Doctor in Materials Chemistry, Sophie Senani is a research engineer in surface treatment at the Airbus Research Center.
“Over the past five years, the collaboration with Olikrom has been the souce of two important innvations in the field of external stimuli-sensitive coatings: pressure or temperature.”
The genesis of the R&D project initially concerned the detection of impacts on composites materials.
The risk of impact during transportation of the different parts of an Airbus from all over Europe to the final assembly line, or even during assembly, cannot be ruled out. Non-destructive testing by ultrasound guarantees the detection of any damage needing repair, but this phase is very long, as it takes approximately two hours per square meter.
The developed paint allows any impact over a defined threshold to be detected by the naked eye. The colour of the paint changes according to a change in pressure following an impact.
“The idea is to facilitate the detection of areas of impact during assembly. In time, inspection using ultrasound will be limited to key area liable to present damage, compared with the whole structure today. This will lead to major savings in production time.”
Alongside this initial project, a heat-sensitive coating for detecting even very localised overheating on parts located near hot areas, such as engine covers, has also been developed.
Again, the aim is to improve safety and quickly identify minor incidents such as hot air leakage in order to plan maintenance work in case of potential risk damage.
“Heat sensitive technology already exists, but the chemistry developed by OliKrom provides a higher level of accuracy in terms of temperature transition thresholds, as well as more lasting performance, which is vital in aeronautics.”
The design of the new paint aims to behave differently according to two temperature thresholds. The initial colour must change at 120°C and again at 140°C.
These two thresholds, while respecting the composite damage safety margins, constitute the first levels of warning for a part located near the engines.
“If we can identify areas of overheating, even small, we can facilitate preventive maintenance and further increase reliability.”
For both innovations, the proof of concept is validated on real parts. Work is currently being conducted into adapting pressure and/or temperature thresholds according to the particular specifications of the parts in question, with the aim of going on to adress the industrialisation phase.