High-strength high-temperature-resistant metal binder as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of binders, and particularly relates to a high-strength high-temperature-resistant metal binder and a preparation method and application thereof. The invention provides a high-strength high-temperature-resistant metal binder as well as a preparation method and application thereof, aiming at the problem that a binder in the prior art cannot be well applied to a long-term high-temperature-resistant metal connection scene. Comprising the following components in parts by mass: 20-40 parts of nano aluminum powder, 10-20 parts of copper powder, 15-25 parts of modified phenolic resin, 5-10 parts of silicon carbide nanowires and 2-5 parts of an antioxidant. The modified phenolic resin with introduced-Si-O-bonds and the nano SiO2 are adopted for synergistic enhancement, so that the temperature resistance of the resin is increased to 400 DEG C from 200 DEG C, the resin provides initial bonding force at low temperature, metal eutectic reaction replaces bearing at high temperature, a stepped bonding mechanism is achieved, meanwhile, through the combination of the nano aluminum powder and the dendritic copper powder in a specific proportion, the bonding strength of the nano aluminum powder and the dendritic copper powder is improved, and the bonding strength of the nano aluminum powder and the dendritic copper powder is improved. And the Al-Cu eutectic reaction temperature is reduced to 300 DEG C by utilizing a nano effect, so that alternative bearing can be effectively carried out, and a stepped bonding mechanism is better realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and particularly relates to a high-strength and high-temperature-resistant metal adhesive, its preparation method and application. Background Art

[0002] Metal connection scenarios such as aerospace engine components, automotive turbocharging systems, and high-temperature pipelines in nuclear power plants that need to withstand high temperatures of 300 - 600 °C for a long time. However, traditional epoxy resin adhesives have poor high-temperature resistance (usually < 200 °C) and cannot meet the requirements of high-temperature environments such as aerospace and automotive engines. Inorganic adhesives (such as silicates) are brittle and the joints are prone to cracking. Existing metal adhesives (such as silver-containing epoxy adhesives) have high costs and insufficient bonding strength for some metals (such as aluminum and titanium). Therefore, there is an urgent need to provide an adhesive that can be better applied to the above metal connection scenarios.

[0003] For example, a Chinese invention patent application discloses an inorganic metal adhesive and its preparation method [Application No.: 201510830575.0]. This invention patent application includes, by weight: 30 - 50 parts of sodium silicate, 30 - 50 parts of potassium silicate, 3 - 5 parts of starch, 3 - 5 parts of methyl cellulose, 3 - 5 parts of polyacrylamide, 1 - 2 parts of calcium silicate, 0.5 - 1 part of sodium hexametaphosphate, 1 - 2 parts of sorbitol, 1 - 2 parts of hydroxylated lecithin, 1 - 2 parts of glyceryl triacetate, 0.1 - 0.5 part of gellan gum, 0.1 - 0.4 part of xanthan gum, 0.1 - 0.2 part of propyl benzoate, 0.1 - 0.2 part of calcium propionate, and 15 - 25 parts of water.

[0004] Although this invention patent application has the advantages that the provided metal adhesive has high bonding strength and is non-toxic, belonging to an environmentally friendly adhesive, it still does not solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to address the above problems and provide a high-strength and high-temperature-resistant metal adhesive, its preparation method and application.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A high-strength and high-temperature-resistant metal adhesive, comprising 20 - 40 parts by mass of nano-aluminum powder, 10 - 20 parts of copper powder, 15 - 25 parts of modified phenolic resin, 5 - 10 parts of silicon carbide nanowires, and 2 - 5 parts of antioxidant.

[0007] In the above high-strength and high-temperature-resistant metal adhesive, the particle size of the nano-aluminum powder is 50 - 100 nm, D50 = 80 nm, and the specific surface area ≥ 15 m 2 / g, purity: ≥99.9%, oxygen content <0.5%. Excessive oxygen content poses a risk of high-temperature oxidation failure; the copper powder has a dendritic structure with a particle size of 1-5 μm; the mass ratio of the nano-aluminum powder to the copper powder is 3:1. At this mass ratio, the eutectic reaction between the two is the most complete.

