Selective laser melting of NiTi stents with open-cell and variable diameter

Maffia, Simone; Finazzi, V.; Berti, Francesca; Migliavacca, Francesco; Petrini, Lorenza; Previtali, Barbara; Demir, Ali Gökhan

doi:10.1088/1361-665x/ac1908

Cited by 21 publications

(10 citation statements)

References 56 publications

(71 reference statements)

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“…The inherent layering effect can be clearly observed in Figure 11 c. Since the SAFs were manufactured on the edge of resolution such layering effect is inevitable. Besides, fused particles on the SAF surface are presented that are common surface defects [ 20 ], but considering synthesized object dimensions these defects become more influential. Both surface irregularities (layering and fused particles) possibly can be removed by chemical etching [ 42 ].…”

Section: Resultsmentioning

confidence: 99%

“…Due to the absence of research dedicated to the manufacturing of NiTi Self-Adjusting Files by LPBF technology, it is worth mentioning alternative micro-scale devices that received increased attention. Several works were dedicated to the investigation of the feasibility of printing stents for coronary vessels from Co-Cr [ 18 ], titanium [ 11 ], steel [ 19 ], and NiTi [ 20 ], which previously were made using laser cutting methods from hollow tubes [ 21 ]. It was demonstrated that resolution, surface finish, and layer bonding dramatically impact the stent performance [ 18 , 19 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

“…Several works were dedicated to the investigation of the feasibility of printing stents for coronary vessels from Co-Cr [ 18 ], titanium [ 11 ], steel [ 19 ], and NiTi [ 20 ], which previously were made using laser cutting methods from hollow tubes [ 21 ]. It was demonstrated that resolution, surface finish, and layer bonding dramatically impact the stent performance [ 18 , 19 , 20 ]. In terms of Nickel-Titanium alloy, both superelasticity and shape memory effect are used for stents to decrease their volume during placement with subsequent extension under temperature influence and to impart a constant load on the walls of the vessel respectively.…”

Section: Introductionmentioning

confidence: 99%

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The Study on Resolution Factors of LPBF Technology for Manufacturing Superelastic NiTi Endodontic Files

et al. 2022

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Laser Powder Bed Fusion (LPBF) technology is a new trend in manufacturing complex geometric structures from metals. This technology allows producing topologically optimized parts for aerospace, medical and industrial sectors where a high performance-to-weight ratio is required. Commonly the feature size for such applications is higher than 300–400 microns. However, for several possible applications of LPBF technology, for example, microfluidic devices, stents for coronary vessels, porous filters, dentistry, etc., a significant increase in the resolution is required. This work is aimed to study the resolution factors of LPBF technology for the manufacturing of superelastic instruments for endodontic treatment, namely Self-Adjusting Files (SAF). Samples of thin walls with different incline angles and SAF samples were manufactured from Nickel-Titanium pre-alloyed powder with a 15–45 μm fraction. The printing procedure was done using an LPBF set-up equipped with a conventional ytterbium fiber laser with a nominal laser spot diameter of 55 microns. The results reveal physical, apparatus, and software factors limiting the resolution of the LPBF technology. Additionally, XRD and DSC tests were done to study the effect of single track based scanning mode manufacturing on the phase composition and phase transformation temperatures. Found combination of optimal process parameters including laser power of 100 W, scanning speed of 850 mm/s, and layer thickness of 20 μm was suitable for manufacturing SAF files with the required resolution. The results will be helpful for the production of NiTi micro objects based on periodic structures both by the LPBF and μLPBF methods.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Study on Resolution Factors of LPBF Technology for Manufacturing Superelastic NiTi Endodontic Files

et al. 2022

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“…At present, there are numerous existing and ongoing studies on the fabrication of SMA components using AM techniques, with a lot of interest given toward its potential in the medical sector. 48,115,116,[118][119][120][121]125,164,165 Maffia et al 166 have investigated the application of SLM for the fabrication of customizable NiTi stents, assessing it to be able to fabricate NiTi open-cell peripheral stents of good geometrical fidelity and high density. Recently, the vivo biocompatibility of load-bearing and load-sharing NiTi implants fabricated through SLM was investigated by Naujokat et al, 167 producing promising results.…”

Section: Current and Future Prospectsmentioning

confidence: 99%

The role of NiTi shape memory alloys in quality of life improvement through medical advancements: A comprehensive review

Nair

Radhika

2022

Proc Inst Mech Eng H

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The significance of advanced smart materials in recent technological research and advancement is apparent from its extensive use in present day devices and instruments. Of the various smart materials in use today, the fascinating category of shape memory alloys (SMAs) is equipped with the ability to return to a previously memorized shape under certain thermomechanical or magnetic stimuli. The unique property of shape memory effect and superelasticity displayed by these materials along with good biocompatibility and corrosion resistance make them ideal for biomedical applications. The various applications of SMAs in surgical instruments, surgical implants, and assistive and rehabilitative devices have significant effect on the day to day life of people in the present age. Majority of these biomedical devices belong to the orthodontic, orthopedic, or surgical fields. Other remarkable applications of SMAs such as in the production of prostheses and orthoses designed through the biomimetic approach are also highly influential in improving the quality of life. The present paper provides an overview of the various properties of shape memory alloys and their applications in the biomedical field over the years, that have had a significant impact on the realm of medical science.

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“…One of the most widespread AM techniques for metals is the Laser Powder Bed Fusion (LPBF), which uses a high-power laser beam to melt locally a layer-wise deposited metallic powder. The recent literature is rich of research works focused on the 4D printing of NiTi, in particular using LPBF [21][22][23][24][25][26][27][28][29][30][31][32][33], showing the interest of the scientific community on this topic, as also evidenced by a substantial number of reviews [13,14,34].…”

Section: Introductionmentioning

confidence: 99%

Building Orientation and Heat Treatments Effect on the Pseudoelastic Properties of NiTi Produced by LPBF

Carlucci

Patriarca

Demir

et al. 2022

Shap. Mem. Superelasticity

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NiTi dominates the market of shape memory materials due to its optimal combination of mechanical, functional, and biocompatibility properties, which enabled its use for several applications, in particular for the biomedical and the aerospace sectors. However, due to its poor machinability, NiTi is a challenging material from the manufacturing standpoint. Therefore, in the last years, researchers have focused on the production of NiTi components by additive manufacturing processes, which also enable the manufacturing of complex shape parts that cannot be produced with conventional methods. The aim of this study is to provide insights on the optimization of the functional performances of NiTi produced by Laser Powder Bed Fusion, leveraging on the building orientation and post-processing heat treatments. Uniaxial mechanical tests have been performed in tension and compression, and the influence of heat treatments and building orientation on the mechanical behavior of pseudoelastic NiTi has been evaluated. Different heat treatment schedules have been evaluated, leading to transformation strains up to 2.7% in tension and 4.6% in compression. This study confirms that Laser Powder Bed Fusion is a promising additive manufacturing technology for the production of net-shape and near defect-free NiTi components, exhibiting remarkable functional properties.

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Selective laser melting of NiTi stents with open-cell and variable diameter

Cited by 21 publications

References 56 publications

The Study on Resolution Factors of LPBF Technology for Manufacturing Superelastic NiTi Endodontic Files

The Study on Resolution Factors of LPBF Technology for Manufacturing Superelastic NiTi Endodontic Files

The role of NiTi shape memory alloys in quality of life improvement through medical advancements: A comprehensive review

Building Orientation and Heat Treatments Effect on the Pseudoelastic Properties of NiTi Produced by LPBF

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