Two-Staged Technology for CoCr Stent Production by SLM

Area of Science:

• Additive Manufacturing
• Materials Science
• Biomedical Engineering

Background:

• Additive manufacturing offers design freedom and automation for producing complex structures.
• Selective laser melting (SLM) is a key 3D printing technology for medical implants, yet its application in stent production requires further investigation.
• Cobalt-Chromium (CoCr) alloys are suitable for medical devices due to their properties.

Purpose of the Study:

• To present the technological aspects of CoCr stent fabrication using selective laser melting (SLM).
• To develop and validate manufacturing regimes for producing dimensionally accurate and high-quality CoCr stents.
• To establish a fundamental approach for CoCr stent SLM fabrication.

Main Methods:

• Characterization of CoCr powder properties (physical, chemical, technological).
• Parametric design of mesh stent models.
• A two-stage SLM process: single-track fusion development and full stent manufacturing.
• Simulation of the single-track fusion process to determine optimal laser synthesis parameters.
• Realization and analysis of 27 SLM manufacturing regimes.
• Investigation of surface roughness control methods.

Main Results:

• Established dependence of single-track width and height on laser power, exposition time, and point distance.
• Identified qualitative characteristics of tracks mimicking stent struts, distinguishing favorable and unfavorable fusion regimes.
• Determined optimal melting bath temperature and laser regimes for stent fabrication.
• Analyzed methods for regulating surface roughness of stent structural elements.

Conclusions:

• The developed two-stage approach provides a fundamental framework for CoCr stent fabrication via SLM.
• The study successfully optimized SLM parameters for producing CoCr stents with improved dimensional accuracy and quality.
• This research addresses a gap in the literature regarding SLM applications for CoCr stent manufacturing.