Time-evolving statistics of cavitation damage on metallic surfaces

Area of Science:

• Materials Science
• Surface Engineering
• Acoustics

Background:

• Acoustic cavitation is a phenomenon involving the formation and collapse of bubbles in a liquid.
• Cavitation can induce significant surface damage on materials due to high-energy impacts.
• Understanding cavitation damage mechanisms is crucial for material durability and performance.

Purpose of the Study:

• To experimentally investigate the statistical characteristics of surface damage induced by acoustic cavitation on polycrystalline aluminium.
• To analyze the evolution of damage morphology and size distribution over time.
• To compare the damage patterns on aluminium with those on a martensitic Cu-Ni-Al crystal.

Main Methods:

• Experimental study of acoustic cavitation effects on material surfaces.
• Surface analysis techniques to characterize crater dimensions (depth, area, eccentricity).
• Statistical analysis of damage distributions, including time-dependent evolution.

Main Results:

• Cavitation on polycrystalline aluminium produces uniformly distributed, crater-like surface defects.
• The size distribution of these craters transitions from a gamma function to a power law over time.
• Martensitic Cu-Ni-Al crystals subjected to cavitation display ramified, fractal-like damage patterns.

Conclusions:

• The statistical nature of cavitation damage differs significantly between polycrystalline metals and crystalline alloys.
• Time-dependent evolution of damage statistics provides insights into the cavitation erosion process.
• Fractal-like patterns on Cu-Ni-Al suggest unique material responses to cavitation stress.