Effect of the W—W contiguity on conductivity of W—Cu composite using the Voronoi diagram

Abstract

Abstract W-15wt.% Cu nanocomposite powder samples were fabricated by ball-milling and subsequent hydrogen-reduction. The powder samples were heated to 1200 °C at 5 and 20 °C min−1 and sintered for 1 h to obtain different sintered microstructures. The homogeneity of the sintered microstructures was evaluated by the standard deviation of the Vickers hardness. The W—W contiguity was calculated by using Voronoi diagrams. The sintered microstructure in case of the 20 °C min−1 sample was more homogeneous and had lower W—W contiguity than the 5 °C min−1 sample. The microstructural homogeneity was directly related to the W—W contiguity. Thermal conductivity of the 20 °C min−1 sample was about 5 % higher than the thermal conductivity of the 5 °C min−1 sample. This indicates that the thermal conductivity is affected by the W—W contiguity resulting from the homogeneity of the sintered microstructure.