The influence of applied electrochemical potential on the erosion-corrosion of aluminium in aqueous silica slurries containing phosphate buffer, 0.5 M NaCl, 0.1 M Na 2 CO 3 and acetic acid was studied over a wide range of potential (from -2.7 to + 2.7 V/SCE) with a modified jet impingement apparatus. The results showed that the erosion-corrosion (EC) rate and resulting surface morphologies can be influenced markedly by the applied potential, and the environmental composition also has a strong effect. In passive film-forming electrolytes, the EC rate was independent of the applied potential at potentials below -2.0 V/SCE (dependent on the pH value). At potentials above -2.0 V/SCE, the EC rate increased almost linearly with the applied potential. Above a certain potential, applied potential had only a small effect on EC rate.In NaCl slurry, pitting corrosion had a marked influence on erosion-corrosion behaviour. The erosion-corrosion rate increased sharply with applied potential above the pitting potential. In 0.1 M Na 2 CO 3 slurry, the EC rate remained constant at potentials below -2.3 V/SCE, and then decreased in the range from -2.3 to -0.5 V/SCE. When the applied potential increased further, the erosion-corrosion rate increased again.These results are discussed and compared with the results of previous work, and a model for the influence of the oxide film on the erosion-corrosion of aluminium is proposed.