and Sn element.

[0007] In some embodiments, the active filler metal further includes auxiliary additive elements in a mass percentage of 0.01% to 10%.

[0008] In some embodiments, the auxiliary additive element comprises one or more combinations of B element, Ti element, Ni element and Pd element.

[0009] In some embodiments, the mass percentage of the B element is 0.01% to 5%.

[0010] In some embodiments, the mass percentage of the B element is 0.01% to 2%, more preferably 0.02% to 1%.

[0011] In some embodiments, the mass percentage of the Ti element is 0.01% to 10%.

[0012] In some embodiments, the mass percentage of the Ti element is 1% to 7%, more preferably 2% to 4%.

[0013] In some embodiments, the mass percentage of the Ni element is 0.03% to 0.9%.

[0014] In some embodiments, the mass percentage of the Ni element is 0.05% to 0.5%, more preferably 0.3% to 0.5%.

[0015] In some embodiments, the mass percentage of the Pd element is 0.01% to 1%.

[0016] In some embodiments, the mass percentage of the Pd element is 0.1% to 0.8%, more preferably 0.3% to 0.5%.

[0017] The second aspect of the present application further provides a preparation method of the active brazing filler of the first aspect, comprising the following steps: mixing and melting corresponding raw materials according to the content of each element to obtain the active brazing filler.

[0018] In some embodiments, the melting temperature is 200°C to 1000°C, and the holding time is 10 min to 20 min.

[0019] The third aspect of the present application further provides the application of the active brazing filler of the first aspect or the active brazing filler prepared by the preparation method of the second aspect in the welding of metal materials and non-metal materials.

[0020] In some embodiments, the non-metal material comprises one of ceramic, glass and graphite, and the metal material comprises one of aluminum, copper and alloys thereof.

[0021] The active brazing filler provided by the present application has high activity, does not need to be pressurized, can realize the welding of components with complex shapes, and forms a good welding interface.

[0022] The preparation process of the active brazing filler is simple, low in cost and excellent in performance.

[0023] The active filler metal can be applied to heterogeneous welding of metal materials and non-metal materials such as graphite, ceramic, glass, etc.

[0024] The above description is only a summary of the technical solutions of the present application. In order to enable a more thorough understanding of the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the specification, and in order to enable the above and other purposes, features and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. DETAILED DESCRIPTION

[0025] Exemplary embodiments of the present application will be described in greater detail below. It should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application can be more thoroughly understood, and the scope of the present application can be conveyed completely to those skilled in the art.

[0026] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps can be employed.

[0027] In the description of the embodiments of the present application, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0028] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents an "or" relationship between the associated objects before and after it.

[0030] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0031] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] The first aspect of the present application provides an active filler metal, which comprises the following components in mass percentage: 10% to 45% of Mg element, and the rest is a metal element of the same kind as the metal to be welded and unavoidable impurities; wherein the metal element of the same kind as the metal to be welded comprises at least one of Al element and Sn element.

[0033] In the embodiments of the present application, the active filler metal is a Mg-containing active filler metal, which is mainly used for heterogeneous welding of metal materials and non-metal materials such as graphite, ceramics, glass and the like. The filler metal has high activity and does not need to be pressurized, and can form a good welding interface.

[0034] The active filler metal provided in the embodiments of the present application can realize heterogeneous welding of metal materials and non-metal materials such as graphite, ceramics, glass and the like under soft soldering temperature (low temperature, below 500℃).

[0035] In some embodiments, the melting point of the active filler metal is between 200℃ and 450℃. Exemplarily, the melting point of the active filler metal can be one of 202℃, 203℃, 412℃, 430℃, 450℃ or any value within the above range.

[0036] In some embodiments, the mass percentage of Mg element is 10% to 45%, so that the active brazing filler metal with high activity can be obtained without pressure, and a good welding interface can be formed. For example, the mass percentage of Mg element can be one of 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, or any value within the above range.

[0037] In some embodiments, the active brazing filler metal comprises a metal element of the same type as the metal to be welded, or comprises a component capable of forming a metal connection of the same type as the metal to be welded. The metal element of the same type as the metal to be welded can be, for example, an Al element, a Sn element, etc.

