CN111302834B - Microwave magnetron insulating ceramic ring - Google Patents

Abstract

The invention provides a microwave magnetron insulating ceramic ring, which includes an annular ceramic base and metallized layers at both ends of the annular ceramic base; the processing method of the metallized layer includes the following steps: S1. The configuration of the plating agent; S2. Treatment of high-purity aluminum blocks and high-purity copper blocks; S3. Pretreatment: soak the annular ceramic substrate in hot-dip flux for 10-20 minutes, then take it out for use; S4. Hot-dip aluminum and copper alloys on one side; S5 . Double-sided hot-dip aluminum and copper alloys; S6. Sidewall cleaning; S7. Electroplating nickel layer; S8. Sidewall cleaning again. The invention adopts the reasonable matching technology of hot-dip aluminum-copper alloy and ceramic crystal phase particles, so that the metallized aluminum-copper alloy layer can be closely combined with the ceramic body during sintering, and then a layer of metal is electroplated on the metallized aluminum-copper alloy layer. Therefore, the surface quality and tensile strength of the ceramic metallization layer are greatly improved, and the service life of the magnetron is prolonged.

Description

A microwave magnetron insulating ceramic ring

technical field

The invention relates to the technical field of material manufacturing, in particular to a microwave magnetron insulating ceramic ring.

Background technique

The magnetron is characterized by high output power, high efficiency, low operating voltage (compared to linear injection microwave tubes), small size, light weight and low cost. With the development of science and technology, magnetrons are widely used in electronics, electric power, chemical industry and other fields, and the demand for metallized ceramics as one of its core components is increasing year by year. At present, in the process of ceramic metallization, because the particle size of the metallized powder is too fine, the surface energy increases, and the powder is not easily dispersed, which affects the flatness and consistency of the metallized layer. However, if the particle size of the metallized powder is too large, the surface energy is reduced, and the sintering temperature is increased, which affects the sintering quality at a given temperature and adversely affects the combination of the metallized layer and the ceramic layer. In addition, the wall thickness of the existing magnetron ceramics is generally 1.65mm, and the ceramic wall is often broken down or cracked due to excessive current generated by the magnetic field in the magnetron, which affects the service life of the magnetron.

Traditional microwave magnetron insulating ceramic rings mainly include vacuum evaporation coating method, vacuum sputtering coating method, Mo-Mn sintering method, etc. However, due to the large wetting angle of liquid metal on the ceramic surface, it is not easy to form effective wetting on ceramics. wet. The specific performance is as follows: ①The interior of ceramics is composed of ionic bonds, covalent bonds and the mixture of the two, while metals are composed of metal bonds. The reaction between the two is difficult, making it difficult for the metal to form an effective wetting on the ceramic surface. ② The metal is not easy to diffuse effectively on the ceramic surface, and the two are difficult to solid solution. ③The difference between the thermal expansion coefficient and thermal conductivity of the two is too large, resulting in a large residual stress on the joint surface of the two in the process of metallization. Therefore, it is quite difficult to directly combine the two effectively, and none of these methods can obtain a uniform metallized coating on the pore wall of the ceramic.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a microwave magnetron insulating ceramic ring, in which a metallized nickel layer is electroplated on the metallized aluminum-copper alloy layer, thereby greatly improving the surface quality and tensile strength of the ceramic metallized layer, and the metal The layer is uniform and delicate, and at the same time, the wall thickness of the ceramic metal layer is effectively increased, so as to avoid the phenomenon that the ceramic wall is broken down or cracked due to the excessive current generated by the magnetic field in the magnetron, and prolong the service life of the magnetron.

The technical scheme of the present invention is realized as follows:

The invention provides a microwave magnetron insulating ceramic ring, comprising the following steps:

S1. The configuration of the plating aid: the plating aid includes NH ₄ Cl, NaF, K ₂ ZrF ₆ , cerium chloride, lanthanum chloride and water, and the above-mentioned raw materials are uniformly mixed in proportion for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: Put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, ultrasonically clean the surface grease with ethanol solution, and then use hot NaOH solution to remove the surface oil. The oxide film is finally washed with deionized water and then dried in an oven;

