Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

The Influence of Laser Surface Remelting (LSR) on the Surface Morphology and in vitro Cell Viability of Additively Manufactured 316L Stainless Steel Bone Plate

Wenhe Feng1, Niyou Wang2, Yin Chi Wan1, Paul Lim Guang Hui1, Lina Yan2 and Gavin Kane O'Neill3 3

1Singapore Institute of Manufacturing Technology (SIMTech), Agency for Science, Technology and Research (A*STAR) Research Entities, 2 Fusionopolis Way, #08-04 Innovis, Singapore 138634

2Department of Mechanical Engineering, 9 Engineering Drive 1, #07-08 Block EA, National University of Singapore, Singapore 117575

3Division of Musculoskeletal Trauma, Department of Orthopaedic Surgery, NUHS Tower Block Level 11, National University Hospital, 1E Kent Ridge Road, Singapore 119228


Additive manufacturing (AM) technologies, for instance, selective laser melting (SLM), have been used to produce orthopaedic metal implants such as bone plates to cater for the fracture fixation needs of patients. The rough and particulate surface is likely to contain loose residual metal powder soluble in vivo, thus presenting a risk of metal toxicity causing harmful effects to the nearby cells and tissue, eventually leading to revision surgery. As a post-process to improve the surface quality, laser surface remelting (LSR) can be applied to eliminate surface pores and residual powder to consequently reduce the health risks. In this study, a 100 W, 1064 µm nanosecond-pulsed laser was used to remelt the surfaces of a simulated 316L stainless steel bone plate placed in argon gas protection. A pore-free and crack-free surface layer was formed on both flat surfaces and lattice structures at a processing efficiency of 100 sec/cm2 area. The surface asperities were removed and consequently the Sa roughness was reduced from 3.10 to 2.86 µm after LSR, but still subject to the inherited waviness. Subsequent in vitro cell viability tests presented no significant adverse effects of human osteoblast-like SAOS2 cells' viability.

Keywords: Laser, Surface Remelting, Additive Manufacturing, Post-process, Cytotoxicity

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