TY - GEN A1 - Meissner, Andreas A1 - Weiß, Sabine A1 - Brauer, H. A1 - Fischer, Annette T1 - Peculiarities in stent fatigue testing T2 - Fatigue 2006, Proceedings 9th International Fatigue Congress May 14-19, 2006 Y1 - 2006 PB - Georgia Institute of Technology CY - Atlanta, Ga. ER - TY - GEN A1 - Weiß, Sabine A1 - Meissner, Andreas A1 - Guillardeau, A. A1 - Dudzinski, Wlodzimierz A1 - Fischer, Annette T1 - Characterisation of microstructure and microtexture of coronary artery stents after fatigue deformation T2 - Fatigue 2006, Proceedings 9th International Fatigue Congress May 14-19, 2006 Atlanta Y1 - 2006 PB - Georgia Institute of Technology CY - Atlanta, Ga. ER - TY - GEN A1 - Amer, A. E. A1 - EL-Ghazaly, S. A. A1 - Shash, Y. S. A1 - Weiß, Sabine T1 - Influence of microstructural changes and grain boundary precipitation on the behaviour of 25Ni-15Cr-2Ti superalloy during high temperature creep T2 - Materials Science Forum Y1 - 2005 SN - 1662-9752 IS - Vol. 475-479 SP - 643 EP - 649 ER - TY - CHAP A1 - Weiß, Sabine A1 - Dudzinski, Wlodzimierz A1 - Tikhovskiy, I. T1 - TEM Observation of Deformation Structures in High Nitrogen Steel T2 - Proceedings of the 7th International Conference on High Nitrogen Steels, Ostend, Belgium, September 19 - 22, 2004 Y1 - 2004 SN - 3-937057-09-9 SP - 225 EP - 228 PB - GRIPS-Media GmbH CY - Bad Harzburg ER - TY - GEN A1 - Tikhovskiy, I. A1 - Fischer, Annette A1 - Weiß, Sabine T1 - Cyclic deformation behaviour of austenitic CrMnMoN steel in solution annealed and cold worked states T2 - High nitrogen steels : international conference Y1 - 2004 IS - 2 SP - 259 EP - 263 ER - TY - CHAP A1 - Weiß, Sabine A1 - Klement, U. T1 - Orientation determination on non planar surfaces T2 - Proceedings of the CHANNEL Users Meeting 2004 in Ribe, Denmark Y1 - 2004 SP - 62 EP - 66 PB - Chalmers University of Technology CY - Göteborg ER - TY - GEN A1 - Tikhovskiy, I. A1 - Weiß, Sabine A1 - Fischer, Annette T1 - Fatigue Damage Evolution of Cold-Worked Austenitic Nickel-Free High-Nitrogen X13CrMnMoN18 14 3 (1.4452) Steel T2 - Proceeding of the Fifth International Conference on Low Cycle Fatigue Y1 - 2003 PB - DVM, Deutscher Verband für Materialforschung und –prüfung e.V. CY - Berlin ER - TY - GEN A1 - Weiß, Sabine A1 - Mattissen, D. A1 - Dudzinski, Wlodzimierz A1 - Fischer, Annette T1 - Microstructure of the Laser Beam Welded Iron-Based Superalloy A286 after High Temperature Creep T2 - Conference Proceedings of the Materials Week, Munich 2002 Y1 - 2002 SN - 3-88355-314-X SN - 978-3-8835-5314-6 SP - S. 142 PB - Werkstoff-Informationsgesellschaft CY - Frankfurt ER - TY - GEN A1 - Weiß, Sabine A1 - Meißner, Andreas A1 - Fischer, Alfons T1 - Microstructural changes within similar coronary stents produced from two different austenitic steels T2 - Journal of the Mechanical Behavior of Biomedical Materials Y1 - 2009 SN - 1751-6161 VL - 2 IS - 2 SP - 210 EP - 216 ER - TY - GEN A1 - Fischer, Annette A1 - Burgaud, D. A1 - Amer, A. E. A1 - Weiß, Sabine T1 - The fatigue Aspect in metal on metal wear T2 - Cost 533 biotribology, materials for improved wear resistance of total artificial joints, 29 october 2007, Fundación Tekniker, Eibar, Spain Y1 - 2007 SN - 978-84-932064-4-4 SP - 35 EP - 44 PB - Tekniker CY - Eibar, Guipúzcoa ER - TY - GEN A1 - Fischer, Annette A1 - Meissner, Andreas A1 - Brauer, H. A1 - Weiß, Sabine T1 - Stent fatigue testing according to in vivo strain cycles T2 - Journal of Biomechanics Y1 - 2006 SN - 1873-2380 VL - 39 IS - Suppl. 1 ER - TY - GEN A1 - Fischer, Alfons A1 - Weiß, Sabine A1 - Wimmer, Markus A. T1 - The Tribological Difference between Biomedical Steels and CoCrMo-Alloys T2 - Journal of the Mechanical Behavior of Biomedical Materials Y1 - 2012 SN - 1878-0180 VL - 9 SP - 50 EP - 62 ER - TY - GEN A1 - Ranjbarnodeh, Eslam A1 - Weiß, Sabine A1 - Hanke, Stefanie A1 - Fischer, Annette T1 - EBSD characterization of the effect of welding parameters on HAZ of AISI409 T2 - Journal of Mining and Metallurgy : B Y1 - 2012 SN - 1450-5339 VL - 48 IS - 1 SP - 115 EP - 121 ER - TY - GEN A1 - Weiß, Sabine A1 - Schnauber, T. A1 - Fischer, Annette ED - Su, Ji T1 - Microstructure Characterization of thin structures after deformation T2 - Materials and devices for smart systems III, symposium held December 1 - 4, 2008, Boston, Massachusetts Y1 - 2009 SN - 978-1-605-11101-8 SP - V11 EP - 19 PB - MRS CY - Warrendale, Pa. ER - TY - GEN A1 - Amer, A. E. A1 - Weiß, Sabine A1 - Fischer, Annette T1 - Improvement of fatigue resistance of low-nickel stainless steels for biomedical applications compared to CoCr-alloys T2 - Steel grips Y1 - 2009 SN - 1866-8453 VL - 7 IS - 6 SP - 457 EP - 461 ER - TY - GEN A1 - Weiß, Sabine A1 - Szymczak, H. A1 - Meissner, Andreas T1 - Fatigue and endurance of coronary stents T2 - Materialwissenschaft und Werkstofftechnik Y1 - 2009 SN - 1521-4052 VL - 40 IS - 1-2 SP - 61 EP - 64 ER - TY - GEN A1 - Garkas, Wagdi A1 - Weiß, Sabine A1 - Wang, Q. M. T1 - (Cr1-x Al x)N as a candidate for corrosion protection in high temperature segments of CCS plants T2 - Environmental Earth Sciences N2 - Three (Cr1−x Al x )N (x = 0.33, 0.5, 0.66) coatings were deposited on Ni-super alloy IN718 using reactive magnetron sputtering. The oxidation behavior of all coatings at 900 °C up to 500 h in air was studied. Furthermore, the corrosion behavior of the (Cr0.33,Al0.66)N coating at 900 °C (corrosion type I) by spraying a uniform salt scale of Na2SO4 on the sample surface (1 mg/cm2) was investigated. It was found that the coated samples indicate significantly