TY - JOUR A1 - Schmitt, Matthias A1 - Gottwalt, Albin A1 - Winkler, Jakob A1 - Tobie, Thomas A1 - Schlick, Georg A1 - Stahl, Karsten A1 - Tetzlaff, Ulrich A1 - Schlip, Johannes A1 - Reinhart, Gunther T1 - Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion JF - Metals N2 - The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed. UR - https://doi.org/10.3390/met11060896 KW - additive manufacturing KW - PBF-LB/M KW - in situ alloying KW - case-hardening steel KW - 16MnCr5 KW - gears KW - multi-material Y1 - 2021 UR - https://doi.org/10.3390/met11060896 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-10976 SN - 2075-4701 N1 - This article belongs to the Special Issue Advances in Additive Manufacturing of Metals VL - 11 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Graf, Karin A1 - Tetzlaff, Ulrich A1 - Biscaia de Souza, Gelson A1 - Scheid, Adriano T1 - Effect of Dilution on the Microstructure and Properties of CoCrMoSi alloy Coatings Processed on High-Carbon Substrate JF - Materials Research: Revista Ibero-Americana de Materiais N2 - The Laves phase reinforced CoCrMoSi alloy system has emerged as a candidate material to protect the surface of components to withstand harsh environments under wear and/or corrosion. However, previous reports have raised some concerns and restricted a wider selection of iron-based substrates to be coated, especially limiting the carbon content. This work aims to outline the Laves - Carbides phases in the microstructure and its effect on the properties of T400 alloy deposited on GGG40 ductile iron. Dilution of 26 % ensured Laves formation either as primary or secondary, due to high-silicon substrate selected. Departing from 41 % dilution, the alloy changed to a completely carbide strengthened system. Therefore, for the lowest dilution the coatings hardness is dictated by Laves phase whereas, for higher ones, carbides are the most influent phases. UR - https://doi.org/10.1590/1980-5373-MR-2018-0502 KW - CoCrMoSi Alloy KW - Microstructure KW - Coatings KW - High-Carbon Substrate Y1 - 2018 UR - https://doi.org/10.1590/1980-5373-MR-2018-0502 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-9593 SN - 1980-5373 SN - 1516-1439 VL - 22 IS - 1 PB - Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) CY - São Carlos ER - TY - JOUR A1 - Gottwalt, Albin A1 - Kubaschinski, Paul A1 - Waltz, Manuela A1 - Tetzlaff, Ulrich T1 - Influence of shear cutting parameters on the edge properties and the fatigue behavior of non‐oriented electrical steel sheets JF - Materials Science & Engineering Technology N2 - The fatigue behavior of a fully processed, non‐oriented electrical steel sheet is investigated for different shear cutting parameters. Therefore, three cutting clearances (15 μm, 35 μm and 50 μm) in combination with two different punching tool wear states (sharp and worn) are compared regarding their mechanical properties. For this purpose, surface measurements, nanoindentation tests and stress‐controlled fatigue tests with a positive load ratio are performed for all six parameter sets. During shear cutting the material gets locally strain‐hardened and a deformed surface with micro‐notches is created. Compared to a polished reference condition, the fatigue strength of the shear‐cut sheets is severely deteriorated. However, the intensity of deterioration varies depending on the shear cutting parameters. For small cutting clearances, the highest fatigue life is observed for a sharp cutting tool. In contrast, for medium and high cutting clearances, samples that are cut with a worn tool achieve higher fatigue lives. Surface characteristics in the fracture zone, which act as a failure‐critical crack location, are considered as the main influencing factor. N2 - Das Ermüdungsverhalten eines vollständig schlussgeglühten, nicht kornorientierten Elektroblechs wird für verschiedene Parameterkombinationen während des Scherschneidens untersucht. Dazu werden drei Schnittspaltbreiten (15 μm, 35 μm und 50 μm) in Kombination mit zwei unterschiedlichen Verschleißzuständen der Stanzwerkzeugen (neuwertig und verschlissen) verglichen. Zu diesem Zweck werden für alle sechs Parametersätze Topographiemessungen, Nanohärtemessungen und spannungsgeregelte Ermüdungsversuche mit einem positiven Lastverhältnis durchgeführt. Die Schnittkanten sind als Folge des Scherschneidens lokal kaltverfestigt und es entsteht zudem eine raue Oberfläche mit Mikrokerben. Im Vergleich zu einem polierten Referenzzustand ist die Ermüdungsfestigkeit der schergeschnittenen Bleche dadurch verschlechtert. Die Intensität der Verschlechterung hängt jedoch von den Scherschneidparametern ab. Bei kleinen Schnittspalten wird die höchste Ermüdungslebensdauer für einen neuwertigen Schneidwerkzeug beobachtet. Im Gegensatz dazu erreichen Proben, die mit einem verschlissenen Werkzeug geschnitten werden, bei mittleren und großen Schnittspalten eine höhere Ermüdungslebensdauer. Die Oberflächenbeschaffenheit in der Bruchzone, die als versagenskritische Anrissposition wirkt, wird hierbei als Haupteinflussfaktor angesehen. T2 - Einfluss von Scherschneidparametern auf die Kanteneigenschaften und das Ermüdungsverhalten von nicht kornorientierten Elektroblechen UR - https://doi.org/10.1002/mawe.202400094 Y1 - 2025 UR - https://doi.org/10.1002/mawe.202400094 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-59378 SN - 0933-5137 VL - 56 IS - 4 SP - 537 EP - 548 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Kiehl, Maximilian A1 - Scheid, Adriano A1 - Graf, Karin A1 - Ernst, Benedikt A1 - Tetzlaff, Ulrich T1 - Coaxial Laser Cladding of Cobalt-Base Alloy Stellite™ 6 on Grey Cast Iron Analysis of the Microstructural and Mechanical Properties Depending on the Laser Power JF - Journal of Materials Engineering and Performance N2 - A high-power diode laser was used to generate single- and multi-bead coatings of Stellite™ 6 by coaxial laser cladding over flat grey cast iron (EN-GJLP-200) as a preliminary study to develop a wear and corrosion resistant coating for brake disks on a cost-effective substrate. In this article, we have focused on a detailed quantitative analysis of the effect of different laser powers (1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 kW) on the bead geometry, dilution, microstructure, and hardness. Coatings dilution or composition depends directly on the laser power as well as bead geometry. The typical microstructure of the coatings comprises a solid solution of α (hcp)- and β (fcc)-Co with a dendritic structure as a metal matrix and an interdendritic lamellar eutectic, which contains predominantly β-Co, chromium carbides Cr7C3 and Cr23C6 as well as blocky tungsten carbide W2C. Coating hardness depends on the chemical composition and microstructure that is modified by the deposition parameters. Low laser power results in high carbide fraction and most refined microstructures, accounting for harder coatings. UR - https://doi.org/10.1007/s11665-022-07358-3 KW - bead geometry KW - grey cast iron KW - hardness KW - laser power KW - microstructure KW - Stellite 6™ Y1 - 2022 UR - https://doi.org/10.1007/s11665-022-07358-3 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-31249 SN - 1544-1024 SN - 1059-9495 VL - 32 IS - 8 SP - 3821 EP - 3838 PB - Springer CY - New York ER - TY - JOUR A1 - Güldali, Derya A1 - De Rose, Angela A1 - Mittag, Max A1 - Grübel, Benjamin A1 - Neuhaus, Holger A1 - Tetzlaff, Ulrich T1 - Interconnection of low-temperature metallization on silicon solar cells - The role of silver in tin-bismuth-based solder alloys JF - Solar Energy Materials and Solar Cells N2 - This study investigates the potential of tin-bismuth (SnBi) alloys micro-alloyed with silver (Ag) to enhance low-temperature (LT) soldering for photovoltaic (PV) modules. The primary focus is on addressing challenges such as intermetallic compound (IMC) formation, which can compromise mechanical strength and durability under thermal cycling, thereby improving the long-term stability of solder joints. A systematic investigation of the influence of the Ag amount is being conducted with the intention to find the optimal alloy composition for SnBi solder joints on LT metallization contacts. The objective is to provide a cost-effective, lead-free alternative for the interconnection of temperature-sensitive solar cells like silicon heterojunction (SHJ) cells. The findings illustrate that the addition of 0.4 %wt. Ag notably enhances the wettability and initial mechanical strength of the solder. An increase in the Ag content to 1.0 %wt. results in an excessive growth of IMC, which in turn leads to increased brittleness and potential long-term stability issues of the solder joint. Thermal cycling tests demonstrate that modules soldered with SnBiAg0.4 exhibited less than -5 % loss in power. This composition represents an optimal balance between performance and cost. These findings show the potential of SnBiAg0.4 as a suitable solder alloy regarding long-term stability and electrical performance for interconnection of LT metallization contacts of solar cells in PV module manufacturing. UR - https://doi.org/10.1016/j.solmat.2025.113488 Y1 - 2025 UR - https://doi.org/10.1016/j.solmat.2025.113488 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-57982 SN - 1879-3398 VL - 2025 IS - 285 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Volpato, Guilherme A1 - de Souza Pinto Pereira, Adriano A1 - Lemos, Georges A1 - Schmitt, Matthias A1 - Glatzel, Uwe A1 - Pyczak, Florian A1 - Tetzlaff, Ulrich A1 - Fredel, Márcio Celso T1 - Out-of-Equilibrium Formation of Ni3Ti η-Phase in Inconel X-750 Produced via Laser Powder Bed Fusion and Spark Plasma Sintering JF - Metallurgical and Materials Transactions A: Physical metallurgy and materials science UR - https://doi.org/10.1007/s11661-022-06946-1 Y1 - 2023 UR - https://doi.org/10.1007/s11661-022-06946-1 SN - 1073-5623 VL - 54 IS - 5 SP - 1924 EP - 1936 PB - Springer CY - Boston ER - TY - JOUR A1 - Volpato, Guilherme A1 - de Souza Pinto Pereira, Adriano A1 - Fredel, Márcio Celso A1 - Tetzlaff, Ulrich T1 - On the Development of a Heat Treatment for Inconel Alloy X-750 Produced Using Laser Powder Bed Fusion JF - Metallurgical and Materials Transactions A: Physical metallurgy and materials science UR - https://doi.org/10.1007/s11661-024-07589-0 Y1 - 2024 UR - https://doi.org/10.1007/s11661-024-07589-0 SN - 1073-5623 VL - 55 IS - 11 SP - 4585 EP - 4599 PB - Springer CY - Boston ER - TY - CHAP A1 - Kubaschinski, Paul A1 - Baruth, Albin A1 - Tetzlaff, Ulrich A1 - Altenbach, Holm A1 - Waltz, Manuela T1 - Untersuchungen zur Ermittlung der zyklischen Kennwerte von dünnem Elektroblech im Rahmen der rechnerischen Lebensdauerabschätzung T2 - Betriebsfestigkeit - Wissensmanagement und Methodenentwicklung entlang der Wertschöpfungskette UR - https://doi.org/10.48447/BF-2022-014 KW - cyclic material properties KW - notch strain approach KW - electrical steel KW - fatigue strength Y1 - 2022 UR - https://doi.org/10.48447/BF-2022-014 SP - 163 EP - 178 PB - DVM