PSI - Issue 15

Enzoh Langi et al. / Procedia Structural Integrity 15 (2019) 41–45 Langi et al. / Structural Integrity Procedia 00 (2019) 000–000

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with an average grain size of 20 µm, for both radial and longitudinal cross sections (Fig. 3(c)). Furthermore, commercial stent has fewer grains across the width of stent strut compared to SLMed tube.

Fig. 3. The Inverse pole figure (IPF) map and grain boundary characters for SLMed tube (a & b) and commercial stent (c & d).

4. Conclusion In this study, the microstructure of 316L SLMed tube was characterised using SEM/EBSD analysis. The SLMed tube has a dominant coarse and columnar grain structure in the middle of the wall, as opposed to equiaxed and fine grains of the commercial stent produced with traditional methods. The chemical composition of 316L SLMed tube is similar to that of commercial stent, but with some differences in weight fractions of alloy elements. Based on the results, additive manufacturing has the potential for manufacturing metallic stents, but further research is needed to address the observed differences in microstructure and chemical composition and their connections with mechanical performance of the device. Acknowledgements We acknowledge the support from the EPSRC (EP/R001650/1), the Royal Society of the UK (IE160066) and the British Heart Foundation (FS/15/21/31424).