higher oxidation and corrosion resistance compared to uncoated Ni super alloy. This is mainly due to the formation of protective Cr2O3 and Al2O3 layers on the coating surface. With the increase of Al content, the coatings exhibited improved oxidation resistance. The formation of thin and adherent Al2O3 scale on the surface of Al rich coating is the reason for its better oxidation behavior. The detailed structures of the oxide scales and the interdiffusion between coating and substrate were studied using energy dispersive X-ray spectroscopy-analysis. Y1 - 2013 UR - http://link.springer.com/article/10.1007/s12665-013-2646-y/fulltext.html U6 - https://doi.org/10.1007/s12665-013-2646-y SN - 1866-6280 SN - 1866-6299 ER - TY - CHAP A1 - Weiß, Sabine A1 - Meissner, Andreas T1 - Austenitic high nitrogen steel: An alternative material for coronary stents? T2 - 8th World Biomaterials Congress 2008, Amsterdam, 28 May - 1 June 2008 Y1 - 2009 SN - 978-1-61567-080-2 PB - Curran Associates Inc. CY - Red Hook, NY ER - TY - GEN A1 - Fischer, Annette A1 - Burgaud, D. A1 - Amer, A. E. A1 - Weiß, Sabine T1 - Fatigue aspects of the generation of nanoparticles during wear of biomedical alloys T2 - 8th World Biomaterials Congress 2008, Amsterdam, 28 May - 1 June 2008 Y1 - 2009 SN - 978-1-61567-080-2 PB - Curran Associates Inc. CY - Red Hook, NY ER - TY - GEN A1 - Kazak, Fedor A1 - Weiß, Sabine T1 - Analysis of the Frequency as an Integral Method for the Testing of Anisotropic 3D Sheet Metal Structure T2 - Materials Testing Y1 - 2014 SN - 0025-5300 VL - 56 IS - 9 SP - 656 EP - 661 ER - TY - GEN A1 - Ranjbarnodeh, Eslam A1 - Weiß, Sabine A1 - Hanke, Stefanie A1 - Fischer, Alfons T1 - EBSD characterization of the effect of welding parameters on HAZ of AlSl409 T2 - Journal of Mining and Metallurgy : B, Metallurgy Y1 - 2012 VL - 48 IS - 1 SP - 115 EP - 121 ER - TY - GEN A1 - Ranjbarnodeh, Eslam A1 - Hanke, Stefanie A1 - Weiß, Sabine A1 - Fischer, Alfons T1 - Effect of welding parameters on the heataffected zone of AlSI409 ferritic stainless steel T2 - International Journal of Minerals, Metallurgy and Materials Y1 - 2012 SN - 1869-103X VL - 19 IS - 10 SP - 923 EP - 929 ER - TY - GEN A1 - Fischer, Annette A1 - Meissner, Andreas A1 - Weiß, Sabine ED - Yuan, Huang ED - Wittmann, Folker H. T1 - Microstructural peculiarities and mechanical properties of coronary stents T2 - Nonlocal Modelling of Failure of Materials, proceedings of an international workshop, University of Wuppertal, June 2007 Y1 - 2007 SN - 978-3-931681-87-6 SP - 91 EP - 104 PB - Aedificatio Publ. CY - Freiburg ER - TY - GEN A1 - Hering, Daniel A1 - Kail, Jochem A1 - Eckert, Sabine A1 - Gerhard, Marc A1 - Meyer, Elisabeth I. A1 - Mutz, Michael A1 - Reich, Michael A1 - Weiss, Ilga T1 - Coarse Woody Debris Quantity and Distribution in Central European Streams T2 - International Review of Hydrobiology KW - coarse woody debris Y1 - 2000 U6 - https://doi.org/10.1002/(SICI)1522-2632(200003)85:1<5::AID-IROH5>3.0.CO;2-X SN - 1522-2632 VL - 85 IS - 1 SP - 5 EP - 23 ER - TY - GEN A1 - Bolz, Sebastian A1 - Oehring, Michael A1 - Lindemann, Janny A1 - Pyczak, Florian A1 - Paul, Jonathan A1 - Stark, Andreas A1 - Lippmann, Thomas A1 - Roth-Fagaraseanu, Dan A1 - Schreyer, Andreas A1 - Weiß, Sabine A1 - Schrüfer, Susanne T1 - Microstructure and mechanical properties of a forged beta-solidifying gamma TiAl alloy in different heat treatment conditions T2 - Intermetallics Y1 - 2015 VL - 2015 IS - 58 SP - 71 EP - 83 ER - TY - GEN A1 - Schulze, Marcus A1 - Seidlitz, Holger A1 - König, Franziska A1 - Weiß, Sabine T1 - Tribological Investigations of PVD Coated Multi-Layer Constructions T2 - Journal of Materials Science Research N2 - Multi-layer constructions become more and more relevant in lightweight applications due to their high strength to weight ratio. They offer excellent crash, damping and recycling properties. Also, the morphology of thermoplastic carbon fibre reinforced plastics (CFRP) render them interesting for large scale manufacturing processes. Nevertheless, a major disadvantage results in a poor resistance against wear and tear, e.g. erosion, which is attributed to weak hardness properties. Hence, this work deals with tribological investigations on orthotropic carbon fibre reinforced polymers (PA 6) either with protective ceramic coating or without. The chosen coating system is a well-known protective covering of metal components, e.g. metal cutting tools, produced by physical vapor deposition (PVD). To characterize the coating system on thermoplastic CFRP, standard analyzing methods are utilized, like optical and scanning electron microscopy (SEM). The tribological investigations are conducted by the tribological ball on disk method to generate wear tracks on the sample surfaces and hence to calculate the wear rates. These results are compared to literature findings with respect to a certain protective coating system (TiN) and a second nano-structured gel coating system, where both systems are deposited on a thermosetting material, i.e. carbon fibre reinforced epoxy resin, respectively. For this purpose the feasibility of depositing a protective ceramic layer on thermoplastic CFRP is demonstrated. First results on suitable surface pre-treatments have shown a significant influence on the coating quality. The improved performance regarding the wear behavior with respect to tribology compared to the poor substrate and existing technologies is shown additionally. KW - thermoplastic composites KW - protective coating systems KW - tribology