An aluminum-based interlayer alloy, its preparation method and application

Abstract

This invention discloses an aluminum-based interlayer alloy, its preparation method, and its applications. The chemical composition of this aluminum-based interlayer alloy, by weight percentage, is: 6.5-8.5% Si, 22.0-24.0% Cu, 1.0-2.5% Ni, 1.0-2.5% Ti, 1.0-2.5% Ag, 0.3-2.0% Mg, 0.3-2.0% Ce, 0.3-1.5% In, and the balance being aluminum. This invention improves the chemical composition of the aluminum-based interlayer alloy by adding Mg, Ce, Ni, Ti, Ag, Zn, and In elements to the existing commercially available Al-Si-Cu solder, and optimizing the content of each component to an optimal range. This results in an aluminum-based interlayer alloy that, as a packaging material, possesses high joint strength and hermeticity.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and more specifically, to an aluminum-based interlayer alloy, its preparation method, and its application. Background Technology

[0002] Kovar alloys, as commonly used sealing alloys, have a dense oxide film, are easy to weld and fuse, have good plasticity, are machinable, and have good wear resistance. They are widely used in devices in industries such as vacuum electronics and power electronics. High-silicon aluminum alloys have recently been mainly used as novel electronic packaging materials. These materials possess excellent thermal conductivity, high specific strength and stiffness, good plating performance with gold, silver, copper, and nickel, are solderable to substrates, and are easy to precision machine. They are a promising electronic packaging material, especially in high-tech fields such as aerospace, space technology, and portable electronic devices.

[0003] High-silicon aluminum alloys have high requirements for the airtightness and integrity of the joints, but not high requirements for the mechanical properties of the welded joints. However, their thermal conductivity is relatively high, and they cannot completely replace Kovar alloys. Therefore, welding high-silicon aluminum alloys with Kovar alloys becomes crucial. In the field of electronic packaging, achieving the connection between high-silicon aluminum alloys and Kovar alloys to prepare new packaging shells can allow components to combine the advantages of both materials, while greatly reducing the weight of packaging materials, saving energy and reducing emissions. This has significant application value for my country's aerospace, defense industry, and electronic packaging construction. However, the main constituent elements of high-silicon aluminum alloys are Al and Si, while the main constituent elements of Kovar alloys are Fe, Co, and Ni. The physical and chemical properties of the two materials are quite different, especially their coefficients of thermal expansion, making the connection between the two different materials quite difficult. Especially in electronic packaging, the temperature cannot be too high, otherwise it may damage electronic components. Vacuum brazing is the optimal choice. First, brazing with a small heat input method will not damage the packaged electronic instruments due to overheating. Second, welding in a vacuum environment prevents the oxidation of high-silicon aluminum alloys, and the microstructure, mechanical properties, and deformation of the welded material are relatively small. We need to develop a new type of solder to achieve connections between dissimilar materials. As an encapsulation material, it must meet certain requirements for strength and airtightness.

[0004] Among the factors affecting the brazing of high-silicon aluminum alloys and Kovar alloys, the development and modification of brazing materials have become key factors in solving the brazing problem. In the brazing process of high-silicon aluminum alloys and Kovar alloys, the most widely used and well-developed active brazing filler metals are Ag-based, Al-Si-Mg, and Al-Si-Cu systems. Silver, being a rare and precious metal and a nationally controlled resource, results in excessively high brazing costs due to its use. Existing Al-based brazing filler metals exhibit relatively low joint strength and hermeticity when welding high-silicon aluminum alloys and Kovar alloys. Facing increasingly stringent packaging requirements, the joint performance of existing Al-based brazing filler metals is becoming increasingly inadequate. Therefore, it is essential to develop a new type of brazing filler metal to achieve the connection between dissimilar materials such as high-silicon aluminum alloys and Kovar alloys, serving as a packaging material that meets increasingly stringent requirements for joint strength and hermeticity.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an aluminum-based interlayer alloy, its preparation method, and its application, so as to improve the joint strength and airtightness of the aluminum-based interlayer alloy as a packaging material.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides an aluminum-based interlayer alloy, wherein the chemical composition of the aluminum-based interlayer alloy, by weight percentage, is: 6.5-8.5% Si, 22.0-24.0% Cu, 1.0-2.5% Ni, 1.0-2.5% Ti, 1.0-2.5% Ag, 0.3-2.0% Mg, 0.3-2.0% Ce, 0.3-1.5% In, and the balance being aluminum.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned aluminum-based interlayer alloy, which includes mixing and melting Si, Cu, Ni, Ti, Ag, Mg, Ce, In and Al in the above weight percentages to prepare an aluminum-based interlayer alloy.

