@article{41500, abstract = {{Titanium alloys, especially β alloys, are favorable as implant materials due to their promising combination of low Young’s modulus, high strength, corrosion resistance, and biocompatibility. In particular, the low Young’s moduli reduce the risk of stress shielding and implant loosening. The processing of Ti-24Nb-4Zr-8Sn through laser powder bed fusion is presented. The specimens were heat-treated, and the microstructure was investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The mechanical properties were determined by hardness and tensile tests. The microstructures reveal a mainly β microstructure with α″ formation for high cooling rates and α precipitates after moderate cooling rates or aging. The as-built and α″ phase containing conditions exhibit a hardness around 225 HV5, yield strengths (YS) from 340 to 490 MPa, ultimate tensile strengths (UTS) around 706 MPa, fracture elongations around 20%, and Young’s moduli about 50 GPa. The α precipitates containing conditions reveal a hardness around 297 HV5, YS around 812 MPa, UTS from 871 to 931 MPa, fracture elongations around 12%, and Young’s moduli about 75 GPa. Ti-24Nb-4Zr-8Sn exhibits, depending on the heat treatment, promising properties regarding the material behavior and the opportunity to tailor the mechanical performance as a low modulus, high strength implant material.}}, author = {{Hein, Maxwell and Lopes Dias, Nelson Filipe and Pramanik, Sudipta and Stangier, Dominic and Hoyer, Kay-Peter and Tillmann, Wolfgang and Schaper, Mirko}}, issn = {{1996-1944}}, journal = {{Materials}}, keywords = {{General Materials Science}}, number = {{11}}, publisher = {{MDPI AG}}, title = {{{Heat Treatments of Metastable β Titanium Alloy Ti-24Nb-4Zr-8Sn Processed by Laser Powder Bed Fusion}}}, doi = {{10.3390/ma15113774}}, volume = {{15}}, year = {{2022}}, } @article{41503, abstract = {{The quasi in-situ indentation behaviour of <110>||BD and <111>||BD-oriented grains in a FeCo alloy is studied in this investigation. The effect of build height on melt pool shape and melt pool size is also studied by finite element method simulations. As the building height increases, the aspect ratio of the elliptical melt pool increases. Correspondingly, the effect of the laser scan speed on the melt pool shape and size is studied by the finite element method, because, as the laser scan speed increases, the aspect ratio of the elliptical melt pool increases, too. The microstructural characterisation of the indentation area before and after indentation is performed by electron backscatter diffraction (EBSD). Based on the EBSD data grain reference orientation deviation (GROD), calculations are performed to describe the effect of indentations on the neighbouring grain orientations. High GROD angles are detected in the neighbouring grain region adjoining the indented grain. An in-depth slip trace analysis shows the activation of all three slip systems ({110}<111>, {112}<111> and {123}<111>) which is also confirmed by slip lines on the sample surface that are detected by laser scanning confocal microscopy. A high concentration of geometrically necessary dislocations (GNDs) are observed on the adjoining area to the indentation. Local surface topography measurements by laser scanning confocal microscopy confirmed the formation of pile-ups near the indentation.}}, author = {{Pramanik, Sudipta and Tasche, Frederik and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{2673-8724}}, journal = {{Magnetism}}, keywords = {{General Earth and Planetary Sciences, General Environmental Science}}, number = {{2}}, pages = {{88--104}}, publisher = {{MDPI AG}}, title = {{{Orientation-Dependent Indentation Behaviour of Additively Manufactured FeCo Sample: A Quasi In-Situ Study}}}, doi = {{10.3390/magnetism2020007}}, volume = {{2}}, year = {{2022}}, } @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{44238, abstract = {{In numerous turbomachinery applications, e.g., in aero-engines with regenerators for improving specific fuel consumption (SFC), heat exchangers with low-pressure loss are required. Pil low-plate heat exchangers (PPHE) are a novel exchanger type and promising candidates for high-speed flow applications due to their smooth profiles avoiding blunt obstacles in the flow path. This work deals with the overall system behavior and gas dynamics of pillow-plate channels. A pillow-plate channel was placed in the test section of a blow-down wind tunnel working with dry air, and compressible flow phenomena were