Integrated top-down process and voxel-based microstructure modeling for Ti-6Al-4V in laser wire direct energy deposition process

• Published in: Materials & design Vol. 247
• Main Authors: Lee, Yousub, Nandwana, Peeyush, Gibson, Brian, Mhatre, Paritosh, Ortega Rojas, Julio, Prabhune, Bhagyashree, Thornton, Aaron, Vaughan, Joshua, Simunovic, Srdjan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2024
• Subjects: Additive manufacturing; Gaussian Process; Microstructure; Ti-6Al-4V; Top-down process modeling; Voxel-based microstructure modeling; Ti-6Al-4V; Gaussian Process; Top-down process modeling; Voxel-based microstructure modeling; Additive manufacturing; Microstructure
• ISSN: 0264-1275
• DOI: 10.1016/j.matdes.2024.113434

[Display omitted] •This research shows the effectiveness of top-down and voxel-based approaches for Ti-6Al-4V microstructure prediction.•A voxel-based microstructure model is proposed using thermal profiles from simulations under actual deformation conditions.•Predicted αw, αgb, αlath and β fractions in Ti-6Al-4V were validated against measured values, with an error margin of 10 %.•A combination of the GP method and voxel-by-voxel approach only requires about 30% of the original data. Laser-wire metal additive manufacturing (AM) is one of the ideal direct energy deposition (DED) processes for creating large-scale parts with a medium level of complexity. However, the DED process involves complex thermal signatures and wide length scales making the fabrication of realistic AM components and part qualification often reliant on experimental trial-and-error optimization. While experimental measurements over the full volume of a part are valuable and necessary, measuring the entire area of a part is significantly laborious and practically infeasible, particularly for large parts in terms of cost and rapid qualification. Therefore, in this work, we developed an effective thermal and microstructure modeling framework based on the Johnson–Mehl-Avrami-Kolmogorov (JMAK) and Koistinen & Marburger (KM) models through a top-down approach that considers plate distortion-affected thermal profiles. A voxel-by-voxel simulation method is used to predict individual phase fractions of Ti-6Al-4 V. The predicted results were validated through detailed metallurgical measurements. A combined voxel-by-voxel approach with a sparse data reconstruction technique produced a near-perfect reconstruction of the original data. This approach anticipates a significant reduction in data points and computation time and resources. Lastly, we conclude with potential extensions of this work to other modeling efforts.