Periodic Reporting for period 1 - MA.D.AM (Modelling Assisted Solid State Materials Development and Additive Manufacturing)
Berichtszeitraum: 2021-06-01 bis 2022-11-30
The rapid development of additive manufacturing (AM) as a high potential and flexible manufacturing technology has opened the possibility to produce parts with customized performance. To utilize the full potential of AM, value-added materials with the desired customized chemistry and properties are demanded, in particular for aerospace applications. Ideally, the subsequent additive process should guarantee that previously customized or tailored properties of the materials are not lost, i.e. without losses of alloying elements due to volatilization or phase segregation. Rather, the deposition process should further improve the properties of the final AM product.
The MA.D.AM project aims to establish novel scientific knowledge for the fabrication of customized high-strength aluminum wires and their application for AM via a fully solid-state based processing route, allowing the production of AM parts with customized mechanical properties. For this purpose, innovative solid-state materials development and AM processes are utilized to obtain alloys beyond known borders. The solid-state Friction Extrusion process allows generating phases under non-equilibrium conditions, leading to so far unexplored microstructural states, enabling the production of novel high-performance wire material with tailored properties. To avoid microstructural deterioration and to preserve or even improve the properties of the designed wires, Solid State Layer Deposition, i.e. Friction Surfacing process is employed. To explore the full capabilities of these processes, the underlying physical relationships along the complete manufacturing chain will be explored via physical models to assist in the experimental alloy and process development. Concepts of machine learning will be employed to establish a digital twin of the process chain.
Therefore, the overarching objective of this project is to establish this experimental reality paired with numerical approaches, leading to a digital twin of the full process chain to ensure its translation to different alloys and AM strategies and to obtain a so far unavailable decryption of the composition-process-(micro)structure-property relationships
The MA.D.AM project aims to establish novel scientific knowledge for the fabrication of customized high-strength aluminum wires and their application for AM via a fully solid-state based processing route, allowing the production of AM parts with customized mechanical properties. For this purpose, innovative solid-state materials development and AM processes are utilized to obtain alloys beyond known borders. The solid-state Friction Extrusion process allows generating phases under non-equilibrium conditions, leading to so far unexplored microstructural states, enabling the production of novel high-performance wire material with tailored properties. To avoid microstructural deterioration and to preserve or even improve the properties of the designed wires, Solid State Layer Deposition, i.e. Friction Surfacing process is employed. To explore the full capabilities of these processes, the underlying physical relationships along the complete manufacturing chain will be explored via physical models to assist in the experimental alloy and process development. Concepts of machine learning will be employed to establish a digital twin of the process chain.
Therefore, the overarching objective of this project is to establish this experimental reality paired with numerical approaches, leading to a digital twin of the full process chain to ensure its translation to different alloys and AM strategies and to obtain a so far unavailable decryption of the composition-process-(micro)structure-property relationships
Experiments were performed to study the process characteristics and microstructural evolution during friction extrusion of aluminum. Two fundamentally different extrusion types have been identified based on the specific process parameters, one leading to a fully homogenous recrystallized fine-grained wire material. Furthermore, the effect of different feedstock materials, such as powder, chips and bulk material, was investigated, identifying the characteristics and different requirements for performing the friction extrusion process efficiently.
In terms of solid state additive manufacturing, preliminary studies of the solid state layer deposition process friction surfacing were performed for AM applications. Next to an in-depth analysis of the temperature evolution and process efficiency, the effect of pre- and post-processing techniques in terms of consolidating volumetric defects was investigated via micro computed tomography. It is shown that hybrid friction diffusion bonding could act as a suitable post-processing for consolidate defects of large scale AM structures produced by FS. The results indicate that FS is very suitable as an AM process, allowing the fabrication of nearly defect-free AM structures with homogeneous microstructural and mechanical properties over the whole structure height.
In terms of modelling, a primary thermodynamic assessment of the unary systems of the considered aluminum alloys was performed via the CALPHAD method. A phase-field finite element formalism for describing precipitation has been implemented in deal II. In terms of process simulation, a thermo-mechanical process simulation of friction extrusion has been validated against experimental data. Additionally, a heat transfer model for friction surfacing has been developed, where the geometry of the applied heat source has been modified for the first time to account for the evolving flash, leading to very good agreement with experimentally obtained spatio-temporal temperature results.
In terms of solid state additive manufacturing, preliminary studies of the solid state layer deposition process friction surfacing were performed for AM applications. Next to an in-depth analysis of the temperature evolution and process efficiency, the effect of pre- and post-processing techniques in terms of consolidating volumetric defects was investigated via micro computed tomography. It is shown that hybrid friction diffusion bonding could act as a suitable post-processing for consolidate defects of large scale AM structures produced by FS. The results indicate that FS is very suitable as an AM process, allowing the fabrication of nearly defect-free AM structures with homogeneous microstructural and mechanical properties over the whole structure height.
In terms of modelling, a primary thermodynamic assessment of the unary systems of the considered aluminum alloys was performed via the CALPHAD method. A phase-field finite element formalism for describing precipitation has been implemented in deal II. In terms of process simulation, a thermo-mechanical process simulation of friction extrusion has been validated against experimental data. Additionally, a heat transfer model for friction surfacing has been developed, where the geometry of the applied heat source has been modified for the first time to account for the evolving flash, leading to very good agreement with experimentally obtained spatio-temporal temperature results.
The project investigate and exploit the unique intrinsic potentials offered by the friction extrusion process. It will be shown that friction extrusion can produce value-added metallic materials with customized chemical composition and microstructures under non-equilibrium conditions. Furthermore, it will be demonstrated that the following solid state AM process will maintain or even improve the original high-performance properties of the wire. To assist the experimental developments, new modeling approaches and concepts will be employed at different length scales.
During the first reporting period, two fundamentally different extrusion types could be identified during friction extrusion for the first time, one leading to a fully recrystallized wire material. Understanding the underlying physical mechanism, will allow the fabrication of homogeneous high-performance wires. In terms of modeling the friction surfacing process, the geometry of the heat source has been modified to account for the evolving flash, leading to a validation of a heat transfer model for friction surfacing for the spatial temperature field.
During the first reporting period, two fundamentally different extrusion types could be identified during friction extrusion for the first time, one leading to a fully recrystallized wire material. Understanding the underlying physical mechanism, will allow the fabrication of homogeneous high-performance wires. In terms of modeling the friction surfacing process, the geometry of the heat source has been modified to account for the evolving flash, leading to a validation of a heat transfer model for friction surfacing for the spatial temperature field.