KW - wear KW - physical vapour deposition Y1 - 2016 U6 - https://doi.org/10.5539/jmsr.v5n1p97 SN - 1927-0585 VL - 5 IS - 1 SP - 97 EP - 106 ER - TY - GEN A1 - Oehring, Michael A1 - Lindemann, Janny A1 - Pyczak, Florian A1 - Paul, Jonathan A1 - Stark, Andreas A1 - Lippmann, Thomas A1 - Schrüfer, Susanne A1 - Roth-Fagaraseanu, Dan A1 - Schreyer, Andreas A1 - Weiß, Sabine T1 - Microstructure and mechanical properties of a forged β-solidifying γ TiAl alloy in different heat treatment conditions T2 - Intermetallics N2 - In the cast condition g titanium aluminide alloys that solidify completely through the b phase are characterized by fine and homogeneous microstructures, weak textures and low segregation. For these reasons such alloys have a relatively good workability and can be closed-die forged without preceding ingot breakdown even if the alloys contain no large fractions of the b phase at the working temperature. The present work was devoted to a combined study of the constitution and microstructural morphologies that develop in various two-step heat treatments of a single-step forged b solidifying alloy. The study included high-energy X-ray diffraction for in situ investigations of the constitution at the heat treatment temperature. It was observed that the phase ransformations are quite sluggish in the material which results in fine microstructures and some conditions that significantly deviate from thermodynamic equilibrium. Further, tensile and creep testing was carried out on the different material conditions in order to identify the range in which the properties can be varied. It is found that this easily forgeable material exhibits comparable strength, ductility and creep strength as more conventional peritectically solidifying alloys. KW - TiAl KW - Titanium Aluminides KW - hot die forging KW - TNB-V4 Y1 - 2015 UR - http://www.sciencedirect.com/science/article/pii/S096697951400301X U6 - https://doi.org/10.1016/j.intermet.2014.11.008 SN - 0966-9795 VL - 2015 IS - 58 SP - 71 EP - 83 ER - TY - GEN A1 - Kazak, Fedor A1 - Weiß, Sabine T1 - Test procedure for fatigue investigations regarding structured sheet metal joints T2 - Materials Testing N2 - The topic of fatigue strength of joints of flat and honeycomb-structured thin sheets has not yet been adequately studied. This concerns, for example,the development of an appropriate test method. In many cases, there is still a lack of information, how effective joints of flat and structured sheet metals are in omparison with reference joints of flat sheets. Combinations of resistance spot-welded specimens of flat and honeycomb-structured thin sheets of deep-drawing steel DC04 with a thickness of 0.5 mm were examined. Adopted clamping plates were applied for the testing. Joined smooth specimens were used as a reference material. The analysis of the frequency [1] was applied for comparison. The fatigue limit of a joint of a flat and a structured sheet metal is not significantly affected by spot welding. The fatigue limit of these spot-welded joints is comparable to that of an non joined honeycomb-structured sheet. By means of frequency or stiffness analysis, stability and damage mechanisms of differently shaped joints were explained. The joining of bridges of the structure shows a better stability than the combination of honeycombs. The stiffness analysis is a favored method for the clarification of the damage mechanisms in a spot-welded joint. The reasons for the low fatigue strength values of the joined flat-structured specimens compared to flat-flat joints are strong notch effects in the bridge area and momentum effects by the structure height of the studied honeycomb structure. The spot weld with a pronounced indentation also affected the fatigue strength of both flat and structured joined sheet metals. Y1 - 2016 SN - 0025-5300 SN - 2195-8572 VL - 58 IS - 2 SP - 109 EP - 116 ER - TY - GEN A1 - Kazak, Fedor A1 - Weiß, Sabine T1 - Comparability of structured and flat reference specimens made of thin sheet metal T2 - Materials Testing N2 - The literature review reveals that the honeycomb-structured thin sheet metals are not adequately investigated with regard to their fatigue strength. A question that remains almost completely ignored in the process is the direct comparability of structured thin sheet metals with flat reference specimens. A thin sheet is not a classic specimen to determine the fatigue strength because of the known problem of the fracture mechanics. Structured thin sheet metals of deep-drawing steel DC04 with a thickness of 0.5 mm were examined. Flat specimens were used as reference material. The frequency analysis was used for comparison. Fundamental differences in the mechanical behavior between flat and structured sheets under cyclic load were observed. Whereas an extremely flat S-N curve in the low-cycle region with a high slope coefficient was observed for the smooth thin sheets, the structured specimens show a curve typical for notched specimens. Moreover, the smooth sheets have a specific cyclic hardening and/or softening behavior. The state of plane stress of a fine sheet in contrast to a multi-axial one for the structured sheet complicates the direct comparison. For this reason, such a comparison with respect to their fatigue strength in the Wohler diagram should only be considered with caution. Y1 - 2015 U6 - https://doi.org/10.3139/120.110748 SN - 0025-5300 SN - 2195-8572 VL - 57 IS - 6 SP - 567 EP - 573 ER - TY - GEN A1 - Weiß, Sabine A1 - Mitevski, Bojan T1 - Microstructure and Deformation