Proposal and evaluation of a novel contactless surface characteristic method for quantifying wire laser additive manufacturing

Wire Laser Additive Manufacturing (WLAM) is an emerging additive manufacturing technique, offering significant advantages such as high efficiency and design flexibility for the rapid fabrication of complex metallic components. However, the absence of a standardized, non-contact surface characterization method limits its industrial adoption. To address this gap, this paper proposes a novel multi-scale surface characterization framework based on three-dimensional point cloud analysis using a FARO laser scanner, enabling rapid and precise assessment of both global geometry and local surface quality in WLAM components. The proposed method integrates automated cross-sectional fitting, Iterative Closest Point (ICP) registration with ideal CAD models, and computation of areal roughness parameters to quantify geometric deviations and micro-scale features. Compared to traditional measurement methods, this proposed approach provides full-field and high-resolution evaluations of surface morphology. Experimental validation using stainless-steel single beads with different working parameters demonstrated strong sensitivity to process variations in wire feed and travel speed, linking deposition parameters directly to surface characteristics. The proposed framework offers a robust foundation for standardized, contactless quality evaluation and offers a promising pathway toward real-time monitoring and closed-loop control in advanced wire-laser additive manufacturing.