Cr(VI)-free pre-treatments for adhesive bonding of aerospace aluminium alloys

For more than six decades, chromic acid anodizing (CAA) has been the central process in the surface pre-treatment of aluminium for adhesively bonded aircraft structures in Europe. Unfortunately, this electrolyte contains hexavalent chromium (Cr(VI)), a compound known for its toxicity and carcinogenic properties. The approaching ban on the use of...

Influence of environmental ageing and displacement rate on crack resistance of adhesives, as determined on adhesive bonded TDCB-specimens

Fracture toughness measurements were carried out to test the ageing behaviour of three adhesives in different environments. It was possible to compare and evaluate adhesives and surface pretreatments. It is doubtful whether the derived R-curves could be used for residual strength calculations in certain environments. Phosphoric acid anodizing...