[0008] In the above-mentioned high-strength and high-temperature-resistant metal binder, the modified phenolic resin is a silane-modified phenolic resin, and its 5% weight loss temperature is 402 °C; the modified phenolic resin contains 5 wt% of nano-SiO2.

[0009] In the above-mentioned high-strength and high-temperature-resistant metal binder, the aspect ratio of the silicon carbide nanowires is above 200; the silicon carbide nanowires are arranged by magnetic field assistance and are vertically oriented.

[0010] In the above-mentioned high-strength and high-temperature-resistant metal binder, the antioxidant is zinc borate.

[0011] A method for preparing the above-mentioned high-strength and high-temperature-resistant metal binder includes the following steps: Step 1: Ball-mill the pretreated nano-aluminum powder and copper powder at 300 rpm for 2 h under the protection of an inert gas to mix them evenly and obtain a mixed powder. Step 2: Ultrasonic for 30 min under the condition of 40 kHz ultrasonic. Dissolve the modified phenolic resin in absolute ethanol (water content <0.1%), and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add an antioxidant and the pretreated silicon carbide nanowires to the mixed slurry prepared in Step 2, stir and dehydrate under vacuum and heat up for curing to obtain the finished metal binder.

[0012] The specific curing process is as follows: The first stage: 120 °C / 1 h, at this time, resin curing changes mainly occur. The second stage: 300 °C / 2 h, at this time, the metal eutectic reaction mainly occurs. Heating rate: 5 °C / min.

[0013] During the whole ball-milling process, the ball-to-material ratio is 10:1, the rotation speed is 300 rpm, and it alternates between forward and reverse (changing direction every 15 min). At the same time, 0.5% stearic acid is added as a process control agent to prevent agglomeration during ball milling.

[0014] In the above-mentioned method for preparing a high-strength and high-temperature-resistant metal binder, the pretreatment step of the nano-aluminum powder is: Place the nano-aluminum powder in dilute hydrochloric acid with a mass fraction of 4-6% for ultrasonic cleaning for 20-40 seconds, rinse with deionized water until pH = 7, and dry under vacuum. The pretreatment steps of the copper powder are as follows: Immerse the copper powder in a formic acid solution with a mass fraction of 8-12% for 30-90 seconds to remove surface oxides, and then dry it by purging with an inert gas.

[0015] In the above method for preparing a high-strength and high-temperature-resistant metal binder, the preparation method of the modified phenolic resin is as follows: React phenol-formaldehyde resin with KH-560 silane coupling agent at 70-90 °C for 2-4 hours. The mass of KH-560 silane coupling agent is 10% of the mass of phenol-formaldehyde resin, and nano-SiO2 is added. The mass of nano-SiO2 is 4-6% of the mass of the modified phenolic resin. Control the hydroxymethyl content at 12-15% to ensure curing activity. The modification is to introduce -Si-O- bonds to improve heat resistance.

[0016] In the above method for preparing a high-strength and high-temperature-resistant metal binder, the pretreatment steps of the silicon carbide nanowires are as follows: Perform plasma activation treatment on the silicon carbide nanowires with a volume ratio of Ar:H2 = 9:1; After adding the pretreated silicon carbide nanowires to the mixed slurry, they are further dispersed by a three-roll grinder and oriented along the Z-axis under a 0.5T magnetic field.

[0017] An application of the above high-strength and high-temperature-resistant metal binder in the fields of aerospace and automotive engines.

[0018] Compared with the existing technology, the advantages of the present invention are as follows: 1. The present invention uses a modified phenolic resin introduced with -Si-O- bonds and nano-SiO2 to synergistically enhance, so that the heat resistance of the resin is increased from 200 °C to 400 °C (the 5% weight loss temperature shown by TGA reaches 402 °C). The resin provides an initial bonding force at low temperature (about 120 °C), and the metal eutectic reaction takes over the load at high temperature, realizing a stepped bonding mechanism.

