A method of high strength ceramic metallization

Abstract

The application discloses a high-strength ceramic metallization method, and innovatively obtains a ceramic grain growth agent, which comprises 75wt%-85wt% metal oxide powder A, 5wt%-10wt% binder A and 5wt%-20wt% solvent A. The ceramic grain growth agent is coated on the position of an alumina ceramic substrate which needs to be metallized, and after sintering, a fine grain and coarse grain double-layer structure is formed on the ceramic substrate. The fine grains in the inner layer can improve the strength of the ceramic substrate, and the coarse grains in the surface layer can improve the penetration pressure of the glass phase in the ceramic substrate during subsequent metallization sintering, promote the penetration of the glass phase in the ceramic substrate into the metallization ink layer, improve the bonding strength of the metallization ink layer and the ceramic substrate, and thus ensure the sealing strength of the ceramic substrate and the metal piece.

Description

Technical Field

[0001] This invention relates to the field of ceramic material processing, and specifically to a method for metallizing high-strength ceramics. Background Technology

[0002] Alumina ceramics are characterized by high strength, good corrosion resistance, and excellent insulation. They are widely used in new energy vehicles, LEDs, semiconductors and other fields, serving functions such as sealing, heat conduction, and structural support.

[0003] When alumina ceramics are used to manufacture sealing ceramic devices for new energy vehicles, they need to be connected to metal parts. However, because ceramics are good insulating materials, ordinary solders cannot wet them, thus preventing direct sealing with metal materials. The solution is to coat the alumina ceramic surface with a molybdenum-manganese metal film, and then sinter it in a nitrogen-hydrogen mixed atmosphere to fuse the alumina ceramic and the molybdenum-manganese metal film together. Subsequently, electroplating, brazing, and other processes are used to connect the alumina ceramic and the metal part. This process of sealing the ceramic with a metal film, forming a metal film on the ceramic surface, is called metallization, also known as primary metallization. Its main mechanism utilizes the glass phase migration and penetration of the ceramic microstructure and the powder metallurgy sintering mechanism to bond the metal material to the ceramic.

[0004] As the performance requirements of new energy vehicles increase, the strength requirements for alumina ceramic packaged devices are also becoming more stringent. To improve the strength of alumina ceramic packaged devices, it is necessary to reduce the grain size of alumina ceramic. However, as the grain size of alumina ceramic decreases, the glass phase osmotic pressure of alumina ceramic on the molybdenum-manganese metal film layer decreases during molybdenum-manganese metallization. This leads to a reduction in the amount of glass phase permeating into the molybdenum-manganese layer, ultimately resulting in a decrease in the strength of ceramic metallization. Consequently, the device is prone to defects such as cracking after brazing. Summary of the Invention

[0005] The purpose of this invention is to provide a method for high-strength ceramic metallization that can ensure both the strength of the alumina ceramic and the sealing strength between the ceramic and the metal part.

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] A method for metallizing high-strength ceramics includes the following steps:

[0008] Step 1: Preparation of ceramic grain growth agent:

[0009] First, 75wt% to 85wt% of metal oxide powder A, 5wt% to 10wt% of binder A and 5wt% to 20wt% of solvent A are premixed, and then ground and dispersed to obtain the ceramic grain growth agent.

[0010] Step 2: Preparation of metallized ink:

[0011] Then, 50wt%–65wt% molybdenum powder, 10wt%–15wt% manganese powder, 1.0wt%–4.0wt% metal oxide powder B, 20wt%–33wt% solvent B, and 0.3wt%–1.0wt% dispersant A are ball-milled and mixed. After mixing, the mixture is dried to obtain a mixed solid. Then, 70wt%–80wt% of the mixed solid, 5wt%–10wt% binder A, and 10wt%–25wt% solvent A are premixed and then ground to obtain the metallized ink.

[0012] Step 3, Metallization and One-Time Sintering:

[0013] Then, the ceramic grain growth agent prepared in step 1 is coated on the metallization site of the alumina ceramic matrix, and sintered at 1500-1600℃ for 0.5-2h to obtain an alumina ceramic matrix with a double-layer grain structure.

[0014] Step 4, Metallization secondary sintering:

[0015] Finally, the metallized ink prepared in step 2 is coated onto an alumina ceramic substrate with a double-layer grain structure, and sintered at 1400-1500°C under a nitrogen-hydrogen mixed atmosphere for 0.5-2 hours to complete the metallization process of the alumina ceramic substrate and obtain a high-strength alumina ceramic with a metallized ink layer.