S3. Pretreatment: soak the annular ceramic substrate in the hot-plating flux for 10-20min, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use organic The silicon sealant seals the furnace body. After the sealant is dry, it starts to heat up to the set temperature, and at the same time, a certain flow of high-purity nitrogen gas is introduced. When the aluminum and copper in the graphite crucible are melted, the annular ceramic matrix is imported from the bottom of the guide rail. Pushing into the guide rail at a constant speed, the annular ceramic substrate contacts the molten aluminum-copper alloy liquid through the window of the graphite guide rail, and then pushes out uniformly and gradually cools together with the aluminum-copper alloy liquid attached to the surface, and a uniform layer of 3-10 can be obtained on the ceramic surface. Micron-thick aluminum-copper alloy film;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are put into a graphite crucible, and the furnace body is sealed with silicone sealant. Pure nitrogen, when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail. The alloy liquid is pushed out at a uniform speed and gradually cooled to obtain double-sided metallized annular ceramics, and the metallized layer is a uniform aluminum-copper alloy film with a thickness of 3-10 microns;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- 15min to obtain metallized ceramic parts;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

S8. Re-cleaning of the sidewall: the inner and outer sidewalls of the metallized ceramic piece after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.1-0.3 microns; then put into deionized water for ultrasonic cleaning for 10-15min to obtain microwaves Magnetron insulating ceramic ring.

As a further improvement of the present invention, the plating aid is prepared from the following raw materials in parts by weight: 70-120 parts of NH ₄ Cl, 0.5-1.5 parts of NaF, 70-120 parts of K ₂ ZrF ₆ , 0.01-120 parts of cerium chloride 0.1 part, 0.01-0.1 part of lanthanum chloride and 300-500 parts of water.

As a further improvement of the present invention, in step S2, the mass percentage concentration of the ethanol solution is 70-90%, the mass percentage concentration of the hot NaOH solution is 10-15%, and the temperature is 40-60° C. The ultrasonic cleaning The power of the high-purity aluminum block is 800-1200W, the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block is greater than 99%.

As a further improvement of the present invention, the temperature of the thermal fluxing agent in step S3 is 40-50°C.

As a further improvement of the present invention, the volume fraction of nitrogen in the high-purity nitrogen in step S4 is greater than 99.995%, the inflow rate of the high-purity nitrogen is 2-5L/min, and the set temperature is 1200-1400°C.

As a further improvement of the present invention, the silicone sealant is selected from one or a mixture of acetic acid type, ketoxime type, alcohol type, amide type, hydroxylamine type and ketone type silicone sealant.

As a further improvement of the present invention, the nickel electroplating solution is prepared from the following raw materials: NiSO ₄ ·6H ₂ O 500-600g/L, NaCl 10-20g/L, H ₃ BO ₃ 20-30g/L , softener BSI 15-30mL/L, wetting agent MA-801-2mL/L, stabilizer PVA-124 0.5-1.2mL/L.

As a further improvement of the present invention, the electroplating process is as follows: using a 267mL Hull cell, taking 250mL plating solution, the anode is a pure nickel plate of 100mm×60mm×3mm, the cathode is a brass sheet of 100mm×65mm×0.3mm, and the temperature is The temperature is 50-60℃, pH is 3.5-4.5, cathode current density is 2-15A/dm ² , current is 2A, glass rod is used to stir back and forth parallel to the cathode near the cathode, the moving rate is 1 time/s, the time is 5- 10min.

The present invention further protects a metallized ceramic prepared by the above method.

The present invention further protects the use of the above-mentioned metallized ceramics in magnetrons.

The present invention has the following beneficial effects: in the present invention, due to the high temperature of hot dip aluminum plating and copper alloy solution, aluminum is prone to form aluminum oxide film, so plating flux NH ₄ Cl is used, and fluorides K ₂ ZrF ₆ and NaF are introduced It can form a continuous, complete and non-porous protective film on the surface of white porcelain; at the same time, it can be removed from the surface of white porcelain immediately when immersed in aluminum and copper alloy liquid; it has adsorption and melting effect on some oxides that appear, and at the same time, it has no effect on aluminum liquid. Pollution, adding rare earth metal chlorides, such as cerium chloride and lanthanum chloride, can refine the grains and improve the surface properties of white porcelain, and the addition of cerium chloride and lanthanum chloride has a synergistic effect;

