is a synthetic oxide ceramic with the chemical formula MgAl₂O₄, densified via high-temperature sintering (typically >1600°C). Its cubic spinel crystal structure endows it with a high melting point (2135°C), exceptional thermal shock resistance, low thermal expansion (7.6×10⁻⁶/K), and outstanding chemical inertness.  

Key Properties & Applications:  

1. High-Temperature Performance  

  Service temperature >1800°C; used in refractory linings for metallurgical furnaces and purging plugs for ladles.  

2. Optical Transparency  

  Achieves high transmittance in near-to-mid IR (0.3~5μm), ideal for missile domes and IR windows.  

3. Corrosion Resistance  

  Superior resistance to alkaline slag erosion vs. alumina, applied in cement rotary kiln hot zones.  

4. Functional Utilization  

  High-purity nano-powders for phosphor substrates/catalyst supports; transparent ceramics for laser gain media.  

Critical Sintering Techniques:  

- Raw Materials: Nano-powders of Al₂O₃ and MgO (purity >99.9%)  

- Additives: LiF/CaO to suppress grain-boundary phases and enhance transparency  

- Processes: Hot Pressing (HP) or Spark Plasma Sintering (SPS) to achieve near-full density (>99.5% TD)