SFB 1120:  Precision manufacturing by controlling melt dynamics and solidification in production processes

Manufacturing processes with the involvement of molten phases, such as metal casting, plastic injection molding, welding processes including additive manufacturing and thermal cutting often can meet the increasing demands for high component precision only with great efforts in the process set up and post-processing steps. By volume contraction during solidification, uneven cooling by limited energy transport and uncontrolled structural formation, a plurality of component inaccuracies occur, which significantly influence the precision of the component. To overcome this current limits for the generation of a high precision parts from melt based processes, a deep understanding of the melt formation, the internal dynamics by external and internal driving forces and the processes occurring during the solidification of the melt is necessary . However, in particular, heat transfer, material conditions and energy transport through liquid phases influence the solidification and volume changing crystallization processes. Moreover temporal and spatial temperature gradients are depending on part geometry and process parameters and are difficult to detect, predict and control.The collaborative research center 1120 addresses this research topics with the aim to give a comprehensive description of melt-based manufacturing technologies such as casting, injection molding, welding, cutting, additive manufacturing and melt based coating. For this processes, in which the material during the process is at least temporarily in a liquid phase a multi-scale description of the involved physical and material based processes will be developed to increase part precision by at least one order of magnitude.To achieve this objective, in a basic research approach all physical and material-related sub-processes, which are involved in melt formation and melt dynamics was characterized with high-resolution methods in time and space. Based on this analysis a deep understanding of the relationships between the sub-processes was developed, including nanoscale nucleation processes up to macroscopic component distortion. The third pillar of the research center is dedicated to new scientific approaches for controlling cooling conditions, energy transfer in the melt phase and solidification as well as microstructure formation. The intended result of the collaborative 1120 research center is the multi-scale control of melt based manufacturing processes from melt formation, via melt flow properties up to melt solidification as a prerequisite for increasing the precision of melt-engineered components.

DFG Programme Collaborative Research Centres

International Connection Austria, Belgium, Switzerland

• A01 - Control of geometry and metallurgy in laser beam micro¬welding by influencing the melt pool dynamics by spatial and temporal adapted energy input (Project Head Gillner, Arnold )
• A02 - Local residual stress buildup during solidification of engineering alloys subject to welding (Project Head Reisgen, Uwe )
• A04 - Simulation supported identification of the effect of weld pool flow on the formation of a precise weld seam (Project Head Mokrov, Oleg )
• A05 - Influence of solid-liquid-reactions in the joint gap on properties of the brazed joint and precision (Project Head Bobzin, Kirsten )
• A06 - Electron Microscopy Analysis of Melting Processes and Solidification Microstructures (Project Head Mayer, Joachim )
• A07 - Utilization of partial metallurgical injection for regulation of solidification forces in fusion welding processes (Project Head Reisgen, Uwe )
• A08 - In-situ diagnostics and control of melt and solidification dynamics during laser beam cutting (Project Heads Gillner, Arnold ;  Poprawe, Reinhart )
• A10 - Development of simulative approaches for systematic design of the properties of plasma sprayed coatings (Project Head Bobzin, Kirsten )
• A11 - Dimensional and shape accuracy for Laser Metal Deposition in additive Manufacturing (Project Heads Poprawe, Reinhart ;  Schleifenbaum, Johannes Henrich )
• A12 - Experimental analysis of thermo-mechanical properties of thermal spray coatings (Project Head Bobzin, Kirsten )
• A13 - Unified particle-based simulation of melt flows and solidification processes considering thermoelasto-viscoplastic solid state behavior to increase precision (Project Heads Bender, Jan Stephen ;  Mokrov, Oleg )
• B01 - Algorithms for the design of the tempering system in injection molds on the basis of a local cooling (Project Head Hopmann, Christian )
• B02 - Numerical Modeling and Compensation of both Shrinkage and Warpage in Injection Molding (Project Heads Behr, Ph.D., Marek ;  Elgeti, Stefanie )
• B03 - Self-Optimizing Process Control Strategies for a Highly Segmented Temperature Control in Injection Moulding (Project Head Hopmann, Christian )
• B04 - Modelling of the injection molding process in due consideration of the thermal coupling between melt, microstructure and mold for a precise prediction of the final part contour (Project Head Hopmann, Christian )
• B05 - Efficient simulation methods for multi-phase flows based on adaptive computational grids in space-time (Project Heads Behr, Ph.D., Marek ;  Gesenhues, Linda )
• B07 - Multiscale thermomechanical Simulation of solid-liquid interactions during solidification (Project Heads Apel, Markus ;  Laschet, Gottfried )
• B08 - Research of precision determining factors in order to minimize distortion in gravity and high pressure die casting processes (Project Head Bührig-Polaczek, Andreas )
• B09 - Thermo-mechanical Multiphase Simulation Applying Local Calculations of Material Properties for Predicting and Minimizing Casting Distortion (Project Head Bührig-Polaczek, Andreas )
• T05 - Distortion minimization by adaptation of the LTT effect for laser beam welding of lightweight structures in rail vehicle construction made of stainless steels (Project Head Reisgen, Uwe )
• T06 - Vermeidung von Flüssigmetallpenetration beim Laserlöten durch Modifikation des lokalen Eigenspannungsaufbaus (Project Head Reisgen, Uwe )
• Z - Central Tasks (Project Head Reisgen, Uwe )

• A03 - Simulation of melt dynamics in laser micro welding using modern and massively parallelized numerical techniques (Project Head Schulz, Wolfgang )
• A09 - Reduction of striations and dross in laser fusion cutting by modelling and simulation of the highly dynamical melt flow (Project Head Schulz, Wolfgang )
• B06 - Three-dimensional modelling and efficient numerical treatment of contact between solids and fluids (Project Head Sauer, Roger A. )
• T01 - Injection-compression moulding of thick-walled plastic optics with appropriate mould temperature control taking into account local cooling requirements (Project Head Hopmann, Christian )
• T03 - Simulative prediction of the manufacturing process in wire-arc additive manufacturing (WAAM) (Project Head Reisgen, Uwe )

Applicant Institution Rheinisch-Westfälische Technische Hochschule Aachen

Participating Institution Access e.V.

Spokespersons Professor Dr. Reinhart Poprawe, until 6/2018; Professor Dr.-Ing. Uwe Reisgen, since 7/2018