@article{VoyerPeterlechnerNoster, author = {Voyer, Joel and Peterlechner, Christian and Noster, Ulf}, title = {Flame sprayed Al-12Si coatings for the improvement of the adhesion of composite casting profiles}, series = {Journal of Thermal Spray Technology}, volume = {17}, journal = {Journal of Thermal Spray Technology}, number = {5-6}, publisher = {Springer}, address = {Boston, Mass.}, issn = {1544-1016}, doi = {https://doi.org/10.1007/s11666-008-9235-8}, pages = {824 -- 830}, abstract = {In this study, flame sprayed Al-12Si coatings were produced on the surface of inlays (aluminum profiles) of composite castings parts. The aim was to enhance the strength between the joining partners inlay and cast. Due to the high surface roughness and the presence of pores in the coatings, combined with the formation of an intermetallic phase at the interface, the adhesion of flame sprayed inlays could be enhanced by a factor of 2 compared to blank inlays and by a factor of 1.3 when compared to sand-blasted inlays. However, results also show that gaps are present, mostly at the interface between the inlays and the flame sprayed coatings, and these gaps have a negative effect on the joining strength of the composite casting parts. Therefore, optimizing the adhesion of the coating on the Al profiles via an improvement in both the sand-blasting and the flame spraying parameters would be beneficial for further enhancement of the adhesion of composite casting parts.}, language = {de} } @article{AntenLebsanftKraussetal., author = {Anten, Kerstin and Lebsanft, Markus and Krauß, M. and Noster, Ulf and Scholtes, Berthold}, title = {Einfluss von Randschichtzustand und Haltezeit auf die thermische Erm{\"u}dung der Magnesiumbasislegierung AZ31}, series = {Materialwissenschaft und Werkstofftechnik}, volume = {43}, journal = {Materialwissenschaft und Werkstofftechnik}, number = {12}, publisher = {Wiley}, pages = {993 -- 1000}, abstract = {Die vorliegende Arbeit befasst sich mit Untersuchungen zur thermischen Erm{\"u}dung der Magnesiumbasislegierung AZ31 im Temperaturbereich zwischen +50°C und +290°C. Die Experimente erfolgten unter konstanter Totaldeformation (out-of-phase-Beanspruchung) und es wurde der Verlauf der Spannungsamplitude sowie der plastischen Dehnungsamplitude {\"u}ber die Zahl der Temperaturzyklen ermittelt. Insbesondere wurde der Einfluss einer mechanischen Oberfl{\"a}chenbehandlung (Festwalzen) sowie von Haltezeiten auf den Verlauf der Sch{\"a}digung untersucht. In beiden F{\"a}llen konnte kein signifikanter Unterschied zu unbehandelten Proben bzw. Beanspruchungen ohne Haltezeit festgestellt werden, welches auf die Wechselwirkungen zwischen Verformungs- und Rekristallisationsprozessen bei der thermischen Erm{\"u}dung zur{\"u}ckzuf{\"u}hren ist.}, language = {en} } @inproceedings{JuijermAltenbergerNosteretal., author = {Juijerm, Patiphan and Altenberger, Igor and Noster, Ulf and Scholtes, Berthold}, title = {Residual stress relaxation and cyclic deformation behavior of deep rolled AlMg4.5Mn (AA5083) at elevated temperatures}, series = {Materials Science Forum}, volume = {490-491}, booktitle = {Materials Science Forum}, publisher = {Trans Tech Publications}, doi = {10.4028/www.scientific.net/MSF.490-491.436}, pages = {436 -- 441}, abstract = {The cyclic deformation behavior of deep rolled and polished aluminium wrought alloy AlMg4,5Mn in the temperature range 20-300°C has been investigated. Results of quasistatic tension and compression tests of untreated specimens in the temperature range 20-300°C are presented. To characterize the fatigue behavior for stress-controlled tests as a function of test temperature, s-n curves, cyclic deformations curves and mean strains as a function of number of cycles are given. The residual stress- and work hardening states near the surface of deep rolled aluminium alloy AlMg4.5Mn before and after fatigue tests were investigated by X-ray diffraction methods. The investigated AlMn4.5Mn aluminium alloy shows cyclic hardening until fracture at all stress amplitudes in stress-controlled fatigue tests at 25-150°C. With increasing temperature the deformation behavior shifts from cyclic hardening to cyclic softening. Below a certain stress amplitude at