Room temperature long-term creep/relaxation behaviour of carbon cathode material

The long term, visco-elastic behaviour of carbon cathode materials used into the Hall-Héroult cell linings has been investigated. The uniaxial compressive creep tests with free lateral strains have been conducted on three different carbon cathode materials (semi-graphitic, graphitic and graphitized) currently used in aluminium reduction cells. The evolution of mechanical properties caused by damaging material has been estimated through cyclic loading tests. Measurements were made of the axial and the radial strains at ambient temperature. The “key” operating mechanisms behind the observed creep phenomenon are evaluated.