@article{41501,
author = {{Tillmann, Wolfgang and Lopes Dias, Nelson Filipe and Kokalj, David and Stangier, Dominic and Hein, Maxwell and Hoyer, Kay-Peter and Schaper, Mirko and Gödecke, Daria and Oltmanns, Hilke and Meißner, Jessica}},
issn = {{0167-577X}},
journal = {{Materials Letters}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}},
publisher = {{Elsevier BV}},
title = {{{Tribo-functional PVD thin films deposited onto additively manufactured Ti6Al7Nb for biomedical applications}}},
doi = {{10.1016/j.matlet.2022.132384}},
volume = {{321}},
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{41502,
author = {{Teng, Zhenjie and Wu, Haoran and Pramanik, Sudipta and Hoyer, Kay-Peter and Schaper, Mirko and Zhang, Hanlong and Boller, Christian and Starke, Peter}},
issn = {{1438-1656}},
journal = {{Advanced Engineering Materials}},
keywords = {{Condensed Matter Physics, General Materials Science}},
number = {{9}},
publisher = {{Wiley}},
title = {{{Characterization and Analysis of Plastic Instability in an Ultrafine‐Grained Medium Mn TRIP Steel}}},
doi = {{10.1002/adem.202200022}},
volume = {{24}},
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{41491,
author = {{Pramanik, Sudipta and Milaege, Dennis and Hoyer, Kay-Peter and Schaper, Mirko}},
issn = {{0921-5093}},
journal = {{Materials Science and Engineering: A}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}},
publisher = {{Elsevier BV}},
title = {{{Additively manufactured novel Ti6Al7Nb circular honeycomb cellular solid for energy absorbing applications}}},
doi = {{10.1016/j.msea.2022.143887}},
volume = {{854}},
year = {{2022}},
}
@article{41489,
abstract = {{In this study, the design, additive manufacturing and experimental as well as simulation investigation of mechanical and thermal properties of cellular solids are addressed. For this, two cellular solids having nested and non-nested structures are designed and additively manufactured via laser powder bed fusion. The primary objective is to design cellular solids which absorb a significant amount of energy upon impact loading without transmitting a high amount of stress into the cellular solids. Therefore, compression testing of the two cellular solids is performed. The nested and non-nested cellular solids show similar energy absorption properties; however, the nested cellular solid transmits a lower amount of stress in the cellular structure compared to the non-nested cellular solid. The experimentally measured strain (by DIC) in the interior region of the nested cellular solid is lower despite a higher value of externally imposed compressive strain. The second objective of this study is to determine the thermal insulation properties of cellular solids. For measuring the thermal insulation properties, the samples are placed on a hot plate; and the surface temperature distribution is measured by an infrared camera. The thermal insulating performance of both cellular types is sufficient for temperatures exceeding 100 °C. However, the thermal insulating performance of a non-nested cellular solid is slightly better than that of the nested cellular solid. Additional thermal simulations predict a relatively higher temperature distribution on the cellular solid surfaces compared to experimental results. The simulated residual stress shows a similar distribution for both types, but the magnitude of residual stress is different for the cellular solids upon cooling from different temperatures of the hot plate.}},
author = {{Pramanik, Sudipta and Milaege, Dennis and Hoyer, Kay-Peter and Schaper, Mirko}},
issn = {{2073-4352}},
journal = {{Crystals}},
keywords = {{Inorganic Chemistry, Condensed Matter Physics, General Materials Science, General Chemical Engineering}},
number = {{9}},
publisher = {{MDPI AG}},
title = {{{Additively Manufactured Nested and Non-Nested Cellular Solids for Effective Stress Distribution and Thermal Insulation Applications: An Experimental and Finite Element Analysis Study}}},
doi = {{10.3390/cryst12091217}},
volume = {{12}},
year = {{2022}},
}
@article{41488,
abstract = {{The additive manufacturing (AM) of innovative lattice structures with unique mechanical properties has received widespread attention due to the capability of AM processes to fabricate freeform and intricate structures. The most common way to characterize the additively manufactured lattice structures is via the uniaxial compression test. However, although there are many applications for which lattice structures are designed for bending (e.g., sandwich panels cores and some medical implants), limited attention has been paid toward investigating the flexural behavior of metallic AM lattice structures with tunable internal architectures. The purpose of this study was to experimentally investigate the flexural behavior of AM Ti-6Al-4V lattice structures with graded density and hybrid Poisson’s ratio (PR). Four configurations of lattice structure beams with positive, negative, hybrid PR, and a novel hybrid PR with graded density were manufactured via the laser powder bed fusion (LPBF) AM process and tested under four-point bending. The manufacturability, microstructure, micro-hardness, and flexural properties of the lattices were evaluated. During the bending tests, different failure mechanisms were observed, which were highly dependent on the type of lattice geometry. The best response in terms of absorbed energy was obtained for the functionally graded hybrid PR (FGHPR) structure. Both the FGHPR and hybrid PR (HPR) structured showed a 78.7% and 62.9% increase in the absorbed energy, respectively, compared to the positive PR (PPR) structure. This highlights the great potential for FGHPR lattices to be used in protective devices, load-bearing medical implants, and energy-absorbing applications.}},