a given temperature deep rolling led to a reduction of the plastic strain amplitude as compared to the untreated state through cyclically stable near-surface work hardening as indicated by stable FWHM-values. This reduction in plastic strain amplitude is associated with enhanced fatigue lives. The effectiveness of deep rolling is governed by the cyclic and thermal stability of near-surface work hardening rather than macroscopic compressive residual stresses. Since near-surface work hardening is known to retard crack initiation, deep rolling is also effective in temperature- and stress ranges where macroscopic compressive residual stresses have relaxed almost completely, but where near-surface work hardening prevails. Above certain stress amplitudes and temperatures, deep rolling has no beneficial effect on the fatigue behavior of AlMg4.5Mn. This is a consequence of instable near-surface microstructures, especially instable near-surface work hardening.}, language = {en} } @article{KettnerNosterKilianetal., author = {Kettner, Michael and Noster, Ulf and Kilian, Helmut and Gradinger, Rudolf and Kuehlein, Wolfgang and Drevenstedt, Armin and Stadler, Franz and Ladstaetter, Elisabeth and Lutz, Andreas}, title = {The InnMag project - Processing Mg for civil aircraft application}, series = {Advanced Engineering Materials}, volume = {9}, journal = {Advanced Engineering Materials}, number = {9}, publisher = {Wiley}, doi = {10.1002/adem.200700143}, pages = {813 -- 819}, abstract = {In the context of the "InnMag" project, partners from industry and science are co-operating to investigate the issues involved in adapting established production processes to the material Mg. The project's aim is to further the deployment of Mg interior parts in civil aircraft. The project covers every production step, from alloy selection, Mg ingot melting, alloying, direct chill casting, extruding, machining, surface treatment and component assembly. This paper discusses the project's targets and the results arrived at so far, particularly in the areas of direct chill casting and extrusion.}, language = {en} } @article{MundlNoster, author = {Mundl, A. and Noster, Ulf}, title = {Topology optimization using a structural component as example}, series = {Konstruktion}, journal = {Konstruktion}, number = {1-2}, publisher = {VDI Fachmedien ; Springer}, address = {D{\"u}sseldorf}, pages = {65 -- 68}, language = {en} } @inproceedings{UcsnikGradingerNosteretal., author = {Ucsnik, Stephan A. and Gradinger, Rudolf and Noster, Ulf and Pahr, Dieter H.}, title = {Finite element based optimization of a novel metal-composite-joint}, series = {1st EUCOMAS, European Conference on Materials and Structures in Aerospace, Conference Berlin, May 26 - 27, 2008 }, booktitle = {1st EUCOMAS, European Conference on Materials and Structures in Aerospace, Conference Berlin, May 26 - 27, 2008 }, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, issn = {0083-5560}, pages = {371 -- 379}, abstract = {Aerospace and automotive industries employ three main techniques to set up joints between metal and fibre reinforced plastics parts (FRP); adhesive bonding, mechanical fastening with rives/bolts and a hybrid combination. A new joint technique has been developed to combine the two advantageous mechanisms form-closure and adhesion in a fibre-friendly way. Prior is established through metal structures (pins) which are perpendicularly welded onto metal surfaces with an arc-welding-process. They intrude into the FRP during lay-up and therefore set up a first connection. The composite-matrix is responsible for latter adhesive bonding and final form closure. Finite-element-analyses of cylindrically shaped joints are carried out to get detailed knowledge of the influence of parameters like pin-number, pin-position, pin-height, pin-form sleeve-geometry, and stiffness behaviour. Long calculation times of 3D-models lead to the introduction of a corresponding 2D-axisymmetric-model which is used to run parameter-studies within a reasonable time. For this novel technique the combination of fibre-friendly form closure and adhesive bonding of interface plays a major role. A well selected amount of vertical reinforcements, their placement and geometrical dimensions will lead to a stiffer joint. Goal is to minimize fibre-deletion and overlap length to improve load-transfer and joint-strength, to reduce weight in high-strength-applications as well as the avoidance of safety rivets.