TY - CHAP A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Sakuma, F. A1 - Khlevnoy, B. A1 - Morozova, S. ED - Zhang, Z.M. ED - Tsai, B.K. ED - Machin, Graham T1 - Blackbody and other Calibration Sources, in Radiometric Temperature Measurements Part I Fundamentals T2 - Experimental Methods in the Physical Sciences Y1 - 2009 UR - http://permalink.bibkatalog.de/BV010604537 SN - 978-0-12-374021-2 VL - 42 SP - 241 EP - 295 PB - Elsevier Academic Press CY - Amsterdam ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Werner, L. A1 - Fischer, J. A1 - Johannsen, U. T1 - Accurate determination of the spectral responsivity of silicon trap detectors between 238 nm and 1015 nm using a laser-based cryogenic radiometer JF - Metrologia Y1 - 2000 UR - http://permalink.bibkatalog.de/BV012573233 IS - 37 SP - 279 EP - 284 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Voigt, P. A1 - Reichling, M. T1 - Measuring local thermal conductivity in polycrystalline diamond with a high resolution photothermal microscope JF - J. Appl. Phys. Y1 - 1997 UR - http://permalink.bibkatalog.de/BV013637659 IS - 81 SP - 2966 EP - 2977 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Fischer, J. A1 - Seidel, J. T1 - A non-contact technique providing improved accuracy in area measurements of radiometric apertures JF - Metrologia Y1 - 2000 UR - http://permalink.bibkatalog.de/BV012573233 IS - 37 SP - 637 EP - 640 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Werner, L. T1 - Calibration and interpolation of the spectral responsivity of silicon photodiode based detectors JF - Sensors & Actuators A: Physical Y1 - 2009 UR - http://permalink.bibkatalog.de/BV013197638 IS - 156 SP - 185 EP - 190 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Klotzbücher, T. A1 - Reichling, M. T1 - Local variation of room temperature thermal conductivity in high quality polycrystalline diamond JF - Appl. Phys. Lett. Y1 - 1998 IS - 73 SP - 756 EP - 758 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Costello, M. A1 - Reichling, M. T1 - The influence of thermal barriers on heat flow in high quality chemical vapour deposited diamond JF - Phys. Rev. Lett. Y1 - 1998 IS - 80 SP - 117 EP - 120 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Bernhard, Frank ED - Bernhard, Frank T1 - Strahlungsthermometrie T2 - Technische Temperaturmessung Y1 - 2014 SN - ISBN 978-3-642-24505-3 PB - Springer ET - 2 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Verhoeven, H. A1 - Reichling, M. A1 - Müller-Sebert, W. A1 - Zachai, R. T1 - Structural limitations to local thermal diffusivity of diamond films JF - Diamond and Related Materials Y1 - 1996 UR - http://permalink.bibkatalog.de/BV013364452 IS - 5 SP - 1012 EP - 1016 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Maznev, A.A. A1 - Reichling, M. T1 - Thermal wave propagation in thin films on substrates JF - J. Appl. Phys Y1 - 1995 UR - http://permalink.bibkatalog.de/BV013637659 IS - 78 SP - 5266 EP - 5269 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Langer, G. A1 - Reichling, M. T1 - Thermal conductivity of thin metallic films measured with the photothermal profile analysis JF - Rev. Sci. Instr. Y1 - 1997 IS - 68 SP - 1510 EP - 1513 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Reichling, M. A1 - Voigt, P. T1 - Quantitative thermal imaging of current densities and heat flow in electronic microstructures JF - Prog. in Nat. Sci. Y1 - 1996 IS - 6 SP - 519 EP - 523 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Reichling, M. A1 - Matthias, E. T1 - Thermoreflectance measurements of single thermal barriers in CVD-diamond JF - Prog. in Nat. Sci. Y1 - 1996 IS - 6 SP - 297 EP - 300 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Voigt, P. A1 - Reichling, M. A1 - Matthias, E. T1 - Photothermal measurement of thermal anisotropy in pyrolytic graphite JF - Appl. Phys. B Y1 - 1996 IS - 62 SP - 493 EP - 497 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Voigt, P. A1 - Reichling, M. T1 - Thermal wave imaging of electrically heated microstructures JF - J. Appl. Phys. Y1 - 1996 IS - 80 SP - 2013 EP - 2018 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Manara, Jochen A1 - Zipf, Matthias A1 - Stark, Thomas A1 - Arduini, Mariacarla A1 - Ebert, Hans-Peter A1 - Tutschke, Andreas A1 - Hallam, Andrew A1 - Hanspal, Jagdevinder A1 - Langley, Mark A1 - Hodge, D. T1 - Development of Long Wavelength Infrared Radiation Thermometry for Measurements in Gas Turbines BT - Key Note Lecture MSE 2016 Y1 - 2016 CY - Darmstadt ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Machin, Graham A1 - Bloembergen, P. A1 - Anhalt, Klaus A1 - Sadli, M. A1 - Saunders, P. A1 - Woolliams, E. A1 - Yamada, Y. A1 - Yoon, H. T1 - Practical implementation of the mise-en-prtique for the definition of the Kelvin above the silver point BT - Tempmeko 2010 Y1 - 2010 CY - Portroz (Slowenien) ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Knopp, Kevin A1 - Lenski, Philipp A1 - Zänglein, Marc A1 - Manara, Jochen A1 - Stark, Thomas A1 - Zipf, Matthias A1 - Arduini, Mariacarla A1 - Schreiber, Ekkehard A1 - Krüger, U. A1 - Schmidt, Franz A1 - Brunner, Martin T1 - Sensor systems for additive manufacturing Y1 - 2018 PB - Key Note Lecture MSE 2018 CY - Darmstadt ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Reichling, M. ED - Nazaré, H. ED - Neves, A.J. T1 - Thermal characterization of diamond materials T2 - Properties and growth of diamond Y1 - 2001 UR - https://books.google.de/books?id=jtC1mUFZfQcC&printsec=frontcover PB - Institution of Electrical Engineers CY - London ER - TY - CHAP A1 - Zink, Markus H. A1 - Dotterweich, C. A1 - Hartmann, Jürgen A1 - Harrer, S. A1 - Hemberger, F. A1 - Ebert, Hans-Peter A1 - Schnitzler, Tim T1 - Phase Change Materials for Use in Thermally and Electrically Stressed Insulation for High Voltage Applications T2 - IEEE Electrical