[0010] Thirdly, the present invention provides the application of the above-mentioned aluminum-based interlayer alloy or the interlayer alloy prepared by the above-mentioned preparation method in welding high-silicon aluminum alloys and Kovar alloys.

[0011] Fourthly, the present invention provides a composite connector of high-silicon aluminum alloy and Kovar alloy, which is obtained by welding using the above-mentioned welding method.

[0012] The present invention has the following beneficial effects:

[0013] This invention improves the chemical composition of an aluminum-based interlayer alloy by adding Mg, Ce, Ni, Ti, Ag, Zn, and In elements to the existing Al-Si-Cu solder. The content of each component is optimized to an optimal range, resulting in an aluminum-based interlayer alloy with high joint strength and hermeticity as a packaging material. This aluminum-based interlayer alloy is suitable for welding various grades of high-silicon aluminum alloys and Kovar alloys, exhibiting superior welding performance compared to the bonding strength of widely used Ag-based, Al-Si-Mg, and Al-Si-Cu solders, thus meeting their industrial application requirements. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the welding assembly of high-silicon aluminum alloy and Kovar alloy in the embodiments and comparative examples;

[0016] Figure 2 The image shows a scanning electron microscope (SEM) image of the joint of a weldment after it has been welded using the powdered brazing filler metal provided in Example 1.

[0017] Figure 3 The image shows the microstructure at the joint of the weldment after welding with the strip brazing filler metal provided in Example 2.

[0018] Figure 4 The image shows the microstructure of the joint of the weldment after welding with the powdered brazing filler metal provided in Example 3. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0020] The following is a further detailed description of the aluminum-based master alloy, its preparation method, and its applications provided by the present invention.

[0021] To meet the increasingly stringent requirements for joint strength and airtightness in packaging materials, the inventors of this invention have optimized the composition of existing Al-Si-Cu solders, providing the following aluminum-based interlayer alloy:

[0022] The chemical composition of this aluminum-based interlayer alloy is: 6.5-8.5% Si, 22.0-24.0% Cu, 1.0-2.5% Ni, 1.0-2.5% Ti, 1.0-2.5% Ag, 0.3-2.0% Mg, 0.3-2.0% Ce, 0.3-1.5% In, and the balance aluminum.

[0023] Specifically, the Si content can be 6.5%, 7.0%, 7.5%, 8.0%, or 8.5%, or any other value within the range of 6.5% to 8.5%.

[0024] The Cu content can be 22%, 23%, or 24%, or any other value within the range of 22-24%.

[0025] The Ni content can be 1%, 1.5%, 2% or 2.5%, or any other value within the range of 1-2.5%.

[0026] The Ti content can be 1%, 1.5%, 2%, or 2.5%, or any other value within the range of 1-2.5%.

[0027] The content of Ag can be 1%, 1.5%, 2% or 2.5%, or any other value within the range of 1-2.5%.

[0028] The Mg content can be 0.3%, 0.5%, 1% or 2%, or any other value within the range of 0.3% to 2%.

[0029] The Ce content can be 0.3%, 0.5%, 1% or 2%, or any other value within the range of 0.3% to 2%.

[0030] The In content can be 0.3%, 0.5%, 1% or 1.5%, or any other value within the range of 0.3% to 1.5%.

[0031] This invention adds an appropriate amount of Mg to the existing Al-Si-Cu brazing filler metal composition. During the welding process, Mg vapor penetrates into the aluminum alloy surface layer and forms a low-melting-point Al-Si-Mg liquid phase with Si that diffuses into the aluminum alloy surface layer. This breaks the bond between the oxide film and the aluminum alloy, and the liquid brazing filler metal then wets and spreads on the surface of the high-silicon aluminum alloy base material.

[0032] Based on the above improvements, the inventors added an appropriate amount of rare earth element Ce. Rare earth element Ce has high surface activity, which can reduce the surface tension of liquid solder, refine the microstructure of solder, and provide good wettability and spreadability during brazing. During the brazing process, as the welding temperature continues to increase, the fine grain structure helps the solder to melt uniformly and quickly.

