Zirconia is an extremely refractory material. It offers chemical and corrosion inertness to temperatures well above the melting point of alumina. The material has low thermal conductivity. It is electrically conductive above 600°C and is used in oxygen sensor cells and as the susceptor (heater) in high temperature induction furnaces. With the attachment of platinum leads, nernst glowers used in spectrometers can be made as a light emitting filament which operates in air.

Key Properties of Zirconium Oxide

- Use temperatures up to 1000°C
- High density
- Low thermal conductivity (20% that of alumina)
- Chemical inertness
- Resistance to molten metals
- Ionic electrical conduction
- Wear resistance
- High fracture toughness
- High hardness

Key Features of Some Advanced Technical Ceramics

Characteristics	Unit	95 Al2O3	99 Al2O3	ZrO2	SSiC	SiSiC	B4C	HPS3N4
Color		white	ivory	white	black	black	black	dark gray
Density	g/cm3	3.65	3.88	6.05	3.12	3.06	2.51	3.25
Young's Modulus	Gpa	280	350	205	400	320	420	310
Vickers Hardness	Gpa	14	20	12	25	22	36	22
Flexural Strength	Mpa	280	300	900	400	300	370	850
Compressive Strength	Mpa	1700	2000	2500	2200	2000	2900	2800
Thermal Conductivity	W/(m?K)	25	30	2.2	100	130	35-40	27
Thermal shock resistance	ΔT(C°)	220	180-200	400	350	220	130	450-650
Max. Working Temperature	C°	1500	1700	850	1500	1300	1500	1200
Volume Resistivity ( 20 C° )	Ω?cm	>10^15	>10^14	>10^12	>10^6	>10^6	_	>10^14

 

Typical Uses of ZrO2

- Precision ball valve balls and seats
- High density ball and pebble mill grinding media
- Rollers and guides for metal tube forming
- Thread and wire guides
- Hot metal extrusion dies
- Deep well down-hole valves and seats
- Powder compacting dies
- Marine pump seals and shaft guides
- Oxygen sensors
- High temperature induction furnace susceptors
- Fuel cell membranes