[0038] In some embodiments, the active brazing filler metal further comprises an auxiliary additive element in a mass percentage of 0.01% to 10%.

[0039] The mass percentage of the auxiliary additive element provided in the embodiments of the present application can be one of 0.01%, 0.02%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any value within the above range.

[0040] In some embodiments, the auxiliary additive element comprises one or more combinations of B element, Ti element, Ni element, and Pd element.

[0041] By adding the auxiliary additive element, the melting point of the brazing filler metal can be reduced, the wettability can be improved, the bonding force between the brazing filler metal and the workpiece to be welded can be improved, and the joint strength and corrosion resistance can be improved.

[0042] In some embodiments, the mass percentage of B element is 0.01% to 5%. The mass percentage of B element provided in the present application can be a value within the range formed by any two values in the above range, such as 0.01% to 2%, 0.02% to 1%, 2% to 5%, and the like. The mass percentage of B element provided in the present application can be one of 0.01%, 0.02%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, or any value within the above range.

[0043] In some embodiments, the mass percentage of Ti element is 0.01% to 10%. The mass percentage of Ti element provided by the present invention can be any value within the range formed by any two values ​​in the above range, for example, it can be 0.01% to 1%, 1% to 7%, 2% to 4%, 4% to 10%, and so on. The mass percentage of Ti element provided by the present invention can also be one of 0.01%, 0.02%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, or any value that satisfies the above range.

[0044] In some embodiments, the mass percentage of Ni element is 0.03% to 0.9%. The mass percentage of Ni element provided by this invention can be any value within the range formed by any two values ​​within the above-mentioned range, for example, it can be 0.03% to 0.05%, 0.05% to 0.5%, 0.3% to 0.5%, 0.5% to 0.9%, and so on. The mass percentage of Ni element provided by this invention can also be one of 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, and 0.9%, or any value satisfying the above-mentioned range.

[0045] In some embodiments, the mass percentage of Pd element is 0.01% to 1%. The mass percentage of Pd element provided by this invention can be any value within the range formed by any two values ​​within the above-mentioned range, for example, it can be 0.01% to 0.1%, 0.1% to 0.8%, 0.3% to 0.5%, 0.5% to 1%, and so on. The mass percentage of Pd element provided by this invention can also be one of 0.01%, 0.02%, 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or any value satisfying the above-mentioned range.

[0046] In embodiments of the present invention, the active solder comprises the following components by mass percentage: 10% to 45% Mg, 0.01% to 10% auxiliary additives, and the remainder being metallic elements similar to the metal to be soldered and unavoidable impurities; wherein, the metallic elements similar to the metal to be soldered include at least one of Al and Sn.

[0047] The second aspect of the present invention provides a method for preparing the active solder described in the first aspect. The key to this preparation method is to mix and melt the corresponding raw materials according to the content of each element to obtain the active solder.

[0048] In the embodiments of the present invention, the preparation process of the active solder is simple, and the prepared active solder has excellent performance.

[0049] In some embodiments, the melting temperature is 200℃~1000℃, and the holding time is 10 min~20 min. Exemplarily, the melting temperature can be one of 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, or 1000℃, or any value satisfying the above range. The holding time can be one of 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, or 20 min, or any value satisfying the above range.

[0050] In some embodiments, the preparation method of active brazing filler metal includes the following steps: vacuum melting Mg metal with other raw materials according to a preset alloy ratio, covering the surface of the molten alloy with an anti-oxidation solvent, and simultaneously adding electromagnetic stirring to make the alloy composition uniform, then removing the surface oxide slag, and pouring the alloy melt into a mold to obtain an active brazing filler metal ingot.

[0051] In some embodiments, vacuum melting includes evacuating the vacuum melting equipment to a vacuum degree of 1×10⁻⁶. -1 Pa, and then inert gas is introduced into the vacuum melting equipment.

[0052] In some embodiments, the antioxidant solvent comprises either rosin or a halide salt, wherein the halide salt comprises sodium chloride, potassium chloride, lithium chloride, zinc chloride, etc.