[0033] The aluminum-based interlayer alloy of this invention also incorporates the alloying strengthening element Ni. Since Ni and Cu have similar crystal structures, their phase diagrams show that they can form an infinitely dissolve solid solution, creating a continuous solid solution. Therefore, Ni can replace some Cu, reducing the formation of brittle metal compounds such as CuAl2, thus increasing the toughness and corrosion resistance of the solder. Simultaneously, the addition of Ni refines the grains in the solder, facilitating the acquisition of superior amorphous or nanocrystalline structures and increasing the solder's wetting ability, resulting in a higher-performance weld joint. However, excessive Ni addition raises the solder's melting point, which is detrimental to the welding of high-silicon aluminum alloys. Furthermore, the main elements of Kovar alloy are Fe, Co, and Ni. Adding Ni to the solder helps reduce the chemical potential difference between the solder and the Kovar alloy side, increasing the weld's corrosion resistance. It also promotes the diffusion of solder elements towards the Kovar alloy side.

[0034] The aluminum-based interlayer alloy of this invention also contains Ti, a transition metal with high chemical reactivity (first ionization energy of 658.8 kJ / mol). It possesses some properties of both metals and nonmetals, exhibiting strong affinity for nonmetallic materials such as ceramics. Ti facilitates wetting of Si particles on the high-silicon aluminum side and reacts with Al and Si to form intermetallic compounds such as AlTi2, AlTi3, and Ti7Al5Si12. Generally, Ti-containing intermetallic compounds have high melting points and are high-temperature stable phases. During welding, these high-temperature stable phases are not easily melted or reacted, remaining as high-temperature reinforcing phases in the weld after welding. This affects joint strength, so the Ti content should not be too high. A suitable amount of small-morphology reinforcing phase in the weld is beneficial for improving weld bonding strength. However, a high content or large morphology of reinforcing phase hinders the flow of brazing filler metal in the weld, resulting in higher stress and brittleness in the brazing filler layer, which is detrimental to obtaining a high-quality joint.

[0035] The aluminum-based interlayer alloy of the present invention also contains the element Ag. The addition of an appropriate amount of Ag can ensure good wetting and dispersion during the welding process of high silicon aluminum alloy and Kovar alloy, thereby obtaining an airtight and firm seal.

[0036] Meanwhile, the aluminum-based intermediate layer alloy of the present invention also contains the element Zn. During the welding process, an appropriate amount of Zn diffuses into the high-silicon aluminum alloy to generate Zn-based solid solution and Zn-Al eutectic structure. Zn-Al solid solution can distort the matrix lattice, resulting in rough slip surface and increasing the resistance to dislocation movement, thus improving the resistance to plastic deformation and strengthening the brazed joint.

[0037] Furthermore, the aluminum-based interlayer alloy of the present invention also contains the element In. The addition of an appropriate amount of In can reduce the melting point of the solder and reduce the welding temperature of vacuum brazing when connecting composite joints of high silicon aluminum alloy and Kovar alloy.

[0038] To further enhance the overall performance of the material, the inventors optimized the composition. In the preferred embodiment, the composition is: 7-8% Si, 22.5-23.5% Cu, 1.5-2.5% Ni, 1.5-2.5% Ti, 1.5-2.5% Ag, 1.0-2.0% Mg, 1.0-2.0% Ce, 1.0-1.5% In, and the balance aluminum.

[0039] In some embodiments, the aluminum-based interlayer alloy is in the form of powder or strip.

[0040] In some embodiments, the aluminum-based interlayer alloy is in powder form with a particle size of 200-600 mesh.

[0041] In some embodiments, the aluminum-based interlayer alloy is in the form of a strip with a thickness of 30μm-90μm and a width of 10-80mm.

[0042] The present invention also provides a method for preparing the above-mentioned aluminum-based interlayer alloy, which includes mixing and melting Si, Cu, Ni, Ti, Ag, Mg, Ce, In and Al according to the above weight percentages to prepare an aluminum-based interlayer alloy.

[0043] In some embodiments, the preparation method further includes preparing the aluminum-based interlayer alloy into powder or strip form.

[0044] In some embodiments, the method for preparing the powdered aluminum-based interlayer alloy includes: mixing the raw materials according to the above weight percentages, and then sequentially vacuum melting, gas atomization and ultrasonic sieving to obtain the powdered aluminum-based interlayer alloy.

[0045] In some embodiments, the raw materials include Si, Cu, Ni, Ti, Ag, Mg, Ce, In and Al with a purity of ≥99.9%.

