CN100541944C - A method of manufacturing an electric heater connector plug - Google Patents

Abstract

The invention relates to a method for manufacturing an electric heater connector plug, which comprises the following process steps: (1) preparation of metallization slurry, (2) slurry coating, (3) metallization sintering, (4) Glazing and firing, (5) electroplating, (6) brazing. Compared with the traditional technology, the present invention adopts the ceramic metallization and sealing process, improves the sintering method and sealing method by adjusting the slurry formula of metal molybdenum and manganese, and utilizes the good corrosion resistance and electrical insulation of ceramic materials characteristics, so that the connector has the characteristics of corrosion resistance, temperature resistance, radiation resistance, air tightness and electrical insulation performance, which can improve the service life of the electric heater and reduce product costs.

Description

A method of manufacturing an electric heater connector plug

technical field

The invention relates to a ceramic metallization sealing process, in particular to a ceramic metallization sealing method for an electric heater connector.

Background technique

Ceramics have high temperature resistance, radiation resistance, good air tightness, and good electrical insulation performance. Ceramics and metals are connected by special welding technology. my country has adopted this technology in electric vacuum devices since the 1950s, and has developed rapidly. The welding methods of sintered metal powder method and active metallization method were quickly mastered. Now my country's ceramic-metal sealing and welding technology has been applied to many industries, and it has entered the stage of self-design and development of new materials and new methods from experimental research and application. With the development of the electronics industry and nuclear energy, many products are manufactured using ceramic-metal sealing technology. At present, the sintered metal powder method is one of the most mature technologies. First, the metallization method of sintered metal powder is used on the ceramic surface, and then brazed with the metal to connect the ceramic and the metal. The specific methods include Mo-Mn method, active Mo-Mn method, W-Fe method and so on.

Since there are many types of ceramics, the metallization components and methods used are also different according to different materials. The metal powder and ceramic substrate must be well sintered together and have a certain strength to meet the technical requirements. At present, molybdenum-manganese metallization is a relatively mature method, but the process is complicated, the production cost is high, and the bonding strength of the metallization layer is low.

Contents of the invention

The purpose of the present invention is to provide a simple process, low cost, and a method for manufacturing an electric heater connector plug with high bonding strength of the metallized layer in order to overcome the defects in the above-mentioned conventional technology.

The purpose of the present invention can be achieved through the following technical solutions: a method for manufacturing an electric heater connector plug, characterized in that the method adopts a ceramic metallization sealing process, and the method includes the following process steps:

(1) Preparation of metallization paste

Configure raw materials according to the following components and content (percentage by weight):

Molybdenum powder: 50-65%;

Manganese powder: 15-25%;

Additives: 15-20%;

Solvent: 2-10%;

Put the four components into the ball mill named ball mill tank, and ball mill in the ball mill for 2 to 5 hours to obtain the molybdenum manganese metal slurry;

(2) Slurry coating

Put the cleaned and dried ceramic tube on the rotating device, paint the metallized slurry on the required parts of the ceramic tube according to the drawings, and dry it after coating. After drying, the thickness of the metallized coating is 50-80 μm;

(3) Metallized sintering

Place the sized ceramic tube on a molybdenum boat, place it in a high-temperature hydrogen furnace for sintering, and control the sintering temperature at 1400-1550°C under a humid hydrogen protective atmosphere, keep it warm for 40-60 minutes, then cool down, and take out the ceramic tube;

(4) Glazing and firing glaze

Glaze the non-metallized surface of the ceramic tube, dry it, and fire the glaze in a high-temperature hydrogen furnace. Under the hydrogen protection atmosphere, the temperature of the glaze firing is controlled at 1200-1300°C, and the temperature is kept for 10-20 minutes;

(5) Electroplating

Carry out nickel plating to the metallized ceramic tube gained in step (4);

(6) Brazing

Install and position the ceramic tube, kovar, metal socket rod, and stainless steel connector base according to the drawings, fix the silver brazing material on the welding part, braze in a brazing furnace, and heat up to 950～1100℃, keep warm for 10～15 minutes.

The particle size of the molybdenum powder and manganese powder is 200-360 mesh.

The ceramic tube is made of alumina ceramics.

Described solvent is to use nitrocellulose solution and ethyl acetate, put nitrocellulose into ethyl acetate and heat, make it dissolve completely and become solvent, its component weight proportion is: ethyl acetate: 90～95%; Cotton: 5-10%.