[0019] 2. The present invention combines a specific ratio of nano-aluminum powder and dendritic copper powder, and uses the nano effect to reduce the Al-Cu eutectic reaction temperature from 550 °C to 300 °C, solving the problem that traditional metal binders require high-temperature sintering. At the same time, the eutectic temperature is reduced to 300 °C, which can effectively take over the load when the resin cannot provide bonding force, and better realize the stepped bonding mechanism.

[0020] 3. The present invention makes the silicon carbide nanowires vertically oriented in the interface region through magnetic field-assisted alignment, forming a "pinning effect", which increases the shear strength by about 40%. Specific Embodiments

[0021] The following further elaborates on the present invention in detail in conjunction with specific embodiments.

[0022] Example 1 This embodiment provides a preparation method of a high-strength and high-temperature-resistant metal binder, comprising the following steps: Step 1: Ball-mill and mix 30 parts of pretreated nano-aluminum powder and 10 parts of copper powder evenly under the protection of argon to obtain a mixed powder; Step 2: Dissolve 20 parts of modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry; Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires to the mixed slurry prepared in Step 2. The aspect ratio of the silicon carbide nanowires is 200, disperse them through a three-roll grinder, and align them along the Z-axis under a 0.5T magnetic field. Vacuum stir to dehydrate and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120°C and keep warm for 1h; The second stage: Heat up to 300°C and keep warm for 2h; Heating rate: 5°C / min; Obtain the finished metal binder product.

[0023] Among them, the pretreatment steps of the nano-aluminum powder are: Place the nano-aluminum powder with a particle size of 80nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically clean it for 30 seconds, and rinse it with deionized water until the pH = 7, and then vacuum dry it.

[0024] The pretreatment steps of the copper powder are: Place the copper powder with a particle size of 1 - 3μm in a formic acid solution with a mass fraction of 10% and soak it for 60 seconds to remove the surface oxide, and then purge and dry it with argon.

[0025] The preparation method of the modified phenolic resin is: React phenol-formaldehyde resin with KH-560 silane coupling agent at 80°C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and add nano-SiO2. The mass of the nano-SiO2 is 5% of the mass of the modified phenolic resin.

[0026] The pretreatment steps of the silicon carbide nanowires are: Perform plasma activation treatment on the silicon carbide nanowires with a volume ratio of Ar:H2 = 9:1.

[0027] The finished metal binder product prepared in this embodiment can be used as a repair binder for aero-engine turbine blades.

[0028] Perform relevant performance tests on the finished metal binder product. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 34.5 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 28.9 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 402 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 100 cycles (-50 - 400 °C) without cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Example 2 This embodiment provides a preparation method of a high-strength and high-temperature-resistant metal binder, comprising the following steps: Step 1: Mix 30 parts of pretreated nano-aluminum powder, 10 parts of copper powder, and 2 parts of boron nitride nanosheets evenly by ball milling under the protection of argon to obtain a mixed powder. Step 2: Dissolve 15 parts of modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add 2 parts of zinc borate and 10 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse them through a three-roll grinder, and align them along the Z-axis under a 0.5T magnetic field. Then, dehydrate and cure it by vacuum stirring. The specific curing process is as follows: The first stage: Heat up to 120°C and hold for 1 h. The second stage: Heat up to 300°C and hold for 2 h. Heating rate: 5°C / min. Obtain the finished product of the metal binder.

[0029] Among them, the pretreatment steps of the nano-aluminum powder are as follows: Place the nano-aluminum powder with a particle size of 50 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically clean it for 30 seconds, then rinse it with deionized water until the pH = 7, and dry it in vacuum.

[0030] The pretreatment steps of the copper powder are as follows: Immerse the copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% for 60 seconds to remove the surface oxide, and dry it by purging with argon.

[0031] The preparation method of the modified phenolic resin is as follows: React phenol-formaldehyde resin with KH-560 silane coupling agent at 80°C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and then add nano-SiO2. The mass of the nano-SiO2 is 5% of the mass of the modified phenolic resin.