[0046] In some embodiments, vacuum melting and gas atomization include: heating raw materials in a vacuum melting device to melt them and obtain a molten liquid, then conveying the molten liquid to an atomizing device and spraying it out at a predetermined flow rate, while simultaneously atomizing the molten liquid with an inert gas to form atomized droplets, and cooling and solidifying the atomized droplets to obtain atomized aluminum alloy powder.

[0047] In some implementations, the heating temperature in the vacuum melting step is 750-850°C.

[0048] Specifically, the heating temperature can be 750℃, 800℃ or 850℃, or any other value within the range of 750-850℃.

[0049] In some embodiments, the inert gas is pretreated before entering the tightly coupled gas atomizing nozzle to atomize the molten liquid.

[0050] In some embodiments, the pretreatment conditions for the inert gas are: a preheating temperature of 550-600°C and an atomization pressure of 4-5.5 MPa.

[0051] Specifically, the preheating temperature can be 550℃, 560℃, 570℃, 580℃, 590℃, or 600℃, or any other value within the range of 550-600℃. The atomization pressure can be 4MPa, 4.5MPa, 5MPa, or 5.5MPa, or any other value within the range of 4-5.5MPa.

[0052] In some embodiments, the inert gas flow rate is 400-550 m / s and the flow rate is 2300-2800 m³ / s. 3 / h; the flow rate of the molten liquid is 350-400Kg / h.

[0053] Specifically, the flow velocity of the inert gas can be 400 m / s, 450 m / s, 500 m / s, or 550 m / s, or any other value within the range of 400-550 m / s. The flow rate can be 2300 m³ / s. 3 / h, 2400m 3 / h, 2500m 3 / h, 2600m 3 / h, 2700m 3 / h or 2800m 3 / h, or 2300-2800m 3 The flow rate of the melt can be any value within the range of / h.

[0054] In some implementations, the pressure of the ambient gas in the atomizing device is 2-3 kPa.

[0055] In some embodiments, the particle size of the powdered aluminum-based interlayer alloy is 200-600 mesh.

[0056] In some embodiments, the method for preparing the strip-shaped aluminum-based interlayer alloy includes: mixing raw materials by weight percentage, vacuum melting to form an alloy ingot, and then rapidly quenching the alloy ingot to form a strip-shaped aluminum-based interlayer alloy.

[0057] In some embodiments, the raw materials include Si, Cu, Ni, Ti, Ag, Mg, Ce, In and Al with a purity of ≥99.9%.

[0058] In some embodiments, vacuum melting includes: heating the raw material to a molten state in a vacuum melting apparatus, holding it at that temperature, and then casting it.

[0059] In some embodiments, the vacuum level in the vacuum melting step is below 5 x 10⁻⁶. -3 After pa, Ar gas is added for atmosphere protection, and the raw material is heated to 700-800℃ and held for 15-30 minutes.

[0060] Specifically, the heating temperature of the raw material can be 700℃, 750℃, or 800℃, or any value between 700℃ and 800℃; the holding time can be 15min, 20min, 25min, or 30min, or any value between 15min and 30min.

[0061] In some implementations, vacuum melting is followed by cutting and polishing of the alloy ingot.

[0062] In some implementations, rapid quenching involves remelting the alloy ingot, holding it at a certain temperature, and then spraying the melt onto the surface of a copper roller to form a strip.

[0063] In some implementations, the holding time is 2-5 minutes, the linear speed of the copper roller is 25-50 m / s, and the melt injection pressure is 0.02-0.06 MPa.

[0064] Specifically, the holding time can be 2 min, 3 min, 4 min, or 5 min, or any value between 2 and 5 min; the linear speed of the copper roller can be 25 m / s, 30 m / s, 35 m / s, 40 m / s, 45 m / s, or 50 m / s, or any value between 25 and 50 m / s; the melt injection pressure can be 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa, or 0.06 MPa, or any value between 0.02 and 0.06 MPa.

[0065] In some embodiments, the thickness of the strip-shaped aluminum-based interlayer alloy is 30 μm-90 μm.

[0066] In some embodiments, the width of the strip-shaped aluminum-based interlayer alloy is 10-80 mm.

[0067] This invention provides the application of the above-mentioned aluminum-based interlayer alloy or the interlayer alloy prepared by the above-mentioned method in welding high-silicon aluminum alloys and Kovar alloys.

[0068] In some embodiments, the welding temperature is 550-600℃, the welding pressure is 0.05-0.5MPa, and the holding time is 10-60min.