The invention adopts the reasonable matching technology of hot-dip aluminum-copper alloy and ceramic crystal phase particles, and without increasing the sintering temperature, the metallized aluminum-copper alloy layer can form a close bond with the ceramic body during sintering, and then the metallized aluminum-copper alloy layer can be closely combined with the ceramic body during sintering. A metallized nickel layer is electroplated on the aluminum-copper alloy layer, which greatly improves the surface quality and tensile strength of the ceramic metallized layer, and the metal layer is uniform and delicate;

The preparation process of the invention is simple, the coverage rate is high during hot-dip aluminum-copper alloy plating, the antenna angle can be reduced to 0°, "perfect wetting" is achieved, and the phenomenon of "extraordinary wetting" between the aluminum-copper alloy liquid and the surface of the annular ceramic substrate is generated; further Electroplating a metal nickel layer on the surface of the alloy layer can effectively increase the wall thickness of the ceramic metal layer, avoid the phenomenon that the ceramic wall is broken down or cracked due to the excessive current generated by the magnetic field in the magnetron, and prolong the life of the magnetron. service life.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the scanning electron microscope picture of the cross-sectional topography of the surface of the annular ceramic substrate through hot-dip aluminum plating and copper samples in Example 3 of the present invention;

FIG. 2 is a transmission electron microscope image of the structures of aluminum, copper film layers and nickel layers in Example 3 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

S1. Flux configuration:

The plating aid is prepared by weight of the following raw materials: 70 parts of NH ₄ Cl, 0.5 parts of NaF, 70 parts of K ₂ ZrF ₆ , 0.01 part of cerium chloride, 0.01 part of lanthanum chloride and 300 parts of water. The ratio is mixed evenly, and it is ready for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 70wt% ethanol solution. The ultrasonic cleaning power is 800W, Then use 10wt% NaOH solution at 40°C to remove the oxide film on the surface, and finally wash it with deionized water and then put it into an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block is greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in a plating flux at 40°C for 10 minutes, then take it out for use;

S4. Hot-dip aluminizing, copper alloy: put the annular ceramic substrate processed in step S3 into the graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use hydroxylamine The furnace body is sealed with type silicone sealant. After the sealant is dried, it starts to heat up to 1200°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 2L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are placed in a graphite crucible, and the furnace body is sealed with silicone sealant. After the sealant is dried, heating is started until 1200 ° C, and the feeding rate is 2L/min. high-purity nitrogen (nitrogen volume fraction greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail and molten aluminum-copper alloy After contacting with the liquid, and then pushing out the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooling, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 100W;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

The electroplating solution is prepared by the following raw materials: NiSO ₄ 6H ₂ O 500g/L, NaCl 10g/L, H ₃ BO ₃ 20g/L, softener BSI 15mL/L, wetting agent MA-80 1mL/L , stabilizer PVA-124 0.5mL/L, the rest is deionized water;

The electroplating process is as follows: 267mL Hull cell is used, 250mL plating solution is taken, the anode is a pure nickel plate of 100mm × 60mm × 3mm, the cathode is a brass sheet of 100mm × 65mm × 0.3mm, the temperature is 50 ° C, the pH is 3.5, and the cathode is The current density was 2A/dm ² , the current was 2A, and a glass rod was used to stir back and forth parallel to the cathode near the cathode, the moving rate was 1 time/s, and the time was 5 min.

S8. Re-cleaning of the sidewall: the inner and outer sidewalls of the metallized ceramic piece after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.1 μm; then put into deionized water for ultrasonic cleaning for 10min to obtain microwave magnetron insulation Ceramic ring.

Example 2

S1. Flux configuration:

The plating aid is prepared by weight of the following raw materials: 120 parts of NH ₄ Cl, 1.5 parts of NaF, 120 parts of K ₂ ZrF ₆ , 0.1 part of cerium chloride, 0.1 part of lanthanum chloride and 500 parts of water. The ratio is mixed evenly, and it is ready for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 90wt% ethanol solution. The ultrasonic cleaning power is 1200W, Then use 15wt% NaOH solution at 60°C to remove the oxide film on the surface, and finally wash it with deionized water and put it into an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in the flux at 40-50℃ for 20min, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use alcohol Type silicone sealant seals the furnace body. After the sealant dries, it starts to heat up to 1400°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 5L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are placed in a graphite crucible, and the furnace body is sealed with silicone sealant. After the sealant is dried, heating is started until 1400 ° C, and the feeding rate is 5L/min. high-purity nitrogen (nitrogen volume fraction greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail and molten aluminum-copper alloy After contacting with the liquid, and then pushing out the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooling, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 150W;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

