Non-destructive characterization of mechanical properties using magnetostrictive magnetoacoustic conversion: Theory...

Mechanical properties are critical parameters of ferromagnetic materials and directly affect their structural reliability and functional stability. Ultrasonic characterization techniques based on the magnetostrictive effect have the advantages of non-contact and high sensitivity. However, the relationship between magnetoacoustic conversion efficiency (MCE) and mechanical properties lacks sufficient theoretical support and the intrinsic mechanism remains unclear. To provide theoretical support for this, a theoretical model of magnetostrictive magnetoacoustic conversion with different mechanical parameters was constructed in this study and the key factors affecting MCE were analyzed in detail for the first time. On this basis, a non-destructive characterization method of evaluating multiple mechanical parameters was developed. Finally, experimental validation was conducted with heat-treated 3Cr13 steel samples. Both theoretical and experimental results showed a significant linear correlation between the mechanical parameters and SH wave MCE curves measured with magnetostrictive transducers. The observed experimental phenomena were consistent with the predicted patterns from the model. This study enriched the magnetoacoustic conversion theory of magnetostrictive ultrasonic transducers and provided new insights into the non-contact and non-destructive characterization of mechanical properties.