CY - Berlin ER - TY - CHAP A1 - Keim, Simon A1 - Tetzlaff, Ulrich A1 - Elger, Gordon T1 - The influence of different-sized Ni micro- and nanopowders on the processing and microstructural properties of Sn-Ag-Cu-solder with low Ag content T2 - Proceedings: IEEE 70th Electronic Components and Technology Conference, ECTC 2020 UR - https://doi.org/10.1109/ECTC32862.2020.00312 KW - Composites KW - Soldering KW - Porosity KW - Microstructure KW - Intermetallics KW - Phase interfaces Y1 - 2020 UR - https://doi.org/10.1109/ECTC32862.2020.00312 SN - 978-1-7281-6180-8 SN - 2377-5726 SP - 2005 EP - 2012 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Bhogaraju, Sri Krishna A1 - Conti, Fosca A1 - Kotadia, Hiren R. A1 - Keim, Simon A1 - Tetzlaff, Ulrich A1 - Elger, Gordon T1 - Novel approach to copper sintering using surface enhanced brass micro flakes for microelectronics packaging JF - Journal of Alloys and Compounds UR - https://doi.org/10.1016/j.jallcom.2020.156043 KW - Metals and alloys KW - Microstructure KW - Surfaces and interfaces KW - Sintering Y1 - 2020 UR - https://doi.org/10.1016/j.jallcom.2020.156043 SN - 1873-4669 VL - 2020 IS - 844 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mokhtari, Omid A1 - Conti, Fosca A1 - Bhogaraju, Sri Krishna A1 - Meier, Markus A1 - Schweigart, Helmut A1 - Tetzlaff, Ulrich A1 - Elger, Gordon T1 - Characterization of tin-oxides and tin-formate crystals obtained from SnAgCu solder alloy under formic acid vapor JF - New Journal of Chemistry UR - https://doi.org/10.1039/C9NJ02135C Y1 - 2019 UR - https://doi.org/10.1039/C9NJ02135C SN - 1369-9261 VL - 43 IS - 26 SP - 10227 EP - 10231 PB - RSC CY - London ER - TY - JOUR A1 - Gottwalt, Albin A1 - Kubaschinski, Paul A1 - Waltz, Manuela A1 - Glatzel, Uwe A1 - Tetzlaff, Ulrich T1 - An experimental setup for fatigue testing of thin electrical steel sheets JF - International Journal of Fatigue N2 - In this study, the fatigue behavior of thin electrical steel sheets under cyclic loading is investigated. Results from strain-controlled and stress-controlled fatigue tests with different specimen geometries and different test setups are presented and compared with conventional testing methods. The results imply that conventional testing methods should be adjusted for testing thin electrical steel sheets because the fatigue life depends significantly on the test setup as well as the specimen geometry. Therefore, this study proposes an improved specimen geometry and test setup for stress- and strain-controlled fatigue tests of thin electrical steel sheets depending on the desired testing parameters. UR - https://doi.org/10.1016/j.ijfatigue.2022.106987 KW - High cycle fatigue KW - Low cycle fatigue KW - Non-oriented electrical steel KW - Specimen geometry KW - Experimental methods Y1 - 2022 UR - https://doi.org/10.1016/j.ijfatigue.2022.106987 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-28822 SN - 0142-1123 VL - 2022 IS - 162 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Thambi, Joel Luther A1 - Schiessl, Andreas A1 - Waltz, Manuela A1 - Lang, Klaus-Dieter A1 - Tetzlaff, Ulrich T1 - Modified Constitutive Creep Laws With Micromechanical Modeling of Pb-Free Solder Alloys JF - Journal of Electronic Packaging UR - https://doi.org/10.1115/1.4035850 KW - failure analysis KW - harsh environment KW - microsystems KW - physics of failure KW - reliability KW - SMT KW - solder KW - thermal analysis Y1 - 2017 UR - https://doi.org/10.1115/1.4035850 SN - 1528-9044 SN - 1043-7398 VL - 139 IS - 3 PB - The American Society of Mechanical Engineers CY - New York ER - TY - JOUR A1 - Thambi, Joel Luther A1 - Tetzlaff, Ulrich A1 - Schiessl, Andreas A1 - Lang, Klaus-Dieter A1 - Waltz, Manuela T1 - High cycle fatigue behaviour and generalized fatigue model development of lead-free solder alloy based on local stress approach JF - Microelectronics Reliability UR - https://doi.org/10.1016/j.microrel.2016.10.004 KW - Sn3.8Ag0.7Cu (SAC) KW - high cycle fatigue KW - local stress KW - FKM guideline KW - cyclic softening KW - stress concentration KW - roughness KW - mean stress KW - solder joint KW - surface mount technology (SMT) KW - stress KW - experimental analysis KW - vibration Y1 - 2016 UR - https://doi.org/10.1016/j.microrel.2016.10.004 SN - 0026-2714 IS - 66 SP - 98 EP - 105 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Corrêa da Silva, Cauê A1 - Volpato, Guilherme A1 - Fredel, Márcio Celso A1 - Tetzlaff, Ulrich T1 - Low-pressure processing and microstructural evaluation of unidirectional carbon fiber-reinforced aluminum-nickel matrix composites JF - Journal of Materials Processing Technology UR - https://doi.org/10.1016/j.jmatprotec.2019.01.032 KW - Aluminum matrix composites KW - Carbon fibers KW - Composite processing KW - Intermetallics KW - Casting Y1 - 2019 UR - https://doi.org/10.1016/j.jmatprotec.2019.01.032 SN - 0924-0136 VL - 2019 IS - 269 SP - 10 EP - 15 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Volpato, Guilherme A1 - Fredel, Márcio Celso A1 - Tetzlaff, Ulrich T1 - Dry Sliding Wear and Fe Contamination of Investment-cast SiC Foam Reinforced Aluminum Matrix Composites T2 - EuroBrake 2019 Conference Proceedings Y1 - 2019 SN - 978-0-9572076-3-9 PB - FISITA CY - Bishops Stortford ER - TY - JOUR A1 - Lemos, Georges A1 - Fredel, Márcio Celso A1 - Pyczak, Florian A1 - Tetzlaff, Ulrich T1 - Influence of distinct manufacturing processes on the microstructure of Ni-based metal matrix composites submitted to long thermal exposure JF - Key