Processing and Performance of Continuous Fiber Ceramic Composites by Preceramic Polymer Pyrolysis: II—Resin Transfer Molding

Abstract

Vacuum Assisted Resin Transfer Molding (VARTM) was used in conjunction with preceramic polymer pyrolysis to manufacture Continuous Fiber Ceramic Composites (CFCCs). Two VARTM techniques were used: (a) the use of injection pressure in the presence of a vacuum and (b) the use of vacuum only without the injection pressure. After initial testing, eight CFCC tubes were fabricated using these techniques. The matrix material used was Blackglas™. C-Nicalon™ in the form of woven fabric and BN-Nextel ®312 in the form of braided textile were used as reinforcements. C-Nicalon™ CFCC tubes with 4%–6% porosity, 55%–57% fiber volume fraction, and 2.12–2.18 g/cm3 density reached convergence by weight in 10 cycles (with about 17 hours per cycle), while BN-Nexlet ®312 CFCC tubes with 4%–6% porosity, 70%–72% fiber volume fraction, and 2.42–2.48 g/cm3 density converged by weight in 8 cycles. TheVARTMprocessing time averaged 15 minutes for each tube. The mechanical performance of the components was evaluated at room and high temperatures using a C-ring test. Scanning Electron Microscopy (SEM) was employed to study the microstructure of the parts. The results show that the without injection pressure technique offers a promising method to produce tubular CFCCs in terms of lower manufacturing costs, part uniformity, and enhanced mechanical properties. BN-coating performs better at high temperature compared with C-coating. Also, a combination of BN-coating and a textile braided architecture of fiber preform proved to enhance the performance of the manufactured CFCCs. Finally, the mechanical performances of the manufactured CFCC tubes using VARTMtechnique were compared with those using a cure-on-the-fly filament winding technique for a similar geometry using the same materials.

Three-dimensional multifunctional hierarchical nanocomposites: multifunctional materials

“…Ghasermi-Nejhad and co-workers [2] demonstrated that the entire process of hierarchical nanomanufacturing of 3-D nanoforests multifunctional nanocomposites consists of the following steps: 1) growth of carbon nanotubes on the surface of woven cloths in the perpendicular direction to give 3-D woven nanoforests cloths, 2) infiltration of nanotube-grafted cloths with a polymer (epoxy) matrix, and 3) fabrication of the laminated composite using a hand lay-up [24][25] technique (or a vacuum assisted resin transfer molding technique [26]. These steps are demonstrated in Figure 1.…”

Experimental Investigation of Optimal Nanoparticle Inclusion for Enhanced Flexural Performance in Continuous Fiber Ceramic Nanocomposites

“…The preceramic polymer pyrolysis route to ceramic chemistry has attracted much attention as it offers a promising and cost-effective way to manufacture CMCs/CFCCs with little to no final machining [21][22][23][24][25][26] and parts with greater compositional homogeneity [27][28][29]. Preceramic polymers are organo-metallic polymers that, after curing, are chemically transformed during their pyrolysis step to yield a contributing ceramic phase(s) in the final ceramic part.…”