Adhesion is a very important surface property, for it affects nearly all applications. Poor adhesion between the metal surface and a passivation film, a paint film, a bonding adhesive or other, can lead to unacceptable product performance in the form of corrosion, loss of appearance and/or structural failure.

Some methods to improve adhesion on aluminium will be discussed in this section.

Also an assembly method using the adhesion property, i.e. adhesive bonding, will be introduced.

Learning Outcomes for this Section

After completing this section, you should be able to:

• list the important metal properties for adhesion
• state the difference between chemical and mechanical adhesion
• list various surface passivation methods to improve adhesion
• explain the link between anodising and adhesion
• explain the phosphating process and its influence on adhesion
• explain silane passivation and its influence on adhesion
• explain the role of surface cleaning/etching on adhesion of organic passivation systems
• explain and give examples of assemblage via adhesive bonding