Engineering Materials UR - https://doi.org/10.4028/www.scientific.net/KEM.809.79 KW - MMC KW - particle reinforcement KW - TiC KW - isothermal aging KW - superalloy KW - Inconel X-750 Y1 - 2019 UR - https://doi.org/10.4028/www.scientific.net/KEM.809.79 SN - 1662-9795 VL - 2019 IS - 809 SP - 79 EP - 86 PB - Trans Tech Publications CY - Baech ER - TY - CHAP A1 - Gulden, Florian A1 - Reinhold, B. A1 - Gramstat, Sebastian A1 - Tetzlaff, Ulrich A1 - Höppel, Heinz Werner ED - Pfeffer, Peter E. T1 - Investigation of the run-in and corrosion behavior of a PEO-coated aluminum brake disc T2 - 10th International Munich Chassis Symposium 2019: chassis.tech plus UR - https://doi.org/10.1007/978-3-658-26435-2_43 Y1 - 2019 UR - https://doi.org/10.1007/978-3-658-26435-2_43 SN - 978-3-658-26435-2 SN - 978-3-658-26434-5 SP - 611 EP - 631 PB - Springer Vieweg CY - Wiesbaden ER - TY - CHAP A1 - Gulden, Florian A1 - Stich, Anton A1 - Gramstat, Sebastian A1 - Höppel, Heinz Werner A1 - Tetzlaff, Ulrich T1 - Investigations of the third body using pin-on-disc and brake dynamometer on all-MMC brake rotors T2 - EuroBrake 2018 Conference Proceedings Y1 - 2018 SN - 978-1-5108-7963-8 SP - 401 EP - 407 PB - FISITA CY - Bishops Stortford ER - TY - JOUR A1 - Benedet Dutra, Gabriel A1 - Tetzlaff, Ulrich A1 - Vieira da Cunha, Tiago A1 - dos Santos, Carlos Eduardo A1 - Lemos, Georges T1 - Microstructural Characterization of an ERNiCrMo-3 and Grey Cast Iron Interface Obtained via TIG Welding JF - Metallurgical and Materials Transactions B UR - https://doi.org/10.1007/s11663-022-02549-8 Y1 - 2022 UR - https://doi.org/10.1007/s11663-022-02549-8 SN - 1073-5615 VL - 53 IS - 4 SP - 2534 EP - 2546 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Kubaschinski, Paul A1 - Gottwalt, Albin A1 - Tetzlaff, Ulrich A1 - Altenbach, Holm A1 - Waltz, Manuela T1 - Modelling and simulation of the hardness profile and its effect on the stress‐strain behaviour of punched electrical steel sheets T1 - Modellierung und Simulation des Härteprofils und dessen Einfluss auf das Spannungs-Dehnungs-Verhalten gestanzter Elektrobleche JF - Materials Science & Engineering Technology N2 - The shear cutting of electrical steel sheets has a significant influence on the magnetic and mechanical material properties. Due to plastic deformation and strain hardening in the area of the punched edge, the electrical steel sheets exhibit a characteristic hardness profile. This study deals with the modelling of the resulting hardness profile by means of finite-element simulations. Elastic-plastic material properties are obtained from spherical nanoindentation testing as a function of the local hardness. In particular, representative stress-strain values are determined by applying Tabor's concept of indentation stress-strain curves. The choice of the appropriate stress- and strain-constraint factors is discussed with respect to the nanoindentation test setup used. Following this, the representative stress-strain values are analytically described to determine true stress-strain curves for the local assignment of different material models depending on the hardness. The implementation of the modelling approach in a finite-element simulation is presented for a punched electrical steel sheet specimen under monotonic loading. The simulation results are basically in good agreement with experimental data and confirm the expected influence on the mechanical material behaviour due to the shear cutting process. N2 - Scherschneiden hat einen wesentlichen Einfluss auf die magnetischen und mechanischen Werkstoffeigenschaften von Elektroblech. Aufgrund plastischer Verformung und Kaltverfestigung im Bereich der Stanzkante weisen Elektroblechschnitte ein charakteristisches Härteprofil auf. Dieses wird in der vorliegenden Arbeit im Rahmen von Finite-Elemente-Simulationen modelliert. Elastisch-plastische Materialeigenschaften werden durch Nanoindentierung mit kugelförmigem Prüfkörper als Funktion der lokalen Härte ermittelt. Dabei handelt es sich um repräsentative Spannungs-Dehnungs- Werte, die sich mithilfe Tabors Konzept aus dem Eindruckversuch bestimmen lassen. Die Wahl geeigneter Spannungs- und Dehnungsproportionalitätsfaktoren wird unter Berücksichtigung des verwendeten Prüfaufbaus diskutiert. Im Anschluss daran erfolgt die analytische Beschreibung der repräsentativen Spannungs-Dehnungs-Werte zur Bestimmung wahrer Spannungs-Dehnungs-Kurven, die basierend auf dem zugehörigen Härtewert zur Zuweisung lokal unterschiedlicher Materialmodelle herangezogen werden. Die Umsetzung des Modellierungsansatzes geschieht für eine gestanzte Elektroblechprobe unter monotoner Beanspruchung. Der Vergleich der Simulationsergebnisse mit experimentellen Daten zeigt grundsätzlich eine gute Übereinstimmung und bestätigt den erwarteten Einfluss des Scherschneidens auf das mechanische Werkstoffverhalten. UR - https://doi.org/10.1002/mawe.202200283 KW - electrical steel KW - hardness distribution KW - material modelling KW - nanoindentation KW - punched edge KW - Elektroblech KW - Härteverteilung KW - Materialmodellierung KW - Nanoindentierung KW - Stanzkante Y1 - 2023 UR - https://doi.org/10.1002/mawe.202200283 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-38333 SN - 0933-5137 VL - 54 IS - 4 SP - 512 EP - 526 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Handwerker, Michael A1 - Kessler, Jörg A1 - Marzbani, Hormoz A1 - Tetzlaff, Ulrich T1 - Annealing of chopped and continuous fibre reinforced polyamide 6 produced by fused filament