Experimental Setup for Nonlinear Ultrasonic Measurements in Metallic Materials (Bespoke High-Power RF System)

The experiments aim to quantify early-stage micro-meso scale damage by measuring the nonlinear elastic response of the material.</p><p dir="ltr"><b>Experimental Configuration & Methodology:</b><br>The setup consists of a high-power RF excitation and data acquisition system integrated with a precision mechanical alignment stage.</p><p dir="ltr"><br></p><ul><li><b>Excitation & Amplification:</b> A RITEC GA-2500A Gated RF Amplifier is used to generate high-power, gated RF burst signals.

This allows for the excitation of finite-amplitude ultrasonic waves necessary to trigger nonlinear effects (e.g., second harmonic generation) in the metallic specimens.</li><li><b>Transducers:</b> Broadband piezoelectric transducers (Olympus V-109, 5 MHz, 0.25 inch; V-110, 5 MHz, 0.5 inch) are employed for transmitting and receiving ultrasonic waves. The 5 MHz frequency is selected for optimal penetration and sensitivity to microstructural damage in metals.</li><li><b>Mechanical Alignment:</b> A custom-built precision alignment stage, featuring manual X-Y-Z micrometer translation and a gimbal mount, ensures sub-millimeter accuracy in transducer positioning and acoustic coupling.</li><li><b>Data Acquisition:</b> Ultrasonic waveforms are recorded using Tektronix MDO3024 and TDS 3014B oscilloscopes.