Vertical vacuum diffusion welding furnace
01-21-2026 Author: KJ technology
Vertical vacuum diffusion welding furnace is a specialized equipment that combines vacuum environment and high temperature and high pressure conditions to achieve atomic level diffusion bonding of materials. It is widely used in the fields of aerospace, electronic packaging, and precision manufacturing. The following provides a detailed analysis from four aspects: working principle, core advantages, key parameters, and selection suggestions:
1. Working principle
The vertical vacuum diffusion welding furnace achieves material connection through the following steps:
Establishment of vacuum environment:
Using a combination of mechanical pumps (such as rotary vane pumps) and diffusion pumps/molecular pumps, the pressure inside the furnace is reduced from atmospheric pressure to 10 ⁻³~10 ⁻⁴ Pa (ultra vacuum), eliminating the pollution of gases such as hydrogen, oxygen, and nitrogen on the welding interface, while removing impurities such as oil and moisture.
High temperature heating and pressure loading:
Raise the furnace temperature to the target value (such as 1000 ℃ required for titanium alloy welding) through molybdenum strip or graphite resistance heating elements, and apply pressure (such as 30-100 tons) using hydraulic cylinders or pneumatic devices to promote atomic diffusion at the material contact surface.
Metallurgical bonding formation:
Under high temperature and high pressure, surface atoms of materials penetrate each other's lattice through diffusion motion, forming metallurgical bonds consistent with the properties of the substrate, avoiding welding defects such as pores and cracks.
2. Core advantages
Wide material adaptability:
It can weld the same or different materials (such as titanium alloy and aluminum alloy, ceramics and metals), especially suitable for refractory metals (such as tungsten and molybdenum) and heat-resistant alloys (such as nickel based high-temperature alloys).
High welding quality:
The joint strength is close to that of the substrate, the organizational performance is stable, the deformation is small, and it is suitable for manufacturing precision products that integrate structure and function (such as hollow blades for aviation engines).
Process flexibility:
Supporting multi temperature zone control (such as three temperature zone design), it can achieve synchronous welding of complex structures (such as honeycomb cores and multi fin channels), improving production efficiency.
3. Key parameters and selection criteria
Effective hot zone size:
Select according to the maximum size of the workpiece, such as 500 × 500 × 600mm, suitable for small and medium-sized parts; The hot zone reaches 1400 × 1400 × 1200mm and can handle large components.
Temperature control:
Maximum temperature: It is necessary to cover the welding requirements of the material (such as 1000 ℃ for titanium alloy and 1700 ℃ for ceramics).
Uniformity: Select models within ± 5 ℃ to ensure consistent welding quality.
Temperature control method: Supports 30 segment intelligent PID program temperature control, achieving precise adjustment of heating rate (such as 0-10 ℃/min) and constant temperature time.
Pressure system:
Loading range: Select according to the thickness of the workpiece (e.g. 30-50 tons suitable for thin plates, 50-100 tons suitable for thick plates).
Pressure accuracy: Select models equipped with pressure sensors and servo control systems to achieve pressure gradient loading and stable maintenance.
Vacuum performance:
Extreme vacuum: It needs to reach 10 ⁻⁶ Torr (about 1.3 × 10 ⁻⁴ Pa) to meet the welding requirements of active metals such as titanium and zirconium.
Extraction time: It takes ≤ 15 minutes from atmospheric pressure to 10 ⁻⁴ Torr to increase production pace.
Equipment structure:
Furnace body design: The double-layer water-cooled structure ensures controllable outer wall temperature at high temperatures while maintaining vacuum sealing.
Type of furnace door: preferably an upward or rotating furnace door, which is convenient for automated operation (such as using a robotic arm to pick up and place workpieces).
4. Typical application scenarios and selection recommendations
Aerospace field:
Requirement: Welding titanium alloy hollow blades and aluminum based composite water-cooled plates.
Recommended model: (Hot zone 700 × 700 × 600mm, maximum pressure 80 tons, temperature uniformity ± 5 ℃), supports synchronous welding of complex structures.
In the field of electronic packaging:
Requirement: Welding of α - Al ₂ O3 ceramics with metallic nickel, high entropy alloys with stainless steel.
Recommended model: (Hot zone 400 × 400 × 400mm, maximum pressure 100 tons, ultimate vacuum 6 × 10 ⁻⁴ Pa), meets the welding requirements of precision components.
In the field of industrial manufacturing:
Requirement: Welding WC Co hard alloy with aluminum and Ni ∝ Al intermetallic compounds.
5. Selection precautions
Brand and Service:
Prioritize selecting manufacturers that provide customized services (such as adjusting the size and number of hot zones), and confirm the warranty period (recommended to be ≥ 1 year) and lifetime maintenance support.
User reputation:
Based on industry cases and third-party evaluations, priority should be given to brands with mature application experience in the aerospace and electronic packaging fields.
Budget balance:
Balancing equipment prices and operating costs (such as energy consumption and maintenance frequency) while meeting process requirements, to avoid overinvestment.
