https://popups.uliege.be/esaform21/index.php?id=1378 Index terms fr 0 https://popups.uliege.be/esaform21/index.php?id=2599 In this study, a data-driven deep learning model for fast and accurate prediction of temperature evolution and melting pool size of metallic additive manufacturing processes are developed. The study focuses on bulk experiments of the M4 high-speed steel material powder manufactured by Direct Energy Deposition. Under non-optimized process parameters, many deposited layers (above 30) generate large changes of microstructure through the sample depth caused by the high sensitivity of the cladding material on the thermal history. A 2D finite element analysis (FEA) of the bulk sample, validated in a previous study by experimental measurements, is able to achieve numerical data defining the temperature field evolution under different process settings. A Feed-forward neural networks (FFNN) approach is trained to reproduce the temperature fields generated from FEA. Hence, the trained FFNN is used to predict the history of the temperature fields for new process parameter sets not included in the initial dataset. Besides the input energy, nodal coordinates, and time, five additional features relating layer number, laser location, and distance from the laser to sampling point are considered to enhance prediction accuracy. The results indicate that the temperature evolution is predicted well by the FFNN with an accuracy of 99% within 12 seconds. Wed, 24 Mar 2021 18:28:20 +0100 Wed, 21 Apr 2021 12:59:30 +0200 https://popups.uliege.be/esaform21/index.php?id=2599 https://popups.uliege.be/esaform21/index.php?id=2812 In the last decade, machine learning is increasingly attracting researchers in several scientific areas and, in particular, in the additive manufacturing field. Meanwhile, this technique remains as a black box technique for many researchers. Indeed, it allows obtaining novel insights to overcome the limitation of classical methods, such as the finite element method, and to take into account multi-physical complex phenomena occurring during the manufacturing process. This work presents a comprehensive study for implementing a machine learning technique (artificial neural network) to predict the thermal field evolution during the direct energy deposition of 316L stainless steel and tungsten carbides. The framework consists of a finite element thermal model and a neural network. The influence of the number of hidden layers and the number of nodes in each layer was also investigated. The results showed that an architecture based on 3 or 4 hidden layers and the rectified linear unit as the activation function lead to obtaining a high fidelity prediction with an accuracy exceeding 99%. The impact of the chosen architecture on the model accuracy and CPU usage was also highlighted. The proposed framework can be used to predict the thermal field when simulating multi-layer deposition. Wed, 24 Mar 2021 19:04:24 +0100 Mon, 12 Apr 2021 11:18:39 +0200 https://popups.uliege.be/esaform21/index.php?id=2812 https://popups.uliege.be/esaform21/index.php?id=4124 In the context of Industry 4.0, interest is increasing towards Additive Manufacturing processes due to their several advantages. Among these, the Direct Laser Deposition (DLD) is an innovative technology for additive metal part fabrication, and it is currently demonstrating its ability to revolutionize the manufacturing industry. It is particularly interesting for industrial applications in terms of reduction of waste materials by starting with fewer feedstocks, reduction of machining time by only have material where it is needed but, above all, it is interesting to extend the life of parts. Indeed, with the DLD, it is possible to repair an item or coat parts via cladding, making it more wear-resistant. It is also possible to give "another life" to broken or waste components, for example, by replacing the damaged area using new material. Moreover, particularly intriguing is the possibility to create hybrid or graded parts by varying material/alloy concentrations. This paper aims to combine the abovementioned advantages to develop tailored structures in order to accomplish complex and functional products. For this purpose, a specific case study was investigated, starting with the study of the appropriate powders to use and ending with the printing process using the DMG Mori Lasertec65. Microstructural and mechanical analyses were carried out to evaluate the products and to validate the process. The final results show the properties and performances of products obtained using this technology. Tue, 30 Mar 2021 17:47:53 +0200 Tue, 30 Mar 2021 17:47:59 +0200 https://popups.uliege.be/esaform21/index.php?id=4124