Grain growth kinetics of mullite in laboratory-produced and commercial alumino silicate fibres was analysed in the temperature range between 1500-1700 deg C. The lab fibres consist of mullite plus traces of a-alumina, while the phase content of the commercial Nextel 720 fibres is about 60wt% mullite plus 40wt% a-alumina. Two different temperature regimes can be distinguished with respect to the grain growth exponents: above 1600 deg C the growth exponent is ~1/3, while below 1600 deg C the growth exponent of ~1/12 is exceptionally low. Laboratory produced and commercial fibres show almost identical mullite grain growth kinetics.
Origin
Institute Materials Research, Germany
Journal Title
Jacs 88 2 2005 488-490
Sector
Glass Fibre
Class
GF 476