Industrial alumina ceramics

Alumina Ceramics are classified into two categories: high-purity and general-purpose types.

High-Purity Alumina Ceramics
With an Al₂O₃ content exceeding 99.9%, these ceramics require sintering temperatures of 1650–1990°C and exhibit transmission wavelengths of 1–6 μm. Typical applications include:

• Replacement of platinum crucibles in glass melting

• Sodium lamp tubes due to optical transmission and resistance to alkali metals

• Integrated circuit substrates and high-frequency insulating materials in electronics

General-Purpose Alumina Ceramics
Classified by Al₂O₃ content into 99-series, 95-series, 90-series, and 85-series (including 75–80% grades). Key properties:

1. High Hardness
   Testing by the Shanghai Institute of Ceramics (CAS) confirms Rockwell hardness of HRA80–90, second only to diamond and significantly exceeding wear-resistant steel and stainless steel.

2. Exceptional Wear Resistance
   Central South University tests show wear resistance 266× that of manganese steel and 171.5× that of high-chromium cast iron. Field surveys over 10+ years demonstrate equipment service life extended by at least tenfold under equivalent conditions.

3. Light Weight
   Density of 3.5 g/cm³—half that of steel—significantly reduces equipment load.

Application Overview

• 99-series: High-temperature crucibles, refractory tubes, ceramic bearings/seals, valve plates

• 95-series: Corrosion- and wear-resistant components

• 85-series: Talc-enhanced electrical/mechanical properties, compatible with Mo/Nb/Ta seals, vacuum electronic devices