@misc{SefidiIsrarBuhletal., author = {Sefidi, Moein Pakdel and Israr, Rameez and Buhl, Johannes and Bambach, Markus}, title = {Rule-Based Path Identification for Direct Energy Deposition}, series = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming}, volume = {47}, journal = {Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming}, editor = {Bambach, Markus}, issn = {2351-9789}, doi = {10.1016/jpromfg.2020.04.133}, pages = {1134 -- 1140}, language = {en} } @misc{BreussBuhlMansouriYarahmadietal., author = {Breuß, Michael and Buhl, Johannes and Mansouri Yarahmadi, Ashkan and Bambach, Markus and Peter, Pascal}, title = {A Simple Approach to Stiffness Enhancement of a Printable Shape by Hamilton-Jacobi Skeletonization}, series = {Procedia Manufacturing}, volume = {Vol. 47}, journal = {Procedia Manufacturing}, issn = {2351-9789}, doi = {10.1016/j.promfg.2020.04.147}, pages = {1190 -- 1196}, abstract = {The 3D-Printing technology is ready to produce parts with specific properties like individual stiffness. Based on a predefined outer shape, the inner structure of a printed part defines mainly the mechanical features. By Hamilton-Jacobi skeletonization, a stiffness enhancement of a printable shape can be achieved in a way, that a novel AM-corner includes linear axis function. Originating in the field of shape analysis in computer vision and graphics, the so-called medial axis transform (MAT) is designed for the computation of a structure that resembles the bone structure of biological shapes. The input for MAT computation is typically a shape's boundary. The arising topological skeletons have proven to provide a useful concept for many applications; however, their computation is generally intricate and also known to rely on many parameters, diminishing the accessibility of skeletonization methods. In this work, the classical Hamilton-Jacobi skeletonization approach is adopted to compute a stability enhancing shape structure. As the basic method has not been designed for the context of additive manufacturing, a set of suitable modifications are introduced to design an algorithm that suits our intended purpose. Unlike the traditional skeletonization schemes, the resulting method appears to be robust and in practice almost completely automated as we can identify useful generic parameter settings. By a finite element method (FEM) study, the elastic stress properties of the AM-corner with linear axis function is validated and printed with in metal (1.4404) with the 3D Selected Laser Melting (SLM) system AconityMIDI. The AM-knot with skeletonization guides approximately 20 times better than a standard knot. While the first obtained results are shown as 2.5 dimensional shapes, it is emphasized that the proposed algorithm offers many possibilities for extensions to three dimensions and variations in context of additive manufacturing.}, language = {en} } @misc{BuhlHartRawungBambach, author = {Buhl, Johannes and Hart-Rawung, Thawin and Bambach, Markus}, title = {Nutzung von Neuralen Netzen zur effizienten Auslegung des Pressh{\"a}rtens von 22MnB5}, series = {Tagungsband zum 15. Erlanger Workshop Warmblechumformung, Erlangen, den 17. November 2020}, journal = {Tagungsband zum 15. Erlanger Workshop Warmblechumformung, Erlangen, den 17. November 2020}, publisher = {Lehrstuhl f{\"u}r Fertigungstechnologie, Friedrich-Alexander-Universit{\"a}t Erlangen-N{\"u}rnberg}, address = {Erlangen}, isbn = {978-3-00-066911-8}, pages = {99 -- 112}, language = {de} } @misc{EisentrautStendalBolzetal., author = {Eisentraut, Mark and Stendal, Johan Andreas and Bolz, Sebastian and Bambach, Markus and Weiß, Sabine}, title = {Applying a softening adapted acceleration to the hot deformation of TNM-B1}, series = {MRS Fall Meeting 2020}, journal = {MRS Fall Meeting 2020}, abstract = {Hot isostatically forged TiAl turbine blades made of TNM-B1 are commercially used in aircraft engines, as they offer significantly lower weight than the traditional nickel-based blades while exhibiting similar strength. Like other TiAl alloys, TNM-B1 displays high peak stress followed by a strong softening behavior (i.e. stress reduction) during hot deformation. This softening can be used to accelerate the deformation process by reducing the processing time and in turn the costs for TNM-B1 parts. In order to avoid increased damage during the accelerated process, a pre-heat treatment (HT) for the hot isostatically pressed material (HIP) is required. To simulate the accelerated forming process, hot compression tests were performed with a DIL805A/D/T dilatometer from TA Instruments (New Castle, Delaware, USA) with different strain rates (0.0013, 0.005, 0.01 and 0.05) and temperatures (T=1150, 1175 and 1200°C). Deformation of the heat-treated state revealed lower flow stress (in both, peak stresses and steady state stresses) and fewer voids compared to the HIP state (Fig. 1.a). The compression test data were used to develop material and temperature specific strain rate profiles based on a material model. Subsequently, hot compression tests were performed with different strain rate profiles (starting strain rates 0.0013 and 0.0052) for the HIP and the HT state. The results were evaluated with regard to their microstructure, deformation, and damage behavior. A reduction of the processing time for all tested strain rates profiles by factors 2-3 could be achieved compared to constant strain rates. Furthermore, the results indicated that the deformation with strain rate profiles (compared to constant strain rates) did not significantly change the resulting microstructure or damage tolerance of the HT state.}, language = {en} } @misc{BrykarczykLenzNeumannetal., author = {Brykarczyk, Daniel and Lenz, Wolfgang and Neumann, Andreas and Bambach, Markus}, title = {Erh{\"o}hung der Lebensdauer metallischer Strahlheizrohre durch den Einsatz strukturierter Bleche}, series = {Prozessw{\"a}rme}, volume = {4}, journal = {Prozessw{\"a}rme}, issn = {2567-3742}, language = {de} }