[0053] In some embodiments, 99.99 wt.% pure metallic Mg and other raw materials are added to a vacuum melting furnace according to an alloy ratio. The alloy surface is covered with an anti-oxidation solvent, and the furnace is then vacuumed to a vacuum degree of 1×10⁻⁶. -1 After purging with nitrogen, the alloy is heated to a melting temperature of 200℃~1000℃ and held for 10 min~20 min while being electromagnetically stirred to ensure uniform alloy composition. Then, surface oxide slag is removed, and the alloy is vacuum cast to obtain an active brazing filler metal ingot.

[0054] In some embodiments, the method for preparing active brazing filler metal further includes converting the ingot of active brazing filler metal into at least one of paste, strip, foil, sheet, wire or powder.

[0055] The third aspect of this invention provides the application of the active solder described in the first aspect or the active solder prepared by the preparation method described in the second aspect in the welding of metallic and non-metallic materials.

[0056] In embodiments of the present invention, the non-metallic material includes one of ceramics, glass, and graphite.

[0057] In embodiments of the present invention, the metallic material includes one of aluminum, copper, and their alloys.

[0058] The present invention also provides a method for welding a metallic material and a non-metallic material, the method comprising placing the active brazing filler metal described in the first aspect or the active brazing filler metal prepared by the preparation method described in the second aspect between the metallic material and the non-metallic material; and performing pressureless brazing on the active brazing filler metal to connect the metallic material and the non-metallic material.

[0059] In some embodiments, the materials are stacked in the order of metallic material - active solder - non-metallic material, ensuring that the active solder completely covers the area to be soldered.

[0060] In some embodiments, the welding method further includes cleaning the metallic and non-metallic materials separately.

[0061] In some embodiments, the oxide layer, oil and impurities on the surface of the non-metallic material are removed by sandpaper or diamond grinding wheel, followed by ultrasonic cleaning with anhydrous ethanol or acetone for 15 minutes, and then dried for later use.

[0062] In some embodiments, a lint-free cloth dampened with anhydrous ethanol is used to gently wipe non-metallic materials, such as glass surfaces, to remove dust and oil; then, diamond polishing paste is used for polishing, followed by rinsing with deionized water to avoid residual abrasive particles.

[0063] In some embodiments, the dense oxide film on the surface of the metal material is removed, ultrasonically cleaned with an organic solvent, dried, and then placed in a dry environment for later use.

[0064] Next, the cleaned non-metallic and metallic materials are stacked in the order of metallic material-active solder-non-metallic material, ensuring that the active solder completely covers the area to be soldered.

[0065] Next, the stacked metal and non-metal materials to be welded are gently clamped together using a high-temperature resistant clamp and placed into a vacuum brazing furnace. After the furnace door is closed, a vacuum is drawn and high-purity inert gas (purity ≥99.99%) is introduced. The temperature is raised to the first brazing temperature at the first heating rate, and after holding at that temperature, the temperature is raised to the second brazing temperature at the second heating rate. After holding at that temperature, the temperature is slowly lowered to below the third brazing temperature at the preset cooling rate. After that, the furnace can be cooled to room temperature.

[0066] In some embodiments, the vacuum level is 1×10⁻⁶. -4 Pa ~ 1×10 -3 Pa. For example, the vacuum level can be 1 × 10⁻⁶. -4 Pa, 1×10 -3 One of Pa or any value that satisfies the above range.

[0067] In some embodiments, a high-purity inert gas is introduced, and the gas pressure is controlled between 0.2 MPa and 0.5 MPa. Exemplarily, the gas pressure can be one of 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, or any value satisfying the above range.

[0068] In some embodiments, the first heating rate is 2°C / min to 10°C / min. Exemplarily, the first heating rate can be one of 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, or any value satisfying the above range.

[0069] In some embodiments, the holding time at the first brazing temperature is 10 min to 20 min. Exemplarily, the holding time can be one of 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, or 20 min, or any value that satisfies the above range.

[0070] In some embodiments, the second heating rate is 1°C / min to 5°C / min. Exemplarily, the second heating rate can be one of 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, or any value satisfying the above range.

[0071] In some embodiments, the second brazing temperature is 300°C to 500°C. Exemplarily, the second brazing temperature can be one of 300°C, 350°C, 400°C, 450°C, 480°C, and 500°C, or any value satisfying the above range.