[0016] In step 1, the metal oxide powder A is one of titanium dioxide, chromium trioxide and manganese oxide, the binder A is one of ethyl cellulose, nitrocellulose and PVB, and the solvent A is one of terpineol, diethylene glycol butyl ether acetate and dihydroterpineol acetate.

[0017] In step 2, the metal oxide powder B is one of titanium dioxide and vanadium pentoxide, the solvent B is one of anhydrous ethanol, isopropanol and ethyl acetate, the dispersant A is one of BYK-111 and BYK-110, the binder A is one of ethyl cellulose, nitrocellulose and PVB, and the solvent A is one of terpineol, diethylene glycol butyl ether acetate and dihydroterpineol acetate.

[0018] In step 1, the particle size of the metal oxide powder A is 0.5-1 μm; in step 2, the particle size of the molybdenum powder is 1.5-3.0 μm; the particle size of the manganese powder is 1.0-3.0 μm; and the particle size of the metal oxide powder B is 0.5-2 μm.

[0019] In step 2, the drying temperature is 80-100℃, and the drying time is 1-3 hours.

[0020] In step 3, the coating method is screen printing or spraying, and the coating thickness is 5-20 μm.

[0021] In step 4, the coating method is screen printing or spraying, and the coating thickness is 10-35 μm.

[0022] The preparation process of the alumina ceramic matrix includes the following steps:

[0023] S1. According to the formula, first put 50wt% to 60wt% alumina powder, 3wt% to 6wt% sintering aid, 0.2wt% to 0.6wt% dispersant B and 35wt% to 45wt% deionized water into a horizontal ball mill for mixing and dispersion to obtain an alumina suspension. The ball mill speed is 20 to 35 rpm and the ball milling time is 12 to 24 hours.

[0024] S2. Then, binder B and plasticizer are added to the alumina suspension and ball-milled to obtain alumina slurry. The ball mill speed is 20-35 rpm and the ball milling time is 2-6 hours.

[0025] The amount of binder B added is 1.0% to 3.0% of the mass of alumina powder, and the amount of plasticizer added is 0.5% to 1.5% of the amount of binder B added.

[0026] S3. Then, the alumina slurry is spray-granulated to obtain alumina granulated powder, which is then pressed into a green body and finally sintered to obtain the alumina ceramic matrix.

[0027] The alumina powder has a particle size of 1.0–3.0 μm. The sintering aid includes 14 wt%–45 wt% SiO2, 15 wt%–23 wt% CaCO3, and 33 wt%–72 wt% talc. The dispersant B is one of ammonium polycarboxylate and maleic anhydride-acrylate copolymer. The binder B is one of polyvinyl alcohol and water-soluble acrylic resin. The plasticizer is one or both of polyethylene glycol and glycerol.

[0028] The spray granulation process is as follows: Alumina slurry is placed into a centrifugal spray granulation tower, and the centrifugal spray granulation conditions are set as follows: inlet air temperature 250~280℃, outlet air temperature 100~110℃, tower pressure -10~50Pa, and alumina granulated powder is obtained by spray granulation.

[0029] The pressing and molding process is as follows: Alumina granulated powder is pressed into a blank using a dry pressing machine, with a pressing pressure of 1–3 t / cm². 2.

[0030] The sintering process is as follows: the green blank is placed in an air sintering furnace for sintering at a temperature of 1580-1650℃ and held for 1-3 hours to obtain the alumina ceramic matrix.

[0031] By adopting the above technical solution, the present invention provides a method for high-strength ceramic metallization, which innovatively obtains a ceramic grain growth agent. The ceramic grain growth agent comprises 75wt% to 85wt% metal oxide powder A, 5wt% to 10wt% binder A, and 5wt% to 20wt% solvent A. The metal oxide powder A is one of titanium dioxide, chromium trioxide, and manganese oxide. The binder A is one of ethyl cellulose, nitrocellulose, and PVB. The solvent A is one of terpineol, diethylene glycol butyl ether acetate, and dihydroterpineol acetate.