The electroplating solution is prepared by the following raw materials: NiSO ₄ 6H ₂ O 600g/L, NaCl 20g/L, H ₃ BO ₃ 30g/L, softener BSI 30mL/L, wetting agent MA-80 2mL/L , stabilizer PVA-124 1.2mL/L, the rest is deionized water;

The electroplating process is as follows: 267mL Hull cell is used, 250mL plating solution is taken, the anode is a pure nickel plate of 100mm × 60mm × 3mm, the cathode is a brass sheet of 100mm × 65mm × 0.3mm, the temperature is 60 ° C, the pH is 4.5, and the cathode is The current density was 15A/dm ² , the current was 2A, and a glass rod was used to stir back and forth parallel to the cathode near the cathode, the moving rate was 1 time/s, and the time was 10 min.

S8. Re-cleaning of the side walls: the inner and outer side walls of the metallized ceramic pieces after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.3 microns; then put into deionized water for ultrasonic cleaning for 15 minutes to obtain microwave magnetron insulation Ceramic ring.

Example 3

S1. Flux configuration:

The plating aid is prepared by weight of the following raw materials: 100 parts of NH ₄ Cl, 1 part of NaF, 100 parts of K ₂ ZrF ₆ , 0.05 part of cerium chloride, 0.05 part of lanthanum chloride and 400 parts of water. The ratio is mixed evenly, and it is ready for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: Put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 80wt% ethanol solution. The ultrasonic cleaning power is 1000W, Then use 12wt% NaOH solution at 50°C to remove the oxide film on the surface, and finally wash it with deionized water and put it in an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in a plating flux at 45°C for 15 minutes, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use acetic acid The furnace body is sealed with type silicone sealant. After the sealant is dried, it starts to heat up to 1300°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 3.5L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are put into a graphite crucible, and the furnace body is sealed with silicone sealant. min of high-purity nitrogen (the volume fraction of nitrogen is greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail. The alloy liquid is contacted, and then pushed out together with the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooled, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 120W;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

The electroplating solution is prepared by the following raw materials: NiSO ₄ 6H ₂ O 550g/L, NaCl 15g/L, H ₃ BO ₃ 25g/L, softener BSI 22mL/L, wetting agent MA-80 1.5mL/ L, stabilizer PVA-124 0.7mL/L, the rest are deionized water;

The electroplating process is as follows: 267mL Hull cell is used, 250mL plating solution is taken, the anode is a pure nickel plate of 100mm × 60mm × 3mm, the cathode is a brass sheet of 100mm × 65mm × 0.3mm, the temperature is 55 ° C, the pH is 4, and the cathode is The current density was 8A/dm ² , the current was 2A, and a glass rod was used to stir back and forth parallel to the cathode near the cathode, the moving rate was 1 time/s, and the time was 7min.

S8. Re-cleaning of the side walls: the inner and outer side walls of the metallized ceramic pieces after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.2 microns; then put into deionized water for ultrasonic cleaning for 12 minutes to obtain microwave magnetron insulation Ceramic ring.

Using the SSX-550 scanning electron microscope of Shimadzu Corporation of Japan, the surface and cross-sectional morphology of the ring-shaped ceramic substrate after hot-dip aluminum plating and copper samples were observed, as shown in Figure 1. The process of hot-dip aluminum and copper plating on the annular ceramic substrate can obtain uniform and flat aluminum and copper film layers on the surface of the annular ceramic substrate. Holes and cracks, it can be seen that the hot-dip aluminum-copper process can form uniform aluminum and copper films on the annular ceramic substrate, and the phenomenon of "super-wetting" of aluminum, copper and annular ceramic substrates appears.

The structures of the aluminum, copper films and nickel layers were observed by JEOL-2011 transmission electron microscope. The results are shown in Figure 2, indicating that the height of these stepped protrusions at the interface of the aluminum, copper films and the nickel layer is about 3-4 nm. Its surface is very flat. And from the lattice image, these steps are obviously epitaxially grown on the surface of the aluminum and copper films. It can be seen that the formed metal layer is uniform and fine.

