Abstract: In order to explore the effects of yarn linear fineness, fiber volume fraction and density of warp and weft on the thermal conductivity of orthogonal three-dimensional woven composites, the orthogonal three-dimensional woven composites were prepared with quartz fiber and epoxy resin as raw materials, and the thermal conductivity coefficient of the composites was measured by transient heat source method. Results indicated that under different processing parameters, fiber volume fraction had the most significant effect on the thermal conductivity of composites; when yarn linear fineness and density of warp and weft were unchanged, and fiber volume fraction was at the range of 45% to 60%, the thermal conductivity coefficient increased by 24.28% in warp direction, 22.71% in weft direction and 17.03% in Z-yarn direction; when different process parameters had an effect on the thermal conductivity of the composites, the anisotropy was exhibited in the three directions, and the thermal conductivity in all three directions was related to the fiber volume fraction in the corresponding direction.

Key words: orthogonal three-dimensional woven; quartz fiber composites; thermal conductivity; anisotropy