Adhesive Bonding of an Aluminum Alloy with and without an Oxide Layer in Atmospheres with Different Oxygen Contents

Abstract

Aluminum surfaces in a normal atmosphere are always coated with a native oxide layer. To prevent a new layer from forming after this oxide layer has been removed, an environment without oxygen must be created. This work uses a new method of doping an inert gas atmosphere with highly reactive silane to ensure technical freedom from oxygen. The influence of the surrounding atmosphere and the influence of the oxide layer on the tensile strength of an aluminum-aluminum joint are investigated. For this purpose, 2-component adhesives are used whose curing mechanisms are fundamentally not based on the reaction with the surrounding atmosphere. The tests are carried out in normal, pure argon, and an oxygen-free argon/silane atmosphere. The experiments show that the surrounding atmosphere influences the strength of the bonded joint. Compared to the oxidized surfaces, the joints of the deoxidized surfaces show a higher tensile strength under constant ambient conditions.