Comparative Example 1

Compared with Example 3, no lanthanum chloride was added to the plating flux, and other conditions were not changed.

S1. Flux configuration:

The plating aid is prepared from the following raw materials by weight: 100 parts of NH ₄ Cl, 1 part of NaF, 100 parts of K ₂ ZrF ₆ , 0.05 part of cerium chloride and 400 parts of water, and the above-mentioned raw materials are uniformly mixed in proportion for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: Put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 80wt% ethanol solution. The ultrasonic cleaning power is 1000W, Then use 12wt% NaOH solution at 50°C to remove the oxide film on the surface, and finally wash it with deionized water and put it in an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in a plating flux at 45°C for 15 minutes, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use acetic acid The furnace body is sealed with type silicone sealant. After the sealant is dried, it starts to heat up to 1300°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 3.5L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are put into a graphite crucible, and the furnace body is sealed with silicone sealant. min of high-purity nitrogen (the volume fraction of nitrogen is greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail. The alloy liquid is contacted, and then pushed out together with the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooled, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 120W;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

The electroplating solution is prepared by the following raw materials: NiSO ₄ 6H ₂ O 550g/L, NaCl 15g/L, H ₃ BO ₃ 25g/L, softener BSI 22mL/L, wetting agent MA-80 1.5mL/ L, stabilizer PVA-124 0.7mL/L, the rest are deionized water;

The electroplating process is as follows: 267mL Hull cell is used, 250mL plating solution is taken, the anode is a pure nickel plate of 100mm × 60mm × 3mm, the cathode is a brass sheet of 100mm × 65mm × 0.3mm, the temperature is 55 ° C, the pH is 4, and the cathode is The current density was 8A/dm ² , the current was 2A, and a glass rod was used to stir back and forth parallel to the cathode near the cathode, the moving rate was 1 time/s, and the time was 7min.

S8. Re-cleaning of the side walls: the inner and outer side walls of the metallized ceramic pieces after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.2 microns; then put into deionized water for ultrasonic cleaning for 12 minutes to obtain microwave magnetron insulation Ceramic ring.

Comparative Example 2

Compared with Example 3, no cerium chloride was added to the plating flux, and other conditions were not changed.

S1. Flux configuration:

The plating aid is prepared by weight of the following raw materials: 100 parts of NH ₄ Cl, 1 part of NaF, 100 parts of K ₂ ZrF ₆ , 0.05 part of lanthanum chloride and 400 parts of water, and the above raw materials are uniformly mixed in proportion and used for later use;

S2. Treatment of high-purity aluminum block and high-purity copper block: Put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 80wt% ethanol solution. The ultrasonic cleaning power is 1000W, Then use 12wt% NaOH solution at 50°C to remove the oxide film on the surface, and finally wash it with deionized water and put it in an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in a plating flux at 45°C for 15 minutes, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use acetic acid The furnace body is sealed with type silicone sealant. After the sealant is dried, it starts to heat up to 1300°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 3.5L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are put into a graphite crucible, and the furnace body is sealed with silicone sealant. min of high-purity nitrogen (the volume fraction of nitrogen is greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail. The alloy liquid is contacted, and then pushed out together with the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooled, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 120W;

S7. Electroplating nickel layer: the metallized ceramic piece obtained in step S6 is immersed in a nickel electroplating solution for electroplating;

The electroplating solution is prepared by the following raw materials: NiSO ₄ 6H ₂ O 550g/L, NaCl 15g/L, H ₃ BO ₃ 25g/L, softener BSI 22mL/L, wetting agent MA-80 1.5mL/ L, stabilizer PVA-124 0.7mL/L, the rest are deionized water;

The electroplating process is as follows: 267mL Hull cell is used, 250mL plating solution is taken, the anode is a pure nickel plate of 100mm × 60mm × 3mm, the cathode is a brass sheet of 100mm × 65mm × 0.3mm, the temperature is 55 ° C, the pH is 4, and the cathode is The current density was 8A/dm ² , the current was 2A, and a glass rod was used to stir back and forth parallel to the cathode near the cathode, the moving rate was 1 time/s, and the time was 7min.