fabrication JF - Composites Part B: Engineering UR - https://doi.org/10.1016/j.compositesb.2021.109119 KW - Annealing KW - Fused filament fabrication KW - Continuous glass fiber KW - Polyamide 6 Y1 - 2021 UR - https://doi.org/10.1016/j.compositesb.2021.109119 SN - 1879-1069 VL - 2021 IS - 223 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Thambi, Joel Luther A1 - Tetzlaff, Ulrich A1 - Schiessl, Andreas A1 - Lang, Klaus-Dieter A1 - Waltz, Manuela T1 - Evaluation of the relationship between stress and lifetime of Pb-free solder joints subjected to vibration load using a generalized local stress approach JF - Microelectronics Reliability UR - https://doi.org/10.1016/j.microrel.2019.113560 KW - SnAgCu KW - High cycle fatigue (HCF) KW - Local stress KW - FKM guideline KW - Stress gradient KW - Roughness KW - Solder alloys KW - Experimental analysis KW - FEA KW - Surface mount technology (SMT) KW - Vibration KW - Harmonic frequency KW - Bulk solder KW - Fatigue KW - Durability KW - Solder joint failure KW - Component testing KW - Material characterisation KW - Chip capacitor KW - Transformer Y1 - 2020 UR - https://doi.org/10.1016/j.microrel.2019.113560 SN - 0026-2714 VL - 2020 IS - 106 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tetzlaff, Ulrich A1 - Gerber, Alexander A1 - Amelang, Rudolf A1 - Lemos, Georges T1 - Investigation of the Creep Resistance of a Spray-Compacted Si-Particle Reinforced Al-Based MMC (Dispal® S270) JF - Key Engineering Materials UR - https://doi.org/10.4028/www.scientific.net/KEM.809.87 KW - Creep resistance KW - MMC KW - particle reinforcement KW - multi-phase KW - microstructure analysis Y1 - 2019 UR - https://doi.org/10.4028/www.scientific.net/KEM.809.87 SN - 1662-9795 VL - 2019 IS - 809 SP - 87 EP - 93 PB - Trans Tech Publications CY - Baech ER - TY - JOUR A1 - Kubaschinski, Paul A1 - Gottwalt, Albin A1 - Tetzlaff, Ulrich A1 - Altenbach, Holm A1 - Waltz, Manuela T1 - Calibration of a combined isotropic-kinematic hardening material model for the simulation of thin electrical steel sheets subjected to cyclic loading T1 - Kalibrierung eines Materialmodells für die Simulation von zyklisch beanspruchten dünnen Elektroblechen unter Berücksichtigung kombinierter isotroper-kinematischer Verfestigung JF - Materials Science & Engineering Technology JF - Materialwissenschaft und Werkstofftechnik N2 - The combined isotropic-kinematic hardening model enables the description of the cyclic transient elastic-plastic material behaviour of steel. However, the determination of the material model parameters and understanding of their influence on the material response can be a challenging task. This study deals with the individual steps of the material model calibration for the simulation of thin electrical steel sheets under cyclic loading. Specific recommendations are made for the determination of kinematic and isotropic hardening material parameters. In particular, the isotropic hardening evolution is described by Voce's exponential law and a simple multilinear approach. Based on the multilinear approach, which allows for different slopes in the evolution of the yield surface size, an alternative calibration of the isotropic hardening component is proposed. As a result, the presence of the yield plateau in the first half cycle can be accurately captured, while convergence issues in the material model definition for numerical simulations can be avoided. The comparison of simulated load cycles with experimental cyclic tests shows a good agreement, which indicates the suitability of the proposed material model calibration for electrical steel. N2 - Die Berücksichtigung kombinierter isotroper-kinematischer Verfestigung ermöglicht die Beschreibung und Modellierung des transienten elastisch-plastischen Werkstoffverhaltens von Stahl. Die Ermittlung der zugrunde liegenden Materialparameter und das Verständnis für deren Einfluss auf die Materialantwort stellt jedoch häufig eine anspruchsvolle Aufgabe dar. In der vorliegenden Arbeit wird auf die einzelnen Schritte bei der Kalibrierung des Materialmodells im Rahmen einer Simulation von zyklisch beanspruchten dünnen Elektroblechen eingegangen. Dabei werden konkrete Empfehlungen für die Ermittlung der kinematischen und isotropen Verfestigungsparameter gegeben. Die Evolutionsgleichung der isotropen Verfestigung wird sowohl durch einen Exponentialansatz nach Voce als auch durch einen einfachen multilinearen Ansatz beschrieben. Basierend auf dem multilinearen Ansatz, der unterschiedliche Steigungen in der Evolution der Fließfläche ermöglicht, wird eine alternative Kalibrierung der isotropen Komponente vorgeschlagen. Dadurch kann das auftretende Fließplateau im ersten Halbzyklus präzise erfasst werden, während Konvergenzprobleme des Materialmodells vermieden werden. Der Vergleich von simulierten Belastungszyklen mit experimentellen Daten zeigt eine gute Übereinstimmung, was für die Eignung des vorgeschlagenen Kalibrierungsprozesses für Elektroblech spricht. UR - https://doi.org/10.1002/mawe.202100341 KW - cyclic plasticity KW - material model KW - combined hardening KW - finite-element simulation KW - electrical steel KW - zyklische Plastizität KW - Materialmodell KW - kombinierte Verfestigung KW - Finite-Elemente-Simulation KW - Elektroblech Y1 - 2022 UR - https://doi.org/10.1002/mawe.202100341 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-22478 SN - 1521-4052 VL - 53 IS - 4 SP - 422 EP - 439 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kiehl, Maximilian A1 - Scheid, Adriano A1 - Graf, Karin A1 - Ernst, Benedikt A1 - Tetzlaff, Ulrich T1 - Coaxial laser cladding of cobalt-base alloy Stellite™ 6 on gray cast iron/investigations on friction, wear versus commercial brake pad, and corrosion characteristics JF - Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering UR - https://doi.org/10.1177/09544070221145512 Y1 - 2023 UR - https://doi.org/10.1177/09544070221145512 SN - 2041-2991 SN - 0954-4070 VL - 237 IS - 14 SP - 3285 EP - 3303 PB - Sage CY - London ER - TY - JOUR A1 - Ernst, Benedikt A1 - Keim, Simon A1 - Tetzlaff, Ulrich T1 - On the anisotropic indentation modulus and anisotropic creep behavior of β-Sn characterized by nanoindentation methods JF - Materials Science and Engineering: A UR - https://doi.org/10.1016/j.msea.2022.143392 Y1 - 2022 UR - https://doi.org/10.1016/j.msea.2022.143392 SN - 1873-4936 SN - 0921-5093 VL - 2022 IS - 848 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Handwerker, Michael A1 - Kessler, Jörg A1 - Marzbani, Hormoz A1 - Tetzlaff, Ulrich T1 - Pressure and heat treatment of continuous fibre reinforced thermoplastics produced by fused filament fabrication JF - Progress in Additive Manufacturing N2 - Fused filament fabrication allows for the additive manufacturing of complex geometries without requiring moulds. However, due to large air voids and poor layer adhesion, the mechanical properties of parts manufactured using fused filament fabrication lag behind those of parts manufactured using conventional techniques. A previous study found that the tensile strength and Young’s modulus of such parts could be increased by a heat-treatment process. However, large air voids were still present after annealing. This study, therefore, investigates the influence of a post-pressure-treatment process on the mechanical performance and the air void ratio of continuous glass fibre-reinforced polyamide 6 in the directions perpendicular to the fibres. Without the treatment, Young’s modulus on the plane parallel to the printing bed is eight times higher than Young’s modulus perpendicular to it. Annealing at 1 MPa homogenises the material and leads to a significant increase of both the tensile strength (55 MPa) and Young’s modulus (5 GPa). Increasing the pressure to 3 MPa only slightly increases the mechanical performance, whereas a further increase to 6 MPa causes no significant changes. UR - https://doi.org/10.1007/s40964-022-00315-5 KW - Pressure treatment KW - Fused filament fabrication KW - Continuous glass fibre KW - Polyamide 6 Y1 - 2022 UR - https://doi.org/10.1007/s40964-022-00315-5 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-31239 SN - 2363-9520 SN - 2363-9512 VL - 8 IS - 2 SP - 99 EP - 116 PB - Springer CY - Cham ER - TY - JOUR A1 - Lemos, Georges A1 - Fredel, Márcio Celso A1 - Pyczak, Florian A1 - Tetzlaff, Ulrich T1 - Creep resistance improvement of a polycrystalline Ni-based superalloy via TiC particles reinforcement JF - Materials Science and Engineering: A UR - https://doi.org/10.1016/j.msea.2022.143821 Y1 - 2022 UR - https://doi.org/10.1016/j.msea.2022.143821 SN - 1873-4936 SN - 0921-5093 VL - 2022 IS - 854 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Volpato, Guilherme A1 - Tetzlaff, Ulrich A1 - Fredel, Márcio Celso T1 - A comprehensive literature review on laser powder bed fusion of Inconel superalloys JF - Additive Manufacturing UR - https://doi.org/10.1016/j.addma.2022.102871 KW - Inconel 718 KW - Inconel 625 KW - Laser powder bed fusion KW - Selective laser melting KW - Additive manufacturing Y1 - 2022 UR - https://doi.org/10.1016/j.addma.2022.102871 SN - 2214-7810 SN - 2214-8604 VL - 2022 IS - 55 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ernst, Benedikt A1 - Kubaschinski, Paul A1 - Schiessl, Andreas A1 - Waltz, Manuela A1 - Höppel, Heinz Werner A1 - Tetzlaff, Ulrich T1 - Comparison of the Young’s modulus of the lead free solder alloy Sn-Ag3.8-Cu0.7 determined by hot tensile tests, ultrasonic measurements and 𝛽-Sn single crystal calculations JF - Materials Science and Engineering: A N2 - Sn-based solders are known for their tendency to form coarse grained microstructures. In combination with the high elastic anisotropy of 𝛽-Sn, the overall elastic properties and their interpretation require a careful discussion of the structure–property-relationship as elastic constants are often important input parameters for creep or fatigue models. This study therefore investigates the influence of microstructure and testing method on the Young’s modulus E for the widespread lead free solder alloy Sn-Ag3.8-Cu0.7 (SAC387) using bulk specimens. Due to its already high homologous temperature at room temperature (Thom ≈ 0.6 = T/Tm for Tm being the melting temperature), hot tensile tests generally bear the risk of superimposed creep deformation. Mechanical testing becomes even more challenging, since yield strengths are usually low for these alloys. Consequently, in addition to the hot tensile tests executed for the engineering strain rate 𝜖̇𝑒 = 1 ⋅ 10−3 s−1, two supplemental methods are used to determine the Young’s modulus comprising of the dynamic resonance frequency measurement and the calculation of the Young’s modulus based on single crystal compliance data of the majority phase 𝛽-Sn.Young’s moduli yielded from dynamic resonance frequency measurement and calculations based on single crystal compliance data showed comparable results of (E35 ◦C ≈ 55 GPa, E80 ◦C ≈ 51 GPa and E125 ◦C ≈ 48 GPa). Hot tensile tests showed similar