TY - JOUR
T1 - Biocorrosion and biodegradation behavior of ultralight Mg-4Li-1Ca (LC41) alloy in simulated body fluid for degradable implant applications
AU - Nene, S.S.
AU - Kashyap, B.P.
AU - Prabhu, N.
AU - Estrin, Y.
AU - Al-Samman, T.
PY - 2015
Y1 - 2015
N2 - 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.
AB - 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.
UR - http://goo.gl/yo1qL3
U2 - 10.1007/s10853-015-8846-y
DO - 10.1007/s10853-015-8846-y
M3 - Article
SN - 0022-2461
VL - 50
SP - 3041
EP - 3050
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 8
ER -