investigated utilizing conventional and focusing schlieren optics; furthermore, static and total pressure measurements were performed. The experiments supported the assumption that the system behavior can be described through a Fanno–Rayleigh flow model. Since only wavy walls with smooth profiles were involved, linearized gas dynamics was able to cover important flow features within the channel. The effects of the wavy wall structures on pressure drop and Mach number distribution within the flow path were investigated, and a good qualitative agreement with theoretical and numerical predictions was found. The present analysis demonstrates that pressure losses in pillow-plate heat exchangers are rather low, although their strong turbulent mixing enables high convective heat transfer coefficients.}}, author = {{Sundermeier, Stephan and Passmann, Maximilian and aus der Wiesche, Stefan and Kenig, Eugeny Y.}}, issn = {{2504-186X}}, journal = {{International Journal of Turbomachinery, Propulsion and Power}}, keywords = {{Mechanical Engineering, Energy Engineering and Power Technology, Aerospace Engineering}}, number = {{2}}, publisher = {{MDPI AG}}, title = {{{Flow in Pillow-Plate Channels for High-Speed Turbomachinery Heat Exchangers}}}, doi = {{10.3390/ijtpp7020012}}, volume = {{7}}, year = {{2022}}, } @article{44243, author = {{Kenig, Eugeny Y.}}, journal = {{Chemical Engineering Transactions}}, pages = {{325--330}}, title = {{{State-of-the-Art Modeling of Separation Columns: A Review}}}, volume = {{94}}, year = {{2022}}, } @inproceedings{33887, author = {{Mamedov, Tural and Schleicher, Eckhard and Schubert, Markus and Ehlert, Thomas and Kenig, Eugeny Y. and Hampel, Uwe}}, booktitle = {{Proceedings of the 12th international conference Distillation & Absorption 2022}}, location = {{Toulouse, France }}, title = {{{Flow Morphology of TEG Desiccant in a Structured Packing Air Dehumidifier Exposed to Floating Conditions}}}, year = {{2022}}, } @inbook{34113, author = {{Haase, Michael and Zimmer, Detmar}}, booktitle = {{Innovative Product Development by Additive Manufacturing 2021}}, isbn = {{9783031059179}}, publisher = {{Springer International Publishing}}, title = {{{Systematic Investigations Concerning Eddy Currents in Additively Manufactured Structures}}}, doi = {{10.1007/978-3-031-05918-6_10}}, 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{34654, author = {{Kusoglu, Ihsan Murat and Vieth, Pascal and Heiland, Steffen and Huber, Florian and Lüddecke, Arne and Ziefuss, Anna Rosa and Kwade, Arno and Schmidt, Michael and Schaper, Mirko and Barcikowski, Stephan and Grundmeier, Guido}}, issn = {{2212-8271}}, journal = {{Procedia CIRP}}, keywords = {{General Medicine}}, pages = {{10--13}}, publisher = {{Elsevier BV}}, title = {{{Microstructure and corrosion properties of PBF-LB produced carbide nanoparticles additivated AlSi10Mg parts}}}, doi = {{10.1016/j.procir.2022.08.046}}, volume = {{111}}, year = {{2022}}, } @article{28766, author = {{Sander, Sascha and Meschut, Gerson and Kroll, U. and Matzenmiller, A.}}, issn = {{0143-7496}}, journal = {{International Journal of Adhesion and Adhesives}}, publisher = {{Elsevier}}, title = {{{Methodology for the systematic investigation of the hygrothermal-mechanical behavior of a structural epoxy adhesive}}}, doi = {{10.1016/j.ijadhadh.2021.103072}}, year = {{2022}}, } @article{23785, abstract = {{Abstract In two-phase flows in which the Capillary number is low, errors in the computation of the surface tension force at the interface cause Front-Capturing methods such as Volume of Fluid (VOF) and Level-Set (LS) to develop interfacial spurious currents. To better solve low Capillary number flows, special treatment is required to reduce such spurious currents. Smoothing the phase indicator field to more accurately compute the curvature or adding interfacial artificial viscosity are techniques that can treat this problem. This study explores OpenFOAM, Fluent and StarCCM+ VOF solvers for the classical case of a static bubble/droplet immersed in a continuous aqueous phase, with the focus on the ability of these solvers to adequately reduce spurious currents. The results are expected to be helpful for practicing chemical engineers who use multiphase CFD solvers in their work.}}, author = {{Inguva, Venkatesh and Schulz, Andreas and Kenig, Eugeny}}, issn = {{1934-2659}}, journal = {{Chemical Product and Process Modeling}}, pages = {{121--135}}, title = {{{On methods to reduce spurious currents within VOF solver frameworks. Part 1: a review of the static bubble/droplet}}}, volume = {{17}}, year = {{2022}}, } @article{44236, author = {{Wende, Marc and Staggenborg, Christoph and Kenig, Eugeny Y.