Bonding of Aluminum Structures with Advanced 1K and 2K Adhesives

As automakers continue their drive to reduce weight in vehicle structures, aluminum has received increased attention as a material of choice. Achieving the weight reduction that aluminum can provide without any loss in structural integrity has posed a distinct challenge. Structural adhesives are now playing an important role in reinforcing aluminum structures, and automakers are finding that adhesive-bonded aluminum structures meet or even exceed the torsional stiffness of welded steel.

This paper describes two structural adhesives which address the particular needs of two distinct aluminum bonding applications. The first adhesive, 3M 5041, is a two-part (2K) induction-curable and room-temperature-curing epoxy adhesive designed for high-volume-production hem flange bonding operations on unprepared oily aluminum. The second adhesive, 3M 5042, is a heat curing one-part (1K) weld-bond epoxy adhesive developed for body structure bonding applications. It will be shown how these new 3M adhesives offer the combination of process friendliness and performance needed to exploit the unique properties of aluminum.