[0032] The pretreatment steps of the silicon carbide nanowires are as follows: Activate the silicon carbide nanowires by plasma with a volume ratio of Ar:H2 = 9:1.

[0033] The finished product of the metal binder prepared in this example can be used as a thermal conductive binder for new energy vehicle battery packs.

[0034] Conduct relevant performance tests on the finished product of the metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 31.4 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 27.8 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 376 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 100 cycles (-50 - 400 °C) without cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Example 3 This example provides a preparation method of a high-strength and high-temperature-resistant metal binder, including the following steps: Step 1: Mix 30 parts of pretreated nano-aluminum powder, 10 parts of copper powder and 1 part of Gd2O3 nanoparticles evenly by ball milling under the protection of argon to obtain a mixed powder; Step 2: Dissolve 25 parts of modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry; Step 3: Add 5 parts of zinc borate and 5 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse them through a three-roll grinder, and align them along the Z-axis under a 0.5T magnetic field. Vacuum stir to dehydrate and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120 °C and keep warm for 1 h; The second stage: Heat up to 300 °C and keep warm for 2 h; Heating rate: 5 °C / min; Obtain the finished metal binder.

[0035] Among them, the pretreatment steps of nano-aluminum powder are: Place nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% for ultrasonic cleaning for 30 seconds, and rinse with deionized water until pH = 7, then vacuum dry.

[0036] The pretreatment steps of copper powder are: Immerse copper powder with a particle size of 1 - 3 μm in formic acid solution with a mass fraction of 10% for 60 seconds to remove surface oxides, and blow dry with argon.

[0037] The preparation method of modified phenolic resin is: React phenol-formaldehyde resin with KH-560 silane coupling agent at 80 °C for 3 hours. The mass of KH-560 silane coupling agent is 10% of the mass of phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and nano-SiO2 is added. The mass of nano-SiO2 is 5% of the mass of modified phenolic resin.

[0038] The pretreatment steps of silicon carbide nanowires are: Activate silicon carbide nanowires by plasma with a volume ratio of Ar:H2 = 9:1.

[0039] The finished metal binder prepared in this example can be used as a binder for the sealing material of nuclear power plant spent fuel containers.

[0040] Perform relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 34.1 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 28.9 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 535 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 100 cycles (-50 - 400 °C) without cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 1 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Mix 30 parts of pretreated nano-aluminum powder and 10 parts of copper powder evenly by ball milling under the protection of argon to obtain a mixed powder; Step 2: Dissolve 20 parts of phenol formaldehyde resin in ethanol under ultrasonic conditions, and then add the mixed powder obtained in Step 1 to obtain a mixed slurry; Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry obtained in Step 2, disperse them through a three-roll grinder, and align them along the Z-axis under a 0.5T magnetic field. Vacuum stir to dehydrate and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120°C and keep warm for 1 h; The second stage: Heat up to 300°C and keep warm for 2 h; Heating rate: 5°C / min; Obtain the finished metal binder.

[0041] Among them, the pretreatment steps of the nano-aluminum powder are as follows: Place the nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% for ultrasonic cleaning for 30 seconds, and rinse with deionized water until the pH = 7, and then dry in vacuum.

[0042] The pretreatment steps of the copper powder are as follows: Place the copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% and soak for 60 seconds to remove the surface oxide, and then purge and dry with argon.

[0043] The pretreatment steps of the silicon carbide nanowires are as follows: Activate the silicon carbide nanowires by plasma with a volume ratio of Ar:H2 = 9:1.

[0044] Carry out relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 23.7 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 27.6 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 200 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 30 cycles (-50 - 400 °C) with cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 2 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Ball-mill and mix 30 parts of pretreated nano-aluminum powder and 10 parts of copper powder evenly under the protection of argon to obtain a mixed powder; Step 2: Dissolve 20 parts of modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder obtained in Step 1 to obtain a mixed slurry; Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry obtained in Step 2, disperse them through a three-roll grinder, and align them along the Z-axis under a 0.5T magnetic field. Vacuum stir to dehydrate and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120°C and keep warm for 1 h; The second stage: Heat up to 300°C and keep warm for 2 h; Heating rate: 5°C / min; Obtain the finished metal binder.