[0072] In some embodiments, the holding time at the second brazing temperature is 10 min to 30 min. Exemplarily, the holding time can be one of 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, or 30 min, or any value within the range described above.

[0073] In some embodiments, the cooling rate is 0.5℃ / min to 5℃ / min. Exemplarily, the cooling rate can be one of 0.5℃ / min, 1℃ / min, 1.5℃ / min, 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, or any value satisfying the above range.

[0074] In some embodiments, the third brazing temperature is 100°C to 300°C. Exemplarily, the third brazing temperature can be one of 100°C, 150°C, 200°C, 250°C, and 300°C, or any value satisfying the above range.

[0075] The present invention also provides a welded product, which is obtained by welding using the above-described welding method.

[0076] In this embodiment of the invention, the joint surface of the welded product was observed to be free of defects such as cracks, pores, and incomplete penetration, and the joint surface was smooth and without obvious defects.

[0077] In some embodiments, the shear strength of the welded joint is ≥30 MPa as measured by a shear test, and the fracture occurs at the non-metallic end.

[0078] In some embodiments, the shear strength of the welded joint is in the range of 30 MPa to 40 MPa.

[0079] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are all conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or through existing methods; unless otherwise specified, the amounts of experimental reagents used are the amounts used in conventional experimental operations; unless otherwise specified, the experimental methods are conventional methods. It should be further noted that the following description is merely exemplary and not a specific limitation of the present invention.

[0080] Example 1 An active brazing filler metal comprises, by weight percentage: 35% Mg, 0.02% B, with the balance being Al and unavoidable impurities. The active brazing filler metal has a melting point of 450°C. When applied to join aluminum alloy and graphite under pressureless conditions, the resulting weld joint exhibits a shear strength of 34 MPa, with fracture occurring at the graphite end.

[0081] The preparation method of this active solder includes the following steps: Al, Mg, and B with a purity of 99.99 wt.% were prepared according to their weight percentages and added to a vacuum melting furnace, and the furnace was evacuated to a vacuum level of 1×10⁻⁶. -1 After filling with nitrogen, the alloy is heated to 500℃ to melt. The surface is covered with rosin, an anti-oxidation solvent, and electromagnetic stirring is applied to make the alloy composition uniform. Then, the surface oxide slag is removed, and the alloy is vacuum cast to prepare the active brazing filler metal.

[0082] The welding of aluminum alloy and graphite using this active brazing filler metal includes the following steps: 1) Remove the oxide layer, oil and impurities from the graphite surface with sandpaper or diamond wheel, then ultrasonically clean with anhydrous ethanol or acetone for 15 minutes, and dry for later use.

[0083] 2) Remove the dense oxide film from the surface of the aluminum alloy, ultrasonically clean it with an organic solvent, dry it, and then place it in a dry environment.

[0084] 3) Stack the treated graphite and aluminum alloy in the following order: aluminum alloy → active brazing filler metal → graphite, ensuring the active brazing filler metal completely covers the area to be welded. Then, gently clamp the assembled parts into the vacuum brazing furnace using a high-temperature resistant clamp. After closing the furnace door, evacuate the furnace to a vacuum level of 1×10⁻⁶. -4 The furnace is filled with high-purity argon gas (purity ≥ 99.99%), and the gas pressure is controlled at 0.5 MPa. The temperature is then increased to 300℃ at a rate of 10℃ / min and held for 20 minutes; the temperature is then increased to 500℃ at a rate of 5℃ / min and held for 30 minutes; after the holding period, the temperature is slowly reduced to below 300℃ at a rate of 5℃ / min, and then cooled to room temperature with the furnace to obtain the aluminum alloy and graphite welded part.

[0085] The joint surface of the aluminum alloy and graphite welded parts was found to be free of defects such as cracks, pores, and incomplete penetration. The joint surface was smooth and free of obvious defects.

[0086] In Example 1, the shear strength of the welded joint was measured to be 34 MPa by shear test. The fracture occurred at the graphite end. The test was conducted in accordance with standard JIS Z3198-7:2003.

[0087] Example 2 An active brazing filler metal comprises, by weight percentage: 30% Mg, 4% Ti, with the balance being Al and unavoidable impurities. The active brazing filler metal has a melting point of 412°C. When used to join aluminum alloy and ceramic under pressureless conditions, the resulting weld joint exhibits a shear strength of 32 MPa, with fracture occurring at the ceramic end.

