Optimizing the transverse thermal conductivity of 2D-SiCf/SiC composites, II. Experimental

Model predictions of the transverse thermal conductivity (Keff) are compared to experimentally determined values as a function of temperature for a commercial 2D-SiCf/SiC made by DuPont from plain weave Hi-NicalonTM fabric and with an ICVI-SiC matrix. Two versions of the DuPont composite were examined: one with a ‘thin’ and one with a ‘thick’ pyrolytic carbon (PyC) fiber coating of thickness 0.110 and 1.044 μm, respectively. Generally good agreement of either the Hasselman–Johnson or the Markworth model predictions (see companion paper, I. Modeling) with measured values of Keff for this composite suggest that these models can be used to predict Keff for composites with various ‘non-ideal’ fiber, interphase and matrix structures. Importantly, the models make it possible to separate the relative component contributions to Keff so that individual component degradation mechanisms can be examined in detail. For the two versions of the well-bonded, as-received DuPont composite made with Hi-NicalonTM woven fabric, at 200 °C constituent values Km=22–25 W/m K (matrix thermal conductivity), Kc≈25 W/m K (PyC-coating thermal conductivity) and heq=2.4×107 W/m2 K (equivalent fiber–matrix interfacial thermal conductance) were determined.