Biocorrosion and biodegradation behavior of ultralight Mg-4Li-1Ca (LC41) alloy in simulated body fluid for degradable implant applications

S.S. Nene, B.P. Kashyap, N. Prabhu, Y. Estrin, T. Al-Samman

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17 Citations (Scopus)

Abstract

Biocorrosion and biodegradation behavior of Mg–4Li–1Ca alloy were investigated for industrially important end product conditions, namely the homogenized, rolled, and rolled ? annealed ones. Among the three, homogenized material showed the highest corrosion rate (27.2 mm/year) in a simulated body fluid (SBF) owing to its coarse grain structure containing long dumbbell-shaped eutectic phase. Rolled annealed material exhibited the lowest corrosion rate (0.94 mm/year) corresponding to the highest corrosion resistance (1.854 kX cm2) in SBF. This higher corrosion resistance is associated with a uniform distribution of corrosion sites and a lower occurrence of twins in the microstructure. However, the rolled material showed a greater corrosion rate due to an appreciable volume fraction of {1011} compression twins, {1012} tension twins, and {1011}–{1012} double twins, which form galvanic couples with the adjacent grains that enhances localized corrosion. A mechanism of biodegradation at the alloy/SBF interface is proposed. It involves the formation of bone-like hydroxyapatite and metastable octa calcium phosphate, along with other degradation products, such as magnesium hydroxide and lithium hydroxide.
Original languageEnglish
Pages (from-to)3041 - 3050
Number of pages10
JournalJournal of Materials Science
Volume50
Issue number8
DOIs
Publication statusPublished - 2015

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