2D ultrasonic array system for the in-situ inspection of single crystal turbine blades

Christopher Lane
Rolls-Royce,
Bristol University

image3Two-dimensional (2D) ultrasonic arrays for non-destructive evaluation enable the detection and characterisation of sub-surface defects in three-dimensions (3D).

One potential industrial application for this technology is the in-situ inspection of jet-engine turbine blades for root cracking. However modern jet-engine turbine blades are cast from single crystals of nickel-based superalloys because of their excellent mechanical properties at high temperature. Single-crystal materials are elastically anisotropic, which causes ultrasonic waves to propagate with different velocities depending on the direction of the wave and which significantly reduces the quality of the inspection.

This project involved the use of wave propagation modelling to correct ultrasonic imaging algorithms and enable the reliable volumetric inspection of single-crystal aerospace components. It also found ways to overcome physical access constraints for in-situ inspection and evaluated defect detection sensitivity and sizing capability.

 

Orientation of the crystal in a turbine blade

Orientation of the crystal in a turbine blade

Drawing of engine probe on the turbine blade

Drawing of engine probe on the turbine blade

 

Typical data display

Typical data display