Insulation Conference Y1 - 2016 VL - 2016 SP - 605 EP - 608 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Hollandt, Jörg A1 - Taubert, Dieter Richard A1 - Werner, L. T1 - Optische Hochtemperaturmesstechnik für die Thermometrie, Radiometrie und Photometrie BT - Sensoren und Messsysteme 2010 Y1 - 2010 CY - Nürnberg ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Ochs, Dennis A1 - Lenski, Philipp A1 - Schiffler, Andreas A1 - Versch, Alexander A1 - Manara, Jochen T1 - Thermal process monitoring for additive manufacturing BT - MSE 2020 Y1 - 2020 CY - Darmstadt ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Nilsson, O. A1 - Fricke, J. T1 - Thermal diffusivity measurements on two-layered systems with the laser-flash method JF - High Temp. - High Press Y1 - 1993 IS - 25 SP - 403 EP - 410 ER - TY - JOUR A1 - Ochs, Dennis A1 - Wehnert, Kira-Kristin A1 - Hartmann, Jürgen A1 - Schiffler, Andreas A1 - Schmitt, Jan T1 - Sustainable Aspects of a Metal Printing Process Chain with Laser Powder Bed Fusion (LPBF) JF - Procedia CIRP N2 - Production companies are getting more and more aware of the relevancy of energy costs and the environmental impact of their manufactured products. Hence, the knowledge about the energy intensity of new process technologies as metal printing becomes increasingly crucial. Therefore, data about the energy intensity of entire process chains allow a detailed assessment of the life cycle costs and environmental impact of metal printed parts. As metal printing with Laser Powder Bed Fusion (LPBF) is applied from rapid prototyping to serial manufacturing processes more and more, sustainability data are useful to support a valid scale-up scenario and energetic improvements of the 3D-printing machinery as well as peripheral aggregates used in the process chain. The contribution aims to increase the transparency of the LPBF process chain in terms of its energy consumption. Therefore a generalized model to assess sustainability aspects of metal printed parts is derived. For this purpose, the LPBF process chain with the essential pre-, main- and post-processes is evaluated regarding its energy intensity. Here, the sub-processes, for example wet and dry cleaning of the printer, sieving of the metal powder or sand-blasting of the part are analyzed as well as the main printing process. Based on the derived experimental data from an installed, industry-like process chain, a model is created, which tends to generalize the experimental findings to evaluate other metal printed parts and process chain variants in terms of their energy intensity. Y1 - 2021 UR - 10.1016/j.procir.2021.01.163 VL - 98 SP - 613 EP - 618 PB - Elsevir ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Lenski, Philipp A1 - Ochs, Dennis A1 - Shandy, Amir A1 - Winterstein, A. A1 - Versch, Alexander A1 - Schiffler, Andreas T1 - Thermische Prozessüberwachung für additive Fertigungsverfahren BT - Temperatur 2020 Y1 - 2020 CY - Berlin ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Dzemko, Mikita A1 - Engelmann, Bastian A1 - Schmitt, Jan T1 - Toward Shifted Production Strategies Through Additive Manufacturing: A Technology and Market Review for Changing Value Chains T2 - 7th CIRP Global Web Conference (86) N2 - In the last decade many different additive manufacturing (AM) technologies for metal, plastic or ceramic processing raise from research to commercialization. As a result, AM grows into different business areas and transforms structures and processes. Hence, the contribution tends to show the change in added values though the availability of different additive manufacturing technologies based on a technology screening and market research. Regarding the named purpose, a broad market research of 83 companies and 339 printer models has been conducted to find patterns of AM technology market share and regions to structure indicators such as accuracy by processed material classes with a specified AM method. Printing materials as metal, plastic, ceramic and carbon have been considered. The categorization is done by the AM principles: power bed fusion, material extrusion, vat photopolymerization and … Y1 - 2019 U6 - https://doi.org/10.1016/j.procir.2020.01.029 VL - 86 SP - 228 EP - 233 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Manara, Jochen A1 - Zipf, Mathias A1 - Stark, Thomas A1 - Knopp, Kevin A1 - Zänglein, Marc A1 - Lenski, Philipp A1 - Schreiber, Ekkehard A1 - Schmidt, Franz A1 - Brunner, Martin A1 - Müller, Michael T1 - Thermophysical property measurements at high-temperatures for power engineering and additive manufacturing processes BT - QIRT 2018, 25 - 29 June 2018, Berlin, Germany N2 - To address the needs for increasing efficiency in power conversion, stratified structures like thermal barrier coatings, are used to increase operation temperature. Also advanced material processing like 3D laser printing of metals and ceramics are based on a layer-to-layer process at high temperatures, resulting in non-homogeneous components. Both systems require more and more detailed investigation methods to characterise the material properties of the resulting structures and to optimize the relevant processes. To address the required needs in advanced material characterisation recently an attempt was started to develop a unique measurement set-up for advanced material characterisation. This method is based on the well know laser flash principle, which was improved by adding supplementary heating sources and additional detection channels. Combining different heating mechanism and heating times with the two-dimensional measuring of the thermal flow across the sample enables the determination of different opto-thermal parameters and other material properties, e.g. mechanical contact, electrical conductivity or optical data, which also depend on or affect the flow of heat. In this