The additives include aluminum oxide powder, calcium oxide powder and silicon oxide powder.

The metallized ceramic tube is nickel-plated, and the components of the electroplating solution are proportioned by weight as follows:

Components Parts by weight

Nickel sulfate 100 parts;

Sodium sulfate 25-35 parts;

Magnesium sulfate 20-30 parts;

10-20 parts of boric acid;

Sodium chloride 3-6 parts.

The electroplating solution is prepared with deionized water, and the plated parts are cleaned with deionized water.

The present invention adjusts the formula of molybdenum-manganese metallization slurry, improves the sintering method, completes one-time brazing, reduces the production cost of the product, and the flexural strength of the ceramic weldment is 8000-10000N/cm ² , compared with the traditional technology, The invention has the following advantages: the bonding strength of ceramic metallization and sintering is high, and the device made by this method has corrosion resistance, temperature resistance, radiation resistance, good air tightness and electrical insulation performance, and it can be used at a temperature of 150 ° C. , Pressure 0.6Mpa, long-term use in a radiation environment and maintain good electrical properties. The connectors manufactured by the ceramic metallization sealing method have changed the situation that the cables of the electric heaters used in nuclear power plant regulators cannot be replaced separately after aging, but must be replaced together with the electric heaters. The service life of the electric heater is extended, the operation and maintenance costs of the nuclear power plant are reduced, the maintenance time is shortened, the problem of replacing cables is solved, and the utility model has better economy.

Description of drawings

Fig. 1 is a structural schematic diagram of the metallized sealing of the electric heater connector of the present invention.

Detailed ways

The present invention adopts the ceramic metallization sealing process to manufacture electric heater connectors, which will be further described below in conjunction with the accompanying drawings through examples, including a first kovar 1, a stainless steel connector base 2, a metallized ceramic tube 3, and a second Kovar 4, metal socket rod 5.

Example 1

As shown in Figure 1, a ceramic metallization sealing method is used to manufacture electric heater connectors, which can be used on tubular electric heaters in special environments such as chemical industry. Using ceramic metallization and sealing method technology, by adjusting the slurry formula of metal molybdenum and manganese, improving the sintering method and sealing method, and using the characteristics of corrosion resistance and good electrical insulation of ceramic materials, this connector is made It has the characteristics of corrosion resistance, temperature resistance, radiation resistance, air tightness and electrical insulation performance, which can increase the service life of the electric heater and reduce the product cost. The specific method steps are as follows:

(1) Preparation of metallization paste

Get 500 grams of 300-order molybdenum powder, 500 grams of 300-order manganese powder, and 500 grams of 300-order additive, and ball mill them in a ball mill for 12 hours respectively before use. Pour 200ml of ethyl acetate into a 500ml ground-mouth bottle, and add 50 grams of nitrocellulose and stir. After 24 hours, the nitrocellulose is completely dissolved and set aside. Take by weighing 200 grams of molybdenum powders, 100 grams of manganese powders, 120 grams of additives and 30 grams of solvents from the ground material, and ball mill and mix them for 3 hours in a ball mill jar. Thereafter, the metallization paste was poured into glassware for later use.

(2) Slurry coating

Put the cleaned and dried ceramic tube on the rotating device, paint the required parts of the ceramic tube by hand according to the drawings, and let it dry after coating. The metallization paste coating thickness is 0.08mm.

(3) Metallized sintering

Place the ceramic tube coated with metallization slurry on a molybdenum boat, place it in a vertical hydrogen furnace, pass nitrogen gas, and then pass hydrogen gas to the furnace outlet to ignite. The hydrogen furnace is energized to raise the temperature. When the furnace temperature reaches 1200°C, use wet hydrogen Gas protection, heat preservation at 1450°C for 60 minutes, then cool down, and take out the ceramic tube. Check to see the metallization and sintering situation, if there are bubbles and cracks, they must be detected and removed as unqualified products.

(4) Electroplating

Put 600 grams of chemically pure nickel sulfate into 4000 ml of deionized water, weigh 250 grams of sodium sulfate, 100 grams of magnesium sulfate, 60 grams of boric acid, and 20 grams of sodium chloride into the solution, and stir until completely dissolved.

