Corrosion behaviour of zinc–cerium alloys: Role of intermetallic phases

New zinc–cerium alloys (up to 5 wt.%) was synthesized and their corrosion behaviour was studied in a reference corrosive media. Metallographic analyses show that cerium is exclusively present in a Zn11Ce intermetallic phase, homogeneously dispersed in the zinc matrix. With an optimal concentration at around 1.5 wt.%, the Zn11Ce phase acts as a tank of cerium to form a protective Ce-enriched passive layer. Nevertheless, at high Ce content, the benefit in terms of corrosion resistance obtained by the incorporation of Ce in the corrosion layer is shaded by the galvanic coupling between the intermetallic phase and the matrix.