}, language = {en} } @incollection{AltenbergerNosterScholtesetal., author = {Altenberger, Igor and Noster, Ulf and Scholtes, Berthold and Ritchie, Robert O.}, title = {High Temperature Fatigue of Mechanically Surface Treated Materials}, series = {Shot peening}, booktitle = {Shot peening}, editor = {Wagner, Lothar}, publisher = {Wiley-VCH}, address = {Weinheim; [Cambridge]}, isbn = {9783527606580}, doi = {10.1002/3527606580.ch62}, pages = {483 -- 489}, abstract = {Introduction The most well known effect of mechanical surface treatments on metallic materials is the improvement in fatigue properties. It is therefore not surprising that most of the archival literature on mechanical surface treatments, such as shot peening, deep rolling and laser shock peening, deals with the effect of near-surface properties on fatigue behavior. Most of these studies, however, are confined to room temperature fatigue behavior; in comparision, the effect of mechanical surface treatment on fatigue behavior at high temperatures has been rarely investigated [1-5]. The reason for this disparity can be found in the popular belief that fatigue strength improvement by mechanical surface treatments is mainly due to the presence of compressive residual stresses, and since such stresses should anneal out at elevated temperatures, mechanical surface treatments for high temperature applications would appear questionable. However, this view may be over simplistic as there is always a possibility that the residual stresses may be at least partially stable at elevated temperatures [6]; in addition, other factors may be involved, such as the nature of the near-surface microstructure. Accordingly, it is the objective of this study to examine the role of mechanical surface treatments on the high temperature fatigue behavior of several metallic engineering materials. Moreover, it is the aim of this work to clarify what are the critical temperature "thresholds' at which near-surface microstructures and residual stresses become unstable and whether this can explain the observed fatigue behavior.}, language = {en} } @book{AltenbergerWagnerMhaedeetal., author = {Altenberger, Igor and Wagner, Lothar and Mhaede, Mansour and Juijerm, Patiphan and Noster, Ulf}, title = {Effect of Deep Rolling on the Cyclic Performance of Magnesium and Aluminium Alloys in the Temperature Range 20-250°C}, series = {The 10th International Conference on Shot Peening (ICSP), Conference Proceedings, Tokyo Japan, 15th to 18th September, 2008}, journal = {The 10th International Conference on Shot Peening (ICSP), Conference Proceedings, Tokyo Japan, 15th to 18th September, 2008}, abstract = {Mechanical surface treatments such as deep rolling or laser-shock peening can markedly affect the cyclic performance of light-weight alloys, especially if significant thick work hardened surface regions are induced. At room temperature, the cyclic deformation behaviour is strongly influenced by the nature of the induced near-surface microstructures provided that they remain stable during fatigue loading. At elevated temperatures, the stability of near-surface work hardening and local microstructures plays an even more important role since the process-induced residual compressive stresses are likely to anneal out partially or completely. This overview illustrates to what extent deep rolling can effect the cyclic performance of various wrought light alloys being fatigue loaded in stress control at ambient and elevated temperatures.