Contact-free Inspection of Adhesive Bonds
What makes automated bond inspection challenging
Today, adhesive bond inspection is still dominated by conventional ultrasonic testing (UT), which struggles with the thin composite skins or metal sheets commonly encountered in bonded (“glued”) structures. Conventional UT also relies on liquid coupling and contact, making it difficult to automate and challenging to apply on complex 3D geometries.
Tap testing is also widely used, but it is highly subjective, cannot be automated, and does not allow for recorded test results. Other methods have their own limitations: thermography is restricted in terms of material types and thicknesses, while radiographic testing is fundamentally limited in detecting thin air gaps, i.e., disbonds in adhesive joints. What is therefore needed is an ultrasonic method capable of fully automated inspection while handling thin skins and complex geometries.
XARION's solution for automated ultrasonic inspection of adhesive joints
XARION offers a laser-based ultrasonic solution for the non-destructive testing (NDT) of adhesive bonds, designed for seamless integration into automated industrial inspection systems like robots, cobots and gantry scanners.
A pulsed laser generates ultrasonic waves directly within the component, while our proprietary Optical Microphone characterizes them. Through the analysis of signal amplitude, frequency and phase, the integrity of the adhesive bond can be ensured in through-transmission or a single-sided configuration. This enables flexible inspection concepts for multi-material components of complex shape.
Flaws that can be assessed range from delaminations and disbonds to porosity, voids, as well as foreign objects and contamination.
Where is XARION's automated bond quality inspection used?
- Composite skin-to-core bonding
- Bonded stringers on aircraft fuselages (see Figure)
- Metal-to-metal sheet joints in automotive structures
- Battery modules with thermal adhesive
- Thin composite and hybrid structures
Benefits of laser-based adhesive bond inspection
- Fully automated and robot-compatible
- Contact-free, no coupling media required
- Single-sided and through-transmission flexibility
- Reduced inspection time and cost