[0032] By first coating the alumina ceramic matrix with a ceramic grain growth agent at the locations requiring metallization, and then sintering, this specially formulated ceramic grain growth agent promotes grain growth on the surface of the ceramic matrix, forming coarse grains. This results in a double-layer structure of fine and coarse grains on the ceramic matrix. The fine grains in the inner layer enhance the strength of the ceramic matrix, while the coarse grains on the surface increase the osmotic pressure of the glass phase in the ceramic matrix during subsequent metallization sintering. This promotes the penetration of the glass phase into the metallization ink layer, improving the bonding strength between the metallization ink layer and the ceramic matrix, thereby ensuring the sealing strength between the ceramic matrix and the metal part. Attached Figure Description

[0033] Figure 1 This is a scanning electron microscope image of the metallized high-strength alumina ceramic obtained in Example 4. Detailed Implementation

[0034] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0035] 1. Preparation of alumina ceramic matrix

[0036] Example 1

[0037] The preparation process of this alumina ceramic matrix includes the following steps:

[0038] S1. According to the ratio, first put 53wt% alumina powder, 5wt% sintering aid, 0.3wt% dispersant B and 41.7wt% deionized water into a horizontal ball mill for mixing and dispersion to obtain an alumina suspension. The ball mill speed is 25rpm and the ball milling time is 15h.

[0039] S2. Then, binder B and plasticizer are added to the alumina suspension, and the mixture is ball-milled to obtain alumina slurry. The ball mill speed is 25 rpm and the ball milling time is 3 hours.

[0040] The amount of binder B added is 1.0% of the mass of alumina powder, and the amount of plasticizer added is 0.78% of the amount of binder added.

[0041] The alumina powder has a particle size of 1.0 to 3.0 μm, the sintering aids include 40 wt% SiO2, 22 wt% CaCO3 and 38 wt% talc, the dispersant B is ammonium polycarboxylate, the binder B is polyvinyl alcohol, and the plasticizer is polyethylene glycol.

[0042] S3. Then, the alumina slurry is spray-granulated to obtain alumina granulated powder, which is then pressed into a green body and finally sintered to obtain an alumina ceramic matrix.

[0043] The spray granulation process is as follows: Alumina slurry is placed into a centrifugal spray granulation tower. The centrifugal spray granulation conditions are set as follows: inlet air temperature 260℃, outlet air temperature 105℃, tower pressure -10Pa. Alumina granulated powder is obtained by spray granulation.

[0044] The pressing process is as follows: Alumina granulated powder is pressed into a green blank using a dry pressing machine. The pressing pressure of the dry pressing machine is 1.2 t / cm². 2 .

[0045] The sintering process is as follows: the green blank is placed in an air sintering furnace for sintering at a temperature of 1580℃ and held for 2 hours to obtain an alumina ceramic matrix.

[0046] Example 2

[0047] The preparation process of this alumina ceramic matrix includes the following steps:

[0048] S1. According to the formula, first put 55wt% alumina powder, 4wt% sintering aid, 0.5wt% dispersant B and 40.5wt% deionized water into a horizontal ball mill for mixing and dispersion to obtain an alumina suspension. The ball mill speed is 20rpm and the ball milling time is 24h.

[0049] S2. Then, binder B and plasticizer are added to the alumina suspension, and the mixture is ball-milled to obtain alumina slurry. The ball mill speed is 20 rpm and the ball milling time is 6 hours.

[0050] The amount of binder B added is 2.0% of the mass of alumina powder, and the amount of plasticizer added is 1.0% of the amount of binder added.

[0051] The alumina powder has a particle size of 1.0 to 3.0 μm, the sintering aids include 15 wt% SiO2, 15 wt% CaCO3 and 70 wt% talc, the dispersant B is ammonium polycarboxylate, the binder B is polyvinyl alcohol, and the plasticizer is glycerol.

[0052] S3. Then, the alumina slurry is spray-granulated to obtain alumina granulated powder, which is then pressed into a green body and finally sintered to obtain an alumina ceramic matrix.

[0053] The spray granulation process is as follows: Alumina slurry is placed into a centrifugal spray granulation tower. The centrifugal spray granulation conditions are set as follows: inlet air temperature 260℃, outlet air temperature 110℃, tower pressure 0Pa. Alumina granulated powder is obtained by spray granulation.

[0054] The pressing process is as follows: Alumina granulated powder is pressed into a green blank using a dry pressing machine. The pressing pressure of the dry pressing machine is 2.0 t / cm². 2 .

