General Information

Ceramic balls are particularly suited to harsh environments. Their main advantages over steel is that they have a density of 40% lower than steel. Have 29% lower thermal expansion and are 150% harder. In certain high-speed applications their life is extended by as much as a hundred times. The three main materials used are Alumina Oxide, Zirconia Oxide and Silicon Nitride.

The following chart shows comparisons between the three.

Material Specifications

	Alumina Oxide	Zirconia Oxide	Silicon Nitride
Composition	99.5% Al2O3 / 0.5% other	97% ZrO2 / 3% MgO	87% Si3N4 / 13% other
Hardness	1700 Hv	80 - 84 Ra	1400 - 1700 Hv
Ultimate Tensile Strength	31,000 psi	60,000 psi	-
Ultimate Compressive Strength	>300,000 psi	285,000 psi	>570,000 psi
Modulus of Elasticity	53 x106 psi	29 x106 psi	44-45 x106 psi
Maximum Working Temperature	1400oC	2400oC	1000oC
Corrosion Resistance	Inert except for hydruofluric and hot concentrated sulphuric acids.	Inert to most substances, not recommended for environments of hydrochloric or strong alkaline solutions.	Inert to most substances.