Alumina ceramics are a type of commonly used wear-resistant ceramic material, with high-purity alumina (AL₂O₃) as the main component. This material has outstanding properties such as excellent hardness, strong corrosion resistance, high mechanical strength, and high temperature resistance, so it is often used in industrial environments with strict requirements on wear resistance, corrosion resistance, and pressure resistance.
After alumina ceramics are installed on the surface of pipelines, chutes, hoppers and various equipment, their service life can be significantly extended. Alumina ceramics are also frequently used in the field of electronic products due to their excellent insulation properties.
Manufacturing Process of Alumina Ceramics
Raw Material Preparation
High-purity Al₂O₃ Powder: Extracted from bauxite via the Bayer process or calcination.
Additive Mixing: Sintering aids (e.g., MgO, SiO₂) added to optimize sintering.
Powder Processing: Ball milling & spray drying to achieve uniform particle size (0.1-1μm).
Forming Techniques
Dry Pressing: Simple shapes (plates/rods) under 50-200 MPa pressure.
Injection Molding: Complex parts via powder-binder mixture injection.
Isostatic Pressing: Uniform density for large/high-performance components.
Sintering
Temperature: 1500°C-1800°C (higher for purer Al₂O₃).
Atmosphere: Air or inert gas (e.g., nitrogen).
Densification: Porosity reduced to <5% for high strength.
Post-Processing
Diamond Machining: Cutting, drilling, grinding with diamond/CBN tools.
Laser Processing: Micro-holes & intricate patterns.
Surface Treatment: Polishing, metallization (Ni/Au coating).
Quality Control
Physical Tests: Hardness (Vickers), density (Archimedes), flexural strength.
Microstructure: SEM analysis for grain size & porosity.
Functional Tests: Insulation resistance, corrosion resistance, thermal stability.
Main uses