}, language = {en} } @incollection{NosterAltenbergerRitchieetal., author = {Noster, Ulf and Altenberger, Igor and Ritchie, Robert O. and Scholtes, Berthold}, title = {Isothermal Fatigue Behavior and Residual Stress States of Mechanically Surface Treated Ti-6Al-4V: Laser Shock Peening vs. Deep Rolling}, series = {Shot peening}, booktitle = {Shot peening}, editor = {Wagner, Lothar}, publisher = {Wiley-VCH}, address = {Weinheim; [Cambridge]}, isbn = {9783527606580}, doi = {10.1002/3527606580.ch57}, pages = {447 -- 453}, abstract = {In this paper, the high-temperature fatigue behavior and residual stress states of a Ti-6Al-4V alloy are investigated after mechanical surface treatment. In particular, the two surface treatments investigated, laser shock peening and deep rolling, were observed to result in significantly different residual stress states. The consequent isothermal fatigue behavior at elevated temperatures, characterized using cyclic deformation curves, are discussed in terms of the stability of the near-surface work hardening and compressive residual stresses. Despite pronounced relaxation of the residual stresses, both laser shock peening and deep rolling led to a significant improvement in the cyclic deformation behavior and, hence, increased fatigue lifetimes at elevated temperatures as compared to untreated materials states.}, language = {en} } @article{NosterScholtes, author = {Noster, Ulf and Scholtes, Berthold}, title = {Isothermal strain-controlled quasi-static and cyclic deformation behavior of magnesium wrought alloy AZ31}, series = {International Journal of Materials Research / Zeitschrift f{\"u}r Metallkunde}, volume = {94}, journal = {International Journal of Materials Research / Zeitschrift f{\"u}r Metallkunde}, number = {5}, doi = {10.1515/ijmr-2003-0098}, pages = {559 -- 563}, abstract = {The low-cycle and high-cycle fatigue behavior of the Mg-base wrought alloy AZ31 is investigated in the temperature range 20- 300 °C using total-strain-controlled push - pull tests. It is shown that the mechanical properties of the material are substantially influenced by the direction dependent formation of deformation twins and resulting deformation asymmetry. As a consequence tensile mean stresses develop during total-strain-controlled fatigue tests without mean strain.}, language = {en} } @article{BitscheNosterPeterlechner, author = {Bitsche, Robert and Noster, Ulf and Peterlechner, Christian}, title = {F{\"u}gepartner schl{\"u}ssig zu Leichtbaukomponenten verbinden?}, series = {Lightweight Design}, volume = {1}, journal = {Lightweight Design}, number = {2}, publisher = {Springer}, doi = {10.1007/BF03223528}, pages = {30 -- 34}, abstract = {Kombinationen aus kraft- und formschl{\"u}ssigen Verbindungen erh{\"o}hen die Leistung bei im Hybridguss verbundenen Gussteilen mit Anbau- oder Einlegeteilen und machen separate F{\"u}geprozesse {\"u}berfl{\"u}ssig. Simulations-Methoden unterst{\"u}tzen das Design kraft- und formschl{\"u}ssiger Verbindungen. Ergebnisse eines Ausdr{\"u}ckversuchs zeigen eine relativ gute {\"U}bereinstimmung zwischen gemessenen und mittels Simulation ermittelten Kraft-Weg-Kurven.}, language = {de} } @incollection{BillingerNoster, author = {Billinger, Wolfgang and Noster, Ulf}, title = {Bauteilfertigung}, series = {Leichtbau}, booktitle = {Leichtbau}, editor = {Degischer, Hans Peter}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {9783527628247}, doi = {10.1002/9783527628247.ch4}, pages = {247 -- 278}, language = {de} } @article{NallaAltenbergerNosteretal., author = {Nalla, Ravi K. and Altenberger, Igor and Noster, Ulf and Liu, G.Y. and Scholtes, Berthold and Ritchie, Robert O.}, title = {On the influence of mechanical surface treatments—deep rolling and laser shock peening—on the fatigue behavior of Ti-6Al-4V at ambient and elevated temperatures}, series = {Materials Science and Engineering: A}, volume = {355}, journal = {Materials Science and Engineering: A}, number = {1-2}, publisher = {Elsevier}, issn = {1873-4936}, doi = {10.1016/S0921-5093(03)00069-8}, pages = {216 -- 230}, abstract = {It is well known that mechanical surface treatments, such as deep rolling, shot peening and laser shock peening, can significantly improve the fatigue behavior of highly-stressed metallic components. Deep rolling (DR) is particularly attractive since it is possible to generate, near the surface, deep compressive residual stresses and work hardened layers while retaining a relatively smooth surface finish. In the present investigation, the effect of DR on the low-cycle fatigue (LCF) and high-cycle fatigue (HCF) behavior of a Ti-6Al-4V alloy is examined, with particular emphasis on the thermal and mechanical stability of the residual stress