• Bonding of surfaces in vehicle construction

    Bonding of surfaces in vehicle construction

Optimizing the pretreatment of metal surfaces for bonding in vehicle construction

Light metal, but difficult to bond

Adhesives have poor bonding properties on aluminum. Aluminum alloys are therefore pretreated in conversion baths in order to prepare them for bonding. Such pretreatment methods are increasing in importance, particularly in vehicle construction.

A current method is immersion bath treatment with the active substances hexafluoro titanic or hexafluoro zirconic acid. The process parameters exposure time, temperature, and concentration have a great influence on the surface free energy and its polar and disperse parts – quantities that are closely linked to the wetting and adhesion behavior of the surface and which therefore greatly influence the adhesive strength and the ageing behavior of the bonded joint.

The Austrian Research Institute ofi has carried out a publicly funded study on the pretreatment of aluminum alloys in which KRÜSS participated. In addition to measurements of the adhesive strength and ageing behavior, contact angle measurements were made in order to investigate the effect of the bath parameters exposure time and temperature on the surface free energy and its polar and disperse parts.

Find out more and download the full application report here: application report AR264.