[0045] Among them, the pretreatment steps of the nano-aluminum powder are as follows: The nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% is placed in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically cleaned for 30 seconds, then rinsed with deionized water until the pH = 7, and dried in vacuum.

[0046] The pretreatment steps of the copper powder are as follows: The copper powder with a particle size of 1 - 3 μm is immersed in a formic acid solution with a mass fraction of 10% for 60 seconds to remove the surface oxide, and then dried by argon purging.

[0047] The preparation method of the modified phenolic resin is as follows: The phenol-formaldehyde resin and KH-560 silane coupling agent are reacted at 80 °C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin, and the measured hydroxymethyl content is 12% at this time.

[0048] The pretreatment steps of the silicon carbide nanowires are as follows: The silicon carbide nanowires are subjected to plasma activation treatment with a volume ratio of Ar:H2 = 9:1.

[0049] Perform relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 26.5 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 27.9 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 350 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 50 cycles (-50 - 400 °C) with cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 3 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Ball-mill and mix 30 parts of pretreated nano-aluminum powder and 10 parts of copper powder evenly under the protection of argon to obtain a mixed powder; Step 2: Dissolve 20 parts of the modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry; Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse by a three-roll mill, and align along the Z-axis under a 0.5 T magnetic field, and dehydrate and cure by vacuum stirring. The specific curing process is as follows: The first stage: Heat up to 120 °C and keep warm for 1 h; The second stage: Heat up to 300 °C and keep warm for 2 h; Heating rate: 5 °C / min; Obtain the finished metal binder.

[0050] Among them, the pretreatment steps of the nano-aluminum powder are as follows: The nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% is placed in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically cleaned for 30 seconds, then rinsed with deionized water until the pH = 7, and dried in vacuum.

[0051] The pretreatment steps of copper powder are as follows: Soak copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% for 60 seconds to remove surface oxides, and then dry it by purging with argon.

[0052] The preparation method of the modified phenolic resin is as follows: React phenol - formaldehyde resin with KH - 560 silane coupling agent at 80 °C for 3 hours. The mass of KH - 560 silane coupling agent is 10% of the mass of phenol - formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and then add nano - TiO₂. The mass of nano - TiO₂ is 5% of the mass of the modified phenolic resin.

[0053] The pretreatment steps of silicon carbide nanowires are as follows: Activate silicon carbide nanowires by plasma with a volume ratio of Ar:H₂ = 9:1.

[0054] Perform relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 26.5 ± 1.2 MPa ASTM D1002 400 °C Shear Strength 27.9 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 350 °C (5% weight loss) ISO 11358 Thermal Cycling Performance 50 cycles (-50 - 400 °C) with cracking MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 4 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Add a total of 40 parts of pretreated nano - aluminum powder and copper powder with a mass ratio of 5:1 under the protection of argon and ball - mill them evenly to obtain a mixed powder. Step 2: Dissolve 20 parts of the modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse them through a three - roll mill, and align them along the Z - axis under a 0.5T magnetic field. Then dehydrate by vacuum stirring and cure by heating. The specific curing process is as follows: The first stage: Heat up to 120 °C and keep it warm for 1 h. The second stage: Heat up to 300 °C and keep it warm for 2 h. Heating rate: 5 °C / min. Obtain the finished metal binder.

[0055] Among them, the pretreatment steps of nano - aluminum powder are as follows: Place nano - aluminum powder with a particle size of 80 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically clean it for 30 seconds, then rinse it with deionized water until the pH = 7, and dry it in vacuum.

[0056] The pretreatment steps of copper powder are as follows: Soak copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% for 60 seconds to remove surface oxides, and then dry it by purging with argon.

