Electric heating vacuum brazing furnace

09-24-2025       Author: KJ technology

Electric heating vacuum brazing furnace is a specialized equipment that uses electric heating technology to achieve precise connection of metal materials in a vacuum environment. It is widely used in aerospace, automotive manufacturing, electronic power, nuclear energy industry and other fields, especially suitable for scenarios that require high welding quality and materials are prone to oxidation. The following is a detailed introduction to its core features, working principle, application areas, and usage precautions:

1. Core Features

High vacuum environment

By using multi-stage vacuum pump sets (such as mechanical pumps, Roots pumps, diffusion pumps), the vacuum degree inside the furnace is reduced to an extremely low level (usually below 10 ⁻ Pa~10 ⁻⁴ Pa), effectively eliminating active gases such as oxygen and nitrogen from the air, avoiding problems such as oxidation, decarburization, and discoloration of the workpiece during heating, and ensuring that the welding joint is bright and dense.

Accurate temperature control

Adopting resistance heating method and equipped with high-precision temperature control system (such as PID controller), the temperature control accuracy can reach ± 1 ℃, and the temperature uniformity in the brazing area is within ± 5 ℃, meeting the process requirements of different materials.

modular design

The equipment has a compact structure and can be customized as a horizontal, well or multi chamber structure according to needs, suitable for processing workpieces of different sizes and shapes.

Multi-functional integration

In addition to brazing, it can also achieve processes such as vacuum annealing, vacuum tempering, and vacuum sintering, achieving "one furnace for multiple uses".

2. Working principle

Creating a vacuum environment

The vacuum pump group extracts the air from the furnace, reaches the set vacuum degree, closes the vacuum valve, and maintains the vacuum state.

Heating process

By using electric heating elements such as resistance wires and graphite heaters, the temperature inside the furnace is raised above the melting point of the brazing material (usually 300 ℃~1200 ℃), causing the brazing material to melt and wet the surface of the base material.

Insulation and cooling

Maintain a certain temperature and time to allow the brazing material to fully diffuse and bond with the base material; Subsequently, the workpiece is cooled naturally or forcibly (such as by injecting high-purity inert gases N ₂, Ar) to achieve the predetermined strength and performance.

3. Application Fields

aerospace

Used for brazing high-temperature alloy components such as engine blades, turbine disks, honeycomb structures, etc., to ensure that the joints maintain high strength and corrosion resistance in high-temperature and high-pressure environments.

automobile manufacturing

Vacuum brazing of aluminum alloy heat exchangers, oil coolers, stainless steel insulated cups and other products to improve heat exchange efficiency and service life.

electronic power

The sintering process of semiconductor components and power rectifier devices, as well as pre-treatment before vacuum coating, ensure product purity and electrical performance.

medical device

Precision welding of biocompatible materials such as stainless steel and titanium alloys meets the strict requirements of medical devices for cleanliness and corrosion resistance.

4. Precautions for use

Pre-operation preparation

Equipment inspection: Confirm that the vacuum pump, heating element, temperature sensor and other components are in good condition, without leakage or damage.

Workpiece cleaning: Remove impurities such as oil stains and oxides from the surface of the workpiece to prevent contamination or defects during the welding process.

Selection of brazing materials: Select appropriate brazing materials (such as silver based, copper based, nickel based brazing materials) based on the composition of the base material and process requirements, ensuring that the melting point of the brazing materials is at least 30 ℃ lower than the solidus temperature of the base material.

Monitoring during operation

Vacuum degree monitoring: Real time monitoring of furnace pressure through a vacuum gauge. If the rate of vacuum degree decrease is abnormal (such as>1kPa/min), immediately stop the machine and check the vacuum system.

Temperature monitoring: Monitor the actual temperature curve through a temperature controller or upper computer software to ensure it matches the set curve; If the temperature fluctuation exceeds ± 1 ℃, immediately check the heating element or control circuit.

Exception handling: If you hear the sound of heating element cracking, motor abnormal noise, or smell the burning smell of insulation material, immediately press the emergency stop button and cut off the power supply.

safety protection

Personal protection: Wear insulated gloves and protective face shields during operation to avoid direct contact with high-temperature furnace bodies or workpieces (temperatures up to 1200 ℃).

Electrical safety: Ensure good grounding of equipment and avoid operating in humid environments; During maintenance, disconnect the power supply and hang a "Do Not Close" sign.

Gas safety: If flammable gases such as hydrogen are used as protective gases, they must be operated in a fume hood and equipped with a gas leak alarm.

maintenance

Daily cleaning: Use a vacuum cleaner or soft bristled brush to clean the residue inside the furnace after each welding to avoid impurities affecting the next welding effect.

Regular calibration: Calibrate temperature sensors, vacuum gauges, and other instruments every 3-6 months to correct measurement errors.

Component replacement: Regularly replace heating elements based on their lifespan (such as 2000-3000 hours for graphite heaters) or degree of oxidation to ensure heating rate and temperature uniformity.