A microstructural investigation of low-temperature crystalline alumina films grown on aluminum

Determination of isoelectric points of metals and metallic alloys by adhesion of latex particles

“…The aluminum and dural samples treated by boiling water exhibited an IEP close to 9. The chemical treatment was intended to form a pseudoboehmite film shaped as petals of about 150 nm [22], and the value obtained is in agreement with the IEP of aluminum hydroxides particles [4]. However, other experimental protocols led to lower IEP values (between 4.5 and 5.5) as found on different faces of a sapphire single crystal [33].…”

“…A chemical treatment, intended to control the nature and the thickness of the oxide layer on the surface, was performed on several samples for two reasons: (1) the surface of aluminum or stainless steel in industrial applications is often treated to increase its efficiency against corrosion, and (2) the chemical treatment and the nature of the oxide layer may have an effect on IEP. The aluminum samples were immersed in boiling high purity water for 30 min in order to allow the growth of a pseudo-boehmite film [22]. The passivation of a stainless steel sample was performed with nitric acid (6 mol L À1 ) at 60°C for 1 h [23].…”

Plasma electrolytic ceramic-like aluminum oxide coatings on iron

“…As is seen from the FTIR spectra (Fig. 8), with an increase in anodizing time and, correspondingly, the formation of thicker coatings, one can observe an essential decrease in the absorbance at 1,057-1,065 cm -1 characteristic for the d AlOH vibrations Al-OH in boehmite c-AlOOH [34], as well as the bands at 690 and 770 cm -1 characteristic of both thin and thick coatings are probably attributed to the OH-translation vibrations in boehmite [34]. The band at 970-980 cm -1 could be assigned to Al-OH deformation in dawsonite-like component of the coating [35].…”

Aluminum oxide thin dielectric film formation under elevated gravity conditions

“…For aluminum electrolytic capacitors, the high surface area is obtained by electrochemical etching and subsequent tunnel-widening. The dielectric film is grown directly on this surface by a boiling water treatment [2] followed by anodization (formation) [3]. The oxide thickness obtained in formation is proportional to the voltage used to form the oxide during anodizing.…”

“…In our previous work, we have examined in detail the structure of crystalline [AlO(OH)] films with various degrees 0040 of crystallinity prepared by reaction of a high-purity, high cubicity Al substrate with deionized water (DI-water) [2] and mixtures of alcohol-DI-water [10]. Temperature and reaction time were the main factors investigated in the growth of these films.…”