paper we describe the implementation of the different optical methods to measure the thermal heat flow by point-like and two-dimensional temperature measurement and present first results on several samples. KW - thermophysical property measurement KW - additive manufacturing process Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-17678 SN - 978-3-940283-94-8 CY - Berlin ER - TY - JOUR A1 - Knopp, Kevin A1 - Shandy, Amir A1 - Manara, Jochen A1 - Vidi, Stephan A1 - Hartmann, Jürgen T1 - Metrologische Apparaturen zur Messung thermophysikalischer Materialeigenschaften bei sehr hohen Temperaturen im EU-Projekt Hi-TRACE JF - FHWS Science Journal N2 - Industriezweige wie die Glas-Industrie, die Kraftwerkstechnik sowie die Luft- und Raumfahrttechnik müssen kontinuierlich neue Methoden entwickeln, sowie bestehende Verfahren optimieren, um in ihren Bereichen wettbewerbsfähig zu sein bzw. neue Anforderungen an Umwelt- und Klimaschutz zu erfüllen. Dies beinhaltet oft die Entwicklung neuer Materialien, die leichter zu fabrizieren sind und sowohl mechanisch als auch thermisch höheren Belastungen standhalten. Für die genannten Industriezweige sind Prozesse mit hohen Betriebstemperaturen bis zu 3.000 °C kennzeichnend und damit ist die Kenntnis von Materialeigenschaften bei diesen extremen Temperaturen von großer Bedeutung. Auch wenn es bereits einige Messapparaturen für die Bestimmung von thermophysikalischen Materialdaten bei hohen Temperaturen gibt, muss die Rückführung dieser auf die SI Basiseinheiten gewährleistet werden, um die Zuverlässigkeit der gemessenen Daten für die Anforderung der genannten Branchen sicherzustellen. Diese Aufgabe ist das Ziel des EMPIR-(European Metrology Programme for Innovation and Research) Projektes Hi-TRACE [1]. Hi-TRACE zielt darauf ab, Referenzapparaturen und neue Methoden für die Messung von thermophysikalischen Materialeigenschaften, (thermische Diffusivität, spezifische Wärme, Emissionsgrad und Schmelztemperatur) sowie der Haftung von Schichten über 1.000 °C zu bestimmen. KW - thermophysik KW - temperatur Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-20046 UR - https://nbn-resolving.org/urn:nbn:de:bvb:863-opus-19389 SN - 2196-6095 VL - 5 IS - 2 SP - 83 EP - 92 ER - TY - JOUR A1 - Ochs, Dennis A1 - Wehnert, Kira-Kristin A1 - Knopp, Kevin A1 - Hartmann, Jürgen A1 - Versch, Alexander A1 - Schiffler, Andreas T1 - Untersuchungen zur Temperaturleitfähigkeit additiv gefertigter Stahlproben in Abhängigkeit der relativen Dichte JF - FHWS Science Journal N2 - Das direkte Metall-Laser-Schmelzen (DMLS) aus der Familie der Additiven Fertigungsverfahren (AM) ermöglicht die schichtweise Erzeugung komplexer dreidimensionaler Geometrien mit hoher relativer Dichte unter Verwendung von Metallpulver als Ausgangsmaterial [1]. Die Technologie wird zunehmend eingesetzt, um innovative Bauteile material- und gewichtssparend herzustellen oder komplexe Produkte ohne zusätzliche Werkzeuge oder Spannvorrichtungen zu fertigen. Darüber hinaus sind Funktionsintegrationen, zum Beispiel Gussformen mit eingeprägten Kühlkanälen, möglich. Da einzelne Metallpulverschichten auf vorhergehende Schichten aufgeschmolzen werden, entstehen während der Herstellung des Bauteils komplexe, zeitabhängige Temperaturprofile [2]. Durch den Einsatz hoher Laserintensitäten und Scangeschwindigkeiten, bei denen die Belichtungszeit der Laserbestrahlung im Bereich von Millisekunden liegt, werden zudem extrem hohe Aufheiz- und Abkühlraten induziert, die zu einzigartigen Mikrostrukturen und Materialeigenschaften führen [3]. Diese extremen Prozessbedingungen können sich jedoch auch negativ auf den Fertigungsprozess auswirken. Bei komplexen Bauteilen bleibt die Prozessstabilität und Qualitätssicherung Umfragen zufolge weiterhin die wichtigste technologische Barriere für den Einsatz additiv gefertigter Bauteile in hochbelasteten oder sicherheitsrelevanten Bereichen [4]. Daher verspricht der Zusammenhang zwischen Temperaturprofil während der Fertigung, relativer Dichte der Bauteile, sowie thermophysikalischer Eigenschaften additiv gefertigter Proben wichtige Erkenntnisse, insbesondere im Hinblick auf eine zerstörungsfreie Qualitätssicherung, sowie neue Anwendungsmöglichkeiten. KW - temperatur KW - additive fertigung Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-19986 UR - https://nbn-resolving.org/urn:nbn:de:bvb:863-opus-19389 SN - 2196-6095 VL - 5 IS - 2 SP - 75 EP - 82 ER - TY - JOUR A1 - Jürgen, Hartmann A1 - Arduini, Mariacarla A1 - Manara, Jochen A1 - Stark, Thomas A1 - Ebert, Hans-Peter T1 - Development and Evaluation of an Improved Apparatus for Measuring the Emissivity at High Temperatures JF - Sensors N2 - An improved apparatus for measuring the spectral directional emissivity in the wavelength range between 1 µm and 20 µm at temperatures up to 2400 K is presented in this paper. As a heating unit an inductor is used to warm up the specimen, as well as the blackbody reference to the specified temperatures. The heating unit is placed in a double-walled vacuum vessel. A defined temperature, as well as a homogenous temperature distribution of the whole surrounding is ensured by a heat transfer fluid flowing through the gap of the double-walled vessel. Additionally, the surrounding is coated with a high-emitting paint and serves as blackbody-like surrounding to ensure defined boundary conditions. For measuring the spectral directional emissivity at different emission angles, a movable mirror is installed in front of the specimen, which can be adjusted by a rotatable arrangement guiding the emitted radiation into the attached FTIR-spectrometer. The setup of the emissivity measurement apparatus (EMMA) and the measurement procedure are introduced, and the derived measurement results are presented. For evaluating the apparatus, measurements were performed on different materials. The