of Coronary Stents from CoCr-Alloys with Different Designs T2 - Materials N2 - Coronary heart disease is still one of the most common sources for death in western industrial countries. Since 1986, a metal vessel scaffold (stent) has been inserted to prevent the vessel wall from collapsing. Most of these coronary stents are made from CrNiMo­steel (316L). Due to its austenitic structure, the material shows a good combination of strength, ductility, corrosion resistance, and biocompatibility. However, this material has some disadvantages like its non-MRI compatibility and its poor fluoroscopic visibility. Other typically used materials are the Co­Base alloys L-605 and F-562 which are MRI compatible as well as radiopaque. Another interesting fact is their excellent radial strength and therefore the ability to produce extra thin struts with increased strength. However, because of a strut diameter much less than 100 μm, the cross section consists of about 5 to 10 crystal grains (oligo­crystalline). Thus, very few or even just one grain can be responsible for the success or failure of the whole stent. To investigate the relation between microstructure, mechanical factors and stent design, commercially available Cobalt-Chromium stents were investigated with focus on distinct inhomogeneous plastic deformation due to crimping and dilation. A characteristic, material related deformation behavior with predominantly primary slip was identified to be responsible for the special properties of CoCr stents. Y1 - 2015 U6 - https://doi.org/10.3390/ma8052467 SN - 1996-1944 VL - 8 IS - 5 SP - 2467 EP - 2479 ER - TY - GEN A1 - Naveed, Muhammad A1 - Flores Renteria, Arturo A1 - Nebel, Daniel A1 - Weiß, Sabine T1 - Study of high velocity solid particle erosion behaviour of Ti2AlC MAX phase coatings T2 - Wear N2 - This research work provides information about the influence of Ti2AlC MAX phase coatings on the erosion resistance of Ti624 2alloy.Flat specimens were coated witha20 µm Ti2AlC film using an industrial siz emagnetron sputtering coater and annealed at 800 °C for 1h in vacuum for the formation of the MAX phase.The erosion resistance of the specimens was tested using high velocity particles at room temperature.The results indicate that the erosion resistance of Ti6242 has been significantly enhanced by the employment of MAX-phase coatings. This demonstrates the capability of using MAX phase coatings as erosion protective medium for engine components exposed to similar damage conditions. Additionally,the results show that uncoated Ti6242 samples with duplex microstructure have a better durability against erosion attack compared to uncoated samples with globular microstructure. KW - Erosion, MAX Phase Y1 - 2015 U6 - https://doi.org/10.1016/j.wear.2015.09.014 SN - 0043-1648 VL - 2015 IS - 342-343 SP - 391 EP - 397 ER - TY - GEN A1 - Naveed, Muhammad A1 - Obrosov, Aleksei A1 - Weiß, Sabine T1 - Investigation of the wear resistance properties of Cr/CrN multilayer coatings against sand erosion T2 - Conference Papers in Science N2 - The wear of metallic components used in gas and steam turbines due to erosive sand particles lead to a tremendous decrease in their lifetime. This wear can be reduced by the use of suitable erosion resistant coatings resulting in lower maintenance costs. In this context, multilayer Cr/CrN PVD coatings using an industrial coater was designed and applied on Inconel 718, a material which finds its application in gas turbines. A variation in the bimodal period has been induced in order to achieve an optimal coating architecture providing optimum properties needed for the erosion resistant coatings. The coating was deposited using a single Cr- target with an induction of N2 during the nitriding phase at a temperature of 480-500 °C and the coating thickness of 24-26 µm was kept constant throughout. The erosion tests were conducted at angles of 30°, 60° and 90°. The sand used for the test is an irregular shaped SiO2. The erosion tests were followed by a detailed microscopic examination of the eroded coating structure in combination with nanoindentation and scratch tests. KW - Cr/CrN multilayer, Erosion, PVD, Coatings Y1 - 2015 U6 - https://doi.org/10.1155/2015/873543 N1 - Article ID 873543 VL - 2015 SP - 1 EP - 10 ER - TY - CHAP A1 - Mlikota, Marjo A1 - Schmauder, Siegfried A1 - Mitevski, Bojan A1 - Weiß, Sabine ED - Deng, Jiamei ED - Liu, Quingjun T1 - Scientific Multiscale and Multidisciplinary Analysis of Deformation and Damage in the Case of Oligocrystalline Structures T2 - Computer Science and Engineering Technology N2 - This paper serves as an overview of the ongoing research in the field of multiscale and multidisciplinary analysis of deformation and damage in the case of oligocrystalline structures. The research focuses on experimental measurement and numerical calculation of ductile failure in the X2CrNiMo18-15-3 (AISI 316L) stainless steel. An embedding numerical technique is employed where crystal plasticity theory is used to represent plastic deformation in the material and element removal technique based on Rice&Tracey damage model for ductile void growth to simulate damage initiation inside the material, which is observed in the experiments. Additionally, the crystal plasticity model is supported by a hierarchical multiscale approach connecting nano-, micro- and meso-scales. Y1 - 2016 SN - 978-981-4651-00-4 SP - 113 EP - 118 PB - World Scientific Publishing CY - Singapore ER - TY - GEN A1 - Schulze, Marcus A1 - Seidlitz, Holger A1 - König, Franziska