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

Abstract

Model predictions of the transverse thermal conductivity ( K eff) are compared to experimentally determined values as a function of temperature for a commercial 2D-SiC f/SiC made by DuPont from plain weave Hi-Nicalon TM 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 K eff for this composite suggest that these models can be used to predict K eff for composites with various ‘non-ideal’ fiber, interphase and matrix structures. Importantly, the models make it possible to separate the relative component contributions to K eff 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-Nicalon TM woven fabric, at 200 °C constituent values K m=22–25 W/m K (matrix thermal conductivity), K c≈25 W/m K (PyC-coating thermal conductivity) and h eq=2.4×10 7 W/m 2 K (equivalent fiber–matrix interfacial thermal conductance) were determined.