Controlled "golf ball shape" structuring of Mg surface under acoustic cavitation

Area of Science:

• Materials Science
• Surface Engineering
• Ultrasound Technology

Background:

• Traditional methods for microstructuring metallic materials often require harsh conditions.
• Developing mild and controlled surface modification techniques is crucial for advanced material applications.

Purpose of the Study:

• To describe the original structuring of magnesium (Mg) materials under ultrasound irradiation in mild conditions.
• To investigate the formation mechanism of golf ball-like structures on Mg surfaces.
• To explore the potential of ultrasound for nano- and micro-structuring metallic materials.

Main Methods:

• Iterative 3D reconstruction of sonicated surfaces.
• Scanning Electron Microscopy (SEM) for microstructure analysis.
• Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) for mass loss determination.
• Contact-angle measurements for surface wettability.
• 3D image analyses for roughness characterization.

Main Results:

• Golf ball-like extended structures were prepared in dilute oxalic solutions at 20°C using 200kHz ultrasound.
• Ultrasound frequency was found to be dependent on the surface effects generated.
• A controlled and localized dissolution of Mg resulted in a strongly wetting surface with 170nm roughness.
• Newly formed secondary phases were observed with surface dissolution progress.

Conclusions:

• The ultrasonic procedure offers an unprecedented method for manufacturing engineered Mg surfaces.
• This approach opens new alternatives for nano- and micro-structuring metallic materials.
• The engineered surfaces may exhibit advanced physical and chemical properties of interest for various applications.