[0055] The sintering process is as follows: the green blank is placed in an air sintering furnace for sintering at a temperature of 1620℃ and held for 2.3 hours to obtain an alumina ceramic matrix.

[0056] Example 3

[0057] The preparation process of this alumina ceramic matrix includes the following steps:

[0058] S1. According to the formula, first put 60wt% alumina powder, 3wt% sintering aid, 0.6wt% dispersant B and 36.4wt% deionized water into a horizontal ball mill for mixing and dispersion to obtain an alumina suspension. The ball mill speed is 35rpm and the ball milling time is 12h.

[0059] S2. Then, binder B and plasticizer are added to the alumina suspension, and the mixture is ball-milled to obtain alumina slurry. The ball mill speed is 35 rpm and the ball milling time is 2 hours.

[0060] The amount of binder B added is 3.0% of the mass of alumina powder, and the amount of plasticizer added is 1.5% of the amount of binder added.

[0061] The alumina powder has a particle size of 1.0 to 3.0 μm, the sintering aids include 25 wt% SiO2, 19 wt% CaCO3 and 56 wt% talc, the dispersant B is maleic anhydride-acrylate copolymer, the binder B is water-soluble acrylic resin, and the plasticizer is polyethylene glycol.

[0062] S3. Then, the alumina slurry is spray-granulated to obtain alumina granulated powder, which is then pressed into a green body and finally sintered to obtain an alumina ceramic matrix.

[0063] The spray granulation process is as follows: Alumina slurry is placed into a centrifugal spray granulation tower. The centrifugal spray granulation conditions are set as follows: inlet air temperature 280℃, outlet air temperature 100℃, tower pressure 3.Pa. Alumina granulated powder is obtained by spray granulation.

[0064] The pressing process is as follows: Alumina granulated powder is pressed into a green blank using a dry pressing machine. The pressing pressure of the dry pressing machine is 3.0 t / cm². 2 .

[0065] The sintering process is as follows: the green blank is placed in an air sintering furnace for sintering at a temperature of 1650℃ and held for 1 hour to obtain an alumina ceramic matrix.

[0066] 2. Metallization process

[0067] Example 4

[0068] A method for metallizing high-strength ceramics includes the following steps:

[0069] Step 1: Preparation of ceramic grain growth agent:

[0070] First, 80 wt% metal oxide powder A, 8 wt% binder A and 12 wt% solvent A are premixed, and then ground and dispersed using a three-roll mill to obtain a ceramic grain growth agent.

[0071] Among them, metal oxide powder A is titanium dioxide with a particle size of 0.5 to 1 μm, binder A is ethyl cellulose, and solvent A is terpineol;

[0072] Step 2: Preparation of metallized ink:

[0073] Then, 55 wt% molybdenum powder, 13 wt% manganese powder, 1.2 wt% metal oxide powder B, 30.3 wt% solvent B and 0.5 wt% dispersant A were ball-milled and mixed, and then dried in an oven at 80°C for 3 hours to obtain a mixed solid. Then, 73 wt% of the mixed solid, 8 wt% binder A and 19 wt% solvent A were premixed and then ground and mixed using a three-roll mill to obtain metallized ink.

[0074] Among them, metal oxide powder B is titanium dioxide with a particle size of 0.5-2 μm, solvent B is ethyl acetate, dispersant A is BYK-111, binder A is nitrocellulose, and solvent A is diethylene glycol butyl ether acetate; the particle size of molybdenum powder is 1.5-3.0 μm, and the particle size of manganese powder is 1.0-3.0 μm.

[0075] Step 3, Metallization and One-Time Sintering:

[0076] Then, the ceramic grain growth agent prepared in step 1 was screen-printed onto the alumina ceramic matrix prepared in Example 1 at the locations requiring metallization. The coating thickness was 10 μm. The matrix was then sintered in an air sintering furnace at 1500 °C for 2 h to obtain an alumina ceramic matrix with a double-layer grain structure.

[0077] Step 4, Metallization secondary sintering:

[0078] Finally, the metallized ink prepared in step 2 was coated onto the alumina ceramic substrate with a double-layer grain structure by spraying. The coating thickness was 25 μm. The substrate was sintered at 1400 °C under a nitrogen-hydrogen mixed atmosphere and held for 1 h to complete the metallization process of the alumina ceramic substrate and obtain a high-strength alumina ceramic with a metallized ink layer.

