| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
|
| Presentation Title |
Densification and Microstructural Evolution and Characterization of Binder Jet Printed and Sintered Porous Ni-Mn-Ga Magnetic Shape-Memory Alloys |
| Author(s) |
Pierangeli Rodriguez De Vecchis, Amir Mostafaei, Markus Chmielus |
| On-Site Speaker (Planned) |
Pierangeli Rodriguez De Vecchis |
| Abstract Scope |
Binder Jet 3D Printing (BJP) of polycrystalline magnetic shape-memory alloys (MSMAs) allow creating complex geometries from pre-alloyed powders. Porous and large-grained microstructures can help increase functionality of polycrystalline MSMAs by decreasing internal constraints to twin boundary motion. This study focuses on the microstructural evolution of BJPed porous Ni-Mn-Ga during isothermal sintering to determine the densification mechanisms taking place over temperature (1070, 1080 and 1090 °C) and time (0-8 h) to tailor the microstructure. Stereology was used to determine the grain and pore size, and sintering mechanisms as defined by Coble’s model for intermediate stage sintering. Sintering at 1070 °C resulted in an interplay of densifying and coarsening mechanisms, while at 1080 °C the dominating mechanism was volume diffusion and at 1090 °C grain boundary diffusion. Additionally, Voronoi tessellation of cross-sectional images was used to validate stereology measurements and explore a more automated image characterization technique for porous structures. |