Experimental investigation on the anisotropic thermal conductivity of C/SiC composite thin slab

Due to the anisotropic fibers and structure distribution, fiber-reinforced composites possess anisotropic mechanical and heat transfer properties. For C/SiC composites, the out-of-plane thermal conductivity was mainly studied whereas the in-plane thermal conductivity received less attentions due to its limited thickness. In this study, the slab module of transient plane source method is adopted to measure the in-plane thermal conductivity of 2D plain woven C/SiC composite slab and the test uncertainty is analyzed numerically for the first time. The numerical investigation proves that the slab module is reliable for measuring the isotropic and anisotropic slabs with in-plane thermal conductivity greater than 10 W·m-1·K-1. The anisotropic thermal conductivity of 2D plain woven C/SiC composite slab is obtained within the temperature range of 20℃-900℃ by combining with the laser flash analysis method to measure the out-of-plane thermal conductivity. The results demonstrate that the out-of-plane thermal conductivity of C/SiC composite decreases with temperature while its in-plane thermal conductivity increases with temperature first and then decreases, and the ratio of in-plane thermal conductivity to out-of-plane thermal conductivity is within 2.2-3.1.