data with the largest deviation at 80 ◦C, where E80 ◦C ≈ 53 GPa was determined. These absolute values and their temperature dependence can be attributed to the microstructure of the cast specimens which show a general preferred orientation of 𝛽-Sn grains close to <110> after analysis via electron backscattered diffraction (EBSD). A comparison with literature data revealed significant differences in the Young’s moduli which are likely to be attributed to differences in the preferred orientation of 𝛽-Sn grains. UR - https://doi.org/10.1016/j.msea.2024.147354 Y1 - 2024 UR - https://doi.org/10.1016/j.msea.2024.147354 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-52143 SN - 1873-4936 SN - 0921-5093 VL - 2024 IS - 916 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gottwalt, Albin A1 - Kubaschinski, Paul A1 - Waltz, Manuela A1 - Tetzlaff, Ulrich T1 - Influence of the cutting method on the fatigue life and crack initiation of non-oriented electrical steel sheets JF - International Journal of Fatigue N2 - The fatigue behavior of thin electrical steel sheets under cyclic loading is investigated in dependence on the edge surface. Therefore, four different edge conditions are compared, whereas the edge is either laser cut, shear cut, wire cut, or polished. Strain- and stress-controlled fatigue tests are performed to determine S-N curves in the low cycle regime as well as in the high cycle regime. Microstructural data is collected by non-contacting (optical) Profilometry, Nanoindentation, X-Ray Diffraction, and Electron Backscatter Diffraction to understand the differences in fatigue life by considering surface roughness, residual stresses, hardness, and microstructure. Shear cut specimens achieve the lowest fatigue life, while the other edge conditions reach relatively similar values in the LCF regime. Crack initiation is mainly intergranular in the case of defect-free edges. This tendency has a considerable influence on the observed fatigue behavior. UR - https://doi.org/10.1016/j.ijfatigue.2023.108073 Y1 - 2023 UR - https://doi.org/10.1016/j.ijfatigue.2023.108073 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-46260 SN - 1879-3452 SN - 0142-1123 VL - 2024 IS - 180 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Gottwalt, Albin A1 - Kubaschinski, Paul A1 - Waltz, Manuela A1 - Völkl, Rainer A1 - Glatzel, Uwe A1 - Tetzlaff, Ulrich T1 - Cyclic deformation behavior of non-oriented electrical steel sheets JF - Materials Science and Engineering: A UR - https://doi.org/10.1016/j.msea.2023.145684 Y1 - 2023 UR - https://doi.org/10.1016/j.msea.2023.145684 SN - 0921-5093 SN - 1873-4936 VL - 2023 IS - 886 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Vieweger, Daniel A1 - Diel, Sergej A1 - Schweiger, Hans-Georg A1 - Tetzlaff, Ulrich T1 - Mechanical Properties of Raw Filaments and Printed Specimens: Effects of Fiber Reinforcements and Process Parameters JF - Polymers N2 - Fused Deposition Modeling (FDM) is a well-established manufacturing method for producing both prototype and functional components. This study investigates the mechanical properties of FDM components by material and process-related influencing variables. Tensile tests were conducted on seven different materials in their raw filament form, two of which were fiber-reinforced, to analyze their material-related influence. To cover a wide range from standard to advanced materials relevant for load-carrying components as well as their respective variations, polylactic acid (PLA), 30% wood-fiber-reinforced PLA, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), a blend of ABS and PC, Nylon, and 30% glass-fiber-reinforced Nylon were selected. The process-related influencing variables were studied using the following process parameters: layer thickness, nozzle diameter, build orientation, nozzle temperature, infill density and pattern, and raster angle. The first test series revealed that the addition of wood fibers significantly worsened the mechanical behavior of PLA due to the lack of fiber bonding to the matrix and significant pore formation. The polymer blend of ABS and PC only showed improvements in stiffness. Significant strength and stiffness improvements were found by embedding glass fibers in Nylon, despite partially poor fiber–matrix bonding. The materials with the best properties were selected for the process parameter analysis. When examining the impact of layer thickness on part strength, a clear correlation was evident. Smaller layer thicknesses resulted in higher strength, while stiffness did not appear to be affected. Conversely, larger nozzle diameters and lower nozzle temperatures only positively impacted stiffness, with little effect on strength. The part orientation did alter the fracture behavior of the test specimens. Although an on-edge orientation resulted in higher stiffness, it failed at lower stresses. Higher infill densities and infill patterns aligned with the load direction led to the best mechanical results. The raster angle had a significant impact on the behavior of the printed bodies. An alternating raster angle resulted in lower strengths and stiffness compared to a unidirectional raster angle. However, it also caused significant stretching due to the rotation of the beads. UR - https://doi.org/10.3390/polym16111576 Y1 - 2024 UR - https://doi.org/10.3390/polym16111576 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-48595 SN - 2073-4360 VL - 16 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Gottwalt, Albin A1 - Kubaschinski, Paul A1 - Waltz, Manuela A1 - Tetzlaff, Ulrich T1 - Influence of Subsequent Heat Treatment on Fatigue Behavior of Shear-Cut Electrical Steel Sheets JF - Alloys N2 - The fatigue behavior of a fully processed, non-oriented electrical steel sheet is investigated in dependence on shear-cutting parameters and a subsequent heat treatment. For this, stress-controlled fatigue tests are performed before and after annealing at 700 °C for a total of six different shear-cutting settings. For all parameters, the fatigue strength of shear-cut sheets is improved by the heat treatment. This is due to reduction in a large part of the strain hardening region as well as the reduction in tensile residual stresses. Both were introduced during shear cutting and act detrimental to the fatigue strength. However, the intensity of this improvement depends on the shear-cutting parameters. This is related to the corresponding edge surfaces characteristically being formed during shear cutting. Specimens cut with a worn cutting tool show a more pronounced increase in fatigue life. In contrast, specimens produced with a sharp-edged cutting tool and high cutting clearance hardly benefit from the heat treatment. This appears to be caused by differences in surface topography, in particular coarse topographical damage in the form of grain breakouts. If these occur during shear cutting, the crack formation is not significantly delayed by additional annealing. UR - https://doi.org/10.3390/alloys3040017 Y1 - 2024 UR - https://doi.org/10.3390/alloys3040017 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-53767 SN - 2674-063X VL - 3 IS - 4 SP - 281 EP - 294 PB - MDPI CY - Basel ER - TY - JOUR A1 - de Souza Pinto Pereira, Adriano A1 - Gutjahr, Jhonattan A1 - Pereira, Milton A1 - Tetzlaff, Ulrich A1 - Fredel, Márcio Celso T1 - Processability of thin-powdered Inconel X750 and TiC metal matrix composite by laser-directed energy deposition JF - Journal of Laser Applications UR - https://doi.org/10.2351/7.0001134 KW - metal matrix composites KW - directed energy deposition KW - laser materials processing KW - Ni-base superalloys KW - particle reinforcement KW - microstructural characterization Y1 - 2023 UR - https://doi.org/10.2351/7.0001134 SN - 1042-346X SN - 1938-1387 N1 - Paper published as part of the special topic on Proceedings of the International Congress of Applications of Lasers & Electro-Optics 2023 VL - 35 IS - 4 PB - LIA CY - Orlando ER - TY - CHAP A1 - Mohd, Zubair Akhtar A1 - Kreiner, Christian A1 - Schmid, Maximilian A1 - Zippelius, Andreas A1 - Tetzlaff, Ulrich A1 - Elger, Gordon T1 - Fully Connected Neural Network (FCNN) Based Validation Framework for FEA Post Processing to Improve SAC Solder Reliability Analysis T2 - 2024 IEEE 10th Electronics System-Integration Technology Conference (ESTC), Proceedings UR - https://doi.org/10.1109/ESTC60143.2024.10712023 Y1 - 2024 UR - https://doi.org/10.1109/ESTC60143.2024.10712023 SN - 979-8-3503-9036-0 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Volpato, Guilherme A1 - de Souza Pinto Pereira, Adriano A1 - Neumeier, Steffen A1 - Hotza, Dachamir A1 - Göken, Mathias A1 - Tetzlaff, Ulrich A1 - Fredel, Márcio Celso T1 - Influence of a Standard Heat Treatment on the Microstructure and Properties of Inconel X‐750 Produced by Laser Powder Bed Fusion JF - Advanced Engineering Materials N2 - The production of nickel‐base superalloys through powder bed fusion using a laser beam (PBF‐LB) offers a promising method for reducing the cost of aeronautical components, especially those with complex geometries. However, when these materials are processed using PBF‐LB, the standard heat treatments developed for conventional manufacturing routes do not consistently yield predictable microstructures or mechanical properties. Thus, this study analyzes how PBF‐LB affects the microstructure and mechanical behavior of Inconel alloy X‐750 when compared to a hot‐rolled counterpart after undergoing a standard precipitation‐hardening heat treatment (solution annealing, stabilization, and precipitation). Microstructure is examined using analytical electron microscopy and high‐energy X‐ray diffraction, while mechanical behavior is assessed through microhardness. Significant differences between both manufacturing routes are detected, so that PBF‐LB processing led to an increase in grain size, anisotropy, fraction of low‐angle grain boundaries, mean angle of misorientation, and dislocation density. Moreover, PBF‐LB promoted the formation of γ′‐Ni3(Al,Ti) and η‐Ni3Ti phases during solution annealing and stabilization, respectively. Notably, the formation of γ′ contributes to an anomalous microhardness increase observed between these steps. These findings suggest that PBF‐LB may inhibit recrystallization and facilitate precipitation during heat treatment, thereby affecting the performance of components produced using this technology. UR - https://doi.org/10.1002/adem.202500306 Y1 - 2025 UR - https://doi.org/10.1002/adem.202500306 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-59386 SN - 1527-2648 VL - 27 IS - 24 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Gulden, Florian A1 - Gramstat, Sebastian A1 - Stich, Anton A1 - Hoppel, Heinz Werner A1 - Tetzlaff, Ulrich T1 - Properties and Limitation of an Oxide Coated Aluminum Brake Rotor JF - SAE Technical Paper UR - https://doi.org/10.4271/2018-01-1877 Y1 - 2018 UR - https://doi.org/10.4271/2018-01-1877 SN - 0148-7191 SN - 2688-3627 PB - SAE CY - Warrendale ER -