author = {{Abdelaal, Osama and Hengsbach, Florian and Schaper, Mirko and Hoyer, Kay-Peter}},
issn = {{1996-1944}},
journal = {{Materials}},
keywords = {{General Materials Science}},
number = {{12}},
publisher = {{MDPI AG}},
title = {{{LPBF Manufactured Functionally Graded Lattice Structures Obtained by Graded Density and Hybrid Poisson’s Ratio}}},
doi = {{10.3390/ma15124072}},
volume = {{15}},
year = {{2022}},
}
@article{41490,
author = {{Hein, Maxwell and Lopes Dias, Nelson Filipe and Kokalj, David and Stangier, Dominic and Hoyer, Kay-Peter and Tillmann, Wolfgang and Schaper, Mirko}},
issn = {{0142-1123}},
journal = {{International Journal of Fatigue}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials, General Materials Science, Modeling and Simulation}},
publisher = {{Elsevier BV}},
title = {{{On the influence of physical vapor deposited thin coatings on the low-cycle fatigue behavior of additively processed Ti-6Al-7Nb alloy}}},
doi = {{10.1016/j.ijfatigue.2022.107235}},
volume = {{166}},
year = {{2022}},
}
@article{30736,
abstract = {{In this study, an innovative friction model is used to improve the quality of clinching process simulations. Consequently, the future over dimensioning can be reduced. Furthermore, the improved prediction quality of the joining process simulation leads to an improvement in the simulation of load-bearing capacity as well. In this way, the entire sampling process can be performed virtually without any experimental investigations. This will contribute to the advancement of lightweight construction in the automotive industry. In this work, the frictional behavior is studied in dependence on the local joining process parameters. As a reference for the numerical investigations, clinch joints by means of a die with fixed geometry are joined. Additionally, a hardness mapping is performed on the microsection of the clinch joints. It shows the local strain hardening, which correlates with the forming degree in the simulation. Based on the occurring contacts and the local joining process parameters in the joining process simulation, the test matrix for the experimental friction tests is defined. The friction tests are carried out on a compression-torsion-tribometer. This type of tribometer is able to apply high interface pressures above the initial yield stress due to the specimen encapsulation. Besides, the pure joining part contact, the contact between the joining part and joining tool can be tested as well. The experimental test setup offers the possibility to evaluate the influences of temperature, relative velocity, interface pressure, and frictional stroke independently. Based on the results of the experimental friction tests, a friction model is created. The resulting friction model is integrated into the numerical joining process simulation via a subroutine. To validate the quality of the new friction modeling, the results of simulations are compared with the experiments in terms of load-stroke diagrams, joint geometry, and hardness mappings on the microsection. }},
author = {{Rossel, Moritz Sebastian and Meschut, Gerson}},
issn = {{1464-4207}},
journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}},
keywords = {{Mechanical Engineering, General Materials Science}},
publisher = {{SAGE Publications}},
title = {{{Increasing the accuracy of clinching process simulations by modeling the friction as a function of local joining process parameters}}},
doi = {{10.1177/14644207221074290}},
year = {{2022}},
}
@article{30962,
abstract = {{ Clinching as a mechanical joining process has become established in many areas of car body. In order to predict relevant properties of clinched joints and to ensure the reliability of the process, it is numerically simulated during the product development process. The prediction accuracy of the simulated process depends on the implemented friction model. Therefore, a new method for determining friction coefficients in sheet metal materials was developed and tested. The aim of this study is the numerical investigation of this experimental method by means of FE simulation. The experimental setup is modelled in a 3D numerical simulation taking into account the process parameters varying in the experiment, such as geometric properties, contact pressure and contact velocity. Furthermore, the contact description of the model is calibrated via the experimentally determined friction coefficients according to clinch-relevant parameter space. It is shown that the assumptions made in the determination of the experimental data in preliminary work are valid. In addition, it is investigated to what extent the standard Coulomb friction model in the FEM can reproduce the results of the experimental method. }},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
issn = {{1464-4207}},
journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}},
keywords = {{Mechanical Engineering, General Materials Science}},
publisher = {{SAGE Publications}},
title = {{{Numerical investigation of a friction test to determine the friction coefficients for the clinching process}}},
doi = {{10.1177/14644207221093468}},
year = {{2022}},
}
@article{34069,
author = {{Schramm, Britta and Martin, Sven and Steinfelder, Christian and Bielak, Christian Roman and Brosius, Alexander and Meschut, Gerson and Tröster, Thomas and Wallmersperger, Thomas and Mergheim, Julia}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{A Review on the Modeling of the Clinching Process Chain - Part I: Design Phase}}},
doi = {{10.1016/j.jajp.2022.100133}},
volume = {{6}},
year = {{2022}},
}
@article{34068,
author = {{Schramm, Britta and Friedlein, Johannes and Gröger, Benjamin and Bielak, Christian Roman and Bobbert, Mathias and Gude, Maik and Meschut, Gerson and Wallmersperger, Thomas and Mergheim, Julia}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{A Review on the Modeling of the Clinching Process Chain - Part II: Joining Process}}},
doi = {{10.1016/j.jajp.2022.100134}},
year = {{2022}},
}
@article{34000,
abstract = {{Abstract
This paper presents the characterization of the microstructure evolution during flow forming of austenitic stainless steel AISI 304L. Due to plastic deformation of metastable austenitic steel, phase transformation from γ-austenite into α’-martensite occurs. This is initiated by the formation of shear bands as product of the external stresses. By means of coupled microscopic and micromagnetic investigations, a characterization of the microstructure was carried out. In particular, this study shows the distribution of the strain-induced α’-martensite and its influence on material properties like hardness at different depths. The microstructural analyses by means of electron backscattered diffraction (EBSD) technique, evidence a higher amount of α’-martensite (ca. 23 %) close to the outer specimen surface, where the plastic deformation and the direct contact with the forming tool take place. In the middle area (ca. 1.5 mm depth from the outer surface), the portion of transformed α’-martensite drops to 7 % and in the inner surface to 2 %. These results are well correlated with microhardness and micromagnetic measurements at different depths. EBSD and atomic force microscopy (AFM) were used to make a detailed characterization of the topography and degree of deformation of the shear bands. Likewise, the mechanisms of nucleation of α’-martensite were discussed. This research contributes to the development of micromagnetic sensors to monitor the evolution of properties during flow forming. This makes them more suitable for closed-loop property control, which offers possibilities for an application-oriented and more efficient production.}},
author = {{Rozo Vasquez, Julian and Kanagarajah, Hanigah and Arian, Bahman and Kersting, Lukas and Homberg, Werner and Trächtler, Ansgar and Walther, Frank}},
issn = {{2195-8599}},
journal = {{Practical Metallography}},
keywords = {{Metals and Alloys, Mechanics of Materials, Condensed Matter Physics, Electronic, Optical and Magnetic Materials}},
number = {{11}},
pages = {{660--675}},
publisher = {{Walter de Gruyter GmbH}},
title = {{{Coupled microscopic and micromagnetic depth-specific analysis of plastic deformation and phase transformation of metastable austenitic steel AISI 304L by flow forming}}},
doi = {{10.1515/pm-2022-0064}},
volume = {{59}},
year = {{2022}},
}
@article{33999,
abstract = {{The production of complex multi-functional, high-strength parts is becoming increasingly important in the industry. Especially with small batch size, the incremental flow forming processes can be advantageous. The production of parts with complex geometry and locally graded material properties currently depicts a great challenge in the flow forming process. At this point, the usage of closed-loop control for the shape and properties could be a feasible new solution. The overall aim in this project is to establish an intelligent closed-loop control system for the wall thickness as well as the α’-martensite content of AISI 304L-workpieces in a flow forming process. To reach this goal, a novel sensor concept for online measurements of the wall thickness reduction and the martensite content during forming process is proposed. It includes the setup of a modified flow forming machine and the integration of the sensor system in the machine control. Additionally, a simulation model for the flow forming process is presented which describes the forming process with regard to the plastic workpiece deformation, the induced α’-martensite fraction, and the sensor behavior. This model was used for designing a closed-loop process control of the wall thickness reduction that was subsequently realized at the real plant including online measured feedback from the sensor system.}},
author = {{Kersting, Lukas and Arian, Bahman and Vasquez, Julian Rozo and Trächtler, Ansgar and Homberg, Werner and Walther, Frank}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{862--874}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Innovative Online Measurement and Modelling Approach for Property-Controlled Flow Forming Processes}}},
doi = {{10.4028/p-yp2hj3}},
volume = {{926}},
year = {{2022}},
}
@article{32869,
abstract = {{The further development of in-mold-assembly (IMA) technologies for structural hybrid components is of great importance for increasing the economic efficiency and thus the application potential. This paper presents an innovative IMA process concept for the manufacturing of bending loaded hybrid components consisting of two outer metal belts and an inner core structure made of glass mat reinforced thermoplastic (GMT). In this process, the core structure, which is provided with stiffening ribs and functional elements, is formed and joined to two metal belts in one single step. For experimental validation of the concept, the development of a prototypic molding tool and the manufacturing of hybrid beams including process parameters are described. Three-point bending tests and optical measurement technologies are used to characterize the failure behavior and mechanical properties of the produced hybrid beams. It was found that the innovative IMA process enables the manufacturing of hybrid components with high energy absorption and low weight in one step. The mass-specific energy absorption is increased by 693 % compared to pure GMT beams.}},
