Work Tube Materials

	The choice of the material for the work tube depends on the temperature of the respective application and on the process parameters, e.g. on pressure, process gas, heating rates etc.
	This means that tight ceramic work tubes, for instance, can only be used up to 1400 ºC under vacuum. If heat treatments under vacuum are desired at higher temperatures, the use of our type HTK chamber furnaces should be considered.
	The gas atmosphere, too, plays an important role when choosing the work tube. In tubes containing SiO2, heat treatments under hydrogen can only be performed up to 1000 ºC. For higher temperatures, only SiC tubes without SiO2 or a tight high-purity Al2O3 tube may be used.
	Process parameters, like heating and cooling speeds, also have a direct effect on the choice of a suitable work tube. For high heating and cooling rates, only materials with a very good or excellent thermal shock resistance may be chosen, i.e. they must have low thermal expansion coefficients and good thermal conduction.

up to 1100 ºC

quartz glass or fused quartz with an excellent thermal shock resistance

up to 1250 ºC

	powder-metallurgic tight APM (CrFeAl alloy)
	good heat stability, low carbonizing rate
	excellent thermal shock resistance

up to 1300 ºC

	porous aluminium silicate with 70-80 weight-% Al2O3
	good to very good thermal shock resistance
	tight Si-SiC with 90 weight-% SiC

up to 1400 ºC

	tight aluminium silicate with 60-76 weight-% Al2O3
	good to very good thermal shock resistance

up to 1600 ºC

	porous R-SiC with 99 weight-% SiC
	very good thermal shock resistance

up to 1700 ºC

	porous high-purity Al2O3 (99.5 weight-%)
	good thermal shock resistance

up to 1800 ºC

	tight high-purity Al2O3 (99.7 weight-%)
	good thermal shock resistance

Special materials (according to client requirements):

	Si3N4
	AIN
	SSiC/NSiC/GPSN

Further Accessories

Ceramic vacuum-formed fibre insulation stoppers

	subframe with integrated power device, gas supply, operation panel, etc.
	laboratory bench (electrically adjustable)
	ceramic, glass-like or metallic support for samples, calibration units for thermo couples, etc.
	moisture sensors, dew point sensors, partial pressure sensors
	movable furnaces with cooling devices
	numerous further accessories available on request