Chapter 9. Structural Ceramics Through Particle-Filled Preceramic Polymers: Supension and Particle Filtration Characterization

Summary

For reliable particle filtration analysis during impregnation molding of particle-filled preceramic polymer (PCP) based continuous fiber ceramic composites, the properties of the injected particle-PCP suspensions must be known (predictable) and the suspension quality reproducible. In this study, a methodology for optimal preparation (homogeneous suspension with low agglomeration) of sterically stabilized α-phase SiC particle — Blackglas™ polymer (AlliedSignal, Inc.) suspensions is presented. The quality of the prepared suspensions is inspected rheologically and visually (through SEM). For determination of particle concentration in suspension samples, an electrostatic spraying set-up has been constructed to produce particle-PCP suspension aerosols that are directed to an aerodynamic particle sizer (APS). Through APS, particle size distribution and concentration in prepared suspensions are obtained. Although the measured values agree qualitatively with expected results, there are quantitative discrepancies due to particle loss during handling and measuring. Further investigation and quantification of particle loss mechanisms are required for reliable measurements with APS. An experimental analysis of particle filtration during impregnation based on the proposed methodology is also planned in the future in which the results will be coupled to previously developed process models for designing optimal processing conditions.