The invention discloses a three-dimensional
fiber prefabricated-part enhancement
mullite composite and a preparation method thereof. The preparation method comprises impregnating three-dimensional
fiber prefabricated parts in an A1203-SiO2 composite
sol to be impregnated, dried and subjected to low-temperature thermal
processing to obtain the A1203-SiO2 impregnated three-dimensional
fiber prefabricated parts; repeating the process till the
weight gaining of the A1203-SiO2 impregnated three-dimensional fiber prefabricated parts is lower than 1% to obtain three-dimensional fiber prefabricated-part first intermediates, performing medium-temperature thermal
processing, subjecting the medium-temperature thermal processed three-dimensional fiber prefabricated-part first intermediates to impregnation, high-pressure
processing,
drying, low-temperature thermal processing and medium-temperature thermal processing, circulation the process till the
weight gaining is lower than 1%, and performing high-temperature
thermal treatment. According to the composite and the preparation method thereof, by three-stage
thermal treatment, the compactness of the three-dimensional fiber prefabricated-part enhancement
mullite can be further improved, and the mechanical performance and the
oxidation resistance of the enhancement composite are enhanced.