The influence of manganese on the AC electrolytic graining of aluminium

Importance of Etch Film Formation During AC Controlled Pitting of Aluminium

“…The mechanism proposed for the initiation at intermetallic particles was that intermetallics do not form a protective oxide layer, therefore even if they are electrochemically less negative than the aluminium they dissolve faster revealing the underlying aluminium surface, which can then act as initiation point. Laevers, (1996) presented the influence of manganese on the electrograining of aluminum. A more uniform final pitting morphology was observed when the amount of manganese present in solid solution was decreased, but this could only be noticed in the more advanced stages of the graining process.…”

“…It is known that during electrograining an etch film is formed masking the aluminium surface, mainly composed of hydrated aluminium ( Figure 6) [Thompson & Wood, 1978, Dowell 1986, Terryn, 1987, Marshall, 1995Laevers, 1996, Amor & Ball, 1998]. The film formation mechanism, morphology and weight differ upon different graining conditions therefore a thorough investigation of several parameters is necessary.…”

“…For 1 wt% of manganese alloyed aluminum plate with most of the manganese (0.9 wt%) present in solid solution, a lateral and unidirectional growth of hemispherical pits occurs, creating worm-like pits [Laevers et al, 1996]. It was assumed that the worm-like pits observed are also influenced by other alloying elements present in solid solution, such as iron, silicon and titanium for AA1050 aluminum [Laevers et al, 1996].…”

“…It was assumed that the worm-like pits observed are also influenced by other alloying elements present in solid solution, such as iron, silicon and titanium for AA1050 aluminum [Laevers et al, 1996].…”

Electrograining of aluminium in HCl: effect of the alloy for high‐speed processing lines

“…On the other hand, the analysis of a high-strength alloy containing Mg (commercial alloy 1020) has also been evaluated with regard to EG speed, surface topography and mechanical properties. In this case Mg is selected because, contrary to other strengthening elements such as Mn, it provides a better topography of round and low-size pits and avoids the apparition of residual flaws, [12] especially in HCl. [10,13]…”