Biodegradable implants have emerged in biomedical applications,particularly for orthopedic fixations,cardiovascular stents,and tissue engineering scaffolds.Unlike permanent implants,they are designed to degrade and be...Biodegradable implants have emerged in biomedical applications,particularly for orthopedic fixations,cardiovascular stents,and tissue engineering scaffolds.Unlike permanent implants,they are designed to degrade and be reabsorbed after implantation in the body,mitigating the need for additional surgeries and reducing associated complications.In particular,Fe-Mn-C alloys constitute a new class of promising metallic materials for medical applications due to their outstanding mechanical properties and their bio-logical performances.This study focuses on improving the degradation rates and cytotoxicity of sintered Fe-Mn-C alloys produced using the powder metallurgy process.To evaluate the impact of different pow-der preparation methods on material properties,two types of powders were used:(1)MX,prepared by mixing Fe,Mn,and C powders for 1 h;and(2)MM,obtained by mechanically milling the same powders for 10 h.Four mixtures with varying proportions of MX and MM were prepared.Two groups of samples were produced:one entirely from MX(A0),and another containing MM at 25 wt.%(A25),50 wt.%(A50),and 75 wt.%(A75).All samples exhibited a complex microstructure comprising ferrite,martensite,and residual austenite.Degradation behavior assessment in Hanks’solution over 14 days showed that adding MM increased the degradation rate,from around 0.04 mmpy for A0 to 0.12 mmpy for A25.Notably,all samples showed similar cell viability,in the range of 83%-89%for 1%extract dilution,and were non-hemolytic,with a hemolysis percentage below 1%.展开更多
The intrinsic magnetic properties of the tetragonal Sm_(14)Fe_(78-x)C_(8) system are investigated.In addition to the sudden drop of σ_(s) and T_(c), an ajiomalous variation of the lattice constants is found.The sign ...The intrinsic magnetic properties of the tetragonal Sm_(14)Fe_(78-x)C_(8) system are investigated.In addition to the sudden drop of σ_(s) and T_(c), an ajiomalous variation of the lattice constants is found.The sign of K_(1) changes from negative to positive between x=15 and 20 at 1.5 Kf thus the cone-type anisotropy becomes uniaxial correspondingly.The intrinsic magnetic hardness effect at low temperature is observed at high Mn content.展开更多
基金supported by the Natural Science and En-gineering Research Council of Canada(Discovery and Alliance),and PRIMA(Quebec Ministry for Economy and Innovation).
文摘Biodegradable implants have emerged in biomedical applications,particularly for orthopedic fixations,cardiovascular stents,and tissue engineering scaffolds.Unlike permanent implants,they are designed to degrade and be reabsorbed after implantation in the body,mitigating the need for additional surgeries and reducing associated complications.In particular,Fe-Mn-C alloys constitute a new class of promising metallic materials for medical applications due to their outstanding mechanical properties and their bio-logical performances.This study focuses on improving the degradation rates and cytotoxicity of sintered Fe-Mn-C alloys produced using the powder metallurgy process.To evaluate the impact of different pow-der preparation methods on material properties,two types of powders were used:(1)MX,prepared by mixing Fe,Mn,and C powders for 1 h;and(2)MM,obtained by mechanically milling the same powders for 10 h.Four mixtures with varying proportions of MX and MM were prepared.Two groups of samples were produced:one entirely from MX(A0),and another containing MM at 25 wt.%(A25),50 wt.%(A50),and 75 wt.%(A75).All samples exhibited a complex microstructure comprising ferrite,martensite,and residual austenite.Degradation behavior assessment in Hanks’solution over 14 days showed that adding MM increased the degradation rate,from around 0.04 mmpy for A0 to 0.12 mmpy for A25.Notably,all samples showed similar cell viability,in the range of 83%-89%for 1%extract dilution,and were non-hemolytic,with a hemolysis percentage below 1%.
基金Supported in part by the Magnetics Open Lab.of Academia Sinica.
文摘The intrinsic magnetic properties of the tetragonal Sm_(14)Fe_(78-x)C_(8) system are investigated.In addition to the sudden drop of σ_(s) and T_(c), an ajiomalous variation of the lattice constants is found.The sign of K_(1) changes from negative to positive between x=15 and 20 at 1.5 Kf thus the cone-type anisotropy becomes uniaxial correspondingly.The intrinsic magnetic hardness effect at low temperature is observed at high Mn content.
