Surface Pitting Analysis


The PolyU Aviation Services Research Centre (ASRC) has developed a system that can automatically detect and analyse pitting corrosion on jet engine blades and vanes without damaging them. Accurately measuring the depth of pitting is crucial as it determines whether components need servicing or replacing. The system is more accurate than human visual inspection and speeds up the inspection process.

  • Surface Pitting Analysis
Commercialisation opportunities
IP licensing
Problem addressed

Pitting corrosion can be found on the airfoils of aircraft engine blades and vanes when they have been in service for a long time. Before this research, the only way to assess the extent of pitting was through visual inspection by the operator. This project has identified for the first time which non-destructive testing technologies are best suited to this task.

  • World’s first non-contact equipment designed specifically to automatically measure corrosion pitting.
  • Relies on an Alicona 3D sensor R25 and a 9M pixel camera coupled with a blue LED dome light and polarised light bars, enabling detection of pitting ranging in size from 20 to 200 microns. Much faster than traditional visual inspection.
  • Images have undergone deep learning based on ViDi Suite to differentiate between pitting and artefacts. System is trained on a representative set of sample images and can automatically learn contextual information such as texture and shape.
Key impact
  • Can automatically detect and assess pitting ranging in size from 20 to 200 microns.
  • Relies on a clear threshold of GOOD/BAD, which is not subject to the operator’s interpretation.
  • Process data is recorded for reporting, archiving, and further analysis if necessary.
  • Cheaper, faster, and more reliable than the existing manual process.
  • Gold Medal at the 2018 Geneva International Exhibition of Inventions
  • Detection of pitting on aircraft engine blades and vanes
  • Detection of corrosion on metallic parts
The Hong Kong Polytechnic University (PolyU)

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