S8. Re-cleaning of the side walls: the inner and outer side walls of the metallized ceramic pieces after electroplating in step S7 are mechanically polished again, and the surface roughness Ra is 0.2 microns; then put into deionized water for ultrasonic cleaning for 12 minutes to obtain microwave magnetron insulation Ceramic ring.

Comparative Example 3

Compared with Example 3, the ring-shaped ceramic substrate was not subjected to the nickel electroplating process.

S1. Flux configuration:

The plating aid is prepared by weight of the following raw materials: 100 parts of NH ₄ Cl, 1 part of NaF, 100 parts of K ₂ ZrF ₆ , 0.05 part of cerium chloride, 0.05 part of lanthanum chloride and 400 parts of water. The ratio is mixed evenly, and it is ready for use;

S2. Treatment of high-purity aluminum block and high-purity copper block: Put the high-purity aluminum block and high-purity copper block into the ultrasonic generator respectively, and ultrasonically clean the surface grease with 80wt% ethanol solution. The ultrasonic cleaning power is 1000W, Then use 12wt% NaOH solution at 50°C to remove the oxide film on the surface, and finally wash it with deionized water and put it in an oven for drying; the aluminum content in the high-purity aluminum block is greater than 99%, and the copper content in the high-purity copper block greater than 99%;

S3. Pretreatment: soak the annular ceramic substrate in a plating flux at 45°C for 15 minutes, then take it out for use;

S4. Hot-dip aluminum and copper alloy plating: put the annular ceramic substrate processed in step S3 into a graphite guide rail, put the high-purity aluminum block and high-purity copper block cleaned in step S2 into a graphite crucible, and use acetic acid The furnace body is sealed with type silicone sealant. After the sealant is dried, it starts to heat up to 1300°C, and at the same time, high-purity nitrogen gas (nitrogen volume fraction greater than 99.995%) at a rate of 3.5L/min is introduced. After the copper is melted, the annular ceramic base is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic base is in contact with the molten aluminum-copper alloy liquid through the window of the graphite guide rail. A uniform 3-10 micron thick aluminum-copper alloy film can be obtained on the ceramic surface;

S5. Double-sided hot-dip aluminum and copper alloy plating: perform double-sided metallization on the single-sided metallized annular ceramic obtained in step S4; The high-purity aluminum block and high-purity copper block cleaned in S2 are put into a graphite crucible, and the furnace body is sealed with silicone sealant. min of high-purity nitrogen (the volume fraction of nitrogen is greater than 99.995%), when the aluminum and copper in the graphite crucible are melted, the annular ceramic substrate is pushed into the guide rail at a constant speed from the entrance below the guide rail, and the annular ceramic substrate passes through the window of the graphite guide rail. The alloy liquid is contacted, and then pushed out together with the aluminum-copper alloy liquid attached to the surface at a uniform speed and gradually cooled, a uniform layer of aluminum-copper alloy film with a thickness of 3-10 microns can be obtained on the ceramic surface;

S6. Side wall cleaning: mechanically polish the inner and outer side walls of the double-sided metallized annular ceramics obtained in step S5, and polish off the aluminum-copper alloy film on the inner and outer side walls, and then put them into water for ultrasonic cleaning for 10- The metallized ceramic parts were obtained in 15 minutes, and the ultrasonic cleaning power was 120W;

Test Example 1

The metallized ceramics prepared in Examples 1-3 of the present invention and Comparative Examples 1-3 were tested for performance, and the results are shown in Table 1.

Table 1

group Metal film layer (μm) Tensile strength (MPa) Magnetron service life (years) Corrosion resistance Withstand temperature (℃) Example 1 17 17.5 10 good 1000 Example 2 19 17.4 10 good 1050 Example 3 twenty two 17.9 10 good 1070 Comparative Example 1 14 10.2 7 generally 670 Comparative Example 2 15 12.3 7 generally 700 Comparative Example 3 7 13.5 4 poor 720

It can be seen from the above table that the metallized ceramic prepared by the method of the present invention has good tensile strength, and the service life is obviously prolonged after being made into a magnetron, and it has good corrosion resistance and heat resistance.

