High vacuum hot press furnace
07-18-2025 Author: KJ technology
High vacuum hot press furnace is an advanced equipment that achieves material densification and hot press forming through heating and pressure application in a vacuum or specific atmosphere environment. It is widely used in powder metallurgy, functional ceramics, hard alloys and other fields. The following is a detailed introduction:
1. Core functions and advantages
Vacuum environment control
Work under high vacuum (or inert gas protection) conditions to avoid material oxidation and maintain surface quality and purity.
Suitable for oxygen sensitive materials (such as certain metals and ceramics) to reduce heat treatment defects (such as cracks and deformations).
Hot pressing technology
By heating and softening the material, while applying pressure (such as using a hydraulic cylinder to drive the pressure head), metallurgical bonding between particles is promoted, and the density and mechanical properties of the material are improved.
It can achieve low-temperature sintering, reduce energy consumption, and shorten production cycles.
Automation and Security
Adopting PLC or computer control system, supporting one click start, full automation operation, real-time display of temperature, pressure and other parameters.
Equipped with over temperature alarm, leakage protection, overvoltage protection and other functions, the operation is safe and reliable.
2. Structural composition
Furnace system
Furnace: Adopting a double-layer water sandwich structure, the inner wall is made of 304 stainless steel or high-temperature resistant ceramics (such as alumina), and the outer wall is made of carbon steel, which can withstand high temperatures and prevent heat loss.
Furnace cover: Designed to be manually fully opened for easy loading and unloading of samples, equipped with sealing strips to ensure vacuum level.
Heating and temperature measurement system
Heating element: Resistance heating (such as graphite resistors and silicon carbide rods), evenly distributed on the inner wall of the furnace to achieve rapid heating.
Temperature measuring device: Thermocouples (such as K-type and S-type) monitor temperature in real time, and PID controller adjusts accurately with an error of ≤± 1 ℃.
pressurized system
Hydraulic station: equipped with imported proportional valve, pressure sensor, displacement display, supporting semi-automatic/automatic pressure regulation, pressure range 0-50MPa.
Pressure head: Bidirectional pressure design ensures uniform material stress and avoids local deformation.
vacuum system
Vacuum pump set: mechanical pump (rough pumping)+Roots pump (medium pumping)+diffusion pump (high vacuum), with a maximum vacuum degree of ≤ 5 × 10 ⁻⁴ Pa.
Valves and pipelines: equipped with inflation valves, exhaust valves, and vacuum butterfly valves, supporting rapid vacuuming and inflation protection.
water-cooling system
Circulating cooling heating elements, furnace body, vacuum pump and other key components to prevent overheating damage, equipped with water cut-off sound and light alarm.
control system
Human machine interface: LCD touch screen displays the operating status, supports process parameter settings, historical data storage and analysis.
Alarm function: Automatic shutdown and alarm in case of overheating, overpressure, or water cut-off, ensuring equipment safety.
3. Application Fields
powder metallurgy
Prepare high-density metal alloys (such as hard alloys and titanium alloys) and improve their strength through metallurgical bonding between particles.
Functional ceramics
Sintering transparent ceramics, industrial ceramics, silicon carbide (SiC), silicon nitride (Si ∝ N ₄), etc. to achieve densification and high performance.
nanomaterials
Synthesize nanoparticles under vacuum or protective atmosphere to avoid agglomeration and maintain material activity.
composite material
Hot pressing metal/ceramic matrix composite materials to enhance wear resistance and corrosion resistance.
4. Key points of operation and maintenance
Operating specifications
Pre startup inspection: Confirm that the water, electricity, and gas sources are normal, the heating chamber is clean, and the valve status is correct.
Vacuum pumping process: First, open the roughing valve. After the vacuum degree is ≤ 600Pa, start the Roots pump. Finally, when the vacuum degree is ≤ 0.1Pa, close the roughing valve.
Pressure control: Calculate the pressure based on the force area of the mold (for example, for a mold with a diameter of 30mm, a rated pressure of 2.1t, and a pressure of 1.7t, set the pressure gauge to 1.4MPa).
Heating rate: It is recommended to be ≤ 20 ℃/min to avoid aging of the heating element.
Routine maintenance
Furnace cleaning: Clean the residue with a soft bristled brush after each experiment, and regularly wipe the inner wall with alcohol.
Sealing strip inspection: Check the sealing strip for aging every week and apply silicone grease for lubrication.
Vacuum system maintenance: Replace vacuum pump oil and clean pipeline dust every month.
Electrical control cabinet: Clean the dust every quarter and check if the wiring connections are loose.
Safety precautions
It is prohibited to introduce highly corrosive gases (such as sulfur and sodium), and special treatment of the furnace must be carried out in advance if necessary.
To prevent the leakage of high-temperature solution to the furnace bottom, a cushion plate or alumina powder can be used for isolation.
In emergency situations, if pressing the 'control power switch' button is ineffective, immediately disconnect the main switch.
5. Development Trends
Efficient and energy-saving: adopting a one to two design (dual compressor, dual furnace body, one control system), reducing land occupation and cost, and improving efficiency.
Intelligent upgrade: Integrating IoT technology to achieve remote monitoring and fault diagnosis.
Multi functional extension: Develop integrated vacuum/atmosphere/hot pressing/sintering equipment to meet complex process requirements.