[0069] Specifically, the welding temperature can be 550℃, 560℃, 570℃, 580℃, 590℃ or 600℃, or any other value within the range of 550-600℃.

[0070] The welding pressure can be 0.08MPa, 0.1MPa, 0.2MPa or 0.4MPa, or any other value in the range of 0.05-0.5MPa.

[0071] The heat preservation time can be 15m, 20min or 25min, or any other value within the range of 10-60min.

[0072] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0073] Example 1

[0074] An aluminum-based interlayer material is composed of the following components in weight percentages: 7.5% Si, 23.0% Cu, 1.5% Ni, 1.5% Ti, 1.5% Ag, 1.0% Mg, 1.0% Ce, 1.0% In, and the balance aluminum.

[0075] A method for preparing powdered aluminum-based interlayer material includes the following steps:

[0076] (1) Raw materials with purities of Al≥99.9%, Cu≥99.9%, Si≥99.9%, Cu≥99.9%, Ni≥99.9%, Ti≥99.9%, Ag≥99.9%, Mg≥99.9%, Ce≥99.9%, and In≥99.9% were pickled for 30 seconds, alkali washed for 30 seconds, and water washed for 10 seconds to remove the surface oxide film. The raw materials of the required aluminum-based intermediate layer alloy were weighed according to the weight ratio.

[0077] (2) Place the prepared raw materials in an induction vacuum melting furnace, heat and melt them into aluminum alloy liquid, and maintain the temperature of the aluminum liquid at 750-850℃, while heating the guide crucible.

[0078] (3) Pour the obtained aluminum alloy liquid into a flow guide crucible, and then transport it to an atomization chamber with high-purity nitrogen gas as the ambient gas. Spray it out at a predetermined flow rate. At the same time, nitrogen gas with a predetermined preheating temperature and predetermined atomization pressure is sprayed out through a tightly coupled gas atomization nozzle to atomize the aluminum liquid and form atomized aluminum liquid droplets. The atomized aluminum liquid droplets are cooled and condensed rapidly under the cooling and protection of the ambient gas in the atomization chamber to form atomized aluminum alloy powder.

[0079] Nitrogen gas, after compression and heating pretreatment, enters the tightly coupled gas atomizing nozzle. Under preheating conditions of 550-600℃ and atomization pressure of 4.5MPa, it is ejected from the nozzle, forming a supersonic mixed gas flow. This flow, at a velocity of 450m / s, atomizes the molten aluminum into fine atomized droplets. The ambient gas pressure in the atomization chamber is maintained at 2.5KPa. The flow rate of the molten aluminum is 380Kg / h. The flow rate of the nitrogen gas is 2600m³ / h. 3 / h.

[0080] (4) The obtained atomized aluminum powder is fed into a grading system using the mixed gas as a transport medium for grading and screening to obtain micro-spherical aluminum alloy powders of different particle sizes. Then, the aluminum alloy powder is placed in an ultrasonic sieve under atmospheric conditions for ultrasonic sieving. Sieving yields 400-mesh spherical powder.

[0081] The prepared aluminum-based intermediate layer powder material was applied to the direct brazing of CE11 high-silicon aluminum alloy and 4J29 Kovar alloy. A schematic diagram of the welding assembly is shown below. Figure 1 As shown. The welding process parameters are: welding temperature set to 580℃, pressure set to 0.15MPa, and holding time set to 25min.

[0082] Microstructure of the welded parts is shown in the figure. Figure 2 As shown.

[0083] Example 2

[0084] An aluminum-based interlayer material is composed of the following components in weight percentages: 7.5% Si, 23.0% Cu, 1.5% Ni, 1.5% Ti, 1.5% Ag, 1.0% Mg, 1.0% Ce, 1.0% In, and the balance aluminum.

[0085] A method for preparing sheet-like aluminum-based interlayer material includes the following steps:

[0086] (1) Raw materials with purities of Al≥99.9%, Cu≥99.9%, Si≥99.9%, Cu≥99.9%, Ni≥99.9%, Ti≥99.9%, Ag≥99.9%, Mg≥99.9%, Ce≥99.9%, and In≥99.9% were pickled for 30 seconds, alkali washed for 30 seconds, and rinsed with water for 10 seconds to remove the surface oxide film. The raw materials were weighed according to the composition of the aluminum-based intermediate layer alloy mentioned above.

[0087] (2) Place the prepared raw materials in an induction vacuum melting furnace and evacuate the furnace to a vacuum level of 5x10. -3After pa, Ar gas is used for atmosphere protection, then the temperature is heated to 750°C. After the material is completely melted, it is held at that temperature for 20 minutes, and then poured in the melting furnace.

