Application of Vacuum Tube CVD Electric Furnace in the New Materials Industry

The vacuum tube CVD electric furnace is widely and deeply applied in the new materials industry. By precisely controlling the reaction conditions, it provides key technical support for the preparation of nanomaterials, high-performance ceramics, high-temperature superconducting materials, and composite materials. The following are specific application scenarios and analysis:

1. Preparation of nanomaterials: precise control of morphology and size
The vacuum tube CVD furnace can synthesize nanomaterials with specific morphology and size by adjusting the reaction temperature, gas flow rate, and substrate material. For example:
Carbon nanotubes (CNTs): A mixture of argon and hydrogen gas is introduced into a quartz tube, and ferrocene is used as a catalyst precursor to crack acetylene/methane at 800-1000 ℃. The growth rate and diameter of CNTs are precisely controlled through a linear heating program to achieve controllable synthesis of single-walled or multi walled structures.
Nano zinc oxide (ZnO): High purity ZnO nanostructures are prepared by densification sintering in an air atmosphere at a temperature of 5 ℃/min to 1500 ℃ for 2 hours, and are used in the fields of optoelectronic devices and sensors.
Technical advantages: The furnace adopts high-purity alumina or corundum tubes, which are resistant to high temperatures and have strong chemical stability, avoiding sample contamination; The Mass Flow Controller (MFC) improves gas flow stability to ± 0.5%, ensuring the repeatability of nanomaterial synthesis.

2. High performance ceramic sintering: significant improvement in density and hardness
The vacuum tube CVD electric furnace tightly binds ceramic particles through high-temperature treatment, improving the density, hardness, and wear resistance of the material. Typical applications include:
Alumina ceramics: The precursor is calcined at 700 ℃ in an oxygen atmosphere to ensure the uniform embedding of lithium ions into the lattice, and to prepare electrolyte materials with high ionic conductivity for use in the field of solid-state batteries.
Silicon nitride ceramics: Short term (second level) treatment at 1000 ℃ under nitrogen protection activates doped atoms, optimizes grain structure, and enhances the fracture toughness and thermal conductivity of ceramics.
Technical advantages: The double-sided heating layout combined with HRE resistance wire (containing rhenium alloy element) can maintain 99.8% resistance stability at a high temperature of 1200 ℃, and the service life is three times longer than traditional nickel chromium wire; The intelligent temperature control system supports 30 segment programmable PID self-tuning, with a temperature control accuracy of ± 1 ℃, meeting the precise requirements of ceramic sintering.

3. Synthesis of High Temperature Superconducting Materials: Breakthrough Increase in Critical Temperature
The vacuum tube CVD electric furnace provides oxygen free and high-temperature environmental conditions for the preparation of high-temperature superconducting materials. For example:
Yttrium Barium Copper Oxide (YBCO): heated to 950 ℃ for 1 hour under a vacuum of 10 ⁻ Pa, and achieved directional growth of superconducting phase by precise control of oxygen partial pressure. Superconducting thin films with critical temperature (Tc) higher than 90K were prepared for use in magnetic resonance imaging (MRI) and superconducting maglev fields.
Technical advantages: 304 stainless steel flange sealing structure combined with fluororubber O-ring, achieving a maximum vacuum degree of -0.1MPa, effectively avoiding material oxidation at high temperatures; The stepped splicing furnace design is optimized through mechanics to achieve uniform stress distribution during the heating process and avoid furnace cracking problems.

4. Preparation of Composite Materials: Optimization of Interface Bonding Strength
The vacuum tube CVD electric furnace deposits reinforcing phases on the substrate surface through gas-phase reactions to enhance the interfacial bonding strength of composite materials. Typical applications include:
Carbon Fiber Reinforced Ceramic Matrix Composite (C/C-SiC): Under argon protection, a silicon carbide (SiC) coating is deposited at 1100 ℃ using methyltrichlorosilane (MTS) as the precursor. By precisely controlling the gas flow ratio (such as MTS: H ₂=1:50), the coating cracking is avoided and the oxidation resistance of the composite material is improved.
Metal based composite materials (MMCs): Aluminum (Al) coating is deposited on the surface of titanium alloy (Ti6Al4V), and vacuum annealing treatment (950 ℃ insulation for 1 hour) is carried out to eliminate internal stress and optimize grain structure, thereby improving the bonding strength between the coating and the substrate.
Technical advantages: The gas control module integrates multiple needle valves and vacuum gauges, which can accurately control the nitrogen/hydrogen mixing ratio (accuracy ± 0.5% VOL), meeting the requirements of metal reduction experiments; Actual testing shows that the time required to evacuate from atmospheric pressure to 10Pa is ≤ 8 minutes, quickly achieving a vacuum environment and improving experimental efficiency.

5. Summary of Technical Advantages
Efficient and energy-saving: using a lightweight alumina ceramic fiber furnace with a thermal conductivity as low as 0.03W/(m · K), saving 60% -80% energy compared to older electric furnaces; The power consumption of heating an empty furnace to 1100 ℃ has decreased from 12kWh to 3.8kWh, and the cost of a single experiment has been reduced by 68%.
Precise control: The intelligent temperature control system supports 30 segment programmable PID self-tuning, with a temperature control accuracy of ± 1 ℃ and a temperature fluctuation amplitude of less than 0.5 ℃; In CVD experiments, it can be ensured that the uniformity of film deposition thickness is better than ± 2%.
High reliability: The furnace tube is made of high-purity materials (such as high-purity corundum tube), and both ends are sealed with stainless steel high vacuum flanges to ensure airtightness and high temperature resistance; The tube furnace has a simple structure, is easy to clean and replace components, and improves equipment stability.