[0079] In this nitrogen-hydrogen mixed atmosphere, hydrogen accounts for 15% of the volume, with the remainder being nitrogen, and the sintering dew point is 20°C.

[0080] Example 5

[0081] A method for metallizing high-strength ceramics includes the following steps:

[0082] Step 1: Preparation of ceramic grain growth agent:

[0083] First, 78 wt% metal oxide powder A, 6 wt% binder A and 16 wt% solvent A are premixed, and then ground and dispersed using a three-roll mill to obtain a ceramic grain growth agent.

[0084] Among them, metal oxide powder A is chromium trioxide with a particle size of 0.5 to 1 μm, binder A is nitrocellulose, and solvent A is diethylene glycol butyl ether acetate;

[0085] Step 2: Preparation of metallized ink:

[0086] Then, 60 wt% molybdenum powder, 10 wt% manganese powder, 2.3 wt% metal oxide powder B, 27.3 wt% solvent B and 0.4 wt% dispersant A were ball-milled and mixed, and then dried in an oven at 100°C for 1 hour to obtain a mixed solid. Then, 80 wt% of the mixed solid, 6 wt% binder A and 14 wt% solvent A were premixed and then ground and mixed using a three-roll mill to obtain metallized ink.

[0087] Among them, metal oxide powder B is titanium dioxide with a particle size of 0.5 to 2 μm, solvent B is isopropanol, dispersant A is BYK-111, binder A is ethyl cellulose, and solvent A is terpineol; the particle size of molybdenum powder is 1.5 to 3.0 μm, and the particle size of manganese powder is 1.0 to 3.0 μm.

[0088] Step 3, Metallization and One-Time Sintering:

[0089] Then, the ceramic grain growth agent prepared in step 1 was sprayed onto the alumina ceramic matrix prepared in Example 2 at the location where metallization was required. The coating thickness was 18 μm. Then, it was sintered in an air sintering furnace at 1580 °C for 1.5 h to obtain an alumina ceramic matrix with a double-layer grain structure.

[0090] Step 4, Metallization secondary sintering:

[0091] Finally, the metallized ink prepared in step 2 was screen-printed onto an alumina ceramic substrate with a double-layer grain structure. The coating thickness was 28 μm. The substrate was then sintered at 1480 °C under a nitrogen-hydrogen mixed atmosphere for 1.5 h to complete the metallization process of the alumina ceramic substrate and obtain a high-strength alumina ceramic with a metallized ink layer.

[0092] In step 4, the hydrogen volume ratio in the nitrogen-hydrogen mixed atmosphere is 30%, and the remainder is nitrogen, with a sintering dew point of 30°C.

[0093] Example 6

[0094] A method for metallizing high-strength ceramics includes the following steps:

[0095] Step 1: Preparation of ceramic grain growth agent:

[0096] First, 85 wt% metal oxide powder A, 10 wt% binder A and 5 wt% solvent A are premixed, and then ground and dispersed using a three-roll mill to obtain a ceramic grain growth agent.

[0097] Among them, metal oxide powder A is manganese oxide with a particle size of 0.5 to 1 μm, binder A is PVB, and solvent A is dihydroterpineol acetate.

[0098] Step 2: Preparation of metallized ink:

[0099] Then, 65 wt% molybdenum powder, 10 wt% manganese powder, 3.0 wt% metal oxide powder B, 21 wt% solvent B and 1.0 wt% dispersant A were ball-milled and mixed, and then dried in an oven at 90°C for 2 hours to obtain a mixed solid. Then, 77 wt% of the mixed solid, 10 wt% binder A and 13 wt% solvent A were premixed and then ground and mixed using a three-roll mill to obtain metallized ink.

[0100] Among them, metal oxide powder B is vanadium pentoxide with a particle size of 0.5 to 2 μm, solvent B is isopropanol, dispersant A is BYK-110, binder A is PVB, and solvent A is dihydroterpineol acetate; the particle size of molybdenum powder is 1.5 to 3.0 μm, and the particle size of manganese powder is 1.0 to 3.0 μm.

[0101] Step 3, Metallization and One-Time Sintering:

[0102] Then, the ceramic grain growth agent prepared in step 1 was sprayed onto the alumina ceramic matrix prepared in Example 3 at the location where metallization was required. The coating thickness was 16 μm. Then, it was sintered in an air sintering furnace at 1520 °C for 0.5 h to obtain an alumina ceramic matrix with a double-layer grain structure.

