Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part I: Design Technique, Modeling and Simulation

Reductions in the beam diameter and pulse duration of focused ultrasound for titanium inspections are believed to result in a signal‐to‐noise ratio improvement for embedded defect detection. It has been inferred from this result that detection limits could be extended to smaller defects through a larger diameter, higher frequency transducer resulting in a reduced beamwidth and pulse duration. Using Continuum Probe Designer™ (Pat. Pending), a transducer array was developed for full coverage inspection of 8 inch titanium billets. The main challenge in realizing a large aperture phased array transducer for billet inspection is ensuring that the number of elements remains within the budget allotted by the driving electronics. The optimization technique implemented by Continuum Probe Designer™ yields an array with twice the aperture but the same number of elements as existing phased arrays for the same application. The unequal area element design was successfully manufactured and validated both numerically and...