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Opening new opportunities for aeronautic, naval and train large components realization with hybrid and twin manufacturing

100%

Rauch M. , Hascoet J.-Y.

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tom Vol. 22, No. 4

5--20

EN

Additive Manufacturing (AM) consist in producing parts by depositing material in successive layers. These step-by-step processes proposes new innovative directions for high value components: complex geometries are accessible without strong efforts (such as hollow or lattice structures which dramatically reduce the component weight while keeping their at least similar mechanical properties), assemblies can be simplified, spare parts can be realized at demand... Hence, AM has benefitted from large research efforts over the last decade, almost all existing industrial sectors have benefitted from them. This paper introduces some opportunities and the associated challenges attached to Additive Manufacturing, to produce large metallic components for naval aeronautics and train industries. In particular, two innovative approaches are discussed in details: hybrid manufacturing and twin manufacturing. Hybrid manufacturing consists in integrating AM together with other processes for the realization of components, with the objective to benefit from the interests of each process while avoiding its drawbacks. Hence, AM can realize complex geometries or offer low buy-to-fly ratios while high speed machining generates very good surface properties (position, roughness). Processes can be carried out sequentially or simultaneously on the features to manufacture and finding the optimal manufacturing work plan can be challenging. The paper introduces some hybrid approaches developed in the laboratory. Twin manufacturing uses models and multiphysics simulation methods to create a digital clone of the process implementation within the manufacturing environment. Manufacturing preparation and optimization can be carried in the virtual workshop where various configurations and choices can be tested before being selected. To enhance its accuracy, the digital twin can also be fed by monitoring data captured during the process. Several digital twins developed in the laboratory are provided. The paper is illustrated with several proof-of-concept parts made with SLM, LMD, WAAM and hybrid approaches in the laboratory. Among them, a hollow propellers that has the same hydrodynamics efficiency for a reduced weight for the naval industry, an aircraft structural panel that demonstrates simplified assemblies increased performance/mass ratio, a train component that shows the ability to produce structural parts at demand.

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Thermal monitoring for Metallic Additive Manufacturing multi-beads multi-layers parts

80%

Rauch M. , Hascoet J.-Y. , Rousseau C. , Ruckert G.

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tom Vol. 21, No. 3

92--100

EN

Among Metallic Additive Manufacturing processes, Directed Energy Deposition (DED) processes are very promising for the Industry. An issue that prevents a larger development of DED is the reliability of the process, since its complexity makes the result of the manufacturing variable. Thermal behavior is a critical aspect for which uncontrolled phenomena can lead to part failure. Some thermal monitoring and closed-loop control methods have been developed, that enables to observe and regulate the heating of the processed part. However, these methods rely on local measures from a region or a single external surface of a part, and thus provide partial information of thermal fields in the whole part volume. This paper proposes a method that combines diverse data to compute online a process indicator that is meaningful for the thermal state of the whole part, and hence for the control of the manufacturing of multi-beads multi-layer parts. A simulation-based model using thermal partial data is proposed. An online monitoring experiment is proposed for validation of the model. Relevance of the control method to ensure mechanical properties of the part is then tested.

3

Impact of a variation in Wire Feed Speed on deposits from the wire arc additive manufacturing (WAAM)

70%

Remy A. , Nwankpa U.-V. , Rauch M. , Hascoet J.-Y. , Ruckert G.

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tom Vol. 24, No. 2

117--128

EN

Metal Additive Manufacturing (MAM) is one of the innovative industrial technologies of the last decade, which presents some benefits as compared to traditional manufacturing techniques. MAM is faster, less expensive, and allow the manufacturing of large, complex components than casting, foundry etc. Understanding the influence of process parameters on the deposited matter and material characteristics is essential for the manufacturing of industrial parts. Current research concentrates on the impact of parameters on the fabricated structure geometry, microstructure and mechanical properties. There are limited number of studies, that focus on the possibility of Wire Feed Speed (WFS) parameter variation during deposition. In this work, a series of trials were realised with Cold Metal Transfer. The results showed that the quantity of material deposited was lesser than the theoretical value. The variation obtained was explained by the difference between the inputted WFS on the generator and the actual WFS output. Hence, the result on the influence of the variation of WFS on bead geometry was applied to a thermofluid model with Ti-6Al-4V alloy to confirm the sensitivity of this parameter in the quantity and geometry of the material deposited.