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Effect of silver in thermal treatments of Fe-Mn-C degradable metals: Implications for stent processing.

ABSTRACT: Twinning-induced plasticity (TWIP) steels are considered excellent materials for manufacturing products requiring extremely high mechanical properties for various applications including thin medical devices, such as biodegradable intravascular stents. It is also proven that the addition of Ag can guarantee an appropriate degradation while implanted in human body without affecting its bioactive properties. In order to develop an optimized manufacturing process for thin stents, the effect of Ag on the recrystallization behavior of TWIP steels needs to be elucidated. This is of major importance since manufacturing stents involves several intermediate recrystallization annealing treatments. In this work, the recrystallization mechanism of two Fe-Mn-C steels with and without Ag was thoroughly investigated by microstructural and mechanical analyses. It was observed that Ag promoted a finer microstructure with a different texture evolution, while the recrystallization kinetics resulted unaffected. The presence of Ag also reduced the effectiveness of the recrystallization treatment. This behavior was attributed to the presence of Ag-rich second phase particles, precipitation of carbides and to the preferential development of grains possessing a {111} orientation upon thermal treatment. The prominence of {111} grains can also give rise to premature twinning, explaining the role of Ag in reducing the ductility of TWIP steels already observed in other works. Furthermore, in vitro biological performances were unaffected by Ag. These findings could allow the design of efficient treatments for supporting the transformation of Fe-Mn-C steels alloyed with Ag into commercial products.

SUBMITTER: Loffredo S

PROVIDER: S-EPMC8777259 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Improving the radiopacity of Fe-Mn biodegradable metals by magnetron-sputtered W-Fe-Mn-C coatings: Application for thinner stents.

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Project description:The aim of this work was to study the effects of Fe and Mn deficiencies and Mn toxicity on the protein profile of the xylem sap of tomato (Solanum lycopersicum), with the aim of elucidating plant response mechanisms to these nutritional stresses. Tomato was chosen as a model plant because the tomato genome has been published and this plant species has adequate root pressure and turgid stems that permit xylem sap sampling in sufficient amounts by de-topping. The high-throughput shotgun analysis has permitted to identify and quantitate a large number of low abundance proteins in the tomato xylem sap.

2017-11-30 | PXD007517 | Pride

Spontaneous Formation of an Fe/Mn Diamond Core: Models for the Fe/Mn Sites in Class 1c Ribonucleotide Reductases.

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