A1 - Weiß, Sabine T1 - Nanoindentation measurements of PVD coated multilayer constructions T2 - Journal of Achievements in Materials and Manufacturing Engineering N2 - Carbon fibre reinforced thermoplastics (CFRP) are intensively used in lightweight applications due to their high strength to weight ratio. In addition they offer good crash, damping and recycling properties. On the basis of their morphology they are suitable for large scale manufacturing processes. A major disadvantage consists of its poor hardness properties, which is again an important requirement to realize a good erosion and wear behaviour. Design/methodology/approach: In this work the application of orthotropic carbon fibre reinforced polymers (PA6), with protective TiAlN coatings, produced by physical vapor deposition (PVD), is investigated. The characterization of the coating is performed by nanoindentation tests, roughness measurements and scanning electron microscopy. Furthermore micro hardness tests on selected well prepared cross sections are conducted, to compare the coating quality with established coating systems. Findings: By applying TiAlN coating, the hardness of the CFRP samples can be increased substantially up to 15 GPa, in comparison to the basic substrate. In addition the quality of the coating surface can be improved significantly by plasma etching pre-treatment. Research limitations/implications: The presented findings are preliminary results to prove the application of a standard processed ceramic coating on new composite types for mass production. The PVD coating process as well as the utilized testing methods are suitable to realize hard coatings on thermoplastic CFRP. This effect can be exploited for several lightweight applications to increase the erosion and wear resistance of composite materials. Originality/value: The presented results show, that ceramic coatings can be deposited on standard thermoplastic CFRP with polyamide 6 matrix. Therewith it can be expected, that the PVD coating process can make a essential contribution to increase the range of applications. KW - Nanoindentation KW - Thermoplastic composites KW - TiAlN-coating Y1 - 2015 UR - http://www.journalamme.org/vol72_2/7221.pdf SN - 1734-8412 VL - 72 IS - 2 SP - 53 EP - 60 ER - TY - GEN A1 - Schulze, Marcus A1 - Seidlitz, Holger A1 - König, Franziska A1 - Weiß, Sabine T1 - Highly wear resistant PVD coatings for CFRP based multi-layer construction T2 - 11th International Scientific-Technical Conference on Advances in Plastics Technology (APT'15) Y1 - 2015 SN - 978-83-63555-47-4 CY - Gliwice ER - TY - GEN A1 - Stechow, Richard A1 - Ivanova, Irina A1 - Naveed, Muhammad A1 - Weiß, Sabine T1 - Sample Preparation of Worn Surfaces for EBSD Analysis T1 - Probenpräparation verschlissener Oberflächen für die EBSD Analyse T2 - Praktische Metallographie Y1 - 2016 U6 - https://doi.org/10.3139/147.110401 SN - 0032-678x SN - 2195-8599 VL - 53 IS - 6 SP - 352 EP - 359 ER - TY - GEN A1 - Naveed, Muhammad A1 - Stechow, Richard A1 - Bolz, Sebastian A1 - Hobusch, Katharina A1 - Weiß, Sabine T1 - Solid Particle Erosion of Heat Treated TNB-V4 at Ambient and Elevated Temperatures T2 - International Journal of Chemical, Molecular, Nuclear, Materials and Metallurgical Engineering Y1 - 2016 VL - 10 IS - 5 SP - 571 EP - 576 ER - TY - GEN A1 - Kazak, Fedor A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Weiß, Sabine T1 - Particularities of testing structured sheet metals in 3-point bending tests T2 - Materials Testing N2 - Thin sheet metals from deep drawing steel DC04 are very often used in the production of car body and case parts. Quality improvement of sheet metal components by new constructive solutions (structuring) as well as adapted joining technology is going on. Structured sheet metals differ from each other by their high bending stiffness. At the same time, they show certain anisotropy due to the structure. Therefore a typical testing method of structured semi-finished parts (single sheet metals, sandwiches)is the bending test. The literature review revealed that in many studies no special demands on tests of structured materials were made. This concerns particularly the structure arrangement, structure direction and structure location of the specimen relative to the mandrel position during bending tests, i. e., the direction of the fixed load relative to the structure. The aim of this study was to determine the influence of the test specification on flexural behavior. In the present paper, honeycomb-structured sheet metals were examined using 3-point bending tests. Bending stiffness and lightweight potential were calculated with respect to the location of load application and compared for different structure arrangements,directions and locations. The influence of the anisotropy on flexural behavior of the honeycomb-patterned sheet metals was moderate. Y1 - 2016 U6 - https://doi.org/10.3139/120.110883 SN - 0025-5300 SN - 2195-8572 VL - 58 IS - 6 SP - 495 EP - 500 ER - TY - GEN A1 - Naveed, Muhammad A1 - Flores Renteria, Arturo A1 - Weiß, Sabine T1 - Role of alloying elements during thermocyclic oxidation of β/γ-TiAl alloys at high temperatures T2 - Journal of Alloys and Compounds N2 - Gamma titanium aluminides are promising alloys known for their good mechanical properties and low densities, but their low oxidation resistance at high temperatures limits their application. This work discusses the thermocyclic oxidation behavior of newly developed β/γ-TiAl alloys at temperatures between 600 °C and 900 °C. An