Morphogenic Modeling of Corrosion Reveals Complex Effects of Intermetallic Particles

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Corrosion is often modeled as a stochastic process.
• Nanoscopic fluctuations are typically considered the primary drivers of corrosion.
• Understanding the underlying mechanisms of corrosion is crucial for material longevity.

Purpose of the Study:

• To investigate the role of micrometer-scale heterogeneities in driving corrosion processes.
• To develop a novel model describing corrosion wave propagation and material loss.
• To validate the model with experimental data and explore new mitigation strategies.

Main Methods:

• Development of a novel excitable reaction-diffusion model.
• Simulation of corrosion waves and material loss on metal surfaces.
• Quantitative analysis using experimental data from Mg-Al-Zn alloy AZ31B.
• Simulation of morphogenic mitigation strategies.

Main Results:

• Corrosion is driven by spatial distribution of micrometer-scale heterogeneities, not nanoscopic fluctuations.
• A reaction-diffusion model accurately captures corrosion wave dynamics and material loss.
• Experimental data for AZ31B validates the model's predictions of wave speed, width, and material loss.
• Identified different corrosion regimes (wave, spot, patchy) and simulated wave-breaking mitigation.

Conclusions:

• Corrosion processes can be deterministic, driven by material structure.
• The developed model provides accurate predictions for specific alloy corrosion.
• Findings open avenues for improved corrosion protection, material design, and predictive models.
• Morphogenic mitigation strategies show promise for controlling corrosion.