@article{41492, abstract = {{The current investigation shows the feasibility of 316L steel powder production via three different argon gas atomisation routes (closed coupled atomisation, free fall atomisation with and without hot gas), along with subsequent sample production by laser powder bed fusion (PBF-LB). Here, a mixture of pure Fe and atomised 316L steel powder is used for PBF-LB to induce a chemical composition gradient in the microstructure. Optical microscopy and μ-CT investigations proved that the samples processed by PBF-LB exhibit very little porosity. Combined EBSD-EDS measurements show the chemical composition gradient leading to the formation of a local fcc-structure. Upon heat treatment (1100 °C, 14 h), the chemical composition is homogeneous throughout the microstructure. A moderate decrease (1060 to 985 MPa) in the sample’s ultimate tensile strength (UTS) is observed after heat treatment. However, the total elongation of the as-built and heat-treated samples remains the same (≈22%). Similarly, a slight decrease in the hardness from 341 to 307 HV1 is observed upon heat treatment.}}, author = {{Pramanik, Sudipta and Andreiev, Anatolii and Hoyer, Kay-Peter and Krüger, Jan Tobias and Hengsbach, Florian and Kircheis, Alexander and Zhao, Weiyu and Fischer-Bühner, Jörg and Schaper, Mirko}}, issn = {{2674-0516}}, journal = {{Powders}}, number = {{1}}, pages = {{59--74}}, publisher = {{MDPI AG}}, title = {{{Powder Production via Atomisation and Subsequent Laser Powder Bed Fusion Processing of Fe+316L Steel Hybrid Alloy}}}, doi = {{10.3390/powders2010005}}, volume = {{2}}, year = {{2023}}, } @article{47122, abstract = {{AbstractFeCo alloys are important materials used in pumps and motors in the offshore oil and gas drilling industry. These alloys are subjected to marine environments with a high NaCl concentration, therefore, corrosion and catastrophic failure are anticipated. So, the surface dissolution of additively manufactured FeCo samples is investigated in a quasi-in situ manner, in particular, the pitting corrosion in 5.0 wt pct NaCl solution. The local dissolution of the same sample region is monitored after 24, 72, and 168 hours. Here, the formation of rectangular and circular pits of ultra-fine dimensions (less than 0.5 µm) is observed with increasing immersion time. In addition, the formation of a corrosion-inhibiting surface layer is detected on the sample surface. Surface dissolution leads to a change in the surface structure, however, no change in grain shape or grain size is noticed. The surface topography after local dissolution is correlated to the grain orientation. Quasi-in situ analysis shows the preferential dissolution of high-angle grain boundaries (HAGBs) leading to a change in the fraction of HAGBs and low-angle grain boundaries fraction (LAGBs). For the FeCo sample, a potentiodynamic polarisation test reveals a corrosion potential (Ecorr) of − 0.475 V referred to the standard hydrogen electrode (SHE) and a corrosion exchange current density (icorr) of 0.0848 A/m2. Furthermore, quasi-in situ experiments showed that grains oriented along certain crystallographic directions are corroding more compared to other grains leading to a significant decrease in the local surface height. Grains with a plane normal close to the $$\langle {1}00\rangle$$ ⟨ 100 ⟩ direction reveal lower surface dissolution and higher corrosion resistance, whereas planes normal close to the $$\langle {11}0\rangle$$ ⟨ 110 ⟩ direction and the $$\langle {111}\rangle$$ ⟨ 111 ⟩ direction exhibit a higher surface dissolution.}}, author = {{Pramanik, Sudipta and Krüger, Jan Tobias and Schaper, Mirko and Hoyer, Kay-Peter}}, issn = {{1073-5623}}, journal = {{Metallurgical and Materials Transactions A}}, keywords = {{Metals and Alloys, Mechanics of Materials, Condensed Matter Physics}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Quasi-In Situ Localized Corrosion of an Additively Manufactured FeCo Alloy in 5 Wt Pct NaCl Solution}}}, doi = {{10.1007/s11661-023-07186-7}}, year = {{2023}}, } @article{33497, author = {{Krüger, Jan Tobias}}, journal = {{crystals}}, title = {{{Adjustment of AgCaLa Phases in a FeMn Matrix via LBM for Implants with Adapted Degradation}}}, doi = {{https://doi.org/10.3390/cryst12081146}}, volume = {{12}}, year = {{2022}}, } @article{36332, abstract = {{AlSi casting alloys combine excellent castability with high strength. Hence, this group of alloys is often used in the automotive sector. The challenge for this application is the brittle character of these alloys which leads to cracks during joint formation when mechanical joining technologies are used. A rise in ductility can be achieved by a considerable increase in the solidification rate which results in grain refinement. High solidification rates can be realized in twin–roll casting (TRC) by water-cooled rolls. Therefore, a hypoeutectic EN AC–AlSi9 (for European Norm - aluminum cast product) is manufactured by the TRC process and analyzed. Subsequently, joining investigations are performed on castings in as-cast and heat-treated condition using the self-piercing riveting process considering the joint formation and the load-bearing capacity. Due to the fine microstructure, the crack initiation can be avoided during joining, while maintaining the joining parameters, especially by specimens in heat treatment conditions. Furthermore, due to the extremely fine microstructure, the load-bearing capacity of the joint can be significantly increased in terms of the maximum load-bearing force and the energy absorbed.}}, author = {{Neuser, Moritz and Kappe, Fabian and Ostermeier, Jakob and Krüger, Jan Tobias and Bobbert, Mathias and Meschut, Gerson and Schaper, Mirko and Grydin, Olexandr}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, keywords = {{Condensed Matter Physics, General Materials Science}}, number = {{10}}, publisher = {{Wiley}}, title = {{{Mechanical Properties and Joinability of AlSi9 Alloy Manufactured by Twin‐Roll Casting}}}, doi = {{10.1002/adem.202200874}}, volume = {{24}}, year = {{2022}}, } @article{31238, author = {{Kupfer, Robert and Köhler, Daniel and Römisch, David and Wituschek, Simon and Ewenz, Lars and Kalich, Jan and Weiß, Deborah and Sadeghian, Behdad and Busch, Matthias and Krüger, Jan Tobias and Neuser, Moritz and Grydin, Olexandr and Böhnke, Max and Bielak, Christian-Roman and Troschitz, Juliane}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Clinching of Aluminum Materials – Methods for the Continuous Characterization of Process, Microstructure and Properties}}}, doi = {{10.1016/j.jajp.2022.100108}}, year = {{2022}}, } @article{34215, abstract = {{Clinching as a mechanical joining technique allows a fast and reliable joining of metal sheets in large-scale production. An efficient design and dimensioning of clinched joints requires a holistic understanding of the material, the joining process and the resulting properties of the joint. In this paper, the process chain for clinching metal sheets is described and experimental techniques are proposed to analyze the process-microstructure-property relationships from the sheet metal to the joined structure. At the example of clinching aluminum EN AW 6014, characterization methods are applied and discussed for the following characteristics: the mechanical properties of the sheet materials, the tribological behavior in the joining system, the joining process and the resulting material structure, the load-bearing behavior of the joint, the damage and degradation as well as the service life and crack growth behavior. The compilation of the characterization methods gives an overview on the advantages and weaknesses of the methods and the multiple interactions of material, process and properties during clinching. In addition, the results of the analyses on EN AW 6014 can be applied for parameterization and validation of simulations.}}, author = {{Kupfer, Robert and Köhler, Daniel and Römisch, David and Wituschek, Simon and Ewenz, Lars and Kalich, Jan and Weiß, Deborah and Sadeghian, Behdad and Busch, Matthias and Krüger, Jan Tobias and Neuser, Moritz and Grydin, Olexandr and Böhnke, Max and Bielak, Christian Roman and Troschitz, Juliane}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Clinching of Aluminum Materials – Methods for the Continuous Characterization of Process, Microstructure and Properties}}}, doi = {{10.1016/j.jajp.2022.100108}}, volume = {{5}}, year = {{2022}}, } @article{40154, abstract = {{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.