[0103] Step 4, Metallization secondary sintering:

[0104] Finally, the metallized ink prepared in step 2 was screen-printed onto an alumina ceramic substrate with a double-layer grain structure. The coating thickness was 16 μm. The substrate was then sintered at 1430 °C under a nitrogen-hydrogen mixed atmosphere for 0.5 h to complete the metallization process of the alumina ceramic substrate and obtain a high-strength alumina ceramic with a metallized ink layer.

[0105] In step 4, the hydrogen volume ratio in the nitrogen-hydrogen mixed atmosphere is 50%, and the remainder is nitrogen, with a sintering dew point of 40°C.

[0106] Comparative Example 1

[0107] A method for metallizing common ceramics includes the following steps:

[0108] Step 1: Preparation of metallized ink:

[0109] First, 65wt% molybdenum powder, 10wt% manganese powder, 3.0wt% metal oxide powder B, 21wt% solvent B and 1.0wt% dispersant A are ball-milled and mixed, and then dried in an oven at 90℃ for 2 hours to obtain a mixed solid. Then, 77wt% of the mixed solid, 10wt% binder A and 13wt% solvent A are premixed and then ground and mixed using a three-roll mill to obtain metallized ink.

[0110] Among them, metal oxide powder B is vanadium pentoxide with a particle size of 0.5 to 2 μm, solvent B is isopropanol, dispersant A is BYK-110, binder A is PVB, and solvent A is dihydroterpineol acetate; the particle size of molybdenum powder is 1.5 to 3.0 μm, and the particle size of manganese powder is 1.0 to 3.0 μm.

[0111] Step 2, Metallization Sintering:

[0112] Then, the metallized ink prepared in step 1 was screen-printed onto the alumina ceramic substrate prepared in Example 3. The coating thickness was 16 μm. Sintering was carried out at 1430 °C under a nitrogen-hydrogen mixed atmosphere and held for 0.5 h to complete the metallization process of the alumina ceramic substrate and obtain an alumina ceramic with a metallized ink layer.

[0113] In step 4, the hydrogen volume ratio in the nitrogen-hydrogen mixed atmosphere is 50%, and the remainder is nitrogen, with a sintering dew point of 40°C.

[0114] 3. Morphological test results

[0115] The morphology of the high-strength alumina ceramic prepared in Example 4 was determined by scanning electron microscopy. The measurement conditions were: test voltage 15 kV, magnification 1000x. Figure 1 As shown, a double-layer structure of fine grains and coarse grains is formed on the surface of this high-strength alumina ceramic, wherein the coarse grains (i.e., fine grains and coarse grains) Figure 1 The thickness of the layer (indicated by the large grain region) is approximately 50–100 μm.

[0116] 4. Tensile test

[0117] A Kovar sheet with a length * width * thickness of 40 * 3 * 0.1 mm was soldered onto the sheet-like metallized alumina ceramic of the examples and comparative examples using AgCu28 solder. The Kovar sheet was then bent at 90°, and a tensile testing machine was used to peel the Kovar sheet off the metallized ink layer. The tensile loading speed was 0.5 mm / min. The tensile force calculation formula is: Metallized tensile force = Maximum tensile force (N) / Kovar sheet width (mm). The results are shown in Table 1.

[0118] Table 1 Tensile Test Results

[0119] plan Metallization tensile strength (N / mm) Example 4 50 Example 5 56 Example 6 53 Comparative Example 1 28

[0120] Experiments show that by coating the alumina ceramic substrate with a ceramic grain grower at the locations where metallization is required, the bonding strength between the metallized ink layer and the ceramic substrate can be improved.