influence of β-stabilizing alloying elements like Nb and V on the oxidation of these alloys has been investigated here. The selected alloys are tested in an in-house developed thermocyclic furnace. The oxidation study is supported by gravimetric measurements along with Scanning Electron Microscopy (SEM) and Electron Diffraction Spectroscopy (EDS) mapping of the oxide layers. Additionally, phase formation after oxidation has been determined using X-Ray Diffraction (XRD). Results show that the Nb containing alloys are more oxidation resistant as compared to V containing alloys. The formation of a mixture of Al2O3 and TiO2 layers was found for all the alloys. The oxide kinetics controlled oxide growth and formation of various phases at different testing temperatures. KW - Aluminum oxide KW - γ-TiAl KW - thermocyclic oxidation KW - β-stabilizing elements Y1 - 2016 U6 - https://doi.org/10.1016/j.jallcom.2016.08.259 SN - 0925-8388 VL - 691 SP - 489 EP - 497 ER - TY - GEN A1 - Bambach, Markus A1 - Sizova, Irina A1 - Bolz, Sebastian A1 - Weiß, Sabine T1 - Devising Strain Hardening Models Using Kocks-Mecking Plots - A Comparison of Model Development for Titanium Aluminides and Case Hardening Steel T2 - Metals KW - titanium aluminides alloy KW - single phase steel KW - hot forming Y1 - 2016 U6 - https://doi.org/10.3390/met6090204 SN - 2075-4701 VL - 6 IS - 9 SP - 204 ER - TY - GEN A1 - Naveed, Muhammad A1 - Obrosov, Aleksei A1 - Zak, Andrzej A1 - Dudzinski, Wlodzimierz A1 - Volinsky, Alex A. A1 - Weiß, Sabine T1 - Sputtering Power Effects on Growth and Mechanical Properties of Cr2AlC MAX Phase Coatings T2 - Metals N2 - Coating growth and mechanical properties of nanolamellar Cr2AlC coatings at various sputtering power were investigated in the present study. Cr2AlC coating was deposited on the IN 718 superalloy and (100) Si wafers by DC magnetron sputtering at different sputtering powers. The structure and properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nanoindentation. It was found that coatings had columnar structure with nanocrystalline substructure. Deposition rate increased with the sputtering power. XRD results showed the presence of the Cr2AlC MAX phase, intermetallic AlCr2 and Cr7C3 carbide phases, along with the change in preferential coating growth orientation. TEM observations confirmed the occurrence of these phases, and the SAED patterns demonstrated significant texture of the coatings. Hardness values were measured in the range between 11–14 GPa, showing a slight increase with the sputtering power. KW - MAX Phase KW - Cr2AlC KW - TEM Y1 - 2016 U6 - https://doi.org/10.3390/met6110265 SN - 2075-4701 VL - 6 IS - 11 SP - 265 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Volinsky, Alex A. A1 - Weiß, Sabine T1 - Substrate Frequency Effects on CrxN Coatings Deposited by DC Magnetron Sputtering T2 - Journal of Materials Engineering and Performance N2 - Controlled ion bombardment is a popular method to fabricate desirable coating structures and modify their properties. Substrate biasing at high frequencies is a possible technique, which allows higher ion density at the substrate compared with DC current bias. Moreover, high ion energy along with controlled adatom mobility would lead to improved coating growth. This paper focuses on a similar type of study, where effects of coating growth and properties of DC magnetron-sputtered chromium nitride (CrxN) coatings at various substrate bias frequencies are discussed. CrxN coatings were deposited by pulsed DC magnetron sputtering on Inconel 718 and (100) silicon substrates at 110, 160 and 280 kHz frequency at low duty cycle. Coating microstructure and morphology were studied by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), scratch adhesion testing and nanoindentation. Results indicate a transformation of columnar into glassy structure of CrxN coatings with the substrate bias frequency increase. This transformation is attributed to preferential formation of the Cr2N phase at high frequencies compared with CrN at low frequencies. Increase in frequency leads to an increase in deposition rate, which is believed to be due to increase in plasma ion density and energy of the incident adatoms. An increase in coating hardness along with decrease in elastic modulus was observed at high frequencies. Scratch tests show a slight increase in coating adhesion, whereas no clear increase in coating roughness can be found with the substrate bias frequency. KW - adhesion of coatings KW - CrN coatings KW - frequency KW - mechanical properties KW - microstructure KW - PVD KW - X-ray diffraction Y1 - 2016 UR - http://link.springer.com/article/10.1007/s11665-016-2426-4 U6 - https://doi.org/10.1007/s11665-016-2426-4 SN - 1544-1024 VL - 26 IS - 1 SP - 366 EP - 373 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Gulyaev, Roman A1 - Zak, Andrzej A1 - Ratzke, Markus A1 - Naveed, Muhammad A1 - Dudzinski, Wlodzimierz A1 - Weiß, Sabine T1 - Chemical and Morphological Characterization of Magnetron Sputtered at Different Bias Voltages Cr-Al-C Coatings T2 - Materials N2 - MAX phases (M = transition metal, A = A-group element, and X = C/N) are of special interest because they possess a unique combination of the advantages of both metals and ceramics. Most attention is attracted to the ternary carbide Cr2AlC because of its excellent high-temperature oxidation, as well as hot corrosion resistance. Despite lots of publications, up to now the influence of bias voltage on the chemical bonding structure, surface morphology, and