[0088] (3) The smelted alloy is mechanically cut, the surface oxide scale and residue are polished, and then it is put into the quartz glass tube of the single roller belt spinning machine.

[0089] (4) The master alloy is remelted in an Ar protective atmosphere. After the alloy is completely melted, it is kept at a temperature of 3 minutes. Then it is spun in a vacuum chamber at a speed of 35 m / s. The linear speed of the copper roller is 35 m / s and the melt injection pressure is 0.05 MPa.

[0090] After the strip is spun, the intermediate layer material is made into a strip with a thickness of 50μm and a width of 60mm.

[0091] The prepared aluminum-based interlayer material was used for brazing CE11 high-silicon aluminum alloy and 4J29 Kovar alloy. A schematic diagram of the welding assembly is shown below. Figure 1 As shown. The welding process parameters are: welding temperature set to 580℃, pressure set to 0.15MPa, and holding time set to 25min.

[0092] Microstructure of the welded parts is shown in the figure. Figure 3 As shown.

[0093] Example 3

[0094] This embodiment is basically the same as Embodiment 1, except that:

[0095] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 1.0% Ni, 1.0% Ti, 2.5% Ag, 1.0% Mg, 2.0% Ce, 1.5% In and the balance aluminum.

[0096] The preparation method of sheet-like aluminum-based interlayer material includes the following steps: Si, Cu, Ni, Ti, Ag, Mg, Ce, In and Al are mixed in proportion, and vacuum melting is first used. The interlayer material is then made into 400-mesh spherical powder by vacuum melting, gas atomization and ultrasonic sieving. The preparation process is the same as in Example 1.

[0097] The prepared aluminum-based intermediate layer powder material was used to directly braze CE11 high-silicon aluminum alloy and 4J29 Kovar alloy. The welding process parameters were: welding temperature 580℃, pressure 0.15MPa, and holding time 25min.

[0098] Microstructure of the welded parts is shown in the figure. Figure 4 As shown.

[0099] Example 4

[0100] This embodiment is basically the same as Embodiment 1, except that:

[0101] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 1.0% Ni, 1.0% Ti, 1.0% Ag, 1.0% Mg, 2.0% Ce, 1.5% In and the balance aluminum.

[0102] A method for preparing sheet-like aluminum-based interlayer material includes the following steps: Si, Cu, Ni, Ti, Ag, Mg, Ce, In, and Al are mixed in a certain proportion. First, vacuum melting is performed. The melted alloy ingot is then cut into alloy strips using wire cutting and mechanical cutting processes. The cut alloy strips are then subjected to sandblasting to remove surface oil. Next, the sandblasted alloy strips are ultrasonically cleaned with alcohol and acetone to remove surface oil. Finally, the cleaned alloy strips are rapidly quenched to produce an interlayer material with a thickness of 50 μm and a width of 60 mm. The preparation process is the same as in Example 2.

[0103] The prepared aluminum-based intermediate layer sheet material was used for direct brazing of CE11 high-silicon aluminum alloy and 4J29 Kovar alloy. The welding process parameters were: welding temperature 580℃, pressure 0.15MPa, and holding time 25min.

[0104] Comparative Example 1

[0105] This comparative example is basically the same as Example 1, except that:

[0106] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 3.0% Ni, 1.5% Ti, 1.5% Ag, 1.0% Mg, 1.0% Ce, 2.0% In and the balance aluminum.

[0107] Comparative Example 2

[0108] This comparative example is basically the same as Example 1, except that:

[0109] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 1.5% Ni, 3.0% Ti, 1.5% Ag, 1.0% Mg, 1.0% Ce, 1.0% In and the balance aluminum.

[0110] Comparative Example 3

[0111] This comparative example is basically the same as Example 1, except that:

[0112] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 1.5% Ni, 1.5% Ti, 1.5% Ag, 1.0% Mg, 1.0% Ce, 3.0% In and the balance aluminum.

[0113] Comparative Example 4

[0114] This comparative example is basically the same as Example 1, except that:

[0115] The composition by weight percentage is: 7.5% Si, 23.0% Cu, 1.5% Ni, 1.5% Ti, 1.5% Ag, 2.0% Mg, 3.5% Ce, 1.0% In and the balance aluminum.

