Alumina powder and white corundum powder have the same appearance and similar names. Many people want to clarify the difference between them. The following distinguishes it from its own composition and tells you the difference:
1. Alumina powder
(1) Appearance: white powder, crystalline phase γ phase;
(2) Color: white, dark blue after calcination.
(3) Content %: greater than 99.9%;
(4) Average particle size (nm): 20±5;
(5) Boiling point: 2980 ℃;
(6) Relative density (water = 1): 3.97-4.0;
(7) Melting point: 2010 ℃-2050 ℃;
2. White corundum powder
(1) Crystal form: trigonal crystal system;
(2) Specific heat (Cal/g.C): 0.26 (20-90C);
(3) Density: 3.90 g/cm3;
(4) Linear expansion coefficient: (7-9)*10^-6/K (0-1600C).
(5) Melting point: 2250C;
(6) Refractive index: e=1.760 w=1.768 (Na line);
(7) *High operating temperature: 1900C;
(8) Hardness: Knoop hardness 2000-2200Kg/mm2, Mohs hardness 9.0;
(9) Thermal conductivity: 900C at room temperature (Cal/cm3.sec.C);
White corundum powder is suitable for the manufacture of ceramics, resin-consolidated abrasive tools, as well as grinding, polishing, sandblasting, precision casting, etc. It can also be used for manufacturing high-grade refractory materials. Alumina powder can be used in heat conduction, polishing, electroplating, catalyst, etc.
