The ability of Mg2Ge crystals to behave as ‘smart release’ inhibitors of the aqueous corrosion of Zn-Al-Mg alloys

In-situ scanning vibrating electrode technique and time-lapse microscopy are used to investigate the influence of germanium additions (0.19–1.8 wt.%) on corrosion performance zinc-aluminium-magnesium model alloys immersed in 0.17 mol.dm?3 NaCl. The addition Ge results formation Mg2Ge a decrease fractional area eutectic phase. A 58 % SVET derived mass loss is achieved at 1.8 wt.% Ge. It proposed that crystals anodically attacked behave as reservoirs Mg2+ ions. Mg(OH)2 precipitated local electrolyte pH stabilises values which zinc surface passive.