1. Equipment Principle and Applications
1.1 Vacuum diffusion welding refers to the process where, under clean vacuum or high-purity gas protection, atoms at the surfaces of identical or dissimilar materials that are in contact are dispersed and bonded together simultaneously under the combined effects of high temperature and pressure. After a specific period, atomic diffusion occurs between the atoms in the bonding layer, ultimately forming a robust, monolithic joint.
1.2 The vacuum diffusion welding furnace is the ideal process equipment for joining high-temperature materials and other high-strength alloy materials together without the need for solder. Typical materials suitable for this welding process include stainless steel, titanium, zirconium, beryllium, high-alloy aluminum, nickel-chromium-iron alloys, and tungsten. The process is also widely used to weld dissimilar metals such as copper-titanium, copper-aluminum, copper-tungsten, and even molybdenum-aluminum, as well as stainless steel bonded with ceramics. Key products manufactured using this technology include heat exchangers, cooling plates, molds, and more.

2. Equipment Features and Advantages
2.1 Effective volume can be designed according to customer requirements
2.2 Maximum operating temperature: 1350°C or 1600°C
2.3 Thyristor controller optimizes the efficiency of the heating element
2.4 Simple and Safe Process Operations
2.5 Multi-link structure design for more uniform pressure distribution
2.6 Proportional valve closed-loop pressure control enables higher constant-pressure accuracy.
2.7 The ultimate vacuum level is better than 1 × 10⁻⁴ Pa
2.8 Fully Automatic Control of the Heating Process
2.9 The temperature uniformity in the effective uniform temperature zone is optimally better than ±5°C.
2.10 Excellent energy-saving performance, with system leakage rates below 10⁻⁶ Pa·s.
2.11 The pressure plate and all pressurized components are replaceable and height-adjustable.
2.12 The material for multi-link rods and pressure plates is selected based on temperature and process requirements—either TZM (titanium-zirconium-molybdenum) alloy or isostatically pressed graphite.
2.13 Extremely short vacuuming and process times
2.14 The equipment features reliable performance, durability, a long service life, and ease of operation, delivering significant economic benefits.
2.15 Guiding the process menu via computer, with the ability to record and store data
2.16 The equipment is equipped with a forced rapid cooling system to enhance production efficiency.

3. Technical Specifications
3.1 Press Structure Type: Two-beam, four-column design—with upper-pressure application and lower-force support.
3.2 Furnace Structure Type: Front-Door or Front-and-Back-Door Design
3.3 Work Area Dimensions: Select Based on Workpiece Specifications
3.4 Maximum Temperature: 1350°C / 1600°C
3.5 Work Area Temperature Uniformity: ≤±5°C (measured using the 9-point method under no-load conditions at 800°C and 1100°C)
3.6 Heating Chamber Design: Square-shaped, with three- or six-zone heating, featuring high-temperature molybdenum heating elements and a fully metallic insulation shield.
3.7 Empty Furnace Heating Rate: 0–15°C/min (adjustable)
3.8 Temperature Control Accuracy: ±1°C
3.9 Ultimate Vacuum Level: ≤1×10⁻⁴ Pa (Molecular Pump) or ≤6×10⁻⁴ Pa (Diffusion Pump)
3.10 Operating vacuum level: ≤6×10⁻³ Pa
3.11 Pressure Rise Rate: ≤0.67 Pa/h
3.12 Pumping Rate: ≤40 min to working vacuum level (cold, no-load, dry condition)
3.13 Number of Cylinders/Press Heads: Select according to specifications
3.14 Hydraulic cylinder displacement control accuracy: 0.1 mm
3.15 Pressure Sensor: Accuracy ±0.3%
3.16 Pressure Regulation Accuracy (Pressure Control Accuracy): ≤ ±1% × Rated Pressure
3.17 Constant pressure time: ≥12 hours
3.18 Top-pressing head dynamic sealing type: Bellows
3.19 Upper platen (pressing head) travel speed: 0–10 mm/s (arbitrarily settable)
3.20 Upper Platen (Punch) Displacement Accuracy: ±0.5 mm
3.21 Press displacement sensor accuracy: ±3μm
3.22 Flatness of each upper and lower platen: ≤0.08 mm
3.23 Parallelism between upper and lower pressure plates: ≤0.1 mm
3.24 Upper punch stroke: ≥150 mm
3.25 Forced Cooling System: Cooling Method – Inert Gas Circulation within the Furnace
3.26 Maximum air-cooling pressure for the forced cooling system: ≤2 bar (absolute pressure)
3.27 Furnace surface temperature: ≤ Room temperature +15°C
3.28 Control Method: Industrial PC-Based Automatic Control System

4. Specifications and Models: See the table below; custom designs based on product specifications are also available.

The QVDB1 model features a single-cylinder pressurization structure and specification.

Serial Number	Model	Effective Work Area Dimensions (Width × Depth × Height)	Permissions Vacuum level	Highest Temperature	Temperature control accuracy Temperature uniformity	Highest Pressure	Constant Pressure Control Accuracy	Note
1	QVDB1-222	200mm × 200mm × 200mm	1 × 10 -4	1600°C	±1°C / ±4°C	50T	3‰ PID	Molecular pump
2	QVDB1-333	300mm × 300mm × 300mm	1 × 10 -4	1600°C	±1°C / ±4°C	80T	3‰ PID	Molecular pump
3	QVDB1-444	400mm × 400mm × 400mm	1 × 10 -4	1600°C	±1°C / ±4°C	100T	3‰ PID	Molecular pump
4	QVDB1-666	600mm × 600mm × 600mm	1 × 10 -4	1600°C	±1°C / ±4°C	200T	3‰ PID	Molecular pump
5	QVDB1-886	800mm × 800mm × 600mm	6 × 10 -4	1350°C	±1°C / ±4°C	400T	3‰ PID	Diffusion pump
6	QVDB1-997	900mm × 900mm × 700mm	6 × 10 -4	1350°C	±1°C / ±4°C	600T	3‰ PID	Diffusion pump

The QVDB2 model features a dual-cylinder pressurization design and specification.

Serial Number	Model	Effective Work Area Dimensions (Width × Depth × Height)	Permissions Vacuum level	Highest Temperature	Temperature control accuracy Temperature uniformity	Highest Pressure	Constant Pressure Control Accuracy	Note
1	QVDB2-6612	600mm × 600mm × 1200mm	6 × 10 -4	1350°C	±1°C / ±4°C	400T	3‰ PID	Diffusion pump
2	QVDB2-8816	800mm × 800mm × 1600mm	6 × 10 -4	1350°C	±1°C / ±4°C	600T	3‰ PID	Diffusion pump
3	QVDB2-9918	900mm × 900mm × 1800mm	6 × 10 -4	1350°C	±1°C / ±4°C	800T	3‰ PID	Diffusion pump

 

 

Vacuum diffusion welding refers to the process in which, under clean vacuum or high-purity gas protection, atoms at the surfaces of identical or dissimilar materials that are brought into contact with each other disperse and bond together under the combined effects of high temperature and pressure. After a certain period, these atoms diffuse into one another across the interfacial layer, ultimately forming a robust, monolithic joint.