[0057] The preparation method of the modified phenolic resin is as follows: React the phenol-formaldehyde resin with KH-560 silane coupling agent at 80 °C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and nano-SiO2 is added. The mass of the nano-SiO2 is 5% of the mass of the modified phenolic resin.

[0058] The pretreatment step of the silicon carbide nanowires is as follows: Plasma activate the silicon carbide nanowires with an Ar:H2 volume ratio of 9:1.

[0059] Perform relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 34.5 ± 1.2 MPa ASTM D1002 Shear Strength at 400 °C 12.3 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 402 °C (5% weight loss) ISO 11358 Thermal Cycling Performance No cracking after 100 cycles (-50 - 400 °C) MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 5 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Ball mill and mix 20 parts of pretreated nano-aluminum powder and 20 parts of copper powder evenly under the protection of argon to obtain a mixed powder. Step 2: Dissolve 20 parts of the modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse by a three-roll mill, and orient along the Z-axis under a 0.5T magnetic field. Vacuum stir to dehydrate and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120 °C and keep warm for 1 h. The second stage: Heat up to 300 °C and keep warm for 2 h. Heating rate: 5 °C / min; Obtain the finished metal binder.

[0060] Among them, the pretreatment step of the nano-aluminum powder is as follows: Place the nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% and ultrasonically clean for 30 seconds, and rinse with deionized water until the pH = 7, then vacuum dry.

[0061] The pretreatment step of the copper powder is as follows: Immerse the copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% for 60 seconds to remove the surface oxide, and then dry by argon purging.

[0062] The preparation method of the modified phenolic resin is as follows: React the phenol-formaldehyde resin with KH-560 silane coupling agent at 80 °C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and nano-SiO2 is added. The mass of the nano-SiO2 is 5% of the mass of the modified phenolic resin.

[0063] The pretreatment steps of the silicon carbide nanowires are as follows: subject the silicon carbide nanowires to plasma activation treatment with an Ar:H2 volume ratio of 9:1.

[0064] Conduct relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 34.5 ± 1.2 MPa ASTM D1002 Shear Strength at 400 °C 15.2 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 402 °C (5% weight loss) ISO 11358 Thermal Cycling Performance No cracking after 100 cycles (-50 - 400 °C) MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 Comparative Example 6 This comparative example provides a preparation method of a metal binder, including the following steps: Step 1: Ball-mill and mix 30 parts of pretreated nano-aluminum powder and 10 parts of copper powder evenly under the protection of argon to obtain a mixed powder. Step 2: Dissolve 20 parts of modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add 3 parts of zinc borate and 7 parts of pretreated silicon carbide nanowires with an aspect ratio of 200 to the mixed slurry prepared in Step 2, disperse them through a three-roll grinder, dehydrate by vacuum stirring and heat up for curing. The specific curing process is as follows: The first stage: Heat up to 120°C and keep warm for 1 h. The second stage: Heat up to 300°C and keep warm for 2 h. Heating rate: 5°C / min. Obtain the finished metal binder.

[0065] Among them, the pretreatment steps of the nano-aluminum powder are as follows: Place the nano-aluminum powder with a particle size of 80 nm and a purity of 99.99% in dilute hydrochloric acid with a mass fraction of 5% for ultrasonic cleaning for 30 seconds, rinse with deionized water until the pH = 7, and dry in vacuum.

[0066] The pretreatment steps of the copper powder are as follows: Immerse the copper powder with a particle size of 1 - 3 μm in a formic acid solution with a mass fraction of 10% for 60 seconds to remove surface oxides, and dry by argon purging.

[0067] The preparation method of the modified phenolic resin is as follows: React phenol-formaldehyde resin with KH-560 silane coupling agent at 80°C for 3 hours. The mass of the KH-560 silane coupling agent is 10% of the mass of the phenol-formaldehyde resin. At this time, the measured hydroxymethyl content is 12%, and nano-SiO2 is added. The mass of the nano-SiO2 is 5% of the mass of the modified phenolic resin.

