Processing and properties of Blackglas (TM)-Nextel (TM) 312 (BN) composites incorporating fillers

Blackglas(TM)-Nextel(TM) 312 (BN) composites with and without filler materi als have been processed and characterized. SIC as inactive filler, and Ti a nd TiB2 as active fillers, were incorporated into the Blackglas resin, and the resulting slurries were painted on Nextel fabrics, The painted fabrics were laminated at 150 degreesC and then pyrolyzed at 1000 degreesC under ni trogen to fabricate ceramic-ceramic composites. The pyrolyzed composites we re infiltrated with the resin up to five times to minimize the porosity and microcracks formed upon pyrolysis. Dimensional changes, open porosity, and densities of the composites were monitored throughout the process. The fle xural strengths of the unfilled and filled composites after 2, 3, 4, and 5 infiltration cycles were measured by four-point bending. It was found that the addition of filler materials eliminated the delamination problem at a l ow number of infiltration cycles; however, the strengths of the filled comp osites did not reach the level of the unfilled composite. Much higher modul i were obtained for the filled composites because of the higher modulus of the filler materials relative to Blackglas,