@article{AbbasBalcBremenetal.2022, author = {Abbas, Karim and Balc, Nicolae and Bremen, Sebastian and Skupin, Marco}, title = {Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding}, series = {Journal of Manufacturing and Materials Processing}, volume = {6}, journal = {Journal of Manufacturing and Materials Processing}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2504-4494}, doi = {10.3390/jmmp6050093}, pages = {1 -- 12}, year = {2022}, abstract = {In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30\% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking.}, language = {en} } @article{AbbasHedwigBalcetal.2023, author = {Abbas, Karim and Hedwig, Lukas and Balc, Nicolae and Bremen, Sebastian}, title = {Advanced FFF of PEEK: Infill strategies and material characteristics for rapid tooling}, series = {Polymers}, volume = {2023}, journal = {Polymers}, number = {15}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/polym15214293}, pages = {Artikel 4293}, year = {2023}, abstract = {Traditional vulcanization mold manufacturing is complex, costly, and under pressure due to shorter product lifecycles and diverse variations. Additive manufacturing using Fused Filament Fabrication and high-performance polymers like PEEK offer a promising future in this industry. This study assesses the compressive strength of various infill structures (honeycomb, grid, triangle, cubic, and gyroid) when considering two distinct build directions (Z, XY) to enhance PEEK's economic and resource efficiency in rapid tooling. A comparison with PETG samples shows the behavior of the infill strategies. Additionally, a proof of concept illustrates the application of a PEEK mold in vulcanization. A peak compressive strength of 135.6 MPa was attained in specimens that were 100\% solid and subjected to thermal post-treatment. This corresponds to a 20\% strength improvement in the Z direction. In terms of time and mechanical properties, the anisotropic grid and isotropic cubic infill have emerged for use in rapid tooling. Furthermore, the study highlights that reducing the layer thickness from 0.15 mm to 0.1 mm can result in a 15\% strength increase. The study unveils the successful utilization of a room-temperature FFF-printed PEEK mold in vulcanization injection molding. The parameters and infill strategies identified in this research enable the resource-efficient FFF printing of PEEK without compromising its strength properties. Using PEEK in rapid tooling allows a cost reduction of up to 70\% in tool production.}, language = {en} } @inproceedings{AbbasThurnKessleretal.2019, author = {Abbas, Karim and Thurn, Laura and Kessler, Julia and Eichler, Fabian}, title = {Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads}, series = {Modern technologies in manufacturing (MTeM 2019)}, volume = {299}, booktitle = {Modern technologies in manufacturing (MTeM 2019)}, number = {Article 01009}, doi = {10.1051/matecconf/201929901009}, pages = {8 Seiten}, year = {2019}, language = {en} } @article{AbdelLatifPeekenBenner1985, author = {Abdel-Latif, Lotfie Ahmed and Peeken, Heinz and Benner, Joachim}, title = {Thermohydrodynamic analysis of thrust-bearing with circular pads running on bubbly oil (BTHD-theory)}, series = {Journal of tribology}, volume = {107}, journal = {Journal of tribology}, number = {4}, isbn = {0742-4787}, issn = {1528-8897}, pages = {527 -- 537}, year = {1985}, language = {en} } @inproceedings{AdomeitWillms1984, author = {Adomeit, G. and Willms, Herbert}, title = {Experimental investigation of the acceleration of deflagration in wake flow}, series = {Safety of thermal water reactors : proceedings of a Seminar on the Results of the European Communities' Indirect Action Research Programme on Safety of Thermal Water Reactors, held in Brussels, 1-3 October 1984 / Commission of the European Communities}, booktitle = {Safety of thermal water reactors : proceedings of a Seminar on the Results of the European Communities' Indirect Action Research Programme on Safety of Thermal Water Reactors, held in Brussels, 1-3 October 1984 / Commission of the European Communities}, editor = {Skupinski, Edwin}, publisher = {Graham \& Trotman [u.a.]}, address = {London Gaithersburg, Md.