Surfaces, interphases and adhesion properties of composites

A project financed by the Danish Agency for Science and Innovation.

Composite materials find increasing usage as construction materials, as the great advantage of composites is, that they can be practically tailor-made for the intended use. Thus, there is a huge potential in that matrices and reinforcement materials can be combined in countless ways. At the same time, the demand for these customized materials is rising as many of the conventional materials are no longer able to live up to increasing demands from offshore, wind, yachting and food industries.

Composite materials are well suited for combining either with themselves or with other materials such as steel and aluminium. The obvious method of joining these materials is with adhesives.

Adhesives can themselves be considered as a kind of composite material and development in adhesives is also driven by the fact that the limit for material performance is constantly pushed forward.

Gluing involves several clear advantages over conventional mechanical joining. Among these is that the stress is distributed over a larger area. This gives improved fatigue properties and absorbs shock, while it minimizes or prevents galvanic corrosion.

A successful use of adhesives depends on many factors, where selection of the adhesive and suitable process conditions are important factors. Moreover, the nature of the surface needs to be taken into account to ensure a reasonable life-time for the adhesive joint. In addition to this, data collected from usage parameters should be subjected to statistical modelling in order to predict the mechanical and chemical stability of the joint.

A major limiting factor for the usage of the full potential of the new composite materials is, however, the limited information about them and about their mechanical and chemical properties, particularly when they are used in new combinations. Many companies are so limited by their “time-to-market” factor, that they have no resources available to consider alternate materials to those, they are already using. This is intensified by the fact that the accessible data about these materials is limited and sparse.

It can be seen from the above, that a significant technological leap can be facilitated by making more of this information available, when a company initiates a development project, so that time and costs for information gathering and testing can be saved. The information in question is especially awareness of new matrix materials, new reinforcement materials and new combinations of these, as well as information about adhesives for bonding of composites.

A report describing the project and an additional report have been prepared.

DMN members can read publications about the project in Danish here >

For further information, please contact:

• Dorte Walzl Bælum
• Network Director
• B.Sc. Chem. Eng., M.Sc. in Business
• M: 60 35 19 90
• E: dwb@dmn-net.com