determined emissivities agree well with values published in literature within the derived relative uncertainties below 4% for most wavelengths. KW - emissivity KW - reflectivity KW - infrared radiation KW - high temperature KW - Temperatur KW - Emissivität Y1 - 2021 UR - https://www.mdpi.com/1424-8220/21/18/6252 U6 - https://doi.org/10.3390/s21186252 SN - 1424-8220 VL - 21 IS - 18 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Litorja, M. A1 - Fowler, J. A1 - Fox, N. A1 - Stock, M. A1 - Razet, A. A1 - Khlevnoy, B. A1 - Ikonen, E. A1 - Machacs, M. A1 - Doytchinov, K. T1 - Final report on the CCPR-S2 supplementary comparison of area measurements of apertures for radiometry JF - Metrologia Y1 - 2007 UR - http://permalink.bibkatalog.de/BV012573233 VL - 44 IS - 02002 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Moritz, W. A1 - Roth, U. A1 - Heyde, M. A1 - Rademann, K. A1 - Reichling, M. T1 - Submicrosecond range surface heating and temperature measurement for efficient sensor reactivation JF - Thin Solid Films Y1 - 2001 UR - http://permalink.bibkatalog.de/BV013351743 IS - 391 SP - 143 EP - 148 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Dobhan, Alexander A1 - Engelmann, Bastian A1 - Eberhardt, Lars A1 - Heusinger, Moritz A1 - Raab, C A1 - Schleif, Frank-Michael A1 - Türk, M. T1 - Optimierung von Prozessen und Werkzeugmaschinen durch Bereitstellung, Analyse und Soll-Ist-Vergleich von Produktionsdaten: Digitalkonferenz Y1 - 2020 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Thuillier, G. A1 - Foujols, T. A1 - Bolsée, D. A1 - Gillotay, D. A1 - Hersé, M. A1 - Petermanns, W. A1 - Decupyer, W. A1 - Mandel, H. A1 - Sperfeld, P. A1 - Taubert, Dieter Richard T1 - SOLAR/SOLSPEC BT - Scientific objectives, instrument performances and its absolute calibration using a blackbody as primary standard source JF - Solar Physics Y1 - 2009 UR - http://permalink.bibkatalog.de/BV021245164 IS - 257 SP - 185 EP - 213 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Lowe, D. A1 - Machin, Graham A1 - Sadli, M. A1 - Yamada, Y. T1 - Thermodynamic temperature determinations of Co-C, Pd-C Pt-C and Ru-C eutectic fixed-points cells JF - Metrologia Y1 - 2006 UR - http://permalink.bibkatalog.de/BV012573233 VL - 43 IS - 2 SP - 78 EP - 83 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Machin, G. A1 - Bloembergen, P. A1 - Sadli, M. A1 - Yamada, Y. T1 - A concerted international project to establish high-temperature fixed-points for primary thermometry JF - International Journal of Thermophysics Y1 - 2007 UR - http://permalink.bibkatalog.de/BV013298193 IS - 28 SP - 1976 EP - 1982 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Reichling, M. ED - Nazaré, H. ED - Neves, A.J. T1 - Thermal transport in diamond T2 - Properties and growth of diamond Y1 - 2001 UR - https://books.google.de/books?id=jtC1mUFZfQcC&printsec=frontcover PB - Institution of Electrical Engineers CY - London ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Sadli, M. A1 - Anhalt, Klaus A1 - Schiller, S. T1 - Thermal effects in the BB3200pg on M-C eutectic implementation JF - International Journal of Thermophysics Y1 - 2009 UR - http://permalink.bibkatalog.de/BV013298193 IS - 30 SP - 69 EP - 76 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - New Developments in High-Temperature Measurement Techniques JF - International Journal of Electrical and Computer Engineering Systems Y1 - 2014 VL - 5 IS - 2 SP - 63 EP - 67 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Engert, J. A1 - Fellmuth, B. A1 - Fischer, Joachim A1 - Hollandt, Jörg A1 - Tegeler, E. A1 - Seidel, J. T1 - Die internationale Temperaturskalen BT - ITS-90 und PLTS-2000 JF - PTB Mitteilungen Y1 - 2007 UR - http://permalink.bibkatalog.de/BV035078972 VL - 117 IS - 3 SP - 236 EP - 242 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Fischer, J. A1 - Johannsen, U. A1 - Werner, L. T1 - Analytical model for the temperature dependence of the spectral responsivity of silicon JF - J. Opt. Soc. Am. B Y1 - 2001 IS - 18 SP - 942 EP - 947 ER - TY - JOUR A1 - Höfflin, Dennis A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Versch, Alexander A1 - Hartmann, Jürgen T1 - Active thermography for in-situ defect detection in laser powder bed fusion of metal JF - Journal of Manufacturing Processes N2 - Additive manufacturing (AM) has revolutionized production by offering design flexibility, reducing material waste, and enabling intricate geometries that are often unachievable with traditional methods. As the use of AM for metals continues to expand, it is crucial to ensure the quality and integrity of printed components. Defects can compromise the mechanical properties and performance of the final product. Non-destructive testing (NDT) techniques are necessary to detect and characterize anomalies during or post-manufacturing. Active thermography, a thermal imaging technique that uses an external energy source to induce temperature variations, has emerged as a promising tool in this field. This paper explores the potential of in-situ non-destructive testing using the processing laser of a PBF-LB/M setup as an excitation source for active thermography. With this technological approach, artificially generated internal defects underneath an intact surface can be detected down to a defect size of 350 μm – 450 μm. