Optimizing contour scanning in SLM for surface enhancement of eutectic high-entropy alloy lattice structures

Purpose This study aims to systematically investigate the influence of contour scanning strategy parameters on the surface quality, dimensional accuracy, microstructure and compressive performance of face-centered cubic (FCC) lattice structures fabricated via selective laser melting (SLM) of eutectic high-entropy alloy (EHEA), with the objective of enhancing their overall performance and facilitating their engineering applications. Design/methodology/approach Through the modulation of laser power and scanning speed of contour scanning, FCC lattice samples with varying linear energy densities were fabricated. The surface morphology, roughness, cross-sectional dimensions and porosity were characterized using optical microscopy, laser confocal microscopy and Image-J software. Microstructural evolution was analyzed via scanning electron microscopy, while the mechanical properties were assessed through uniaxial compression testing using a universal testing machine. Findings The results indicate that an appropriate contour scanning energy density (e.g. 16.7 J/mm²) can significantly improve surface quality, reduce porosity and enhance dimensional consistency. Compared to the condition without contour scanning, the specific first peak force and specific energy absorption increased by 12.62% and 12.58%, respectively. Under identical lattice topology, the specific first peak force of EHEA lattice structures is approximately 43% higher than that of AlSi10Mg. Originality/value To the best of the authors’ knowledge, this study represents the first systematic application of the contour scanning strategy in the SLM fabrication of EHEA lattice structures, revealing the underlying mechanisms by which surface morphology, microstructure and mechanical properties are regulated under different energy densities. It provides an effective process optimization approach for the fabrication of high-performance high-entropy alloy lattice structures and holds significant potential for engineering applications.