Stress-dependent ultrasonic scattering in polycrystalline materials

Area of Science:

• Materials Science
• Acoustics
• Solid Mechanics

Background:

• Polycrystalline materials exhibit stress-dependent elastic moduli.
• Ultrasonic wave scattering is influenced by material microstructure and stress.
• Understanding acoustoelasticity is crucial for non-destructive stress evaluation.

Purpose of the Study:

• To develop a statistically based model for ultrasonic wave scattering in stressed polycrystals.
• To incorporate stress-dependent elastic moduli into scattering cross-section definitions.
• To analyze the influence of stress on ultrasonic scattering coefficients.

Main Methods:

• A statistically based model was developed using stress-dependent elastic moduli.
• Nine stress-dependent differential scattering cross-sections were defined for longitudinal and transverse waves.
• Scattering coefficients were evaluated for uniaxially stressed polycrystalline aluminum.

Main Results:

• Ultrasonic scattering in aluminum showed higher sensitivity to uniaxial stress compared to phase velocity.
• The study analyzed the impact of wave direction, frequency, and grain size on scattering coefficients.
• Stress-dependent scattering properties were successfully modeled.

Conclusions:

• The developed model enhances understanding of acoustoelasticity's influence on wave propagation in stressed materials.
• This research supports the advancement of techniques for monitoring and measuring stress in metallic components.
• Ultrasonic scattering offers a promising avenue for stress characterization in polycrystals.