states and the near-surface microstructures. Preliminary results on laser shock peened Ti-6Al-4V are also presented for comparison. Particular emphasis is devoted to the question of whether such surface treatments are effective for improving the fatigue properties at elevated temperatures up to ∼450 °C, i.e. at a homologous temperature of ∼0.4T/Tm (where Tm is the melting temperature). Based on cyclic deformation and stress/life (S/N) fatigue behavior, together with the X-ray diffraction and in situ transmission electron microscopy (TEM) observations of the microstructure, it was found that deep rolling can be quite effective in retarding the initiation and initial propagation of fatigue cracks in Ti-6Al-4V at such higher temperatures, despite the almost complete relaxation of the near-surface residual stresses. In the absence of such stresses, it is shown that the near-surface microstructures, which in Ti-6Al-4V consist of a layer of work hardened nanoscale grains, play a critical role in the enhancement of fatigue life by mechanical surface treatment.}, language = {en} } @article{NosterScholtes, author = {Noster, Ulf and Scholtes, Berthold}, title = {Bauschingerefekt und mechanische Zwillingsbildung der Magnesiumlegierung AZ31}, series = {H{\"a}rterei-technische Mitteilungen : HTM ; Zeitschrift f{\"u}r Werkstoffe, W{\"a}rmebehandlung, Fertigung}, volume = {58}, journal = {H{\"a}rterei-technische Mitteilungen : HTM ; Zeitschrift f{\"u}r Werkstoffe, W{\"a}rmebehandlung, Fertigung}, publisher = {Hanser}, pages = {322 -- 327}, language = {de} } @article{BartschBurgerGradetal., author = {Bartsch, Alexander and Burger, Moritz and Grad, Marius and Esper, Lukas and Schultheiß, Ulrich and Noster, Ulf and Schratzenstaller, Thomas}, title = {Enhancement of laser cut edge quality of ultra-thin titanium grade 2 sheets by applying an in-process approach using modulated Yb:YAG continuous wave fiber laser}, series = {Discover Mechanical Engineering}, journal = {Discover Mechanical Engineering}, number = {10}, publisher = {Springer}, doi = {10.1007/s44245-023-00018-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-65647}, pages = {9}, abstract = {Titanium is used in many areas due to its excellent mechanical, biological and corrosion-resistant properties. Implants often have thin and filigree structures, providing an ideal application for fine cutting with laser. In the literature, the main focus is primarily on investigating and optimizing the parameters for titanium sheets with thicknesses greater than 1 mm. Hence, in this study, the basic manufacturing parameters of laser power, cutting speed and laser pulse of a 200 W modulated fiber laser are investigated for 0.15 mm thick grade 2 titanium sheets. A reproducible, continuous cut could be achieved using 90 W laser-power and 2 mm/s cutting-speed. Pulse pause variations between 85 and 335 μs in 50 μs steps and a fixed pulse width of 50 μs show that a minimum kerf width of 23.4 μm, as well as a minimum cut edge roughness Rz of 3.59 μm, is achieved at the lowest pulse pause duration. An increase in roughness towards the laser exit side, independent of the laser pulse pause duration, was found and discussed. The results provide initial process parameters for cutting thin titanium sheets and thus provide the basis for further investigations, such as the influence of cutting gas pressure and composition on the cut edge.}, language = {en} } @unpublished{GradHaagHahnetal., author = {Grad, Marius and Haag, Lydia and Hahn, Konstantin and Schultheiß, Ulrich and Esper, Lukas and Noster, Ulf}, title = {Influence of carbon content on the formation of TiC at diffusion bonded titanium-steel interface}, publisher = {Elsevier}, doi = {10.2139/ssrn.4261928}, abstract = {Hot pressing of pure Ti and various carbon steels in a temperature range of 950 - 1050 °C creates an up to 9 μm thick compound layer of TiC at the Ti/ steel interface. The calculation of the activation energy for layer formation is 126.5 - 136.7 kJ/mol, independent of the steels carbon content. As the carbon content of the steel increases, the layer thickness also increases, which provides enormous potential for the surface modification of Ti/ Ti-alloys.