Abstract

Porous Nickel-Titanium shape memory alloys (NiTi-SMAs) have attracted much attention in biomedical applications due to their high range of pure elastic deformability (i.e., superelasticity) as well as their bone-level modulus of elasticity (E≈12-20 GPa). In recent years, Selective Laser Melting (SLM) has been used to produce complex NiTi components. The focus of this study is to investigate the superelasticity and compressive properties of SLM NiTi-SMAs. To this aim, several NiTi components with different level of porosities (32- 58%) were fabricated from Ni50.8Ti (at. %) powder via SLM PXM by Phenix/3D Systems, using optimum processing parameter (Laser power-P=250 W, scanning speed-v=1250mm/s, hatch spacing-h=120μm, layer thickness-t=30μm). To tailor the superelasticity behavior at body temperature, the samples were solution annealed and aged for 15 min at 350°C. Then, transformation temperatures (TTs), superelastic response, and cyclic behavior of NiTi samples were studied. As the porosity was increased, the irrecoverable strain was observed to be higher in the samples. At the first superelastic cycle, 3.5%, 3.5%, and 2.7% strain recovery were observed for the porosity levels of 32%, 45%, and 58%, respectively. However, after 10 cycles, the superelastic response of the samples was stabilized and full strain recovery was observed. Finally, the modulus of elasticity of dense SLM NiTi was decreased from 47 GPa to 9 GPa in the first cycle by adding 58% porosity.

Document Type

Conference Proceeding

Publication Date

3-22-2018

Notes/Citation Information

Published in Proceedings of SPIE, v. 10596, Behavior and Mechanics of Multifunctional Materials and Composites XII, article 105960H, p. 1-7.

© 2018 SPIE. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

Narges Shayesteh Moghaddam, Soheil Saedi, Amirhesam Amerinatanzi, Ahmadreza Jahadakbar, Ehsan Saghaian, Haluk Karaca, and Mohammad Elahinia, "Influence of SLM on compressive response of NiTi scaffolds," Proc. SPIE 10596, Behavior and Mechanics of Multifunctional Materials and Composites XII, 105960H (March 22, 2018). DOI: https://doi.org/10.1117/12.2305251

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Digital Object Identifier (DOI)

https://doi.org/10.1117/12.2305251

Funding Information

The authors would like to acknowledge the financial support provided for the project “Nitinol Commercialization Accelerator” by the Ohio Department of Development through Grants WP 10-010, and TVSF awards.

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