[0121] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A method for metallizing high-strength ceramics, characterized in that: Includes the following steps: Step 1: Preparation of ceramic grain growth agent: First, 75 wt %~85 wt % Metal oxide powder A, 5 wt %~10 wt % Adhesive A and 5 wt %~20 wt The ceramic grain growth agent is obtained by premixing with solvent A and then grinding and dispersing. Step 2: Preparation of metallized ink: Then 50 wt %~65 wt % molybdenum powder, 10 wt %~15 wt % manganese powder, 1.0 wt %~4.0 wt % Metal oxide powder B, 20 wt %~33 wt % Solvent B and 0.3 wt %~1.0 wt Dispersant A was ball-milled and mixed, then dried to obtain a mixed solid. Then 70% of the mixture was... wt %~80 wt % mixed solids, 5 wt %~10 wt % Adhesive A and 10 wt %~25 wt Solvent A is premixed, and then ground and mixed to obtain the metallized ink; Step 3, Metallization and One-Time Sintering: Then, the ceramic grain growth agent prepared in step 1 is coated on the metallization site of the alumina ceramic matrix, and sintered at 1500~1600℃ for 0.5~2 h to obtain an alumina ceramic matrix with a double-layer grain structure. Step 4, Metallization secondary sintering: Finally, the metallized ink prepared in step 2 is coated onto an alumina ceramic substrate with a double-layer grain structure, and sintered at 1400~1500℃ in a nitrogen-hydrogen mixed atmosphere for 0.5~2 h to complete the metallization process of the alumina ceramic substrate and obtain a high-strength alumina ceramic with a metallized ink layer. In step 1, the metal oxide powder A is one of titanium dioxide, chromium trioxide and manganese oxide, the binder A is one of ethyl cellulose, nitrocellulose and PVB, and the solvent A is one of terpineol, diethylene glycol butyl ether acetate and dihydroterpineol acetate. In step 2, the metal oxide powder B is one of titanium dioxide and vanadium pentoxide, the solvent B is one of anhydrous ethanol, isopropanol and ethyl acetate, the dispersant A is one of BYK-111 and BYK-110, the binder A is one of ethyl cellulose, nitrocellulose and PVB, and the solvent A is one of terpineol, diethylene glycol butyl ether acetate and dihydroterpineol acetate.

2. The method for high-strength ceramic metallization according to claim 1, characterized in that: In step 1, the particle size of the metal oxide powder A is 0.5~1 μm; in step 2, the particle size of the molybdenum powder is 1.5~3.0 μm; the particle size of the manganese powder is 1.0~3.0 μm; and the particle size of the metal oxide powder B is 0.5~2 μm.

3. The method for high-strength ceramic metallization according to claim 1, characterized in that: In step 2, the drying temperature is 80~100 ℃, and the drying time is 1~3 h.

4. The method for high-strength ceramic metallization according to claim 1, characterized in that: In step 3, the coating method is screen printing or spraying, and the coating thickness is 5~20 μm.

5. The method for high-strength ceramic metallization according to claim 1, characterized in that: In step 4, the coating method is screen printing or spraying, and the coating thickness is 10~35 μm.

6. The method for high-strength ceramic metallization according to claim 1, characterized in that: The preparation process of the alumina ceramic matrix includes the following steps: S1. According to the ratio, first mix 50... wt %~60 wt % alumina powder, 3 wt %~6 wt % sintering aid, 0.2 wt %~0.6 wt % Dispersant B and 35 wt %~45 wt Deionized water was mixed and dispersed in a horizontal ball mill to obtain an alumina suspension. The ball mill speed was 20~35 rpm and the ball milling time was 12~24 h. S2. Then, binder B and plasticizer are added to the alumina suspension and ball-milled to obtain alumina slurry. The ball mill speed is 20~35 rpm and the ball milling time is 2~6 h. The amount of binder B added is 1.0% to 3.0% of the mass of alumina powder, and the amount of plasticizer added is 0.5% to 1.5% of the amount of binder B added. S3. Then, the alumina slurry is spray-granulated to obtain alumina granulated powder, which is then pressed into a green body and finally sintered to obtain the alumina ceramic matrix.

7. The method for high-strength ceramic metallization according to claim 6, characterized in that: The spray granulation process is as follows: Alumina slurry is placed into a centrifugal spray granulation tower, and the centrifugal spray granulation conditions are set as follows: inlet air temperature 250~280℃, outlet air temperature 100~110℃, tower pressure -10~50 Pa, and alumina granulated powder is obtained by spray granulation.

8. The method for high-strength ceramic metallization according to claim 6, characterized in that: The pressing and molding process is as follows: Alumina granulated powder is pressed into a blank using a dry pressing machine, with a pressing pressure of 1~3 t / cm. 2 .

9. The method for high-strength ceramic metallization according to claim 6, characterized in that: The sintering process is as follows: the green blank is placed in an air sintering furnace for sintering at a temperature of 1580~1650℃ and held for 1~3 hours to obtain the alumina ceramic matrix.

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