Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies

Krüger, Jan Tobias; Hoyer, Kay-Peter; Hengsbach, Florian; Schaper, Mirko

doi:10.1016/j.jmrt.2022.06.006

Cited by 3 publications

(52 citation statements)

References 114 publications

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“…The structure of the melt pools ( Figure 3 b) and the structure of columnar dendritic solidification ( Figure 3 c) are observable. Thus, the structure of segregations of Mn along the microstructure observed by Krüger et al [ 63 ] becomes visible during the immersion test, and the influence of segregations on the degradation is conclusive.…”

Section: Resultsmentioning

confidence: 70%

“…The powders with a nominal particle size between 20 and 63 µm are produced via argon gas atomization. All powders have a suitable particle size distribution that is almost within the desired range and an almost spherical shape with only a few satellites [ 63 , 64 ]. Upright plates with a size of 2.5 × 10 × 12.5 mm³ are manufactured with an SLM 280 HL (SLM Solutions Group AG, Lübeck, Germany) in an argon atmosphere (layer thickness: 50 µm, scanning velocity: 750 mm/s, laser power: 280 W, hatch distance: 110 µm) [ 63 , 64 ].…”

Section: Methodsmentioning

confidence: 99%

“…All powders have a suitable particle size distribution that is almost within the desired range and an almost spherical shape with only a few satellites [ 63 , 64 ]. Upright plates with a size of 2.5 × 10 × 12.5 mm³ are manufactured with an SLM 280 HL (SLM Solutions Group AG, Lübeck, Germany) in an argon atmosphere (layer thickness: 50 µm, scanning velocity: 750 mm/s, laser power: 280 W, hatch distance: 110 µm) [ 63 , 64 ]. The resulting FeMn matrix is characterized by an austenitic structure and segregations of Mn along with the melt-pool structure of LBM as well as the columnar dendritic solidification structure.…”

Section: Methodsmentioning

confidence: 99%

“…The AgCaLa phases contain 75.8 wt.-% Ag, 10.6 wt.-% Ca, 5.4 wt.-% La, 5.2 wt.-% Mn, and 3.9 wt.-% O. A detailed characterization of the LBM-processed materials and conventionally processed AgCaLa alloy has been carried out by Krüger et al [ 41 , 63 , 64 ]. In the following, the samples are designated as FeMn, FeMnAg, and FeMnAgCaLa.…”

Section: Methodsmentioning

confidence: 99%

“…During the subsequent continuous melting process characterized by a small melt pool, a strong melt flow, and rapid melting and solidification, the Ag is incorporated into the bulk material. By the modification of the raw material and the LBM process, the chemical composition and the morphology of the Ag and AgCaLa phases are adaptable [ 22 , 62 , 63 , 64 ]. The raw material for the AgCaLa phases is obtained by conventional alloying and subsequent gas atomization, whereas the final structure and chemical composition of the AgCaLa inside the FeMn matrix are influenced by the LBM process [ 41 , 64 ].…”

Section: Introductionmentioning

confidence: 99%

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FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

Krüger

Hoyer²,

Huang³

et al. 2022

JFB

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The development of bioresorbable materials for temporary implantation enables progress in medical technology. Iron (Fe)-based degradable materials are biocompatible and exhibit good mechanical properties, but their degradation rate is low. Aside from alloying with Manganese (Mn), the creation of phases with high electrochemical potential such as silver (Ag) phases to cause the anodic dissolution of FeMn is promising. However, to enable residue-free dissolution, the Ag needs to be modified. This concern is addressed, as FeMn modified with a degradable Ag-Calcium-Lanthanum (AgCaLa) alloy is investigated. The electrochemical properties and the degradation behavior are determined via a static immersion test. The local differences in electrochemical potential increase the degradation rate (low pH values), and the formation of gaps around the Ag phases (neutral pH values) demonstrates the benefit of the strategy. Nevertheless, the formation of corrosion-inhibiting layers avoids an increased degradation rate under a neutral pH value. The complete bioresorption of the material is possible since the phases of the degradable AgCaLa alloy dissolve after the FeMn matrix. Cell viability tests reveal biocompatibility, and the antibacterial activity of the degradation supernatant is observed. Thus, FeMn modified with degradable AgCaLa phases is promising as a bioresorbable material if corrosion-inhibiting layers can be diminished.

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Section: Resultsmentioning

confidence: 70%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

Krüger

Hoyer²,

Huang³

et al. 2022

JFB

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Modification of Iron with Degradable Silver Phases Processed via Laser Beam Melting for Implants with Adapted Degradation Rate

et al. 2022

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Adjustment of AgCaLa Phases in a FeMn Matrix via LBM for Implants with Adapted Degradation

Krüger

2022

Crystals

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For many applications, implants overtake body function for a certain time. Bioresorbable implants reduce patient burden as they prevent adverse consequences due to remaining implants or operations for removal. Such materials are in clinical use but do not fulfill the requirements of all applications. Iron (Fe) is promising to develop further bioresorbable materials as it offers biocompatibility and good mechanical properties. Alloying, e.g., with manganese (Mn), is necessary to adapt the mechanical behavior and the degradation rate. However, the degradation rate of FeMn is too low. The creation of phases with high electrochemical potential evokes anodic dissolution of the FeMn, increasing the degradation rate. Therefore, silver (Ag), which is insoluble with Fe, has high potential, is biocompatible, and offers antibacterial properties, can be used. Powder-based processes such as laser beam melting (LBM) are favorable to process such immiscible materials. A degradable Ag alloy has to be used to enable the dissolution of Ag phases after the FeMn. This study reports first about the successful processing of FeMn with 5 wt.% of a degradable Ag–calcium–lanthanum (AgCaLa) alloy and enables further targeted adaption due to the gained understanding of the effects influencing the morphology and the chemical composition of the Ag phases.

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Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies

Cited by 3 publications

References 114 publications

FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

Modification of Iron with Degradable Silver Phases Processed via Laser Beam Melting for Implants with Adapted Degradation Rate

Adjustment of AgCaLa Phases in a FeMn Matrix via LBM for Implants with Adapted Degradation

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