Additive remanufacturing (AReM): integrated product-process design for functional upgrades of existing components by directed energy deposition

Directed Energy Deposition (DED) is increasingly utilized for the construction of large components, repair of worn and damaged parts, and integration into Hybrid Manufacturing systems to leverage diverse technological features. A burgeoning application of DED is in Additive Remanufacturing (ARem), by which existing components can be enhanced with additional features and materials to improve functionalities. This paper presents a systematic and integrated approach for Design for Additive Remanufacturing (DARem), focusing on the optimization of product structural requirements to enhance performance and the process design to minimize flaws while ensuring material integrity and expected tolerances. The suggested approach involves product and process design phases within a computer aided design platform. Identification of critical issues in the original product design is the fundamental phase that drives the selection of the appropriate materials and quantities for deposition. Next, topological optimization is employed to shape and position additional volumes, generating enhanced design variants. A simulation phase ends the product design steps, assessing the actual improvement of the component over its original design. Subsequent phases are related to process design assessment. Selection of process parameters and build strategies, and next, the behavioral simulation of deposition are fundamental to verify feasibility and generate paths instructions. Finally, thermomechanical simulation is conducted to estimate the final component state accurately, ensuring it meets functional requirements before proceeding to actual manufacturing pre-processing, material deposition, and post-processing phases. A case study involving an automotive suspension component is used to demonstrate the feasibility of the proposed integrated approach. Experimental phases are performed to define DED material properties for the redesign and investigate the reliable simulation of process-induced distortions. By reducing stress in critical areas through localized deposition of 316L stainless steel alloy using laser powder DED, the study explores the impact of toolpath strategies on process-induced distortions through a Design of Experiments (DoE) approach. The results confirm the feasibility of the deposition process in meeting functional requirements, particularly geometrical tolerances, highlighting the potential of DARem for the redesign and enhancement of existing components. This integrated approach not only consolidates remanufacturing procedures but also promotes the use of simulation tools to preemptively address potential issues, ensuring efficient, one-shot component creation.