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-57601 SN - 1526-6125 VL - 131 SP - 1758 EP - 1769 PB - Elsevier BV ER - TY - JOUR A1 - Höfflin, Dennis A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Manara, Jochen A1 - Hartmann, Jürgen T1 - Pixelwise high-temperature calibration for in-situ temperature measuring in powder bed fusion of metal with laser beam JF - Heliyon N2 - High-temperature calibration methods in additive manufacturing involve the use of advanced techniques to accurately measure and control the temperature of the build material during the additive manufacturing process. Infrared cameras, blackbody radiation sources and non-linear optimization algorithms are used to correlate the temperature of the material with its emitted thermal radiation. This is essential for ensuring the quality and repeatability of the final product. This paper presents the calibration procedure of an imaging system for in-situ measurement of absolute temperatures and temperature gradients during powder bed fusion of metal with laser beam (PBF-LB/M) in the temperature range of 500 K–1500 K. It describes the design of the optical setup to meet specific requirements in this application area as well as the procedure for accounting the various factors influencing the temperature measurement. These include camera-specific effects such as varying spectral sensitivities of the individual pixels of the sensor as well as influences of the exposure time and the exposed sensor area. Furthermore, influences caused by the complex optical path, such as inhomogeneous transmission properties of the galvanometer scanner as well as angle-dependent transmission properties of the f-theta lens were considered. A two-step fitting algorithm based on Planck's law of radiation was applied to best represent the correlation. With the presented procedure the calibrated thermography system provides the ability to measure absolute temperatures under real process conditions with high accuracy. Y1 - 2024 U6 - https://doi.org/10.1016/j.heliyon.2024.e28989 SN - 2405-8440 VL - 10 IS - 7 PB - Elsevier BV ER - TY - GEN A1 - Höfflin, Dennis A1 - Schiffler, Andreas A1 - Hartmann, Jürgen A1 - Sauer, Christian T1 - Dual Scan head approach for in-situ defect detection in laser powder bed fusion of metals - Dataset N2 - This dataset contains thermographic data from a study on in-situ defect detection in the Laser Powder Bed Fusion of Metals (PBF-LB/M) process. The data was collected using a novel experimental setup named Synchronized Path Infrared Thermography (SPIT), which employs a dual scan head configuration. One scan head directs the processing laser, while the second scan head positions the measurement field of an infrared (IR) camera. This setup allows for the precise analysis of the cooling behavior of the material decoupled from the immediate laser-material interaction zone. The experiments were conducted on pre-fabricated stainless steel (EOS StainlessSteel PH1, DIN 14540) samples with embedded, cylindrical subsurface defects of varying diameters. A single layer of metal powder was applied to these samples and then fused by the laser. The dataset includes a series of measurements where process parameters, specifically the volumetric energy density and the laser scanning speed, were systematically varied to assess their influence on defect detection reliability. The provided data consists of raw thermographic recordings, which capture the surface temperature distribution in the heat-affected zone behind the melt pool. These recordings can be used to identify localized areas of elevated temperature caused by the insulating effect of the subsurface defects, which impede heat transfer into the substrate. This dataset is valuable for researchers working on process monitoring, defect detection algorithms, and the validation of thermal simulations in additive manufacturing. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.15727369 ER - TY - GEN A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Höfflin, Dennis A1 - Hartmann, Jürgen T1 - Temporally Gated Active Thermography for Defect Detection in Laser-Based Powder Bed Fusion of Metals - Dataset N2 - This HDF5-dataset contains in-situ high-speed infrared thermography data acquired during the Laser-Based Powder Bed Fusion (PBF-LB/M) process. The data was collected using a Synchronized Path Infrared Thermography (SPIT) setup, which employs a dual-scanhead configuration to guide both the processing laser and the thermal camera's field of view. The primary feature of this dataset is the application of a temporally gated acquisition strategy. The infrared camera's integration time (800 µs) was synchronized with a modulated processing laser (500 Hz) to capture thermal data exclusively during the laser-off phases. This method effectively isolates the material's thermal emission from high-intensity laser reflections. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.17747278 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Ring, E.F.J. A1 - Ammer, K. A1 - Land, D. A1 - Thomas, R. A1 - Hand, J.W. ED - Zhang, Z.M. ED - Tsai, B.K. ED - Machin, G. T1 - Infrared and Microwave Medical Thermometry in Radiometric Temperature Measurements Part II BT - Applications T2 - Experimental Methods in the Physical Sciences Y1 - 2009 UR - http://permalink.bibkatalog.de/BV010604537 SN - 978-0-12-375091-4 VL - 43 SP - 393 EP - 448 PB - Elsevier Academic Press CY - Amsterdam ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Struß, O. A1 - Gaertner, R. A1 - Ishii, J. ED - Zhang, Z.M. ED - Tsai, B.K. ED - Machin, Graham T1 - Industrial Applications of Radiation Thermometry, in Radiometric Temperature Measurements Part II BT - Applications T2 - Experimental Methods in the Physical Sciences, Volume 43 Y1 - 2009 UR - http://permalink.bibkatalog.de/BV010604537 SN - 978-0-12-375091-4 VL - 43 SP - 1 EP - 56 PB - Elsevier Academic Press CY - Amsterdam ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Edler, F. T1 - Simultaneous contact and non-contact measurements of the melting temperature of a Ni-C fixed-point cell JF - International Journal of Thermophysics Y1 - 2007 UR - http://permalink.bibkatalog.de/BV013298193 IS - 28 SP - 2002 EP - 2008 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Meindl, P. A1 - Taubert, Dieter Richard A1 - Werner, L. T1 - Traceable Radiometric Calibration of