Modeling and Experimental Characterization of Bonding Delaminations in Single-Element Ultrasonic Transducer

Area of Science:

• Materials Science
• Acoustics
• Non-destructive Testing

Background:

• Ultrasonic transducer performance relies on intact adhesion between components like the active element, backing, and matching layer.
• Loss of adhesion, or delamination, can severely impair transducer functionality.
• Understanding delamination effects is crucial for maintaining transducer reliability.

Purpose of the Study:

• To numerically and experimentally investigate the impact of bonding delaminations on single-element ultrasonic transducer performance.
• To analyze two delamination locations (ceramic-backing and ceramic-matching layer) and three shapes (circular, annular, sector).
• To establish electromechanical admittance (EMA) changes as an indicator for delamination detection.

Main Methods:

• Finite element method (FEM) simulations to model delamination effects on transducer EMA.
• Experimental assembly of single-element transducers with 3D printed components and PZT samples.
• Fabrication of transducers with specific delamination types (DT-I, DT-II, DT-III).
• Electromechanical admittance (EMA) measurements using an impedance analyzer.

Main Results:

• Numerical simulations and experimental results demonstrated a strong correlation between delaminations and EMA variations.
• Different delamination types and locations produced distinct changes in the EMA spectra.
• The study confirmed that EMA is a sensitive parameter for detecting and assessing delamination severity.

Conclusions:

• Bonding delaminations significantly alter the electromechanical admittance (EMA) of ultrasonic transducers.
• EMA analysis provides a reliable method for identifying the occurrence and severity of delaminations.
• This research offers valuable insights for the quality control and maintenance of ultrasonic transducer systems.