[0116] Comparative Example 5

[0117] The aluminum-based interlayer material in this comparative example is in strip form, and its chemical composition is: Ag57.6-Cu22.4-In10-Sn10. The preparation method is the same as in Example 1.

[0118] The prepared aluminum-based intermediate strip material was used for direct brazing of CE11 high-silicon aluminum alloy and 4J29 Kovar alloy. The welding process parameters were: welding temperature 600℃, pressure 0.15MPa, and holding time 25min.

[0119] Comparative Example 6

[0120] This comparative example provides an Al-Si-Mg strip solder with the chemical composition of Al-11.5Si-1.5Mg. The preparation method and welding process parameters are the same as in Example 1.

[0121] Comparative Example 7

[0122] This comparative example provides an Al-Si-Cu strip solder with the chemical composition of Al-7.5Si-23Cu. The preparation method and welding process parameters are the same as in Example 2.

[0123] Experimental Example

[0124] The joints of the welded components from Examples 1-4 and Comparative Examples 1-7 were subjected to performance testing. The experimental data are recorded in the table below.

[0125] Table 1 Comparison of experimental group data

[0126]

[0127] As shown in Table 1, when the aluminum-based interlayer alloy provided in the embodiments of the present invention is welded to high-silicon aluminum alloy and Kovar alloy, the shear strength at the joint after welding is high, which is significantly better than the existing Al-Cu-In-Sn, Al-Si-Mg and Al-Si-Cu brazing fillers provided in Comparative Examples 5, 6 and 7. Comparing Examples 1-4 with Comparative Examples 1-4, it is found that if the chemical composition does not include certain chemical elements required by this application or the composition ratio is not within the scope of protection of the present invention, the joint strength of the brazing filler after welding high-silicon aluminum alloy and Kovar alloy is lower than the bonding strength of commercial Al-Cu-In-Sn solder, but equal to the bonding strength of commercial Al-Si-Mg and Al-Si-Cu solder. At the same time, the airtightness leakage rate of the joint after welding is also lower than that of commercial Al-Cu-In-Sn joint, and equal to that of commercial Al-Si-Mg and Al-Si-Cu solder joint.

[0128] In summary, the aluminum-based interlayer alloy provided by this invention, by adding Mg, Ce, Ni, Ti, Ag, and In to the existing Al-Si-Cu solder, results in good welding performance and high joint shear strength when applied to the welding of high-silicon aluminum alloys and Kovar alloys.

[0129] The method for preparing the aluminum-based interlayer alloy provided by this invention is simple and can produce the aluminum-based interlayer alloy provided by this invention.

[0130] The welding method for high-silicon aluminum alloys and Kovar alloys provided by this invention, due to the use of the aluminum-based intermediate layer alloy provided by this invention to weld high-silicon aluminum alloys and Kovar alloys, results in welded parts with good performance, high joint strength, and good airtightness.

[0131] The composite connector made of high-silicon aluminum alloy and Kovar alloy provided by this invention is obtained by welding using the welding method provided in the embodiments of this invention. The joint of this composite connector has good mechanical properties.

[0132] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aluminum-based interlayer alloy, characterized by, The chemical composition of the aluminum-based interlayer alloy is 7.5% Si, 23% Cu, 1.0%-1.5% Ni, 1%-1.5% Ti, 1.5%-2.5% Ag, 1.0% Mg, 1.0%-2.0% Ce, 1%-1.5% In, and the balance of aluminum, in terms of weight percentage.

2. The aluminum-based interlayer alloy of claim 1, wherein, The aluminum-based interlayer alloy is in the form of powder or ribbon.

3. The aluminum-based interlayer alloy of claim 2, wherein, The aluminum-based interlayer alloy is in the form of powder, and the particle size is 200-600 mesh.

4. The aluminum-based interlayer alloy of claim 2, wherein, The aluminum-based interlayer alloy is in the form of ribbon, and the thickness is 30 µm-90 µm, and the width is 10-80 mm.

5. The method of producing an aluminum-based interlayer alloy according to any one of claims 1 to 4, characterized in that, The preparation method comprises mixing raw materials according to the weight percentage and melting to prepare the aluminum-based interlayer alloy.

6. The method of producing an aluminum-based interlayer alloy according to claim 5, characterized by, The raw materials include Si, Cu, Ni, Ti, Ag, Mg, Ce, In, and Al.

7. The method of producing an aluminum-based interlayer alloy according to claim 5, characterized by, The preparation method further comprises preparing the aluminum-based interlayer alloy into powder or ribbon.

