@misc{TurabovEvdokimovNikitinetal., author = {Turabov, Dashqin and Evdokimov, Anton and Nikitin, Alexander and Ossenbrink, Ralf and Michailov, Vesselin}, title = {Vorhersage des Elektrodenverschleißes beim Widerstandspunktschweißen von Aluminium durch dynamische Widerstandsmessung}, series = {DVS Congress 2023, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vortr{\"a}ge der Veranstaltung in Essen vom 11. bis 14. September 2023 ; (Langfassungen der Beitr{\"a}ge auf USB-Karte)}, volume = {389 / 2023}, journal = {DVS Congress 2023, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vortr{\"a}ge der Veranstaltung in Essen vom 11. bis 14. September 2023 ; (Langfassungen der Beitr{\"a}ge auf USB-Karte)}, publisher = {DVS Media GmbH}, address = {D{\"u}sseldorf}, isbn = {978-3-96144-230-0}, pages = {780 -- 787}, abstract = {Das Widerstandspunktschweißen ist ein weit verbreitetes Schweißverfahren, insbesondere bei der Karosserieherstellung in der Automobilbranche. Im Hinblick auf den Leichtbau werden zunehmend Aluminiumlegierungen verwendet. Das Hauptproblem beim Widerstandspunktschweißen von Aluminiumlegierungen ist der schnelle Elektrodenverschleiß. Dadurch wird die Qualit{\"a}t und Effizienz des Schweißprozesses beeintr{\"a}chtigt. Die Elektrodenstandmenge ist erreicht, wenn die Schweißverbindung eines der Qualit{\"a}tskriterien nicht erf{\"u}llt. Um die Elektrodenstandmenge zu ermitteln, werden in der Industrie im Rahmen der Schweißnahtqualifizierung zeit- und ressourcenaufw{\"a}ndige Methoden, u. a. zerst{\"o}rende Pr{\"u}fmethoden, verwendet. In dieser Arbeit wird eine Methode zur Vorhersage des kritischen Elektrodenverschleißes beim Aluminiumschweißen durch Messung des dynamischen Widerstandes vorgeschlagen. In umfangreichen Versuchsreihen an einer automobiltypischen Al-Legierung der 5000er Gruppe wurden dynamische Widerstandsmessungen durchgef{\"u}hrt. Aus den Widerstandsmesswerten konnte ein Indikator ermittelt werden, welcher auf das Auftreten von Poren in Schweißverbindung und auf einen bald auftretenden kritischen Elektrodenverschleiß hinweist.}, language = {de} } @misc{KotlarskiOrmanovaOssenbrinketal., author = {Kotlarski, Georgi and Ormanova, Maria and Ossenbrink, Ralf and Nikitin, Alexander and Doynov, Nikolay and Valkov, Stefan and Michailov, Vesselin}, title = {Fabrication and Characterization of Wire Arc Additively Manufactured AlSi5 Structures}, series = {Metals}, volume = {12}, journal = {Metals}, number = {11}, issn = {2075-4701}, abstract = {For the purpose of this research, single track details were manufactured in the shape of thin walls with a length of 100 mm and a height of 80 mm. Two welding speeds were chosen for this experiment-13.3 mm/s and 20.0 mm/s corresponding to the following heat inputs: 120 J/mm and 80 J/mm. The gas metal arc welding (GMAW) method was used for the build-up of the specimens in the cold arc pulse mode. The structure of the specimens was studied using X-ray diffraction (XRD) analysis carried out with CuKα radiation with a wavelength of 1.5406 Ǻ, optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Furthermore, the Vickers hardness of the samples was determined using a ZwickRoell DuraScan 10/20 G5 unit at a force of 1 N. A preferred crystallographic orientation towards the (200) plane was observed in all cases, however a vastly textured structure was observed with inclusions of peaks in the (111), (220), and (311) crystallographic planes. The full width at half maximum (FWHM) of samples taken from different stages of build-up was calculated indicating an increase of the dislocation density at the more advanced stages of specimen growth. Despite that an increase of the hardness was observed towards the top of both specimens. This is attributed to the change in the structure of the αAl + Si formations from an irregular one at the bottom of the specimens, towards a fibrous one at the top. The results are discussed in regard to the optimization of the build-up process during wire arc additive manufacturing (WAAM).}, language = {en} } @misc{KoehlerNikitinSonnenfeldetal., author = {K{\"o}hler, Marcel and Nikitin, Alexander and Sonnenfeld, Peter and Ossenbrink, Ralf and J{\"u}ttner, Sven}, title = {Wire Arc Additive Manufacturing of Aluminum Foams Using TiH2-Laced Welding Wires}, series = {Materials}, volume = {17}, journal = {Materials}, number = {13}, publisher = {MDPI AG}, issn = {1996-1944}, doi = {10.3390/ma17133176}, abstract = {Composite materials made from aluminum foam are increasingly used in aerospace and automotive industries due to their low density, high energy absorption capacity, and corrosion resistance. Additive manufacturing processes offer several advantages over conventional manufacturing methods, such as the ability to produce significantly more geometrically complex components without the need for expensive tooling. Direct Energy Deposition processes like Wire Arc Additive Manufacturing (WAAM) enable the additive production of near-net-shape components at high build rates. This paper presents a technology for producing aluminum foam structures using WAAM. This paper's focus is on the development of welding wires that are mixed with a foaming agent (TiH2) and produce a foamed weld metal as well as their processing using MIG welding technology.}, language = {en} }