Additive Manufacturing and Innovative Powder Processing of Functional and Magnetic Materials: Shape Memory Alloys
Sponsored by: TMS Functional Materials Division, TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Magnetic Materials Committee, TMS: Powder Materials Committee
Program Organizers: Emily Rinko, Honeywell Fm&T; Iver Anderson, Iowa State University Ames Laboratory; Markus Chmielus, University of Pittsburgh; Emma White, DECHEMA Forschungsinstitut; Deliang Zhang, Northeastern University; Andrew Kustas, Sandia National Laboratories; Kyle Johnson, Sandia National Laboratories
Wednesday 4:00 PM
March 2, 2022
Room: 262C
Location: Anaheim Convention Center
Session Chair: Markus Chmielus, University of Pittsburgh
4:00 PM Introductory Comments
4:05 PM
Microstructure of Additively Manufactured Magnetic Shape Memory Alloys: Jakub Toman1; Tyler Paplham1; Pierangeli Rodriguez de Vecchis1; Aaron Acierno1; Amir Mostafaei2; Erica Stevens1; Markus Chmielus1; 1University of Pittsburgh; 2Illinois Institute of Technology
Ni-Mn-Ga-based magnetic shape memory alloys have been recently fabricated by binder jet 3D printing, direct laser deposition, selective laser melting, and 3D ink printing additive manufacturing (AM). Each of these fundamentally different AM techniques results in functional magnetic materials with very different as-manufactured and final microstructures and properties. While energy-beam-based AM methods melt feedstock powder and build dense as-printed parts, other AM methods, e.g. non-energy-beam-based methods, build highly porous green samples. Nevertheless, for all AM method, post-AM processing is needed to either homogenize highly segregated microstructures or to (partially) densify porous green structures. In this talk, the microstructures and properties of additively manufactured Ni-Mn-Ga magnetic shape memory alloys and post-processing routes will be compared, and paths to functionality will be discussed.
4:25 PM
Controlled Shape-morphing Metallic Components for Deployable Structures: Gianna Valentino1; Ian McCue2; Steven Storck1; Morgana Trexler1; 1Johns Hopkins University Applied Physics Lab; 2Northwestern University
Transformational advances in additive manufacturing combined with the unique functional behavior of shape memory alloys (SMAs) has propelled the field of 4D printing. In this study, we leverage multiple processing pathways with additive manufacturing to design and fabricate SMA components capable of precise, self-guided shape change that could actuate large-scale (up to 25x25x33 cm3) structures under thermal stimuli. The dual benefits of minor alloy dopants and laser processing parameters were identified to be the most effective method to engineer SMA joints and hinges with locally tailored transformation temperatures over a 90 °C range. Custom-designed plywood-style NiTi hinges with self-regulating features enabled tight bend radii and compact packing sizes. These novel SMAs hinges facilitated deployable structures that can expand 3-7x their stowed area. The fundamental understanding and demonstration of tailored and controlled complex shape-morphing kinematics, without specialized and heavy external motors, lays the groundwork for future SMA-enabled deployables in remote environments.
4:45 PM
Selective Laser Melting of NiTi: Experiments and Modeling to Correlate Hatch Spacing, Texture, Residual Stress, and Superelastic Response: Peter Anderson1; Natalie Zeleznik1; Alejandro Hinojos1; Mohammadreza Nematollahi2; Narges Shayesteh3; Soheil Saedi4; Mohammad Elahinia2; Haluk Karaca5; James Cawley5; Michael Mills1; 1Ohio State University; 2University of Toledo; 3University of Texas at Arlington; 4University of Arkansas at Little Rock; 5University of Kentucky
Recent work has demonstrated that Ni50.8Ti49.2 (at%) samples fabricated by selective laser melting (SLM) can provide up to 5.6% superelastic compressive strain without any post heat treatment. Of particular interest is the ability to manipulate texture and superelastic response by varying the hatch spacing used in the SLM process. Samples with 80 micron hatch spacing display relatively stable superelastic stress-strain response under repeated mechanical cycling while those with 180 micron hatch spacing exhibit ratcheting and evolution to a more linearized response during cycling. The underlying physics for the different responses are explored using mechanics modeling that captures the effects of texture and residual stress on cyclic stress-strain response. The results indicate that a variety of superelastic responses may be attained through the manipulation of hatch spacing during SLM processing. This offers a wide functional space within which to design SMA devices.