author = {{Stallmeister, Tim and Tröster, Thomas}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{1457--1467}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{In-Mold-Assembly of Hybrid Bending Structures by Compression Molding}}},
doi = {{10.4028/p-5fxp53}},
volume = {{926}},
year = {{2022}},
}
@article{30213,
abstract = {{Requirement changes and cascading effects of change propagation are major sources of inefficiencies in product development and increase the risk of project failure. Proactive change management of requirement changes yields the potential to handle such changes efficiently. A systematic approach is required for proactive change management to assess and reduce the risk of a requirement change with appropriate effort in industrial application. Within the paper at hand, a novel method for Proactive Management of Requirement Changes (ProMaRC) is presented. It is developed in close collaboration with industry experts and evaluated based on workshops, pilot users’ feedback, three industrial case studies from the automotive industry and five development projects from research. To limit the application effort, an automated approach for dependency analysis based on the machine learning technique BERT and semi-automated assessment of change likelihood and impact using a modified PageRank algorithm is developed. Applying the method, the risks of requirement changes are assessed systematically and reduced by means of proactive change measures. Evaluation shows high performance of dependency analysis and confirms the applicability and usefulness of the method. This contribution opens up the research space of proactive risk management for requirement changes which is currently almost unexploited. It enables more efficient product development.}},
author = {{Gräßler, Iris and Oleff, Christian and Preuß, Daniel}},
issn = {{2076-3417}},
journal = {{Applied Sciences}},
keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}},
number = {{4}},
publisher = {{MDPI AG}},
title = {{{Proactive Management of Requirement Changes in the Development of Complex Technical Systems}}},
doi = {{10.3390/app12041874}},
volume = {{12}},
year = {{2022}},
}
@article{44469,
author = {{Menge, Dennis and Schmid, Hans-Joachim}},
issn = {{1022-1360}},
journal = {{Macromolecular Symposia}},
keywords = {{Materials Chemistry, Polymers and Plastics, Organic Chemistry, Condensed Matter Physics}},
number = {{1}},
publisher = {{Wiley}},
title = {{{Low Temperature Laser Sintering with PA12 and PA6 on a Standard System}}},
doi = {{10.1002/masy.202100397}},
volume = {{404}},
year = {{2022}},
}
@article{32068,
abstract = {{Inspired by plant grafting, grafted vortex beams can be formed through grafting two or more helical phase profiles of optical vortex beams. Recently, grafted perfect vortex beams (GPVBs) have attracted much attention due to their unique optical properties and potential applications. However, the current method to generate and manipulate GPVBs requires a complex and bulky optical system, hindering further investigation and limiting its practical applications. Here, a compact metasurface approach for generating and manipulating GPVBs in multiple channels is proposed and demonstrated, which eliminates the need for such a complex optical setup. A single metasurface is utilized to realize various superpositions of GPVBs with different combinations of topological charges in four channels, leading to asymmetric singularity distributions. The positions of singularities in the superimposed beam can be further modulated by introducing an initial phase difference in the metasurface design. The work demonstrates a compact metasurface platform that performs a sophisticated optical task that is very challenging with conventional optics, opening opportunities for the investigation and applications of GPVBs in a wide range of emerging application areas, such as singular optics and quantum science.}},
author = {{Ahmed, Hammad and Intaravanne, Yuttana and Ming, Yang and Ansari, Muhammad Afnan and Buller, Gerald S. and Zentgraf, Thomas and Chen, Xianzhong}},
issn = {{0935-9648}},
journal = {{Advanced Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
number = {{30}},
publisher = {{Wiley}},
title = {{{Multichannel Superposition of Grafted Perfect Vortex Beams}}},
doi = {{10.1002/adma.202203044}},
volume = {{34}},
year = {{2022}},
}
@article{46012,
abstract = {{Nickel–iron oxide electrocatalysts prepared via a rapid electrodeposition are promising candidates for non-enzymatic glucose sensors.}},
author = {{Ni, Ming and Tan, Minyuan and Pan, Ying and Zhu, Chuhong and Du, Haiwei}},
issn = {{2050-7526}},
journal = {{Journal of Materials Chemistry C}},
keywords = {{Materials Chemistry, General Chemistry}},
number = {{35}},
pages = {{12883--12891}},
publisher = {{Royal Society of Chemistry (RSC)}},
title = {{{Rapid preparation of self-supported nickel–iron oxide as a high-performance glucose sensing platform}}},
doi = {{10.1039/d2tc03176k}},
volume = {{10}},
year = {{2022}},
}