Comparative investigation into the corrosion of different bronze alloys suitable for outdoor sculptures

Several bronze alloys, suitable for production of outdoor sculptures, were developed in the frame of the European project “Eureka–Bronzart”. The elemental composition of the alloys was established to fulfil specific criteria such as: reduction of lead content, good resistance toward corrosion and aesthetic characteristics conformable to artistic purposes. After metallurgical characterization, the resistance toward corrosion was evaluated in artificial environments. Ageing experiments were performed in a salt spray cabinet and in a climatic chamber in the presence of a controlled concentration of SO2. The Thin Layer Activation method (TLA) was applied to calculate the thickness loss of activated specimens exposed to artificial corrosive atmospheres. After artificial ageing experiments the surface of the materials was investigated by SEM-EDS techniques. The bronze alloys containing different percentage of nickel showed the best properties of resistance toward corrosion.