[0088] The preparation method of this active solder includes the following steps: Metallic Al, Mg, and Ti with a purity of 99.99 wt.% were prepared according to their weight percentages and added to a vacuum melting furnace, and then vacuumed to a concentration of 1 × 10⁻⁶. -1 After filling with nitrogen, the alloy is heated to 480°C to melt. The surface is covered with rosin, an anti-oxidation solvent, and electromagnetic stirring is applied to make the alloy composition uniform. Then, the surface oxide slag is removed, and the alloy is vacuum cast to prepare the active brazing filler metal.

[0089] The welding of aluminum alloys and ceramics using this active brazing filler metal includes the following steps: 1) Remove the oxide layer, oil and impurities from the ceramic surface with sandpaper or diamond wheel. After the surface becomes rough, ultrasonically clean it with anhydrous ethanol or acetone for 20 minutes and then dry it for later use.

[0090] 2) Remove the dense oxide film from the surface of the aluminum alloy, ultrasonically clean it with an organic solvent, dry it, and then place it in a dry environment.

[0091] 3) Stack the treated ceramics and aluminum alloys in the order of aluminum alloy → active brazing filler metal → ceramics, ensuring that the active brazing filler metal completely covers the area to be welded. Then, gently clamp the assembled parts to be welded using a high-temperature resistant clamp and place them into the vacuum brazing furnace. After closing the furnace door, evacuate the furnace to a vacuum level of 1×10⁻⁶. -4 The furnace is filled with high-purity argon gas (purity ≥ 99.99%), and the gas pressure is controlled at 0.5 MPa. The temperature is then increased to 300℃ at a rate of 10℃ / min and held for 20 minutes; the temperature is then increased to 480℃ at a rate of 5℃ / min and held for 10 minutes; after the holding period, the temperature is slowly reduced to below 300℃ at a rate of 5℃ / min, and then cooled to room temperature with the furnace to obtain the aluminum alloy and ceramic welded parts.

[0092] The joint surface of the aluminum alloy and ceramic welded parts was found to be free of defects such as cracks, pores, and incomplete penetration. The joint surface was smooth and free of obvious defects.

[0093] In Example 2, the shear strength of the welded joint was measured to be 32 MPa using the same test method as in Example 1 (refer to standard JIS Z3198-7:2003), and the fracture occurred at the ceramic end.

[0094] Example 3 An active brazing filler metal comprises, by weight percentage: 22% Mg, 0.2% Pd, 0.05% Ni, with the balance being Sn and unavoidable impurities. The active brazing filler metal has a melting point of 202°C. When applied to join copper alloy and graphite under pressureless conditions, the resulting weld joint exhibits a shear strength of 35 MPa, with fracture occurring at the graphite end.

[0095] The preparation method of this active solder includes the following steps: Metallic Sn, Mg, Ni, and Pd with a purity of 99.99 wt.% were prepared according to their weight percentages and added to a vacuum melting furnace, and then vacuumed to a concentration of 1 × 10⁻⁶. -1 After filling with nitrogen, the alloy is heated to 300°C to melt. The surface is covered with rosin, an anti-oxidation solvent, and electromagnetic stirring is applied to make the alloy composition uniform. Then, the surface oxide slag is removed, and the alloy is vacuum cast to prepare the active brazing filler metal.

[0096] The active brazing filler metal is used to weld copper alloys to graphite. The welding method includes the following steps: 1) Remove the oxide layer, oil and impurities from the graphite surface with sandpaper or diamond wheel, then ultrasonically clean with anhydrous ethanol or acetone for 10 minutes, and dry for later use.

[0097] 2) Remove surface oxides from copper alloys, ultrasonically clean with organic solvents, dry and then place in a dry environment.