}, isbn = {0-86010-678-0}, pages = {294 -- 304}, year = {1984}, language = {en} } @techreport{AdomeitWillms1984, author = {Adomeit, G. and Willms, Herbert}, title = {Experimental investigation of the acceleration of deflagration in wake flow : final report. - (Euratom-publications-EUR ; 9593 : Nuclear science and technology)}, publisher = {Commission of the European Communities}, address = {Luxembourg}, isbn = {92-825-4699-3}, pages = {III, 119 S.}, year = {1984}, language = {en} } @article{AhmedReisgenSchleseretal.2010, author = {Ahmed, Essam and Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg}, title = {On formability of tailor laser welded blanks of DP/TRIP steel sheets}, series = {Science and technology of welding and joining}, volume = {15}, journal = {Science and technology of welding and joining}, number = {5}, publisher = {Maney}, address = {Leeds}, issn = {1743-2936}, doi = {10.1179/136217110X12731414739754}, pages = {337 -- 342}, year = {2010}, abstract = {This paper aims to evaluate the formability of tailor welded blanks of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets. In this work, bead on plate butt joints of 2·5 mm DP600 and 1·2 mm TRIP700 steel sheets were performed using CO2 laser beam welding. Microhardness measurements and transverse tensile testing were carried out to characterise the welds. The formability of base metals and welds were investigated by standard Erichsen test. In a perpendicular tensile test to the weld line, all specimens were fractured at the TRIP base metal, and the strengths were somewhat higher than those of base metal. There was a significant reduction in formability caused by welding of the DP600/TRIP700 steel sheets, and the formability increased with increasing welding speed.}, language = {en} } @inproceedings{AlhwarinFerreinGebhardtetal.2015, author = {Alhwarin, Faraj and Ferrein, Alexander and Gebhardt, Andreas and Kallweit, Stephan and Scholl, Ingrid and Tedjasukmana, Osmond Sanjaya}, title = {Improving additive manufacturing by image processing and robotic milling}, series = {2015 IEEE International Conference on Automation Science and Engineering (CASE), Aug 24-28, 2015 Gothenburg, Sweden}, booktitle = {2015 IEEE International Conference on Automation Science and Engineering (CASE), Aug 24-28, 2015 Gothenburg, Sweden}, doi = {10.1109/CoASE.2015.7294217}, pages = {924 -- 929}, year = {2015}, language = {en} } @inproceedings{AnikFrohberg1989, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Thermodynamic behaviour of oxygen in molten metallic alloys}, series = {Thermochemistry of alloys : recent developments of experimental methods ; [proceedings of the NATO Advanced Study Institute on Thermochemistry of Alloys, Recent Developments of Experimental Methods, Kiel, F.R.G., August 17 - 27, 1987]. - (NATO ASI series : Series C ; 286)}, booktitle = {Thermochemistry of alloys : recent developments of experimental methods ; [proceedings of the NATO Advanced Study Institute on Thermochemistry of Alloys, Recent Developments of Experimental Methods, Kiel, F.R.G., August 17 - 27, 1987]. - (NATO ASI series : Series C ; 286)}, editor = {Brodowsky, Horst}, publisher = {Springer}, address = {Dordrecht [u.a.]}, isbn = {0-7923-0434-9}, pages = {419 -- 428}, year = {1989}, language = {en} } @article{AnikFrohberg1984, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Thermodynamics and solubility of oxygen in liquid copper-lead alloys at 1200°C from E.M.F. measurements}, series = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, volume = {88}, journal = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, number = {8}, issn = {0940-483X}, pages = {707 -- 710}, year = {1984}, language = {en} } @article{AnikFrohberg1987, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Thermodynamics and solubility of oxygen in liquid bismuth-lead and bismuth-antimony alloys}, series = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, volume = {91}, journal = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, number = {7}, issn = {0940-483X}, pages = {790 -- 794}, year = {1987}, language = {en} } @article{AnikFrohberg1984, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Investigations of the thermodynamics of oxygen