8. The method of producing an aluminum-based interlayer alloy according to claim 7, characterized by, The preparation method of the aluminum-based interlayer alloy in powder form comprises mixing raw materials according to the weight percentage, and then vacuum melting, gas atomization, and ultrasonic screening in sequence to prepare the aluminum-based interlayer alloy in powder form.

9. The method of producing an aluminum-based interlayer alloy according to claim 8, characterized by, The raw materials include Si, Cu, Ni, Ti, Ag, Mg, Ce, In, and Al, each with a purity of ≥99.9%.

10. The method of producing an aluminum-based interlayer alloy according to claim 8, characterized by, The vacuum melting and gas atomization comprise heating the raw materials in a vacuum melting device to melt and obtain a molten liquid, then conveying the molten liquid to an atomization device, and spraying out at a predetermined flow rate while atomizing the molten liquid with inert gas to form mist droplets, which are cooled and solidified to obtain atomized aluminum alloy powder.

11. The method of producing an aluminum-based interlayer alloy according to claim 10, characterized by, The heating temperature in the vacuum melting step is 750-850 ℃.

12. The method of producing an aluminum-based interlayer alloy according to claim 10, characterized by, The inert gas is preprocessed and then enters a tight-coupling gas atomization nozzle to atomize the molten liquid.

13. The method of producing an aluminum-based interlayer alloy according to claim 12, characterized by, The preprocessing conditions of the inert gas are a preheating temperature of 550-600 ℃ and an atomization pressure of 4.0-5.5 MPa.

14. The method of producing an aluminum-based interlayer alloy according to claim 12, characterized by, The flow rate of the inert gas is 400-550 m / s, the flow is 2300-2800 m 3 / h; the flow of the molten liquid is 350-400 Kg / h.

15. The method of making an aluminum-based interlayer alloy of claim 10, wherein, The pressure of the environmental gas in the atomization device is 2.0-3.0 Kpa.

16. The method of making an aluminum-based interlayer alloy of claim 10, wherein, The particle size of the aluminum-based interlayer alloy in powder form is 200-600 mesh.

17. The method of producing an aluminum-based interlayer alloy according to claim 7, characterized by, The preparation method of the aluminum-based interlayer alloy in ribbon form comprises mixing raw materials according to the weight percentage, melting to prepare an alloy ingot, and then rapidly quenching the alloy ingot to prepare the aluminum-based interlayer alloy in ribbon form.

18. The method of producing an aluminum-based interlayer alloy according to claim 17, characterized by, The raw materials include Si, Cu, Ni, Ti, Ag, Mg, Ce, In, and Al, each with a purity of ≥99.9%.

19. The method of making an aluminum-based interlayer alloy of claim 17, wherein, The vacuum melting comprises heating the raw materials to a molten state and then holding and pouring in a vacuum melting device.

20. The method of making an aluminum-based interlayer alloy of claim 19, wherein, The vacuum degree in the vacuum melting step is less than 5x10 -3 The raw material is heated to 700-800℃ under Ar atmosphere protection, and the holding time is 15-30 min.

21. The method of making an aluminum-based interlayer alloy of claim 20, wherein, After vacuum melting, the alloy ingot is also cut and polished.

22. The method of making an aluminum-based interlayer alloy of claim 17, wherein, The rapid quenching comprises remelting and holding the alloy ingot, and then spraying the melt onto the surface of a copper roller to form a ribbon.

23. The method of producing an aluminum-based interlayer alloy according to claim 22, characterized by, The holding time is 2-5 min, the linear speed of the copper roller is 25-50 m / s, and the spraying pressure of the melt is 0.02-0.06 MPa.

24. The method of making an aluminum-based interlayer alloy of claim 17, wherein, The thickness of the aluminum-based interlayer alloy in ribbon form is 30 µm-90 µm.

25. The method of making an aluminum-based interlayer alloy of claim 17, wherein, The width of the aluminum-based interlayer alloy in ribbon form is 10-80 mm.

26. Use of the aluminum-based interlayer alloy according to any one of claims 1 to 4 or the interlayer alloy prepared according to the method of any one of claims 5 to 25 for welding high-silicon aluminum alloys and Kovar alloys.

27. The use according to claim 26, characterized in that, The welding temperature of the welding is 550-600℃, the welding pressure is 0.05-0.5MPa, and the holding time is 10-60min.

28. A composite joint of high-silicon aluminum alloy and Kovar alloy, characterized by The welding is obtained by using the welding method according to claim 26 or 27.

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