[0098] 3) Stack the treated graphite and copper alloy in the following order: copper alloy → active brazing filler metal → graphite, ensuring the active brazing filler metal completely covers the area to be welded. Then, gently clamp the assembled parts into the vacuum brazing furnace using a high-temperature resistant clamp. After closing the furnace door, evacuate the furnace to a vacuum level of 1×10⁻⁶. -3 The furnace is filled with high-purity argon gas (purity ≥ 99.99%), and the gas pressure is controlled at 0.5 MPa. The temperature is then increased to 150℃ at a rate of 10℃ / min and held for 10 minutes; the temperature is then increased to 300℃ at a rate of 5℃ / min and held for 10 minutes; after the holding period, the temperature is decreased to 100℃ at a rate of 0.5℃ / min, and the furnace can be cooled to room temperature to obtain a copper alloy and graphite welded part.

[0099] The joint surface of the copper alloy and graphite welded parts was found to be free of defects such as cracks, pores, and incomplete penetration. The joint surface was smooth and free of obvious defects.

[0100] In Example 3, the shear strength of the welded joint was measured to be 35 MPa using the same test method as in Example 1 (refer to standard JIS Z3198-7:2003), and the fracture occurred at the graphite end.

[0101] Example 4 An active brazing filler metal comprises, by weight percentage: 10% Mg, 2% Ti, 0.03% B, with the balance being Sn and unavoidable impurities. The active brazing filler metal has a melting point of 203°C. When applied to joining copper alloys and glass under pressureless conditions, the resulting weld joint exhibits a shear strength of 37 MPa, with fracture occurring at the glass end.

[0102] The preparation method of this active solder includes the following steps: Sn, Mg, Ti, and B with a purity of 99.99 wt.% were prepared according to their weight percentages and added to a vacuum melting furnace, and the furnace was evacuated to a vacuum level of 1×10⁻⁶. -1 After filling with nitrogen, the alloy is heated to 500℃ to melt, and the surface is covered with rosin, an anti-oxidation solvent. At the same time, electromagnetic stirring is applied to make the alloy composition uniform. Then, the surface oxide slag is removed, and the alloy is vacuum cast to prepare the active brazing filler metal.

[0103] The active brazing filler metal is used for welding copper alloys to glass. The welding method includes the following steps: 1) Wipe the glass surface gently with a lint-free cloth dampened with anhydrous ethanol to remove dust and oil; polish with diamond polishing paste, then rinse with deionized water to avoid leaving any abrasive particles.

[0104] 2) Remove surface oxides from copper alloys, ultrasonically clean with organic solvents, dry and then place in a dry environment.

[0105] 3) Stack the treated glass and copper alloy in the following order: copper alloy → active brazing filler metal → glass, ensuring the active brazing filler metal completely covers the area to be welded. Then, gently clamp the assembled parts with a high-temperature resistant clamp and place them into the vacuum brazing furnace. After closing the furnace door, evacuate the furnace to a vacuum level of 1×10⁻⁶. -3 The furnace was filled with high-purity argon gas (purity ≥ 99.99%), and the gas pressure was controlled at 0.2 MPa. The temperature was then increased to 150℃ at a rate of 2℃ / min and held for 10 minutes; the temperature was then increased to 300℃ at a rate of 1℃ / min and held for 30 minutes; after the holding period, the temperature was decreased to 100℃ at a rate of 0.5℃ / min, and then cooled to room temperature with the furnace to obtain the copper alloy and glass welded part.

[0106] The joint surface of the copper alloy and glass welded parts was found to be free of defects such as cracks, pores, and incomplete penetration. The joint surface was smooth and free of obvious defects.

[0107] In Example 4, the shear strength of the welded joint was measured to be 37 MPa using the same test method as in Example 1 (refer to standard JIS Z3198-7:2003), and the fracture occurred at the glass end.

[0108] Example 5 An active brazing filler metal comprises, by weight percentage: 35% Mg, 14% Ti, with the balance being Al and unavoidable impurities. The active brazing filler metal has a melting point of 430°C. When applied to join aluminum alloy and graphite under pressureless conditions, the resulting weld joint exhibits a shear strength of 30 MPa, with fracture occurring at the graphite end.

[0109] The preparation method of this active solder includes the following steps: Metallic Al, Mg, and Ti with a purity of 99.99 wt.% were prepared according to their weight percentages and added to a vacuum melting furnace, and then vacuumed to a concentration of 1 × 10⁻⁶. -1 After filling with nitrogen, the alloy is heated to 500℃ to melt, and the surface is covered with rosin, an anti-oxidation solvent. At the same time, electromagnetic stirring is applied to make the alloy composition uniform. Then, the surface oxide slag is removed, and the alloy is vacuum cast to prepare the active brazing filler metal.