mechanical properties of the film is still not well understood. In the current study, Cr-Al-C films were deposited on silicon wafers (100) and Inconel 718 super alloy by dc magnetron sputtering with different substrate bias voltages and investigated using Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), and nanoindentation. Transmission Electron Microscopy (TEM) was used to analyze the correlation between the growth of the films and the coating microstructure. The XPS results confirm the presence of Cr2AlC MAX phase due to a negative shift of 0.6–0.9 eV of the Al2p to pure aluminum carbide peak. The XRD results reveal the presence of Cr2AlC MAX Phase and carbide phases, as well as intermetallic AlCr2. The film thickness decreases from 8.95 to 6.98 µm with increasing bias voltage. The coatings deposited at 90 V exhibit the lowest roughness (33 nm) and granular size (76 nm) combined with the highest hardness (15.9 GPa). The ratio of Al carbide to carbide-like carbon state changes from 0.12 to 0.22 and correlates with the mechanical properties of the coatings. TEM confirms the columnar structure, with a nanocrystalline substructure, of the films. KW - XPS KW - AFM KW - MAX phase KW - TEM KW - chemical bonding KW - surface morphology Y1 - 2017 UR - http://www.mdpi.com/1996-1944/10/2/156/htm U6 - https://doi.org/10.3390/ma10020156 SN - 1996-1944 VL - 10 IS - 2 SP - 156 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Gulyaev, Roman A1 - Ratzke, Markus A1 - Volinsky, Alex A. A1 - Bolz, Sebastian A1 - Naveed, Muhammad A1 - Weiß, Sabine T1 - XPS and AFM Investigations of Ti-Al-N Coatings Fabricated Using DC Magnetron Sputtering at Various Nitrogen Flow Rates and Deposition Temperatures T2 - Metals N2 - Ti-Al-N coatings were deposited by direct current magnetron sputtering (DCMS) onto IN 718 at different nitrogen flow rates and deposition temperatures. The coatings’ properties were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) as well as nanoindentation. It was found that higher deposition temperature leads to higher surface roughness and nitrogen flux influences the shape of grains. According to XPS, the bonding structure of all coatings exhibited the (Ti,Al)N phase. Mechanical properties depend on the Al content within the films. The coating with the best mechanical properties (deposited at 500 °C and 20 standard cubic centimeters per minute (sccm)) was further deposited onto tungsten carbide (WC) cutting tools for cylindrical turning experiments. A quasi-constant flank wear was observed until a machining volume of 23,500 mm³. KW - Ti-Al-N coatings KW - DC magnetron sputtering KW - XPS KW - AFM KW - nitrogen flow rate KW - surface morphology Y1 - 2017 UR - http://www.mdpi.com/2075-4701/7/2/52/htm U6 - https://doi.org/10.3390/met7020052 SN - 2075-4701 VL - 7 IS - 2 SP - 52 ER - TY - CHAP A1 - Schulze, Marcus A1 - Seidlitz, Holger A1 - König, Franziska A1 - Weiß, Sabine ED - Dobrzański, Leszek A. T1 - Nanoindentation measurements of PVD coated multilayer constructions T2 - Programme and proceedings of the 22nd Winter International Scintific Conference on Achivements in Mechanical and Materials Engineering (AMME'15), Gliwice - Zakopane (Poland), 2015 Y1 - 2015 SN - 978-83-63553-39-5 PB - Gliwice CY - International OCSCO World Press ER - TY - GEN A1 - Obrosov, Aleksei A1 - Sutygina, Alina A1 - Volinsky, Alex A. A1 - Manakhov, Anton A1 - Weiß, Sabine A1 - Kashkarov, Egor B. T1 - Effect of Hydrogen Exposure on Mechanical and Tribological Behavior of CrₓN Coatings Deposited at Different Pressures on IN718 T2 - Materials N2 - In the current study, the properties of the CrₓN coatings deposited on the Inconel 718 superalloy using direct current reactive magnetron sputtering are investigated. The influence of working pressure on the microstructure, mechanical, and tribological properties of the CrₓN coatings before and after high-temperature hydrogen exposure is studied. The cross-sectional scanning electron micrographs indicate the columnar structure of the coatings, which changes from dense and compact columns to large columns with increasing working pressure. The Cr/N ratio increases from 1.4 to 1.9 with increasing working pressure from 300 to 900 mPa, respectively. X-ray diffraction analysis reveals a change from mixed hcp-Cr₂N and fcc-CrN structure to approximately stoichiometric Cr₂N phase. After gas-phase hydrogenation, the coating deposited at 300 mPa exhibits the lowest hydrogen absorption at 600 °C of all investigated coatings. The results indicate that the dense mixed cubic and hexagonal structure is preferential for hydrogen permeation resistance due to the presence of cubic phase with higher packing density in comparison to the hexagonal structure. After hydrogenation, no changes in phase composition were observed; however, a small amount of hydrogen is accumulated in the coatings. An increase of coating hardness and elastic modulus was observed after hydrogen exposure. