Steatite and cordieritte ceramics

Steatite ceramics                               comstruction insulating material

Cordieritte ceramics                         electrical applications, power resistors, bodls of infra-red- radiators,  catalyst carriers of engines exhausts

Table 2: Specifikation/Properties  of dolomitic ceramics.

			Material
			STEATIT	CORDIERIT
Qualification based on  ČSN EN 60672			C 221	C 410
Trade description			FR 59/8	TH 7/7 R12 BM
	Symbol	Units
Open porosity	pa	[%]	0	0.5
Bulk density	ρa	[g.cm^-3]	2.7	2.1
Modulus of elasticity	E	[GPa]	110	-
Flexural strength	σ	[MPa]	140	60
Mean coefficient of linear thermal expansion	α30-600	[10^-6 K^-1]	7-9	2-4
Thermal conductivity	λ30-100	[Wm^-1K^-1]	2-3	1.2-2.5
Resistance to thermal shock	ΔT	[K]	100	250
Relative permittivity	εr	-	6	5
Volume resistivity in terms of temperature	ρv,30	[Ω.m]	10^11	10^10
	ρv,200	[Ω.m]	10^9	10^6
Colour			beige	grey