}}, issn = {{0009-2509}}, journal = {{Chemical Engineering Science}}, keywords = {{Applied Mathematics, Industrial and Manufacturing Engineering, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Modelling and simulation of zero-gravity distillation units with metal foams}}}, doi = {{10.1016/j.ces.2021.117097}}, volume = {{247}}, year = {{2022}}, } @inproceedings{33479, author = {{Bothe, Mike and Lutters, Nicole and Kenig, Eugeny Y.}}, booktitle = {{Proceedings of the 12th international conference Distillation & Absorption 2022}}, location = {{Toulouse, France}}, title = {{{Model Based and Experimental Analysis of the Dynamic Reactive Absorption Loop Behavior}}}, year = {{2022}}, } @inbook{44266, author = {{Kenig, Eugeny Y.}}, booktitle = {{Process Intensification by Reactive and Membrane-assisted Separations}}, editor = {{Skiborowski, Mirko and Górak, Andrzej}}, isbn = {{9783110720464}}, publisher = {{De Gruyter}}, title = {{{Modeling Concepts for Reactive Separations}}}, doi = {{10.1515/9783110720464}}, year = {{2022}}, } @article{31496, abstract = {{Carbon fiber reinforced plastics (CFRPs) gained high interest in industrial applications because of their excellent strength and low specific weight. The stacking sequence of the unidirectional plies forming a CFRP laminate, and their thicknesses, primarily determine the mechanical performance. However, during manufacturing, defects, e.g., pores and residual stresses, are induced, both affecting the mechanical properties. The objective of the present work is to accurately measure residual stresses in CFRPs as well as to investigate the effects of stacking sequence, overall laminate thickness, and the presence of pores on the residual stress state. Residual stresses were measured through the incremental hole-drilling method (HDM). Adequate procedures have been applied to evaluate the residual stresses for orthotropic materials, including calculating the calibration coefficients through finite element analysis (FEA) based on stacking sequence, laminate thickness and mechanical properties. Using optical microscopy (OM) and computed tomography (CT), profound insights into the cross-sectional and three-dimensional microstructure, e.g., location and shape of process-induced pores, were obtained. This microstructural information allowed for a comprehensive understanding of the experimentally determined strain and stress results, particularly at the transition zone between the individual plies. The effect of pores on residual stresses was investigated by considering pores to calculate the calibration coefficients at a depth of 0.06 mm to 0.12 mm in the model and utilizing these results for residual stress evaluation. A maximum difference of 46% in stress between defect-free and porous material sample conditions was observed at a hole depth of 0.65 mm. The significance of employing correctly calculated coefficients for the residual stress evaluation is highlighted by mechanical validation tests.}}, author = {{Wu, Tao and Kruse, Roland and Tinkloh, Steffen Rainer and Tröster, Thomas and Zinn, Wolfgang and Lauhoff, Christian and Niendorf, Thomas}}, issn = {{2504-477X}}, journal = {{Journal of Composites Science}}, keywords = {{Engineering (miscellaneous), Ceramics and Composites}}, number = {{5}}, publisher = {{MDPI AG}}, title = {{{Experimental Analysis of Residual Stresses in CFRPs through Hole-Drilling Method: The Role of Stacking Sequence, Thickness, and Defects}}}, doi = {{10.3390/jcs6050138}}, volume = {{6}}, 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{32814, author = {{Wu, T. and Degener, S. and Tinkloh, Steffen Rainer and Liehr, A. and Zinn, W. and Nobre, J.P. and Tröster, Thomas and Niendorf, T.}}, issn = {{0263-8223}}, journal = {{Composite Structures}}, keywords = {{Civil and Structural Engineering, Ceramics and Composites}}, publisher = {{Elsevier BV}}, title = {{{Characterization of residual stresses in fiber metal laminate interfaces - A combined approach applying hole-drilling method and energy-dispersive X-ray diffraction}}}, doi = {{10.1016/j.compstruct.2022.116071}}, year = {{2022}}, } @inproceedings{44267, author = {{Wende, Marc and Kenig, Eugeny Y.}}, booktitle = {{Proceedings Int. Conf. „Distillation and Absorption 2022”}}, title = {{{Modeling of a hybrid process combining zero-gravity distillation and vapor permeation}}}, year = {{2022}}, }