The metallized ceramic tube was polished with sandpaper, the pH value was 5, the current density of electroplating was 1.0A/dm2, the electroplating time was 40min, and the coating thickness was 8μm.

(5) Brazing

Install and position the ceramic tube, kovar, metal socket rod, and stainless steel connector base according to the drawings, fix the silver brazing material on the welding part, braze in a brazing furnace, raise the temperature to 950°C, and keep it warm for 10 minutes ,cool down. The connector plug is made, and the sealing test and electrical performance test are carried out to ensure the sealing and electrical insulation of the plug.

Example 2

(1) Preparation of metallization paste

Get 500 grams of 300-order molybdenum powder, 500 grams of 300-order manganese powder, and 500 grams of 300-order additive, and ball mill them in a ball mill for 12 hours respectively before use. Pour 285g of ethyl acetate into a 500ml ground-mouth bottle, and add 15 grams of nitrocellulose and stir. After 24 hours, the nitrocellulose is completely dissolved and set aside. Take by weighing 250 grams of molybdenum powders, 125 grams of manganese powders, 100 grams of additives and 25 grams of solvents from the ground material, and ball mill and mix them for 5 hours in a ball mill jar. Thereafter, the metallization paste was poured into glassware for later use.

(2) Slurry coating

Put the cleaned and dried ceramic tube on the rotating device, paint the required parts of the ceramic tube by hand according to the drawings, and let it dry after coating. The metallization paste coating thickness is 0.05mm.

(3) Metallized sintering

Place the ceramic tube coated with metallization slurry on a molybdenum boat, place it in a vertical hydrogen furnace, pass nitrogen gas, and then pass hydrogen gas to the furnace outlet to ignite. The hydrogen furnace is energized to raise the temperature. When the furnace temperature reaches 1200°C, use wet hydrogen Gas protection, heat preservation at 1400°C for 60 minutes, then cool down, and take out the ceramic tube. Check to see the metallization and sintering situation, if there are bubbles and cracks, they must be detected and removed as unqualified products.

(4) glazed firing glaze

Glaze the non-metallized surface of the ceramic tube, dry it, and fire it in a high-temperature hydrogen furnace. Under a hydrogen protective atmosphere, the temperature of the firing glaze is controlled at 1300°C and kept for 20 minutes.

(5) Electroplating

Put 1000 grams of chemically pure nickel sulfate into 4000 ml of deionized water, weigh 250 grams of sodium sulfate, 200 grams of magnesium sulfate, 100 grams of boric acid, and 30 grams of sodium chloride into the solution, and stir until completely dissolved.

The metallized ceramic tube was polished with sandpaper, the pH value was 5, the current density of electroplating was 1.0A/dm2, the electroplating time was 40min, and the coating thickness was 8μm.

(6) Brazing

Install and position the ceramic tube, kovar, metal socket rod, and stainless steel connector base according to the drawings, fix the silver brazing material on the welding part, braze in a brazing furnace, raise the temperature to 980°C, and keep it warm for 15 minutes ,cool down. The connector plug is made, and the sealing test and electrical performance test are carried out to ensure the sealing and electrical insulation of the plug.

Example 3

(1) Preparation of metallization slurry:

Get 500 grams of 300-order molybdenum powder, 500 grams of 300-order manganese powder, and 500 grams of 300-order additive, and ball mill them in a ball mill for 12 hours respectively before use. Pour 270g of ethyl acetate into a 500ml grinding bottle, and add 30g of nitrocellulose and stir. After 24 hours, the nitrocellulose is completely dissolved and set aside. Take by weighing 325 grams of molybdenum powders, 75 grams of manganese powders, 75 grams of additives and 25 grams of solvents from the ground material, and ball mill and mix for 2 hours in a ball mill jar. Thereafter, the metallization paste was poured into glassware for later use.

(2) Slurry coating

Put the cleaned and dried ceramic tube on the rotating device, paint the required parts of the ceramic tube by hand according to the drawings, and let it dry after coating. The metallization paste coating thickness is 0.05mm.

(3) Metallized sintering

Place the ceramic tube coated with metallization slurry on a molybdenum boat, place it in a vertical hydrogen furnace, pass nitrogen gas, and then pass hydrogen gas to the furnace outlet to ignite. The hydrogen furnace is energized to raise the temperature. When the furnace temperature reaches 1300°C, use wet hydrogen Gas protection, heat preservation at 1550°C for 40 minutes, then cool down, and take out the ceramic tube. Check to see the metallization and sintering situation, if there are bubbles and cracks, they must be detected and removed as unqualified products.

