Community Research and Development Information Service - CORDIS


Composites involving steel and organic materials, used for example in sandwich panels on motor vehicles, require non-destructive testing to ensure than the product is homogeneous and to guarantee adhesion properties. This project aimed to compare mechanical and non-mechanical methods of measuring the adhesiveness of polymers to their steel substrate. The first part of this report covers the development of non-destructive methods for detecting bonding defects, using four different techniques: conventional ultrasonics, acoustic microscopy, infra-red thermography and neutron radiography. The second part concerns the mechanical tests used, and their usefulness in measuring adhesion, and the last part compares the results of the two kinds of tests. The most effective non-destructive techniques of defect detection proved to be ultrasonics and neutron radiography, though the latter is not practicable for industrial use. It was seen that present ways of interpreting mechanical adhesion tests were inadequate, because they did not take into account the stiffness of the steel substrates in the bonded assemblies. Conclusions of the comparison were that none of the non-destructive techniques used is capable of evaluating the state of adhesion between the two steel faces, and therefore they could not be related to the peel and tensile/shear tests. In certain cases, the non-destructive tests detected defects which did not modify at all the results of the mechanical tests.

Additional information

Authors: IRSID (FR),
Bibliographic Reference: EUR 18437 FR (1998)
Availability: Available from OOPEC Sales agents
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top