[0110] The welding of aluminum alloy and graphite using this active brazing filler metal includes the following steps: 1) Remove the oxide layer, oil and impurities from the graphite surface with sandpaper or diamond wheel, then ultrasonically clean with anhydrous ethanol or acetone for 10 minutes, and dry for later use.

[0111] 2) Remove the dense oxide film from the surface of the aluminum alloy, ultrasonically clean it with an organic solvent, dry it, and then place it in a dry environment.

[0112] 3) Stack the treated graphite and copper alloy in the following order: copper alloy → active brazing filler metal → graphite, ensuring the active brazing filler metal completely covers the area to be welded. Then, gently clamp the assembled parts into the vacuum brazing furnace using a high-temperature resistant clamp. After closing the furnace door, evacuate the furnace to a vacuum level of 1×10⁻⁶. -4 The furnace is filled with high-purity argon gas (purity ≥ 99.99%), and the gas pressure is controlled at 0.5 MPa. The temperature is then increased to 300℃ at a rate of 10℃ / min and held for 10 minutes; the temperature is then increased to 500℃ at a rate of 5℃ / min and held for 30 minutes; after the holding period, the temperature is slowly reduced to below 300℃ at a rate of 5℃ / min, and then cooled to room temperature with the furnace to obtain the aluminum alloy and graphite welded part.

[0113] The joint surface of the aluminum alloy and graphite welded parts was found to be free of defects such as cracks, pores, and incomplete penetration. The joint surface was smooth and free of obvious defects.

[0114] In Example 5, the shear strength of the welded joint was measured to be 30 MPa using the same test method as in Example 1 (refer to standard JIS Z3198-7:2003), and the fracture occurred at the graphite end.

[0115] The Mg-containing active brazing filler metal provided by this invention has a simple preparation process and excellent performance. It can be used for heterogeneous welding of metallic materials with non-metallic materials such as graphite, ceramics, and glass. Moreover, the brazing filler metal has high activity, does not require pressure, and forms a good welding interface.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An active solder, characterized in that, Includes the following components by mass percentage: The amount of Mg is 10%~45%, and the remainder consists of metallic elements similar to those in the metal to be welded, as well as unavoidable impurities. The metal element that is similar to the metal to be welded includes at least one of the following: Al and Sn.

2. The active solder as described in claim 1, characterized in that, The active solder also includes 0.01% to 10% auxiliary additives by mass percentage; Preferably, the auxiliary additive element includes one or more combinations of B, Ti, Ni and Pd elements.

3. The active solder as described in claim 2, characterized in that, The mass percentage of element B is 0.01% to 5%; Preferably, the mass percentage of element B is 0.01% to 2%, more preferably 0.02% to 1%.

4. The active solder as described in claim 2, characterized in that, The mass percentage of the Ti element is 0.01% to 10%; Preferably, the mass percentage of the Ti element is 1% to 7%, more preferably 2% to 4%.

5. The active solder as described in claim 2, characterized in that, The mass percentage of Ni is 0.03% to 0.9%; Preferably, the mass percentage of Ni element is 0.05% to 0.5%, more preferably 0.3% to 0.5%.

6. The active solder as described in claim 2, characterized in that, The mass percentage of the Pd element is 0.01% to 1%; Preferably, the mass percentage of the Pd element is 0.1% to 0.8%, more preferably 0.3% to 0.5%.

7. A method for preparing an active solder according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: The active solder is obtained by mixing and melting the corresponding raw materials according to the content of each element.

8. The preparation method according to claim 7, characterized in that, The melting temperature is 200℃~1000℃, and the holding time is 10 min~20 min.

9. The application of the active brazing filler metal as described in any one of claims 1 to 6, or the active brazing filler metal prepared by the preparation method as described in any one of claims 7 to 8, in the welding of metallic and non-metallic materials.

10. The application as described in claim 9, characterized in that, The non-metallic material includes one of ceramics, glass, and graphite, and the metallic material includes one of aluminum, copper, and their alloys.