Polymeric precursor pyrolysis for flexural property evaluation of continuous fiber ceramic nanocomposites with nanoparticles

摘要

The effects of nanoparticles on processing and flexural mechanical performance of Nicalon/KiON CERASET~R continuous fiber ceramic composites by preceramic polymer pyrolysis method have been investigated. Five different nanoparticles varying in size from 15 to 55 nm were used. These nanoparticles are: titanium oxide, yttrium oxide, zinc oxide, silicon carbide, and carbon. Ceramic fiber reinforcements (Nicalon~(TM)) and preceramic polymer (KiON CERASET~R) was mixed with nano-size fillers in the presence of a surfactant agent to give a good dispersion of the particles during the process. Two different types of nanoparticle filled composites were manufactured. The first one followed neat preceramic polymer reinfiltration cycle; whereas the second system was manufactured with corresponding nanoparticle dispersed preceramic polymer reinfiltration. For comparison purposes, samples without nanoparticles were also manufactured. A characterization analysis of the samples using scanning electron microscopy revealed good quality of the parts. In general, the weight gain percentage at each stage of reinfiltration/pyrolysis for both types of nanoparticle filled ceramic composites is consistently less than that for ceramic composites manufactured without nanoparticles. This indicates the compactness of the nanocomposites. Four-point bending test was also conducted to evaluate the flexural mechanical performance of the ceramic composites samples at room temperature. Nanoparticle filled samples consistently showed significant improvement in flexural strength compared to their counterparts without nanoparticle reinforcement.