(4) glazed firing glaze

The non-metallized surface of the ceramic tube is glazed, dried, and placed in a high-temperature hydrogen furnace for firing the glaze. Under a hydrogen protective atmosphere, the temperature of the firing glaze is controlled at 1200°C and kept for 10 minutes.

(5) Electroplating

Put 1000 grams of chemically pure nickel sulfate into 4000 ml of deionized water, weigh 250 grams of sodium sulfate, 200 grams of magnesium sulfate, 100 grams of boric acid, and 30 grams of sodium chloride into the solution, and stir until completely dissolved.

The metallized ceramic tube was polished with sandpaper, the pH value was 5, the current density of electroplating was 1.0A/dm2, the electroplating time was 40min, and the coating thickness was 8μm.

(6) Brazing

Install and position the ceramic tube, kovar, metal socket rod, and stainless steel connector base according to the drawings, fix the silver brazing material on the welding part, braze in a brazing furnace, raise the temperature to 980°C, and keep it warm for 10 minutes ,cool down. The connector plug is made, and the sealing test and electrical performance test are carried out to ensure the sealing and electrical insulation of the plug.

Claims (7)

1. A manufacturing method of an electric heater connector plug, characterized in that, the method adopts a ceramic metallization sealing process, and the method comprises the following process steps: (1) Preparation of metallization paste Configure raw materials according to the following components and content (percentage by weight): Molybdenum powder: 50-65%; Manganese powder: 15-25%; Additives: 15-20%; Solvent: 2～10%; Put the four components into the ball mill named ball mill tank, and ball mill in the ball mill for 2 to 5 hours to obtain the molybdenum manganese metal slurry; (2) Slurry coating Put the cleaned and dried ceramic tube on the rotating device, paint the metallized slurry on the required parts of the ceramic tube according to the drawings, and dry it after coating. After drying, the thickness of the metallized coating is 50-80 μm; (3) Metallized sintering Place the sized ceramic tube on a molybdenum boat, place it in a high-temperature hydrogen furnace for sintering, and control the sintering temperature at 1400-1550°C under a humid hydrogen protective atmosphere, keep it warm for 40-60 minutes, then cool down, and take out the ceramic tube; (4) Glazing and firing glaze Glaze the non-metallized surface of the ceramic tube, dry it, and fire the glaze in a high-temperature hydrogen furnace. Under the hydrogen protection atmosphere, the temperature of the glaze firing is controlled at 1200-1300°C, and the temperature is kept for 10-20 minutes; (5) Electroplating Carry out nickel plating to the metallized ceramic tube gained in step (4); (6) Brazing Install and position the ceramic tube, kovar, metal socket rod, and stainless steel connector base according to the drawings, fix the silver brazing material on the welding part, braze in a brazing furnace, and heat up to 950～1100℃, keep warm for 10～15 minutes. 2. A method for manufacturing electric heater connectors and plugs according to claim 1, characterized in that the particle size of the molybdenum powder and manganese powder is 200-360 mesh. 3. A method for manufacturing an electric heater connector plug according to claim 1, wherein the ceramic tube is made of alumina ceramics. 4. The manufacturing method of a connector plug for an electric heater according to claim 1, wherein the solvent is a solution of nitrocellulose and ethyl acetate, and the nitrocellulose is heated in ethyl acetate, It is completely dissolved to become a solvent, and the weight ratio of its components is: ethyl acetate: 90-95%; nitrocellulose: 5-10%. 5. A method of manufacturing an electric heater connector plug according to claim 1, wherein the additives include alumina powder, calcium oxide powder, and silicon oxide powder. 6. A method of manufacturing an electric heater connector plug according to claim 1, characterized in that, the metallized ceramic tube is nickel-plated, and the components of the electroplating solution are proportioned by weight as follows: Components Parts by weight Nickel sulfate 100 parts; Sodium sulfate 25-35 parts; Magnesium sulfate 20-30 parts; 10-20 parts of boric acid; Sodium chloride 3-6 parts. 7. A method for manufacturing an electric heater connector plug according to claim 6, wherein the electroplating solution is prepared with deionized water, and the plated parts are cleaned with deionized water.

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