Mechanical and physical properties of Cu₂O-xCu cermet

Cu₂O/xCu (x=0∼25wt.%) cermets as novel inert anode materials for aluminum production were prepared via hot pressing technology with different processing parameters. The compressive strength, thermal shock resistance, thermal expansion coefficient, thermal conductivity, and dc electrical conductivity at room temperature of Cu₂O / xCu cermets were tested. The dependence of dc electrical conductivity on temperature of Cu₂O/xCu cermets with Cu content lower and higher than the percolation threshold was investigated as well. The thermal expansion coefficient, the compressive strength, the thermal conductivity and the electrical conductivity of Cu₂O / xCu cermets increase with the Cu content, however, the thermal shock resistance decreases with the increase of Cu content. High temperature electrical conductivity measurements showed that with the increase of temperature, the electrical conductivity of the cermet increases when the Cu content is lower than the percolation threshold, while decreases when the Cu content is higher than the percolation threshold. The microstructure analysis suggests that the electrical conductivity of Cu ₂O / xCu cermets depends on the shape, size, and distribution of Cu phase.