@Article{icces.2023.010163,
AUTHOR = {Enzoh Langi, Liguo Zhao},
TITLE = {Microstructures	and	Nanomechanical	Properties	of	Additively	 Manufactured	Metallic	Stents},
JOURNAL = {The International Conference on Computational \& Experimental Engineering and Sciences},
VOLUME = {25},
YEAR = {2023},
NUMBER = {3},
PAGES = {1--1},
URL = {http://www.techscience.com/icces/v25n3/53851},
ISSN = {1933-2815},
ABSTRACT = {Additive	 manufacturing	 emerges	 as	 an	 innovative	 technology	 to	 fabricate	 medical	 stents	 used	 to	 treat	
blocked	arteries.	However,	there	is	a	lack	of	study	of	underlying	microstructure	and	mechanical	properties	
of	 additively	 manufactured	 stent.	 In	 this	 work,	 additively	 manufactured	 316L	 stainless	 steel	 stent	 was	
investigated,	 with	 electrochemical	 polishing	 being	 used	 to	 improve	 the	 surface	 finish.	 Microstructural	
characterisation	 was	 carried	 out	 using	 optical	 microscopy,	 scanning	 electron	 microscopy,	 and	 electron	
backscatter	diffraction.	The	hardness	and	elastic	modulus	were	measured	using	Berkovich	nanoindentation,	
with	 an	 emphasis	 on	 the	 effect	 of	 grain	 orientation.	 In	 addition,	 spherical	 nanoindentation	 was	 used	 to	
obtain	 indentation	 stress-strain	 curves	 based	 on	 load-displacement	 responses.	 The	 results	 showed	 that	
electrochemical	polishing	was	effective	in	reducing	the	average	surface	roughness,	although	not	reaching	
the	 level	 of	 commercial	 stent.	 The	 additively	 manufactured	 stent	 demonstrated	 a	 hierarchical	 grain	
microstructure	with	columnar	grains	and	cellular	sub-grains,	as	opposed	to	equiaxed	fine	grains	and	twins	
in	commercial	stent.	The	hardness	and	modulus	of	additively	manufactured	stent	were	higher	than	those	of	
the	commercial	one.	The	grains	close	 to	 the	(111)	orientation	exhibited	 the	highest	hardness	and	elastic	
modulus	followed	by	(101)	and	(001)	orientations.	The	indentation	stress-strain	curves,	yield	strength,	and	
hardening	behaviour	of	additively	manufactured	stent	were	similar	to	those	of	commercial	stent.	This	work	
provides	a	helpful	understanding	of	the	microstructure	and	properties	of	additively	manufactured	stent	and	
outlines	the	technical	barriers	in	the	development	of	additive	technology	for	innovative	manufacturing	of	
stent.},
DOI = {10.32604/icces.2023.010163}
}