Fracture toughness

SILICON NITRIDE	HIGH LOW	4-5	High toughness Thermal shock resistant Tight tolerances
ZIRCONIA		4-5	Toughness Mechanical Strength High Heat Resistance Corrosion Resistance
SILICON CARBIDE		4-5	Hardness Mechanical strength Variable electrical resistivity Distinct properties that can be tailored
ALUMINA		3-5	General use Wear resistance Electrical insulator Dielectric strength Low dielectric loss