Semiconductor Detectors and their Application for Thermodynamic Temperature Measurement JF - MAPAN - Journal of Metrology Society of India Y1 - 2010 VL - 25 IS - 3-10 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Edler, F. T1 - Kombi-Fixpunktzelle zur Erzielung kleinster metrologischer Unsicherheiten JF - Sensor Magazin Y1 - 2007 UR - http://permalink.bibkatalog.de/BV037313622 IS - 1 SP - 20 EP - 21 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Keawprasert, T. A1 - Anhalt, Klaus A1 - Taubert, Dieter Richard T1 - Monochromator-based Absolute Calibration of Radiation Thermometers JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 1697 EP - 1706 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Taubert, Dieter Richard A1 - Hollandt, Jörg T1 - Absolute radiometry for the MeP-K BT - The irradiance measurement method JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 1707 EP - 1718 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Friedrich, R. A1 - Gutschwager, B. A1 - Taubert, Dieter Richard T1 - High-Accuracy Radiation Thermometry at the National Metrology Institute of Germany BT - the PTB JF - High Temperatures - High Pressures Y1 - 2005 VL - 35/36 IS - 4 SP - 379 EP - 415 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - High-temperature measurement techniques for the application in photometry radiometry and thermometry JF - Physics Reports Y1 - 2009 UR - http://permalink.bibkatalog.de/BV012962270 VL - 469 SP - 205 EP - 269 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Völker, S. T1 - Thermal management of light sources JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 513 EP - 522 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Gutschwager, B. A1 - Struss, O. T1 - Strahlungsthermometrie BT - Temperaturen berührungslos messen JF - Automatisierungstechnische Praxis Y1 - 2006 IS - 6 SP - 70 EP - 81 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Anhalt, Klaus T1 - Radiation thermometry capabilities of the PTB up to 3200 K JF - MEASURE Y1 - 2008 IS - 3 SP - 26 EP - 34 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - New Developments in High-Temperature Measurement Techniques JF - International Journal of Electrical and Computer Engineering Systems Y1 - 2014 VL - 5 IS - 2 SP - 63 EP - 67 ER - TY - JOUR A1 - Blotevogel, Thomas A1 - Egermann, Jan A1 - Goldlücke, Jürgen A1 - Leipertz, Alfred A1 - Hartmann, Matthias A1 - Schenk, Martin A1 - Berckmueller, Martin T1 - Developing Planar Laser-Induced Fluorescence for the Investigation of the Mixture Formation Process in Hydrogen Engines JF - SAE Paper Y1 - 2004 UR - http://permalink.bibkatalog.de/BV013334911 IS - 2004-01-1408 ER - TY - CHAP A1 - Blotevogel, Thomas A1 - Goldlücke, Jürgen A1 - Egermann, Jan A1 - Leipertz, Alfred A1 - Hartmann, Matthias A1 - Rottengruber, Hermann ED - Eichlseder, Helmut T1 - Untersuchung der Gemischbildung von Gasmotoren mit Hilfe laseroptischer Messverfahren T2 - Der Arbeitsprozess des Verbrennungsmotors (10. Tagung) Y1 - 2005 SP - 139 EP - 166 PB - Verlag der Technischen Universität Graz CY - Graz ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Edler, F. A1 - Anhalt, Klaus T1 - Neuartige eutektische Metall-Kohlenstoff-Hochtemperaturfixpunkte für die Thermometrie JF - PTB Mitteilungen Y1 - 2007 UR - http://permalink.bibkatalog.de/BV035078972 VL - 117 IS - 3 SP - 256 EP - 260 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Taubert, Dieter Richard A1 - Monte, C. A1 - Gutschwager, B. A1 - Baltruschat, C. A1 - Hollandt, Jörg A1 - Kochems, D. A1 - Küchel, C. T1 - The Spectral Photon Flux of the Radiometric Calibration Spectral Source for the NIRSpec Instrument of the James Webb Space Telescope JF - Metrologia Y1 - 2009 UR - http://permalink.bibkatalog.de/BV012573233 IS - 46 SP - 207 EP - 212 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Thomas, R. A1 - Hill, K.D. A1 - Steele, A.G. A1 - Ma, C.K. T1 - Bilateral comparison of the NRC and PTB local realizations of the ITS-90 between the silver point and 1700 °C using vacuum tungsten strip lamps as transfer standards JF - Metrologia Y1 - 2006 UR - http://permalink.bibkatalog.de/BV012573233 VL - 43 IS - 03003 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Friedrich, R. A1 - Taubert, Dieter Richard A1 - Hollandt, Jörg T1 - Improved calibration of the spectral responsivity of interference filter radiometers in the visible and near infrared spectral range at PTB JF - Metrologia Y1 - 2003 UR - http://permalink.bibkatalog.de/BV012573233 IS - 40 SP - 35 EP - 38 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Zelenjuk, A. A1 - Taubert, Dieter Richard T1 - New PTB Set-up for the absolute calibration of the spectral responsivity of radiation thermometers JF - International Journal of Thermophysics Y1 - 2009 UR - http://permalink.bibkatalog.de/BV013298193 IS - 30 SP - 192 EP - 202 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Ma, C.K. A1 - Gibson, C. T1 - Decreasing dependence of the calibration of the tungsten strip lamp on the temperature of the lamp base with increasing filament length JF - Metrologia Y1 - 2005 UR - http://permalink.bibkatalog.de/BV012573233 IS - 42 SP - 383 EP - 388 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Wang, Y. A1 - Yamada, Y. T1 - Large and small aperture Fixed-point cells of Cu, Pt-C, and Re-C JF - International Journal of Thermophysics Y1 - 2008 UR - http://permalink.bibkatalog.de/BV013298193 IS - 29 SP - 969 EP - 983 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Werner, L. T1 - Radiation thermometry towards the triple point of water? JF - International Journal of Thermophysics Y1 - 2008 UR - http://permalink.bibkatalog.de/BV013298193 IS - 29 SP - 1052 EP - 1065 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - Correct consideration of the index of refraction using blackbody radiation JF - Optics Express Y1 - 2006 UR - http://permalink.bibkatalog.de/BV013253264 VL - 14 IS - 18 SP - 8121 EP - 8126 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - Advanced comparator method for measuring ultra small aperture areas JF - Meas.Sci.Techn. Y1 - 2001 IS - 12 SP - 1678 EP - 1682 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Lowe, D. A1 - Anhalt, Klaus T1 - Construction and validation of a platinum-carbon eutectic fixed-point JF - Metrologia Y1 - 2008 UR - http://permalink.bibkatalog.de/BV012573233 IS - 45 SP - 325 EP - 329 ER - TY - JOUR A1 - Höfflin, Dennis A1 - Hartmann, Jürgen A1 - Rosilius, Maximilian A1 - Seitz, Philipp A1 - Schiffler, Andreas T1 - Opto-Thermal Investigation of Additively Manufactured Steel Samples as a Function of the Hatch Distance JF - Sensors N2 - Nowadays, additive manufacturing processes are becoming more and more appealing due to their production-oriented design guidelines, especially with regard to topology optimisation and minimal downstream production depth in contrast to conventional technologies. However, a scientific path in the areas of quality assurance, material and microstructural properties, intrinsic thermal permeability and dependent stress parameters inhibits enthusiasm for the potential degrees of freedom of the direct metal laser melting process (DMLS). Especially in quality assurance, post-processing destructive measuring methods are still predominantly necessary in order to evaluate the components adequately. The overall objective of these investigations is to gain process knowledge make reliable in situ statements about component quality and material properties based on the process parameters used and emission values measured. The knowledge will then be used to develop non-destructive tools for the quality management of additively manufactured components. To assess the effectiveness of the research design in relation to the objectives for further investigations, this pre-study evaluates the dependencies between the process parameters, process emission during manufacturing and resulting thermal diffusivity and the relative density of samples fabricated by DMLS. Therefore, the approach deals with additively built metal samples made on an EOS M290 apparatus with varying hatch distances while simultaneously detecting the process emission. Afterwards, the relative density of the samples is determined optically, and thermal diffusivity is measured using the laser flash method. As a result of this pre-study, all interactions of the within factors are presented. The process variable hatch distance indicates a strong influence on the resulting material properties, as an increase in the hatch distance from 0.11 mm to 1 mm leads to a drop in relative density of 57.4%. The associated thermal diffusivity also reveals a sharp decrease from 5.3 mm2/s to 1.3 mm2/s with growing hatch distances. The variability of the material properties can also be observed in the measured process emissions. However, as various factors overlap in the thermal radiation signal, no clear assignment is possible within the scope of this work. KW - additive manufacturing processes KW - material Y1 - 2021 U6 - https://doi.org/10.3390/s22010046 SN - 1424-8220 VL - 22 IS - 1 PB - MDPI ER - TY - JOUR A1 - Wehnert, Kira-Kristin A1 - Ochs, Dennis A1 - Schmitt, Jan A1 - Hartmann, Jürgen A1 - Schiffler, Andreas T1 - Reducing Lifecycle Costs due to Profile Scanning of the Powder Bed in Metal Printing JF - Procedia CIRP 98 N2 - First time right is one major goal in powder based 3D metal printing. Reaching this goal is driven by reducing life cycle costs for quality measures, to minimize scrap rate and to increase productivity under optimal resource efficiency. Therefore, monitoring the state of the powder bed for each printed layer is state of the art in selective laser melting. In the most modern approaches the quality monitoring is done by computer vision systems working with an interference on trained neural networks with images taken after exposure and after recoating. There are two drawbacks of this monitoring method: First, the sensor signals - the image of the powder bed - give no direct height information. Second, the application of this method needs to be trained and labeled with reference images for several cases. The novel approach presented in this paper uses a laser line scanner attached to the recoating machine. With this new concept, a direct threshold measure can be applied during the recoating process to detect deviations in height level without prior knowledge. The evaluation can be done online during recoating and feedback to the controller to monitor each individual layer. Hence, in case of deviations the location in the printing plane is an inherent measurement and will be used to decide which severity of error is reported. The signal is used to control the process, either by starting the recoating process again or stopping the printing process. With this approach, the sources of error for each layer can be evaluated with deep information to evaluate the cause of the error. This allows a reduction of failure in the future, which saves material costs, reduces running time of the machine life cycle phase in serial production and results in less rework for manufactured parts. Also a shorter throughput time per print job results, which means that the employee can spent more time to other print jobs and making efficient use of the employee’s work force. In summary, this novel approach will not only reduce material costs but also operating costs and thus optimize the entire life cycle cost structure. The paper presents a first feasibility and application of the described approach for test workpieces in comparison to conventional monitoring systems on an EOS M290 machine. Y1 - 2021 UR - 10.1016/j.procir.2021.01.175 VL - 98 SP - 684 EP - 689 PB - Elsevir ER - TY - JOUR