What is calcined alumina powder?
Calcined alumina powder, primarily composed of alpha-alumina, is made from industrial aluminum hydroxide or alumina through a carefully controlled calcination process in a specialized high-temperature kiln.
This process isn't simply "drying," but rather a magical process of dehydration and crystal transformation. At high temperatures (typically above 1200°C), the raw material loses its water of crystallization, completely transforming its crystal structure from its low-temperature, transitional state to the most stable and hardest alpha-type crystal structure. This transformation gives it unparalleled properties:
High hardness (9 on the Mohs scale, second only to diamond)
High melting point (over 2050°C)
Excellent wear and corrosion resistance
Good insulating properties
Chemically inert (unreactive with most chemicals)
Core Features and Benefits: Why is it so indispensable?
Excellent Mechanical Properties: Its high hardness and wear resistance make it an ideal choice for manufacturing grinding and polishing materials (such as grinding wheels and cutting discs) and wear-resistant components (such as ceramic liners and nozzles).
Excellent Thermal Stability: Its extremely high melting point and thermal shock resistance enable it to withstand extreme environments, leading to its widespread use in refractories, high-temperature kiln furniture, and aerospace.
Electrical Insulation: High-purity calcined alumina is an excellent electrical insulator and a key material for integrated circuit substrates, electronic ceramics, and spark plugs.
Chemical Inertness: Acid and alkali resistant, it resists corrosion and remains stable in harsh chemical environments, making it a common choice for chemical fillers and biomedical ceramics.
Widely used in everyday applications, from cutting-edge technology.
Grinding Industry: Serves as a core abrasive for bonded abrasives (resin/ceramic grinding wheels) and coated abrasives (sandpaper).
Refractory Materials: Used in the production of high-temperature kiln linings required in industries such as steel, iron, glass, and cement, offering long life and excellent stability.
Advanced Ceramics: Used in the manufacture of high-tech ceramic products such as electronic substrates, ceramic sealing rings, cutting tools, and artificial joints.
New Materials: Used as a coating material for lithium battery separators, improving battery safety and cycle life. It is also a key raw material for 3D printing high-performance ceramics.