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Huang, Jingyuan and Filor, Viviane and Mateus-Vargas, Rafael Hernan and Oltmanns, Hilke and Meißner, Jessica and Grundmeier, Guido and Schaper, Mirko}}, issn = {{2079-4983}}, journal = {{Journal of Functional Biomaterials}}, keywords = {{Biomedical Engineering, Biomaterials}}, number = {{4}}, pages = {{185}}, publisher = {{MDPI AG}}, title = {{{FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability}}}, doi = {{10.3390/jfb13040185}}, volume = {{13}}, year = {{2022}}, } @article{33723, abstract = {{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.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Huang, Jingyuan and Filor, Viviane and Mateus-Vargas, Rafael Hernan and Oltmanns, Hilke and Meißner, Jessica and Grundmeier, Guido and Schaper, Mirko}}, issn = {{2079-4983}}, journal = {{Journal of Functional Biomaterials}}, keywords = {{Biomedical Engineering, Biomaterials}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability}}}, doi = {{10.3390/jfb13040185}}, volume = {{13}}, year = {{2022}}, } @article{33498, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Andreiev, Anatolii and Schaper, Mirko and Zinn, Carolin}}, journal = {{Advanced Engineering Materials}}, title = {{{Modification of Iron with Degradable Silver Phases Processed via Laser Beam Melting for Implants with Adapted Degradation Rate}}}, doi = {{https://doi.org/10.1002/adem.202201008}}, year = {{2022}}, } @article{41494, abstract = {{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.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Huang, Jingyuan and Filor, Viviane and Mateus-Vargas, Rafael Hernan and Oltmanns, Hilke and Meißner, Jessica and Grundmeier, Guido and Schaper, Mirko}}, issn = {{2079-4983}}, journal = {{Journal of Functional Biomaterials}}, keywords = {{Biomedical Engineering, Biomaterials}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability}}}, doi = {{10.3390/jfb13040185}}, volume = {{13}}, year = {{2022}}, } @article{32332, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Hengsbach, Florian and Schaper, Mirko}}, issn = {{2238-7854}}, journal = {{Journal of Materials Research and Technology}}, keywords = {{Metals and Alloys, Surfaces, Coatings and Films, Biomaterials, Ceramics and Composites}}, pages = {{2369--2387}}, publisher = {{Elsevier BV}}, title = {{{Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies}}}, doi = {{10.1016/j.jmrt.2022.06.006}}, volume = {{19}}, year = {{2022}}, } @article{41498, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Hengsbach, Florian and Schaper, Mirko}}, issn = {{2238-7854}}, journal = {{Journal of Materials Research and Technology}}, keywords = {{Metals and Alloys, Surfaces, Coatings and Films, Biomaterials, Ceramics and Composites}}, pages = {{2369--2387}}, publisher = {{Elsevier BV}}, title = {{{Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies}}}, doi = {{10.1016/j.jmrt.2022.06.006}}, volume = {{19}}, year = {{2022}}, } @article{30103, author = {{Huang, Jingyuan and Orive, Alejandro Gonzalez and Krüger, Jan Tobias and Hoyer, Kay-Peter and Keller, Adrian and Grundmeier, Guido}}, issn = {{0010-938X}}, journal = {{Corrosion Science}}, keywords = {{General Materials Science, General Chemical Engineering, General Chemistry}}, pages = {{110186}}, publisher = {{Elsevier BV}}, title = {{{Influence of proteins on the corrosion of a conventional and selective laser beam melted FeMn alloy in physiological electrolytes}}}, doi = {{10.1016/j.corsci.2022.110186}}, volume = {{200}}, year = {{2022}}, } @article{41504, author = {{Huang, Jingyuan and Gonzalez Orive, Alejandro and Krüger, Jan Tobias and Hoyer, Kay-Peter and Keller, Adrian and Grundmeier, Guido}}, issn = {{0010-938X}}, journal = {{Corrosion Science}}, keywords = {{General Materials Science, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Influence of proteins on the corrosion of a conventional and selective laser beam melted FeMn alloy in physiological electrolytes}}}, doi = {{10.1016/j.corsci.2022.110186}}, volume = {{200}}, year = {{2022}}, } @article{41493, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Andreiev, Anatolii and Schaper, Mirko and Zinn, Carolin}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, keywords = {{Condensed Matter Physics, General Materials Science}}, publisher = {{Wiley}}, title = {{{Modification of Iron with Degradable Silver Phases Processed via Laser Beam Melting for