CONCLUSIONS
The results from various materials suggested:
- a power law relationship between CBA and tensile strength values, CBA = A smaxn where A is equal to 5.86 and n (-1.18). This relationship can be fitted accurately (R2=0.95).
- a power law relationship between CBA and the Young modulus, CBA = B En where B is equal to 35.66 and n (-0.87). The fitting is less accurate than the previous, with a coefficient of determination R2 of 0.83.
- an increase of CBA with thickness: the stress is spread over the total thickness of the coating, which allows the coating closest to the surface to be subjected to considerably less stress
- an increase of CBA with higher values of ?r.
In general, the coatings that have a better chance of bridging cracks have an appreciable thickness as well as some extensibility and rather low stiffness.