AFBMA Grade 25 Alumina Balls

AFBMA Grade 25 Alumina Balls (alumina spheres) are engineered for high-precision applications requiring dimensional accuracy and durability. Composed of high-purity alumina, these ceramic balls are used in precision bearing systems, ball milling media, and catalytic support structures. Their high hardness, wear resistance, and thermal stability make them ideal for industries such as aerospace, automotive, and materials processing, where low friction and high-temperature operation are critical. In research and development, these alumina balls are utilized for tribological testing, grinding of hard materials, and heterogeneous catalysis studies, supporting advancements in ceramic engineering, energy storage, and nanomaterials research.

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Tolerance

Properties

Reference & Citations

each

Tolerances

Ball/Sphere

Diameter	Standard	±5%
Diameter	Precision	See Item

Material Properties for Ceramics

Chemical Resistance

Element	Value
Acids - concentrated	Good
Acids - dilute	Good
Alkalis	Good
Halogens	Good
Metals	Good

Electrical Properties

Element	Value
Dielectric constant	9-10.1
Dielectric strength( kV mm⁻¹ )	Oct-35
Volume resistivity( Ohmcm )	>10¹⁴@25

Physical Properties

Element	Value
Apparent porosity( % )	0
Water absorption - saturation( % )	0
Density( gcm⁻³ )	3.9

Thermal Properties

Element	Value
Melting point( C )	2100
Upper continuous use temperature( C )	1700
Specific heat( J K⁻¹ kg⁻¹ )	850-900@25°C
Thermal conductivity( W m⁻¹ K⁻¹ )	26-35@20°C
Coefficient of thermal expansion( x10⁻⁶ K⁻¹ )	8@20-1000°C

Mechanical Properties

Element	Value
Tensile modulus( GPa )	300-400
Hardness - Knoop( kgf mm⁻² )	2100
Hardness - Vickers( kgf mm⁻² )	1500-1650
Shear strength( MPa )	330
Tensile strength( MPa )	260-300