}, language = {en} } @unpublished{BurgerBartschGradetal., author = {Burger, Moritz and Bartsch, Alexander and Grad, Marius and Esper, Lukas and Schultheiß, Ulrich and Noster, Ulf and Schratzenstaller, Thomas}, title = {Enhancement of laser cut edge quality of ultra-thin titanium grade 2 sheets by applying in-process approach using modulated Yb:YAG continuous wave fibre laser}, doi = {10.21203/rs.3.rs-2520041/v1}, abstract = {Titanium is used in many areas due to its excellent mechanical, biological and corrosion-resistant properties. Implants often have thin and filigree structures, providing an ideal application for laser fine cutting. In literature, the main focus is primarily on investigating and optimizing the parameters for titanium sheet thicknesses greater than 1 mm. Hence, in this study, the basic manufacturing parameters of laser power, cutting speed and laser pulsing of a 200 W modulated fibre laser are investigated for 0.15 mm thick titanium grade 2 sheets. A reproducible, continuous cut could be achieved using 90 W laserpower and 2 cutting-speed. Pulse pause variations between 85-335 μs in 50 μs steps and fixed pulse duration of 50 μs show that a minimum kerf width of 23.4 μm, as well as a minimum cut edge roughness Rz of 3.59 μm, is achieved at the lowest pulse pause. An increase in roughness towards the laser exit side, independent of the laser pulse pause, was found and discussed. The results provide initial process parameters for cutting thin titanium sheets and thus provide the basis for further investigations, such as the influence of cutting gas pressure and composition on the cut edge.}, language = {en} } @misc{EsperNosterSchultheissetal., author = {Esper, Lukas and Noster, Ulf and Schultheiss, Ulrich and Bund, Andreas}, title = {Quasi-in-Situ Analysis of Electropolished Additively Manufactured Stainless Steel Surfaces}, series = {ECS Meeting Abstracts, F01: Advances in Industrial Electrochemistry and Electrochemical Engineering}, volume = {MA2023-02}, journal = {ECS Meeting Abstracts, F01: Advances in Industrial Electrochemistry and Electrochemical Engineering}, publisher = {The Electrochemical Society}, issn = {2151-2043}, doi = {10.1149/MA2023-02241342mtgabs}, pages = {1342 -- 1342}, abstract = {Progress in additive manufacturing is leading to the emergence of new areas of application. Laser Powder Bed Fusion (L-PBF) is increasingly used for the development of metallic medical implants, but for high-risk implants like vascular support structures (stents), surface quality is critical to ensure successful implantation without harming the surrounding tissue and ensure the patients' health. Therefore, enhancing the surface quality is crucial. Electropolishing is a method for removing surface roughness by smoothing out micro-peaks and valleys. However, L-PBF structures have a high surface roughness due to metal particles adhering on the surface. To achieve a smooth surface for additively manufactured implants like stents using electropolishing, the removal of these particles needs to be studied in more detail. The objective of this study is to examine the electropolishing mechanism of 316L stainless steel samples additively manufactured through Laser Powder Bed Fusion (L-PBF). The main objective is to investigate the removal properties and surface characteristics during electropolishing. To achieve this, various surfaces were characterized for morphology and roughness during Hull cell experiments. Markings are utilized on the Hull cell sample surfaces to identify points of interest during quasi-in-situ measurements. The surfaces are then analyzed after multiple time steps, applying different currents to investigate particle dissolution. The surface characteristics are analyzed through scanning electron microscopy, and surface roughness is analyzed using laser scanning microscopy. The results show that the electropolishing process preferentially removes the adhering particles present on the surface of the samples. Increasing the current density results in faster particle dissolution and a smoother surface (see Figure 1a and b). The mechanism of material removal of various surface features, as shown in Figure 1 (red circle, yellow arrow and red square), was assessed based