A1 - Hay, Bruno A1 - Beaumont, Oliver A1 - Lambeng, Nora A1 - Cataldi, Michel A1 - Lorrette, Christophe A1 - Knopp, Kevin A1 - Hartmann, Jürgen A1 - Beckstein, Fabia A1 - Stobitzer, Dorothea A1 - Milošević, Nenad A1 - Stepanic, Nenad A1 - Wu, Jiyu A1 - Mildeova, Petra T1 - Inter‑laboratory Comparison on Thermal Diffusivity Measurements by the Laser Flash Method at Ultra‑high Temperature JF - International Journal of Thermophysics N2 - thermal diffusivity measurements by the laser flash method in the temperature range from 23 °C to 3000 °C. The main objective was to assess the variability and coherency of thermal diffusivity measurements performed at ultra-high temperatures at the European level. Three refractory materials (molybdenum, tungsten and isotropic graphite IG210) were selected for this inter-laboratory comparison, due to their high melting point. The disk-shaped specimens needed were machined from the same blocks of materials in order to reduce any potential scattering of results between participants due to inhomogeneity effects. The homogeneity of the sets of specimens was studied by the pilot laboratory (LNE) before launching the comparison process. Thermal diffusivity measurements were then carried out by the seven participants on the three materials during two successive thermal cycles up to the maximum temperatures that can be reached by the devices used. The analysis of results showed a good agreement between the participants for temperatures above 400 °C, with relative deviations within the uncertainties of measurement and lower than ± 4 % for molybdenum, ± 5 % for isotropic graphite and ± 9 % for tungsten. Y1 - 2023 UR - https://doi.org/10.1007/s10765-023-03159-5 VL - 2023 SP - 44 EP - 48 ER - TY - JOUR A1 - Manara, Jochen A1 - Hartmann, Jürgen A1 - Kerwagen, Fabian A1 - Maak, Christoph A1 - Muscio, Albert A1 - Paeth, Heiko A1 - Ebert, Hans-Peter T1 - Passive Radiative Cooling Materials with Special Focus on the Reduction of Urban Heat Island Effect: A Current Summarized Classification of Need, Approaches and Characterization Methods JF - International Journal of Thermophysics N2 - Rapidly rising global temperatures and the intensification of the urban heat island (UHI) effect necessitate new, energy-efficient solutions to mitigate heat stress in cities. Passive radiative cooling (PRC) offers a highly promising, low-energy pathway to achieve sub-ambient temperatures by reflecting incoming solar radiation while emitting long-wave infrared radiation through the atmospheric infrared window. This review summarizes key aspects of PRC and its role in reducing UHI impacts. Furthermore the fundamental physics of heat transfer and radiative heat exchange, including the materials properties such as solar reflectance and thermal emissivity which are correlated with the figures of merit, temperature drop below ambient temperature and cooling power. A comprehensive classification of current PRC materials is presented based on both structural architectures and physical effects. Additionally an overview on measurement techniques are employed to determine the performance of PRC materials, focusing on the key performance indicators. For this purpose in-field as wells as laboratory measurement techniques are introduced and opportunities in standardizing testing protocols are highlighted. Finally, future research directions are outlined, focusing on novel material development, theoretical advancements, scalable fabrication processes, and integration strategies within urban infrastructures. These innovations are important for enhancing building energy efficiency, reducing urban heat stress, and promoting sustainable urban development in the face of climate change. Y1 - 2025 U6 - https://doi.org/10.1007/s10765-025-03529-1 VL - 46 IS - 58 ER - TY - CHAP A1 - Blotevogel, Thomas A1 - Goldlücke, Jürgen A1 - Egermann, Jan A1 - Leipertz, Alfred A1 - Hartmann, Matthias A1 - Schenk, Martin A1 - Berckmüller, Martin ED - Dingel, Oliver T1 - Gemischbildungsuntersuchung in Gasmotoren mittels optischer Messverfahren, speziell in Wasserstoffmotoren T2 - Gasfahrzeuge N2 - Planar laser-induced fluorescence (PLIF) has been successfully used for the investigation of the mixture formation process in hydrogen engines for passenger cars. Detailed information has been obtained about process development (qualitative measurement) and on fuel/air-ratio (quantitative measurement) inside the combustion chamber. These results can be used for further optimization of mixture formation and combustion process concerning emissions and fuel consumption. The measurement technique used is not only limited to hydrogen or to passenger car engines, but can also be applied to other fuel gases like natural gas or to other engine sizes like bus engines. The main topic of this paper is the experimental verification of the procedure which was executed by simultaneous PLIF and Raman scattering measurements. By Raman scattering the fuel/air-ratio can directly be determined from direct concentration measurements of the different gas species. The fuel/air-ratios determined by PLIF and Raman measurements are in good agreement indicating that a quantitative fuel/air-ratio measurement during the mixture formation process of gas and hydrogen engines is possible by PLIF. This fact is also confirmed by other measurements, e.g., global fuel/air-ratio calculated from measured intake air and fuel gas flow. KW - Wasserstoff Gasmotor Laser Optische Messtechnik Y1 - 2004 SN - 3816924395 SP - 205 EP - 229 PB - expert verlag CY - Renningen ER - TY - JOUR A1 - Strasser, Claire A1 - Moukhina, Elena A1 - Hartmann, Jürgen T1 - Time–Temperature-Transformation (TTT) Cure Diagram of an Epoxy–Amine System JF - Macromolecular Theory and Simulations Y1 - 2024 UR - https://doi.org/10.1002/mats.202400039 VL - 33 IS - 6 SP - 2400039 ER -