In Comparative Example 1 and Comparative Example 2, lanthanum chloride and cerium chloride were not added respectively, which reduced the surface performance of white porcelain, so that the structure of the aluminum-copper film layer was loose and failed to be tightly connected, thereby reducing the performance of the obtained metallized ceramic. ;

Comparative Example 3 uses hot-dip aluminum and copper alloy layers, only has a single metal layer, and the metal film is relatively thin, which greatly reduces the service life of the obtained magnetron, and has poor corrosion resistance and heat resistance.

Compared with the prior art, in the present invention, due to the high temperature of hot dip aluminum plating and copper alloy solution, aluminum is prone to form aluminum oxide film, so plating flux NH ₄ Cl is used, and fluorides K ₂ ZrF ₆ and NaF are introduced. , can form a continuous, complete and non-porous protective film on the surface of white porcelain (annular ceramic substrate); at the same time, it can be removed from the surface of white porcelain (annular ceramic substrate) immediately when immersed in aluminum and copper alloy solutions; some oxides appear. At the same time, it has no pollution to the aluminum liquid. Adding rare earth metal chlorides, such as cerium chloride and lanthanum chloride, can refine the grains and improve the surface properties of white porcelain (ring ceramic matrix). The addition of cerium and lanthanum chloride has a synergistic effect;

The invention adopts the reasonable matching technology of hot-dip aluminum-copper alloy and ceramic crystal phase particles, and without increasing the sintering temperature, the metallized aluminum-copper alloy layer can form a close bond with the ceramic body during sintering, and then the metallized aluminum-copper alloy layer can be closely combined with the ceramic body during sintering. A metallized nickel layer is electroplated on the aluminum-copper alloy layer, which greatly improves the surface quality and tensile strength of the ceramic metallized layer, and the metal layer is uniform and delicate;

The preparation process of the invention is simple, the coverage rate is high during hot-dip aluminum-copper alloy plating, the antenna angle can be reduced to 0°, "perfect wetting" is achieved, and the phenomenon of "extraordinary wetting" between the aluminum-copper alloy liquid and the surface of the annular ceramic substrate is generated; further Electroplating a metal nickel layer on the surface of the alloy layer can effectively increase the wall thickness of the ceramic metal layer, avoid the phenomenon that the ceramic wall is broken down or cracked due to the excessive current generated by the magnetic field in the magnetron, and prolong the life of the magnetron. service life.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (7)

1. A microwave magnetron insulating ceramic ring is characterized in that: the metal plating structure comprises an annular ceramic matrix and metallization layers at two ends of the annular ceramic matrix; the processing method of the metallization layer comprises the following steps:

s1, preparing a plating assistant agent: the plating assistant agent comprises NH₄Cl、NaF、K₂ZrF₆Cerium chloride, lanthanum chloride and water, and the raw materials are uniformly mixed according to a proportion for later use;

the plating assistant agent is prepared from the following raw materials in parts by weight: NH (NH)₄70-120 parts of Cl, 0.5-1.5 parts of NaF and K₂ZrF₆70-120 parts of cerium chloride, 0.01-0.1 part of lanthanum chloride and 500 parts of water 300-;

s2, treating the high-purity aluminum block and the high-purity copper block: respectively putting a high-purity aluminum block and a high-purity copper block into an ultrasonic generator, ultrasonically cleaning the grease on the surface by using an ethanol solution, removing an oxide film on the surface by using a hot NaOH solution, finally cleaning by using deionized water, and then putting into an oven for drying;

s3, pretreatment: soaking the annular ceramic matrix in the hot plating assistant for 10-20min, and taking out for later use;

s4, single-side hot-dip aluminum plating and copper alloy plating: putting the annular ceramic substrate processed in the step S3 into a graphite guide rail, putting the high-purity aluminum block and the high-purity copper block cleaned in the step S2 into a graphite crucible, sealing the furnace body by using an organic silicon sealant, starting to heat the furnace body until the temperature is set after the sealant is dried, simultaneously introducing high-purity nitrogen with a certain flow rate, pushing the annular ceramic substrate into the guide rail from an inlet below the guide rail at a constant speed after the aluminum and the copper in the graphite crucible are melted, contacting the annular ceramic substrate with molten aluminum-copper alloy liquid through a window of the graphite guide rail, then pushing the annular ceramic substrate out at a constant speed together with the aluminum-copper alloy liquid attached to the surface, and gradually cooling the annular ceramic substrate to obtain single-sided metalized layer, wherein the metalized layer is a uniform aluminum-copper alloy film with the thickness of 3-10 microns;

