Abstract
Aluminum specimens were treated chemically for 20min with (1) pure water, (2) sodium aluminate solution, and (3) sodium aluminate solution bubbled with CO2 during the treatment. Each specimen was then examined by infrared reflectance spectra (IRRS), scanning electron microscopy (SEM) and X-ray diffraction. The films formed in the solutions (1), (2) and (3) at 95°C as well as in the solution (2) at 50°C were proved to be boehmite, whereas no boehmite was detectable in the case of the treatment in the solution (1) and (3) at 50°C.
