The influence of porosity and morphology of hydrated oxide films on epoxy-aluminium bond durability

Abstract

Clad aluminium alloy was pretreated by immersion in boiling water for times ranging between 30 s and 4 h. The chemical and physical properties of the lms produced in the 100 ± C water were characterized by techniques including X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), scanning electron microscopy (SEM), and secondary ion mass spectrometry (SIMS). The durability of the bonds formed between the boiling water lms and a rubber-toughened epoxy adhesive was assessed in terms of the lm properties and fracture analysis of failed wedge specimens. In the early pretreatment stage, bond durability was limited by the fracture of the porous oxide lm at the lm -metal interface. For immersion times greater than 4 min, a decrease in lm porosity and bond durability was observed.

Fabrication of superhydrophobic nanostructured surface on aluminum alloy

“…At 2-minute immersion time, only the weak peak at 3420 cm -1 was seen. As the immersion time increased, the 3420 cm -1 peak shifted to 3300 cm -1 and the shoulder moved into a peak at 3100 cm -1 [21]. ( Fig.…”

Accelerated growth of oxide film on aluminium alloys under steam: Part I: Effects of alloy chemistry and steam vapour pressure on microstructure

“…The vapour pressure of the steam is high at high temperature, which resulted in the higher thickness of the oxide. The initial growth of the oxide was higher due to the diffusion and dissolution mechanism explained by many researchers in literature [27,34,35]. However with the increase in thickness of the oxide layer, rate control shifts to the diffusion of H + through the steam generated oxide film which results in the higher oxide thickness for short time treatment as compared to 10 min.…”

“…Alwitt [10] reported that in the range of 100-374°C the only oxide phase existing is boehmite under hydrothermal or steam conditions, which is in agreement with the present findings. The mechanism of oxide film growth from aluminium and water reaction has been extensively studied [25][26][27]. The reaction between aluminium and water/water vapour results in the formation of amorphous hydrous oxide film [10].…”

Accelerated growth of oxide film on aluminium alloys under steam: Part II: Effects of alloy chemistry and steam vapour pressure on corrosion and adhesion performance

“…The presence of hydroxyl group is an important aspect due to the possibility of forming bonds by donating negatively charged oxygen [24]. Rider [25] reported that adhesion and durability of applied epoxy coating was affected by boiling water treatment of aluminium. Strålin and Hjertberg [26] found that the adhesion of ethylene vinyl acetate polymer with a pseudo-boehmite aluminium oxyhydroxide layer is stronger than with a dehydroxylated aluminium oxide.…”