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient up to 20%–30%. The best value of 0.25 was reached for hydrogen exposed CrₓN coating deposited at 300 mPa. KW - CrₓN coatings KW - PVD KW - hydrogenation KW - tribology KW - mechanical properties KW - GDOES Y1 - 2017 UR - http://www.mdpi.com/1996-1944/10/5/563/htm U6 - https://doi.org/10.3390/ma10050563 SN - 1996-1944 VL - 10 IS - 5 SP - 563 ER - TY - CHAP A1 - Obrosov, Aleksei A1 - Kashkarov, Egor B. A1 - Weiß, Sabine A1 - Volinsky, Alex A. ED - Tiwari, Ashutosh T1 - Mechanical and tribological behaviour of hydrogenated CrxN coatings deposited at different pressure and voltages on IN718 T2 - American Advanced Materials Congress 2016 N2 - Hydrogen degradation is a serious problem in industrial applications like power plants (boilers, turbines), marine structures, car and aircraft components, as it leads to failures as well as to deterioration of properties. Inconel 718 is one of the most commonly used materials for these applications. Different metal nitrides like TiN coatings have been deposited in past to prevent hydrogen degradation, which are also known for their high hardness and good wear resistance [1, 2]. However, reports on hydrogen degradation of CrN coatings, which shows better oxidation and corrosion resistance, higher temperature stability and lower friction coefficient than TiN [3, 4] has not been reported till now. Despite a lot of publications about CrN films, up to now the effect of hydrogenation on mechanical and tribological properties of CrN coatings is still not completely understood. In the current work CrxN coatings were deposited by Direct Current Magnetron Sputtering (dcMS) on Inconel 718 substrate at different chamber pressures and substrate voltages. Substrate voltage is one of the most important process parameters which determines the structure of the coating and the adhesion between substrate and coating. Simultaneously a study of the chamber pressure is also needed to understand the deposited structure and growth rate because at higher pressures the high number of argon atoms reduce the number of ionized ions available for the deposition leading to low deposition rates [5]. Gas-phase hydrogenation of the samples was performed at a temperature of 600° C and hydrogen pressure of 2 atm. It was found that CrxN coatings are resistant against hydrogen exposure as compared to uncoated surfaces. The results of changes in the mechanical, tribological properties and phase composition of the coatings after hydrogenation are discussed. Coating microstructure was studied by scanning electron microscopy (SEM). The mechanical properties of the coatings were characterized by means of nanoindentation and scratch test. KW - CrxN coating KW - mechanical properties KW - microstructure KW - hydrogenation KW - XRD Y1 - 2016 SN - 978-91-88252-03-6 PB - VBRI Press CY - Linköping ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Krupp, Ulrich A1 - Solovev, Mikhail A1 - Weiß, Sabine T1 - Investigation of TiAlN HiPIMS coating deposited on the newly developed Ni-based superalloy AD730 N2 - The development of new alloys for gas turbine engines has been focused on withstanding against increasing service temperatures. AD730™ is a recently developed nickel-based superalloy for turbine disk applications with superior properties at 700°C, which is higher than the common service temperature for IN718. Use of coatings to enhance the properties of materials, such as wear resistance is widely known in various applications. This research presents an experimental study of TiAlN coatings, deposited onto AD730 superalloy using High Power Impulse Magnetron Sputtering (HiPIMS). Phase structure and chemical composition of the TiAlN films were characterized by X-ray diffractometry. Transmission electron microscopy as well as scanning electron microscopy were used to analyze the microstructure of the coating. Mechanical properties, including hardness, Young's modulus, and adhesion strength were measured using nanoindentation und scratch test. KW - TiAlN coating KW - HiPIMS KW - Ni-based superalloy KW - AD730 TEM XRD Y1 - 2016 UR - http://www.pse-conferences.net/poster-wednesday.html UR - http://www.pse-conferences.net/tl_files/abstract-print/PSE2016-PO3023.pdf N1 - 16th International Conference on Plasma Surface Engineering ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Weiß, Sabine T1 - Effect of pulse time on structure and mechanical properties of HPPMS deposited AlTiN coatings N2 - The use of PVD AlTiN as a protective coating on cutting tools is well known. With the introduction of pulsed deposition techniques like High Power Pulsed Sputtering (HPPMS), a possibility is provided to the coating developers to design their coatings by the variation in pulse parameters. To analyze the effect of pulse time HPPMS AlTiN coatings were deposited on Si (100) as well as 100Cr6 steel plates at a temperature of 500°C in a reactive gas environment. Oscilloscope measurements depicted a change in current-voltage characteristics with variation in pulse time. This influence the coating structure, deposition rates and phase formations as well. Nanoindentation results show a variation in the mechanical properties of the coatings with the change in pulse time. This study focuses on the potential of HPPMS technology for enhancement of mechanical and structural properties of AlTiN coating. KW - HPPMS KW - AlTiN KW - wear KW - cutting tools KW - pulse time Y1 - 2016 UR - http://www.pse-conferences.net/poster-wednesday.html UR - http://www.pse-conferences.net/tl_files/abstract-print/PSE2016-PO3055.pdf N1 - 16th International Conference on Plasma Surface Engineering ER - TY - CHAP A1 - Bambach, Markus A1 - Sizova, Irina A1 - Bolz, Sebastian A1 - Weiß, Sabine T1 - Development of a dynamic recrystallization model for a β-solidifying titanium aluminide alloy using Kocks-Mecking plots T2 - ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, Nantes, France, 27-29 April 2016 Y1 - 2016 SN - 978-0-7354-1427-3 U6 - https://doi.org/10.1063/1.4963545 SP - 160002-1 EP - 160002-7 PB - AIP Publishing CY - Melville, New York ER -