Forensic Engineering
We investigate the causes of failures in an industrial process or commercial product and propose customized solutions to resolve them.
Problem
Our client has a paint adhesion problem on metal pieces. They are receiving customer complaints that the paint is peeling off, exposing the base metal, which leads to an aesthetic failure.
Objective
Find the cause of poor paint adhesion and correlate this failure with possible subsequent manipulations both by the factory and by the customer.
ATRIA Solution
Different tests were carried out to characterize the surface of the samples, both reference pieces, without failure, and pieces with peeling paint.
The first test that was carried out was the FIBSEM. The objective was to see if there were flaws in the lower layers of the paint, but only superficial flaws were observed. Through this test, it was concluded that the failure did not come from internal defects, it was merely superficial.
An XPS analysis was also performed to see compositional differences in the most superficial layer. In the surface analysis, no difference in chemical elements was found. In the samples in which the base metal was visible, due to the poor adhesion of the paint, metallic elements typical of the composition of the base metal were observed.By means of the GC-MS assay, the elements or chemical compounds that are present in said sample are analyzed with a solvent scan. Different compounds were observed depending on the type of sample (with defect and without defect). Of these elements, two corresponded to compounds present in adhesives or paints.
As a final conclusion, it was established that the failure of adhesion could come from chemicals such as isopropanol, alcohol, hydroalcoholic gel that affects the paint and produces its cracking.
