Blisk inspection

Measuring Systems: Combination of  MicroCam-3D, MicroCam-4D and/or BoreInspect
Keywords: aeronautics, aviation, bladed disks, IBRs, integrally bladed rotors, cooling holes

In aviation mechanics, a blisk (also known as an integrally bladed rotor, IBR) is an engine compressor component comprised of a rotor disc and blades. A blisk can be machined from a solid piece of material or made by welding individual blades to the rotor disk. The blades are pre-drilled with minute cooling holes.  At inspection time, these cooling holes present a sudden and sharp edge in the scanned surface and are problematic for many 3D measurement technologies. But not for all.

The non-contact probes of these fiber-based low-coherence profilometers easily reach between blisk blades to acquire high-precision 3D measurements as follows:

  • The fiber-based 3 mm side-viewing optical probe is mounted onto a robotic arm to automate the blisk blade inspection process (below left)
  • The probe scans in a collinear fashion – the laser beam is emitted and received along an identical axis – and therefore does not require an angle to measure sharp edges. The size and incident angle of the miniscule cooling holes can thus be determined
  • The acquired blade surface data may be imported into CAD software for defect detection (below center and below right)

Fiber-based 3mm side-viewing probe on a robotic arm inspects blisk surfaces.

Blisk surfaces inspected by a fiber-based 3mm side-looking probe on a robotic arm

Scanned 3D part to CAD Analysis

Acquired 3D part to CAD analysis

Defect Identification and Classification

Defect identification and classification

Novacam’s Microcam systems can be adapted to all your blisk inspection needs, providing capabilities from simple GD&T verification to 100% detect detection. In addition to the side-looking probes described above, also available for blisk measurements are

  • Rotational scanners that quickly acquire the entire inner surfaces of the blisks (see BoreInspect system), and
  • Galvo (raster) scanners that acquire open surfaces in the most efficient manner.

All Novacam probes and scanners are easily deployed as robot end-effectors.  Multiple probes and scanners may be connected to the same profilometer, bringing additional ROI to our aerospace clients.

Advantage of scanning with fiber-based probes

Novacam 3D profilometers scan with fiber-based non-contact probes. The probes

  • deploy at a distance from the detector, without signal degradation
  • are rugged enough to withstand hostile environments
  • allow for flexible in-process set-up
  • come in a range of sizes and designs to suit each particular application