What ceramics can be sintered in a ceramic hot press sintering furnace?

The ceramic hot press sintering furnace can achieve densification sintering of various high-performance ceramic materials through the synergistic effect of high temperature, high pressure, and controllable atmosphere. Its core advantage lies in suppressing abnormal grain growth, eliminating pores, and promoting interfacial bonding between materials, thereby preparing high-strength, high hardness, high thermal conductivity, or special functional ceramics. The following are the main types of ceramics that can be sintered and their typical applications:

1. Structural ceramics (high-strength, high hardness materials)
Silicon nitride ceramics (Si ∝ N ₄)
Sintering conditions: 1700-1850 ℃, 20-50 MPa axial pressure, nitrogen or argon protective atmosphere.
Characteristics: Bending strength of 800-1200 MPa, fracture toughness of 6-10 MPa · m ¹/², high temperature resistance.
Applications: Aircraft engine turbine rotors, ceramic bearings, cutting tools.
Silicon carbide ceramics (SiC)
Sintering conditions: 1900-2200 ℃, 30-50 MPa pressure, argon or vacuum environment.
Features: Hardness up to 25 GPa (Mohs hardness 9.5), high thermal conductivity, and strong corrosion resistance.
Applications: Nuclear reactor control rods, semiconductor wafer carriers, bulletproof armor.
Zirconia ceramics (ZrO ₂)
Sintering conditions: 1400-1600 ℃, 10-30 MPa pressure, air or argon atmosphere.
Characteristics: The phase transformation toughening effect is significant (increasing fracture toughness by 3-5 times), and the bending strength is high.
Applications: Dental implants, mobile phone backplates, oxygen sensors.

2. Functional ceramics (materials with special physical/chemical properties)
Transparent ceramics
Materials: Aluminum Nitride (AlN), Magnesium Aluminum Spinel (MgAl ₂ O ₄), Yttrium Aluminum Garnet (YAG).
Sintering conditions: 1800-2000 ℃, 10-30 MPa pressure, high vacuum (10 ⁻ ³ Pa) or nitrogen atmosphere.
Characteristics: High light transmittance and high thermal conductivity.
Applications: Laser windows, infrared detector substrates, high-pressure sodium lamp tubes.
High thermal conductivity ceramic substrate
Materials: Aluminum nitride (AlN), silicon carbide (SiC) reinforced aluminum based composite materials.
Sintering conditions: 1750-1900 ℃, 20-40 MPa pressure, nitrogen atmosphere.
Features: Matching thermal expansion coefficient with silicon chip, high thermal conductivity.
Application: Power electronic module packaging, LED heat dissipation substrate.
Bioceramics
Materials: Hydroxyapatite (HA), Bioactive Glass (BG), Zirconia (ZrO ₂).
Sintering conditions: 1200-1400 ℃, 10-20 MPa pressure, air or steam atmosphere.
Characteristics: Excellent compatibility with human bone tissue and high bending strength.
Applications: Artificial joints, dental restorative materials, bone filling scaffolds.

3. Composite ceramics (multiphase synergistic reinforcement materials)
cermet
Materials: tungsten copper alloy (W-Cu), titanium carbide based metal ceramic (TiC Ni).
Sintering conditions: 1400-1600 ℃, 20-40 MPa pressure, hydrogen or vacuum environment.
Characteristic: Combining metal toughness and ceramic hardness.
Applications: High voltage electrodes, mold materials, rocket nozzles.
Fiber reinforced ceramic matrix composites (CMCs)
Materials: Silicon carbide fiber-reinforced silicon carbide (SiC/SiC), aluminum oxide fiber-reinforced aluminum oxide (Al ₂ O3/Al ₂ O3).
Sintering conditions: 1800-2000 ℃, 30-50 MPa pressure, argon atmosphere.
Features: Improved fracture toughness and significantly improved thermal shock resistance.
Application: Combustion chambers for aircraft engines, hot end components for hypersonic aircraft.

4. Nuclear Energy and Energy Materials
nuclear fuel ceramics
Materials: Uranium dioxide (UO ₂), uranium carbide (UC).
Sintering conditions: 1700-2000 ℃, 30-50 MPa pressure, argon or hydrogen atmosphere.
Characteristics: Density greater than theoretical density, high thermal conductivity.
Application: Nuclear reactor fuel pellets.
Solid state electrolyte ceramics
Materials: Yttrium stabilized zirconia (YSZ), lanthanum gallate (LaGaO3).
Sintering conditions: 1400-1600 ℃, 10-20 MPa pressure, air or wet hydrogen atmosphere.
Characteristics: High oxygen ion conductivity and excellent chemical stability.
Application: Solid oxide fuel cell (SOFC) electrolyte layer.

5. Optimization direction of sintering process
Gradient sintering: By controlling the temperature in zones (temperature difference ≤ 50 ℃), the gradient distribution of material composition or porosity is achieved, which improves the interfacial bonding strength of composite materials.
Rapid sintering: using graphite heating combined with pulse pressure to shorten the sintering cycle.
In situ reaction sintering: Introducing gases (such as N ₂, CH ₄) during the sintering process to participate in chemical reactions, generating reinforcing phases (such as TiN, SiC), and improving material properties.