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1

Novel one-degree of freedom helix machine architecture for additive manufacturing

100%

Neel T. L. , Hascoet J.-Y.

Journal of Machine Engineering

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2022

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tom Vol. 22, No. 3

5--18

EN

Additive manufacturing has been relying on conventional machinery architecture. Conventionally, the architecture used is a Cartesian set-up. The X-Y-Z axis move independently to move the tool on the X-Y plan and increment the Z-axis when the layer is finished. The machine architecture in this paper simplifies the design by constraining the machine to have solely one-degree of freedom. One degree of freedom is also known as a helix linkage. If individually controlled tools are placed all along the rotating arm, then this movement allows an opportunity to deposit material in a single sweeping motion. To increase furthermore the output, multiple arms can be added at a fixed angle. Finally, because of the predictive motion, multiple helix machines can be synchronized to create collaboratively a bigger part. This type of manufacturing process has potential applications in binder jetting, material jetting, and selective laser sintering.

2

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

100%

Rauch M. , Hascoet J.-Y.

Journal of Machine Engineering

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2022

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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.

3

A novel method for additive manufacturing of complex shape curved parts by using variable height layers

80%

Rauch M. , Dorado J. P. , Hascoet J.-Y. , Ruckert G.

Journal of Machine Engineering

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2021

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tom Vol. 21, No. 3

80--91

EN

The Wire Arc Additive Manufacturing process (WAAM) is designed for the manufacture of large metallic parts with no joints, very little waste material and hardly any support. It is gaining its space inside the naval, aeronautics and space industries. However, there are key challenges to be solved in order to increase the performance of the WAAM process. Parts with curved shapes are difficult to manufacture with regular parallel layers without support because of an excessive overhang in certain regions. This paper proposes a methodology that solves this issue, by using incrementally angled layers with variable bead height, which eliminates or decreases the overhang between layers. This solution uses an angled rotary positioner (or other method for moving the part in a controlled way) and controls key parameters like the travel speed, the deposition angle, the available bead height difference, etc. The efficiency of the developed proposal is shown with the manufacture of a large curved steel (316L) piece as a use-case.

4

A novel slicing strategy for continuous printing with a helix 3D printer

80%

Neel T. L. , Mesto T. , Hascoet J.-Y.

Journal of Machine Engineering

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2022

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tom Vol. 22, No. 3

31--43

EN

Additive manufacturing is an essential solution in the production of parts. Model slicing is an important step of the 3D printing process. The slicing of the layers is the core part of the additive manufacturing because it transforms the 3D model to a 2D profile layer for the printer to manufacture. A novel machine architecture deposits with a helical path. The helical architecture provides a continuous rotation that allows printing continuously without any interruption. Therefore there are no more starting and ending point at each layer. This paper proposes a slicing method compatible with this type of machine. Continuous printing is made as a function of z-level, so at each angle of rotation, the level of z will be incremented. Finally, these disks can be combined as one image to be sent to the ink-jet as a continuous printing. To illustrate this novel slicing methodology a model is sliced.

5

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

80%

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

Journal of Machine Engineering

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2021

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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.

6

The potential of additive manufacturing of metal components to reduce environmental impacts

80%

Balidas A. , Kerbrat O. , Hascoet J.-Y.

Journal of Machine Engineering

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2024

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tom Vol. 24, No. 2

94--104

EN

Additive manufacturing (AM) is used in metal part forming for its innovative character but its potential for sustainability is uncertain. The energy and material consumption required for manufacturing are significant. Thus, the research question of this article is: "What are the current uses of AM that present a real potential for reducing environmental impact?". The WAAM (Wire Arc Additive Manufacturing) process appears to be the most energy-efficient in comparison to other AM processes. A process parameters study shows that deposition rate has a substantial impact on energy consumption. This parameter represents the amount of material deposited in a unit of time and is directly linked to productivity. It appears that an increase of the deposition rate leads to a reduction in energy consumption. Experiments on WAAM with a high deposition rate permits to create a database of energy and material consumption. This database is then used to identify cases of parts made with WAAM that offer a significant impact reduction compared with conventional manufacturing processes.

7

Open-loop control system for high precision extrusion-based bioprinting through machine learning modelling

80%

Arduengo J. , Hascoet N. , Chinesta F. , Hascoet J.-Y.

Journal of Machine Engineering

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2024

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tom Vol. 24, No. 1

103--117

EN

Bioprinting is a process that uses 3D printing techniques to combine cells, growth factors, and biomaterials to create biomedical components, often with the aim of imitating natural tissue characteristics. Typically, 3D bioprinting adopts a layer-by-layer method, using materials known as bio-inks to build structures resembling tissues. This study introduces an open-loop control system designed to improve the accuracy of extrusion-based bioprinting techniques, which is composed of a specific experimental setup and a series of algorithms and models. Firstly, a method employing Logistic Regression is used to select the tests that will serve to train and test the following model. Then, using a Machine Learning Algorithm, a model that allows the optimization of printing parameters and enables process control through an open-loop system was developed. Through rigorous experimentation and validation, it is shown that the model exhibits a high degree of accuracy in independent tests. Thus, the control system offers predictability and adaptability capabilities to ensure the consistent production of high-quality bioprinted structures. Experimental results confirm the efficacy of this machine learning model and the open-loop control system in achieving optimal bioprinting outcomes.

8

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.

Journal of Machine Engineering

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2024

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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.