CORROSION BEHAVIOUR IN NEUTRAL ENVIRONMENT OF SOME TERNARY TITANIUM ALLOY

The purpose of this paper is to determine the effect of the alloying elements on the passive filmformation on the Ti-Mo-Ni alloy, in concentrated chloride solutions, at high temperatures. Thealloying of titanium with molybdenum and nickel has the following effects on the passivitybehaviour of ternary Ti-0.5Mo-1Ni alloy: the shifting in noble direction of the alloy corrosionpotential due to the couple galvanic effect of the molybdenum and nickel; the enlargement of thealloy passive potential range, as result of the molybdenum and nickel participation with itsinsoluble compounds at the consolidation of the alloy passive film; the decrease of the alloypassive current densities because of the same consolidation effect of the passive layer; both thetitanium and Ti-0.5Mo-1Ni alloy do not present pitting corrosion; the decrease of the alloycorrosion rates in concentrated chloride solutions, in comparison with base metal.