[0068] The pretreatment steps of the silicon carbide nanowires are as follows: Subject the silicon carbide nanowires to plasma activation treatment with an Ar:H2 volume ratio of 9:1.

[0069] Conduct relevant performance tests on the finished metal binder. The test standards and test results are as follows: Test Items Test Results Test Standards Room Temperature Shear Strength 24.7 ± 1.2 MPa ASTM D1002 Shear Strength at 400 °C 20.5 ± 1.8 MPa GB / T 7124 - 2008 Thermal Decomposition Temperature (TGA) 402 °C (5% weight loss) ISO 11358 Thermal Cycling Performance No cracking after 100 cycles (-50 - 400 °C) MIL-STD-810G Salt Spray Test (2000 h) No corrosion, strength retention rate 95% ASTM B117 The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar means for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A high-strength and high-temperature-resistant metal binder, characterized in that: It includes 20 - 40 parts by mass of nano - aluminum powder, 10 - 20 parts of copper powder, 15 - 25 parts of modified phenolic resin, 5 - 10 parts of silicon carbide nanowires, and 2 - 5 parts of antioxidant.

2. The high-strength and high-temperature resistant metal binder according to claim 1, wherein: The particle size of the nano - aluminum powder is 50 - 100 nm; the copper powder has a dendritic structure with a particle size of 1 - 5 μm; the mass ratio of the nano - aluminum powder to the copper powder is 3:

1.

3. A high-strength and high-temperature-resistant metal binder according to claim 1, characterized in that: The modified phenolic resin is a silane - modified phenolic resin, and its 5% weight - loss temperature is 402 °C; the modified phenolic resin contains 5 wt% of nano - SiO₂.

4. The high-strength and high-temperature resistant metal binder according to claim 1, wherein: The aspect ratio of the silicon carbide nanowires is above 200; the silicon carbide nanowires are arranged by magnetic - field assistance and are vertically oriented.

5. The high-strength and high-temperature resistant metal binder according to claim 1, wherein: The antioxidant is zinc borate.

6. A method for preparing a high-strength and high-temperature resistant metal binder as described in any one of claims 1-5, characterized in that, It includes the following steps: Step 1: Ball - mill and mix the pretreated nano - aluminum powder and copper powder evenly under the protection of inert gas to obtain a mixed powder. Step 2: Dissolve the modified phenolic resin in ethanol under ultrasonic conditions, and then add the mixed powder prepared in Step 1 to obtain a mixed slurry. Step 3: Add the antioxidant and the pretreated silicon carbide nanowires to the mixed slurry prepared in Step 2, stir and dehydrate under vacuum and heat - cure to obtain the finished metal binder.

7. The preparation method according to claim 6, characterized in that: The pretreatment step of the nano - aluminum powder is: Ultrasonically clean the nano - aluminum powder in dilute hydrochloric acid with a mass fraction of 4 - 6% for 20 - 40 seconds, rinse with deionized water until pH = 7, and dry under vacuum. The pretreatment step of the copper powder is: Immerse the copper powder in a formic acid solution with a mass fraction of 8 - 12% for 30 - 90 seconds to remove surface oxides, and blow - dry with inert gas.

8. The preparation method according to claim 6, characterized in that: The preparation method of the modified phenolic resin is: React phenol - formaldehyde resin with KH - 560 silane coupling agent at 70 - 90 °C for 2 - 4 hours, and add nano - SiO₂, and the mass of nano - SiO₂ is 4 - 6% of the mass of the modified phenolic resin.

9. The preparation method according to claim 6, characterized in that: The pretreatment step of the silicon carbide nanowires is: Activate the silicon carbide nanowires by plasma with a volume ratio of Ar:H₂ = 9:

1. After adding the pretreated silicon carbide nanowires to the mixed slurry, it is also dispersed by a three - roll mill and oriented along the Z - axis under a 0.5 T magnetic field.

10. Application of a high - strength and high - temperature - resistant metal binder as described in any one of claims 1 - 5 in the fields of aerospace and automotive engines.