The UTC Graduate School is pleased to announce that Merna Abdrabo will present Master's research titled, Effect of Sol-gel Sealing on Corrosion Fatigue Behavior of PEO-coated Magnesium Alloy on 06/18/2026 at 2:30 pm in Engineering Building, room 403. Everyone is invited to attend. 

Engineering

Chair: Dr. Mohammad Mahtabi

Abstract:

Magnesium and its alloys represent a promising alternative to common implant materials such as titanium, stainless steel and chromium alloys. This is due to their mechanical properties that are more suitable to those of the human bone, reducing the risk of stress shielding. In addition, their biodegradability eliminates the need for secondary removal surgeries. However, Mg suffers from rapid corrosion rates in physiological environments. As a result, research studies have focused on improving its corrosion resistance through the application of plasma electrolytic oxidation (PEO) coatings. Despite succeeding in mitigating the corrosion rate, PEO coatings introduce pores and microcracks which can be severely detrimental to fatigue performance. Therefore, this study aims to investigate the effect of sealing those surface defects by applying layers of sol-gel thin films on the fatigue resistance of Mg-based biomedical implants. Fatigue tests were conducted on both uncorroded and pre-corroded samples, covering both high and low cycle fatigue loading. Three testing groups were involved; bare Mg, PEO-coated Mg and hybrid-coated (PEO and sol-gel) Mg. The results indicated distinct fatigue behavior between corrosion fatigue and fatigue loading in air. Under ambient air conditions, both coated groups exhibited shorter fatigue lives under high cycle fatigue conditions, with minimal differences observed between coated and bare groups under low cycle fatigue. On the other hand, under corrosion fatigue conditions, both coated groups showed infinite life under high cycle fatigue, with small differences in fatigue life under low cycle fatigue. Characterization tests including scanning electron microscopy (SEM), roughness measurements, corrosion immersion tests and potentiodynamic polarization (PDP) tests were conducted and reported in this thesis.