and the determination of the miscibility gap in the system copper-oxygen-lead at 12000C}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {75}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {8}, issn = {0044-3093}, pages = {586 -- 589}, year = {1984}, language = {en} } @article{AnikFrohberg1983, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Investigation of the thermodynamics of oxygen and the determination of phase boundaries in the system copper-oxygen-bismuth at 12000C}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {8}, issn = {0044-3093}, pages = {530 -- 534}, year = {1983}, language = {en} } @article{AnikFrohberg1988, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Thermodynamics of oxygen in the copper-antimony system at 1473K}, series = {Erzmetall : Rohstoffgewinnung, Verarbeitung, Recycling, Umwelttechnik}, volume = {41}, journal = {Erzmetall : Rohstoffgewinnung, Verarbeitung, Recycling, Umwelttechnik}, number = {10}, issn = {0044-2658}, pages = {498 -- 501}, year = {1988}, language = {en} } @article{AnikFrohbergKapoor1983, author = {Anik, Sabri and Frohberg, Martin G. and Kapoor, Madan Lal}, title = {Experiments and theoretical considerations on the solution of oxygen in binary metal alloys}, series = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, volume = {87}, journal = {Berichte der Bunsengesellschaft f{\"u}r physikalische Chemie}, number = {12}, issn = {0005-9021}, pages = {1201 -- 1204}, year = {1983}, language = {en} } @article{AnikFrohbergKapoor1983, author = {Anik, Sabri and Frohberg, Martin G. and Kapoor, Madan Lal}, title = {Prediction of thermodynamic properties of oxygen in binary metallic solvents}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {6}, issn = {0044-3093}, pages = {372 -- 375}, year = {1983}, language = {en} } @article{AnikKapoorFrohberg1983, author = {Anik, Sabri and Kapoor, Madan Lal and Frohberg, Martin G.}, title = {Thermodynamic behaviour of oxygen in molten substitutional alloy solvents}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {1}, issn = {0044-3093}, pages = {53 -- 58}, year = {1983}, language = {en} } @article{BeckenbachScheidweiler2016, author = {Beckenbach, Isabel and Scheidweiler, Robert}, title = {Perfect ƒ-Matchings and ƒ-Factors in Hypergraphs - A Combinatorial Approach}, series = {Discrete Mathematics}, volume = {240}, journal = {Discrete Mathematics}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2192-7782}, doi = {10.1016/j.disc.2017.05.005}, pages = {2499 -- 2506}, year = {2016}, abstract = {We prove characterizations of the existence of perfect ƒ-matchings in uniform mengerian and perfect hypergraphs. Moreover, we investigate the ƒ-factor problem in balanced hypergraphs. For uniform balanced hypergraphs we prove two existence theorems with purely combinatorial arguments, whereas for non-uniform balanced hypergraphs we show that the ƒ-factor problem is NP-hard.}, language = {en} } @inproceedings{BeerHaidnWillms1995, author = {Beer, Stefan and Haidn, O.J. and Willms, Herbert}, title = {Control of stoichiometric propellant supply in an H2/O2-spinning reserve system}, series = {Combustion technologies for a clean environment : selected papers from the proceedings of the first international conference, Vilamoura, Portugal, September 3 - 6, 1991. - (Energy, combustion and the environment ;1)}, booktitle = {Combustion technologies for a clean environment : selected papers from the proceedings of the first international conference, Vilamoura, Portugal, September 3 - 6, 1991. - (Energy, combustion and the environment ;1)}, editor = {Carvalho, Maria da Gra{\c{c}}a}, publisher = {Gordon and Breach}, address = {Basel [u.a.]}, isbn = {2-88124-619-2}, pages = {825 -- 838}, year = {1995}, language = {en} } @inproceedings{BraunChengDoweyetal.2020, author = {Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Survey on Security Concepts to Adapt Flexible Manufacturing and Operations Management based upon Multi-Agent Systems}, series = {2020 IEEE 29th International Symposium on Industrial Electronics (ISIE)}, booktitle = {2020 IEEE 29th International Symposium on Industrial Electronics (ISIE)}, doi = {10.1109/ISIE45063.2020.9152210}, year = {2020}, language = {en} }