The long-term corrosion of aluminium in alkaline media

The aluminum chemistry and corrosion in alkaline solutions

“…For immersion times beyond 40 days, in solution of pH 10 and 11, the weight losses were similar to these measured at 40 days, indicating that there is no significant weight loss during the last 20 days. Generally similar trends were evident for immersion at 60 o C [62], with initial high rates of weight loss which decreased with immersion time, particularly beyond 20 days. The weight losses are converted into corrosion rates which were shown in Fig.…”

“…It has been experimentally found that the corrosion rate depends logarithmically on the pH [62], different dependencies being noted on either side of the pH at which the corrosion rate is at its minimum (close to pH 6). These results were reported by Chatalov [67] and Pourbaix et al [68].…”

“…And it is also considered by several other authors such as Refs. [57,[60][61][62][63][64]. The potential changes at aluminum surface in alkaline solution as a function of time are shown in Fig.…”

“…On the other hand, Vujicic and Loverecek reported corrosion rates about 50% higher than those of Chatalov's. Long-term corrosion test results of aluminum in sodium hydroxide solution over the pH range of 8-13 were carried out by McKee and Brown [70] up to one week and over the pH range of 7-12 were carried out by Tabrizi et al [62] up to 80 days. A summary of corrosion rate data of aluminum in alkaline solution are given in Table 3.…”

Adhesive strength of powder coated aluminium substrates

“…4 and 5). The degreased specimens revealed a hydrated oxide layer, of crystalline appearance, suggesting generation of bayerite [23]. EDX analysis, showed the presence of oxygen and aluminium, as expected, and a low yield of carbon.…”