Tunable Corrosion Resistance of Az31b Magnesium Via Ald-Deposited Al2O3 Coatings
Faculty Mentor Information
Dr. Corey Efaw, Boise State University
Presentation Date
7-2025
Abstract
Magnesium is known for its high strength to weight ratio and is used in industries like aerospace and automotive. These same properties make it a promising material for biodegradable medical implants. When placed in the body, magnesium gradually corrodes, allowing for natural resorption, unlike permanent materials such as titanium or stainless steel. However, its corrosion rate is often too fast, leading to structural failure or gas buildup before healing is complete. This project explores the use of aluminum oxide (Al₂O₃) coatings applied using Atomic Layer Deposition (ALD) to slow the degradation of AZ31B, a magnesium alloy. ALD enables precise control of coating thickness and uniformity, which can be used to fine tune implant lifetimes. Atomic Force Microscopy (AFM), Quantitative Nanomechanical Mapping (QNM), and Kelvin Probe Force Microscopy (KPFM) were used to assess coating quality, mechanical properties, and surface potential. These tools provided nanoscale insight into surface smoothness, stiffness, and corrosion susceptibility. Results showed that thicker coatings led to more stable surface potentials and better protection. Tuning degradation is critical for matching the body’s natural healing timeline, and magnesium’s breakdown products have also been shown to support osteogenesis, making it especially valuable for bone related applications.
Tunable Corrosion Resistance of Az31b Magnesium Via Ald-Deposited Al2O3 Coatings
Magnesium is known for its high strength to weight ratio and is used in industries like aerospace and automotive. These same properties make it a promising material for biodegradable medical implants. When placed in the body, magnesium gradually corrodes, allowing for natural resorption, unlike permanent materials such as titanium or stainless steel. However, its corrosion rate is often too fast, leading to structural failure or gas buildup before healing is complete. This project explores the use of aluminum oxide (Al₂O₃) coatings applied using Atomic Layer Deposition (ALD) to slow the degradation of AZ31B, a magnesium alloy. ALD enables precise control of coating thickness and uniformity, which can be used to fine tune implant lifetimes. Atomic Force Microscopy (AFM), Quantitative Nanomechanical Mapping (QNM), and Kelvin Probe Force Microscopy (KPFM) were used to assess coating quality, mechanical properties, and surface potential. These tools provided nanoscale insight into surface smoothness, stiffness, and corrosion susceptibility. Results showed that thicker coatings led to more stable surface potentials and better protection. Tuning degradation is critical for matching the body’s natural healing timeline, and magnesium’s breakdown products have also been shown to support osteogenesis, making it especially valuable for bone related applications.