on the experimental results of the surface structures seen on the SEM images. It was found that different surface features were removed during the experiment at different polishing times and current densities. The amount of charge flowed was found to correlate with surface morphology. Based on the obtained results, various surface features (such as large adherent particles, agglomerates of smaller particles, and valleys) and their changes with increasing test duration and current density were observed by quasi-in situ analyses. A reduction in the diameter of round particles adhering to the surface was observed at both low and higher current densities (see Figure 1a red circle a). Increasing the polishing time resulted in leveling of both large particles and valleys (see Figure 1b red square). Also, dissolution of agglomerates of smaller particles occurred at different polishing times as a function of current density and polishing time (see Figure 1a yellow arrow) are observed. Smoothed surface structures can be observed in regions with equivalent surface charge density (see Figure 2). As a result, comparable surface morphologies may appear at the same area charge density, irrespective of a specific current density. So, it may be adequate to only consider the amount of charge flowed to describe the electropolishing of additive materials. In conclusion, comprehending the dissolution characteristics of particles on L-PBF surfaces is essential for attaining satisfactory surface finish in electropolishing. The results of this study offer valuable perspectives into the electropolishing mechanism of additively manufactured 316L stainless steel and can guide future investigations on surface finishing and polishing of additive manufactured implants like stents. Figure 1}, language = {en} } @article{GradSchultheissDiemaretal., author = {Grad, Marius and Schultheiß, Ulrich and Diemar, Andreas and Spieß, Lothar and Noster, Ulf}, title = {Preparation methodology for the microstructural characterization of diffusion layers in a titanium/steel composite}, series = {Practical Metallography}, volume = {61}, journal = {Practical Metallography}, number = {12}, publisher = {Walter de Gruyter GmbH}, issn = {2195-8599}, doi = {10.1515/pm-2024-0087}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-78346}, pages = {938 -- 946}, abstract = {Hot pressing of titanium and carbon steel leads to the formation of a diffusion layer at the interface. Depending on the carbon content of the steel used, it either exclusively contains TiC or additional other phases. In the case of steel with a medium carbon concentration (0.67 wt.\% C), a pure TiC layer forms. A preparation methodology was developed to make statements about functional and microstructural properties of the respective layers such as layer thickness, porosity, or grain size. However, apart from the diffusion layer's microstructure, it also reveals the microstructure of the two base substrates. A comparison based on electron backscatter diffraction (EBSD) examinations yields similar results in terms of microstructure. A micrograph analysis based on the new preparation methodology also allows confirming the element distribution measurement by glow discharge optical emission spectroscopy (GDOES). The methodology therefore provides a way of quickly and reliably controlling the layer formation during the hot pressing process of titanium and carbon steel.}, language = {en} } @inproceedings{AltenbergerNallaNosteretal., author = {Altenberger, Igor and Nalla, Ravi K. and Noster, Ulf and Liu, G.Y. and Scholtes, Berthold and Ritchie, Robert O.}, title = {Effects of Deep Rolling on the Fatigue Behavior of Ti-6Al-4V at Ambient and Elevated Temperatures}, series = {Ti-2003 Science and Technology, Proceedings of the 10th World Conference on Titanium, held at the CCH-Congress Center Hamburg, Germany 13-18 July 2003, Vol 1}, booktitle = {Ti-2003 Science and Technology, Proceedings of the 10th World Conference on Titanium, held at the CCH-Congress Center Hamburg, Germany 13-18 July 2003, Vol 1}, editor = {L{\"u}tjering, G. and Albrecht, J.}, publisher = {Wiley}, organization = {Wiley}, isbn = {3-527-30306-5}, pages = {1059 -- 1066}, language = {en} }