Additive Manufacturing of Functional and Energy Materials: Poster Session
Sponsored by: TMS: Additive Manufacturing Committee
Program Organizers: Sneha Prabha Narra, Carnegie Mellon University; Markus Chmielus, University of Pittsburgh; Mohammad Elahinia, University of Toledo; Reginald Hamilton, Pennsylvania State University
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
A-16 (Digital): Quantitative Microstructure Study of Binder-jet Printed and Sintered Ni-Mn-Ga Alloy: Chuyuan Zheng1; Amir Mostafaei2; Pierangeli Rodriguez1; Erica Stevens1; Ian Nettleship1; Markus Chmielus1; 1University of Pittsburgh; 2Carnegie Mellon University
Ni-Mn-Ga alloy is a multi-functional ferromagnetic material and exhibits in the modulated martensite phase the magnetic shape memory effect. For enhanced magnetic-field-induced strain (MFIS), porosity is included to reduce twin-twin and twin-grain boundary interactions. Binder-jet printing and subsequent partial sintering provides an approach to introduce controlled porosity in a manner that is consistent with near-net shaping of green bodies suitable for practical applications. However, the process-structure relationships between binder-jet printing and the microstructure of the sintered alloy remain unstudied. In this work, the effect of sintering temperature and time was systematically evaluated. Micrographs were quantitatively analyzed to reveal the mesoscale microstructural evolution during sintering. Micro-CT was used to characterize, in 3D, the large defects generated during printing to establish their consequent effect on the final microstructure.
A-17: Layered Binder Jet Printing of Functional Ni-Mn-Ga Alloys: Katerina Kimes1; Erica Stevens1; Jeffrey Martin1; Pierangeli Rodriguez De Vecchis1; Danielle Brunetta1; Markus Chmielus1; 1University of Pittsburgh
This study investigates the feasibility of 3D printing multi-material layered structures via binder jetting methodologies. A manual binder jet printer that enables printing with two different materials simultaneously, and with a magnetic field, was designed and built. Samples were printed from ball-milled powder. Testing was done to determine acceptable layer thickness, dry time, and binder saturation for samples with sufficient green strength. After printing, samples were sintered in a purged argon atmosphere to densify the parts. Microstructure was investigated using SEM. Element distribution at layer interfaces and throughout layers was analyzed using EDS and part density was determined by image analysis of optical micrographs. Additionally, phase transformation and Curie temperatures were identified using DSC and magnetic properties were measured using VSM. It was found that layered printing provides the opportunity to create samples with multiple compositions that show phase transformations within two distinct temperature ranges.