Implants with Adapted Degradation Rate}}}, doi = {{10.1002/adem.202201008}}, year = {{2022}}, } @article{24790, abstract = {{Implants often overtake body function just for a certain time and remain as an unnecessary foreign body or have to be removed. Thus, resorbable implants are highly beneficial to reduce patient burden. Besides established materials, Iron-(Fe)-based alloys are in focus due to superior mechanical properties and good biocompatibility. However, their degradation rate needs to be increased. Phases with high electrochemical potential could promote the dissolution of residual material based on the galvanic coupling. Silver (Ag) is promising due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. But to prevent adverse consequences the Ag-particles, remaining after dissolution of the matrix, need to dissolve. Thus, a bioresorbable Ag-alloy is required. Regarding the electrochemical potential and degradation behavior of binary alloys, Cerium (Ce) and Lanthanum (La) are well-suited considering their biocompatibility and antibacterial behavior. Accordingly, this research addresses AgCe and AgCeLa alloys as additives for Fe-based materials with adapted degradation behavior. Furthermore, degradable Ag-alloys combined with inert implant materials could enable the controlled release of antibacterial active Ag-ions.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0167-577X}}, journal = {{Materials Letters}}, title = {{{Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants}}}, doi = {{10.1016/j.matlet.2021.130890}}, volume = {{306}}, year = {{2021}}, } @article{41509, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0167-577X}}, journal = {{Materials Letters}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, publisher = {{Elsevier BV}}, title = {{{Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants}}}, doi = {{10.1016/j.matlet.2021.130890}}, volume = {{306}}, year = {{2021}}, } @article{41514, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Filor, Viviane and Pramanik, Sudipta and Kietzmann, Manfred and Meißner, Jessica and Schaper, Mirko}}, issn = {{0925-8388}}, journal = {{Journal of Alloys and Compounds}}, keywords = {{Materials Chemistry, Metals and Alloys, Mechanical Engineering, Mechanics of Materials}}, publisher = {{Elsevier BV}}, title = {{{Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation}}}, doi = {{10.1016/j.jallcom.2021.159544}}, volume = {{871}}, year = {{2021}}, } @article{24087, abstract = {{Resorbable implants are highly beneficial to reduce patient burden since they need not be removed after a defined period. Currently, magnesium (Mg) and polymers are being applied as bioresorbable materials. However, for some applications the insufficient mechanical properties and high degradation rate of Mg cause the need for new materials. Iron (Fe)-based alloys are promising due to their biocompatibility and good mechanical properties, but their degradation rate is too low and needs to be adapted eg. via alloying with manganese (Mn). Besides, phases with high electrochemical potential lead to increased degradation of residual material with lower potential based on the galvanic coupling. Here, silver (Ag) is promising for the formation of such phases due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. Since remaining silver particles can lead to adverse consequences as thrombosis, these particles need to dissolve after the matrix material. Thus a silver alloy with high electrochemical potential, biocompatibility, and adjusted degradation behavior is required as an additive for iron-based bioresorbable materials. Several silver alloying systems are possible, but regarding the electrochemical potential and degradation behavior of binary alloys, calcium (Ca) and lanthanum (La) are best-suited considering their biocompatibility. Accordingly, this research addresses AgCa and AgCaLa alloys as additives for iron-based degradable materials with adapted degradation behavior.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Filor, Viviane and Pramanik, Sudipta and Kietzmann, Manfred and Meißner, Jessica and Schaper, Mirko}}, issn = {{0925-8388}}, journal = {{Journal of Alloys and Compounds}}, title = {{{Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation}}}, doi = {{10.1016/j.jallcom.2021.159544}}, year = {{2021}}, }