Detection of paint defects by microscopy 

What was the challenge or problem to solve?

The objective of the study was the microscopic inspection of the paint applied on the same steel substrate, to determine why a certain aesthetic defect (veil effect) appears in defective samples, and thus comply with ISO 12944.

Detection of paint defects by microscopy 
Detection of paint defects by microscopy 

How was it addressed or what was the solution?

The Forensic Engineering team was tasked with solving this problem.

To know the cause of failure, correct and defective samples were analyzed using electron microscopy techniques (SEM and EDX) with a Phenom ProX de Thermofischer Scientific.

Thanks to this, it was discovered that the veil that forms on the surface is derived from a higher concentration of metallic particles, which are not distributed homogeneously on the surface, and create that visual effect of different reflection of the incident light.

Challenge

  • Need to know the cause that generates the appearance of the veil in the painting
  • Proposed solutions to prevent the failure from reoccurring

Solution

  • Microscopic inspection of paint distribution
  • Characterization of its elemental composition