s5, double-sided hot-dip aluminum plating and copper alloy plating: carrying out double-sided metallization on the single-sided metalized annular ceramic obtained in the step S4; putting the end face of the ring-shaped ceramic substrate which is metalized upwards into a graphite guide rail, putting the high-purity aluminum block and the high-purity copper block which are cleaned in the step S2 into a graphite crucible, sealing a furnace body by using an organic silicon sealant, starting to heat until the set temperature is reached after the sealant is dried, simultaneously introducing high-purity nitrogen with a certain flow rate, pushing the ring-shaped ceramic substrate into the guide rail from an inlet below the guide rail at a constant speed after the aluminum and the copper in the graphite crucible are melted, contacting the ring-shaped ceramic substrate with molten aluminum-copper alloy liquid through a window of the graphite guide rail, then pushing the ring-shaped ceramic substrate out together with the aluminum-copper alloy liquid attached to the surface and gradually cooling to obtain double-sided metalized ring-shaped ceramic, wherein the metalized layer is a uniform aluminum-copper alloy film with the thickness of 3;

s6, side wall cleaning: mechanically polishing the inner side wall and the outer side wall of the double-sided metalized annular ceramic obtained in the step S5, polishing off aluminum-copper alloy films of the inner side wall and the outer side wall by using an electric-shock method, and then putting the aluminum-copper alloy films into water for ultrasonic cleaning for 10-15min to obtain a metalized ceramic piece;

s7, nickel layer electroplating: soaking the metallized ceramic piece obtained in the step S6 in nickel electroplating solution for electroplating;

s8, cleaning the side wall again: mechanically polishing the inner side wall and the outer side wall of the metalized ceramic piece electroplated in the step S7 again, wherein the surface roughness Ra is 0.1-0.3 micrometer; and then putting the ceramic ring into deionized water for ultrasonic cleaning for 10-15min to obtain the microwave magnetron insulating ceramic ring.

2. The microwave magnetron insulating ceramic ring as claimed in claim 1, wherein the concentration of the ethanol solution in step S2 is 70-90% by mass, the concentration of the hot NaOH solution in mass is 10-15% by mass, the temperature is 40-60 ℃, the power of the ultrasonic cleaning is 800-1200W, the content of aluminum in the high-purity aluminum block is greater than 99%, and the content of copper in the high-purity copper block is greater than 99%.

3. The microwave magnetron insulating ceramic ring according to claim 1, wherein the temperature of the thermal promoter in step S3 is 40-50 ℃.

4. The microwave magnetron insulating ceramic ring as claimed in claim 1, wherein the volume fraction of nitrogen in the high purity nitrogen gas in step S4 is greater than 99.995%, the flow rate of the high purity nitrogen gas is 2-5L/min, and the set temperature is 1200-1400 ℃.

5. The microwave magnetron insulating ceramic ring according to claim 1, wherein the silicone sealant is one or a mixture of several of acetic acid type, ketoxime type, alcohol type, amide type, hydroxylamine type and ketone type silicone sealants.

6. The microwave magnetron insulating ceramic ring according to claim 1, wherein the nickel plating solution is prepared quantitatively from the following raw materials: NiSO₄·6H₂O 500-600g/L，NaCl 10-20g/L，H₃BO₃20-30g/L, softening agent BSI15-30mL/L, wetting agent MA-801-2mL/L and stabilizer PVA-1240.5-1.2 mL/L.

7. The microwave according to claim 1The magnetron insulating ceramic ring is characterized in that the electroplating process comprises the following steps: adopting 267mL of Hehr bath, collecting 250mL of plating solution, anode being 100mm × 60mm × 3mm pure nickel plate, cathode being 100mm × 65mm × 0.3mm brass sheet, temperature being 50-60 deg.C, pH being 3.5-4.5, cathode current density being 2-15A/dm²And the current is 2A, a glass rod is adopted to stir back and forth in parallel with the cathode near the cathode, the moving speed is 1 time/s, and the time is 5-10 min.

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