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 (E12-20 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.
|Title of host publication||Behavior and Mechanics of Multifunctional Materials and Composites XII|
|Editors||Hani E. Naguib|
|State||Published - 2018|
|Event||Behavior and Mechanics of Multifunctional Materials and Composites XII 2018 - Denver, United States|
Duration: Mar 5 2018 → Mar 8 2018
|Name||Proceedings of SPIE - The International Society for Optical Engineering|
|Conference||Behavior and Mechanics of Multifunctional Materials and Composites XII 2018|
|Period||3/5/18 → 3/8/18|
Bibliographical noteFunding 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.
© 2018 SPIE.
- Compressive response
- Porous NiTi
- Selective laser melting
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering