The formation of aluminum carbide was studied in Aluminium-carbon diffusion couple experiments with and without thin layer of cryolite. Electrochemical environments in Hall-Heroult cell were also simulated in laboratory electrolysis cell. The interaction of carbon with aluminum was studied with the influence of electrochemical reactions corresponding to both real and inverted electrochemical cells and with no aluminum present initially. The cross sections of the various cells were characterized by optical and electron microscopy. A close to compact layer of aluminum carbide was observed on...