Additive Manufacturing of Functional, Energy, and Magnetic Materials: Advanced Manufacturing of Magnetic Materials
Sponsored by: TMS Functional Materials Division, TMS: Additive Manufacturing Committee, TMS: Magnetic Materials Committee
Program Organizers: Markus Chmielus, University of Pittsburgh; Sneha Prabha Narra, Carnegie Mellon University; Mohammad Elahinia, University of Toledo; Reginald Hamilton, Pennsylvania State University; Iver Anderson, Iowa State University Ames Laboratory

Wednesday 2:00 PM
March 17, 2021
Room: RM 2
Location: TMS2021 Virtual

2:00 PM  Invited
Development of High-temperature Permanent Magnet Alloys for Additive Manufacturing: Ryan Ott1; Emrah Simsek1; Rakesh Chaudhary1; Scott McCall2; Alex Baker2; 1Ames Laboratory/Cmi; 2Lawrence Livermore National Laboratory
    Advanced magnet materials are increasingly being incorporated into applications that require smaller dimensions, and often, complex geometries. Machining these magnets from sintered blocks can lead to large manufacturing waste, which negatively affects critical material usage. Bonded magnets offer greater processing flexibility, but the energy product is limited by the binder phase. To address this challenge, we have used combinatorial synthesis and high-throughput characterization to identify permanent magnet compositions compatible with additive manufacturing (AM) synthesis. Here we discuss developing SmCo-based alloys that can be synthesized via directed energy deposition that show enhanced thermal stability. The effects of alloying additions and post synthesis heat treatments on the alloy coercivity are discussed.

2:20 PM  
Advanced Design for Lightweighting Wind Power Generators Using Additively Manufactured Hard and Soft Magnets: Latha Sethuraman1; Ganesh Vijayakumar1; Shreyas Ananthan1; Jonathan Keller1; M.Parans Paranthaman2; 1National Renewable Energy Laboratory; 2Oak Ridge National Laboratory
    Improving power densities using lightweight electric generators is currently a key motivation within the wind turbine industry for reducing the costs of wind energy. However, reducing the weight of wind power generators contrasts with the principles of optimizing for lower-cost and high-volume production resulting in sub-optimal use of expensive rare-earth magnets and electrical steel. Traditional design of these machines using advanced electrical steel grades with higher saturation flux density and higher-grade permanent magnets translate to poor scaling.In this work we present results from a novel approach for light weighting the active materials in the rotor of a 15MW permanent magnet wind generator using advanced topology optimization enabled by machine learning with different compositions of additively manufactured hard and soft magnet materials. This work was supported by the U.S.Department of Energy-sponsored research program MADE3D (Manufacturing and Additive Design of Electric machines enabled by 3-Dimensional printing).

2:40 PM  
An Additive Manufacturing Design Approach to Achieving High Strength and Ductility in Traditionally Brittle Alloys via Laser Powder Bed Fusion: Andrew Kustas1; Tomas Babuska1; Kyle Johnson1; Trevor Verdonik2; Samuel Subia1; Brandon Krick3; Donald Susan1; 1Sandia National Laboratories; 2Lehigh University; 3Florida State University
    Additive Manufacturing (AM) presents unprecedented opportunities to enable design freedom in parts that are unachievable via conventional manufacturing. However, AM-processed components generally lack the necessary performance metrics for widespread commercial adoption. We present a novel AM processing and design approach using removable heat sink artifacts to tailor the mechanical properties of traditionally low strength and low ductility alloys. The design approach is demonstrated with the Fe-50 at.% Co alloy, as a model material of interest for electromagnetic applications. AM-processed components exhibited unprecedented performance, with a 300 % increase in strength and an order-of-magnitude improvement in ductility relative to conventional wrought material. These results are discussed in the context of product performance, production yield, and manufacturing implications toward enabling the design and processing of high-performance, next-generation components, and alloys. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525

3:00 PM  
Cold Spray of Permanent Magnets: Alexander Baker1; Richard Thuss2; Nathan Woollett1; Elis Stavrou1; Scott McCall1; Harry Radousky1; 1Lawrence Livermore National Laboratory; 2TTEC LLC
     Cold Spray Deposition entrains micron scale particles in supersonic gas to direct high-density deposition, but has typically been limited to ductile metals. Recently, we have demonstrated its extension to brittle functional materials, including hard and soft magnets. A range of feedstock powders can be sprayed onto substrates ranging from quartz to copper, and onto curved surfaces. The magnetic properties of the deposited material are governed by powder size and the gas velocity and temperature, formation of deleterious secondary phases can be suppressed by correct choice of processing conditions. A summary of structural, compositional and magnetic characterization results will be presented, highlighting the flexibility and strengths of this manufacturing technique, and offering perspectives for future applications it will enable.Prepared by LLNL under Contract DE-AC52-07NA27344.

3:20 PM  
Establishing Fundamentals for Laser Metal Deposition of Functional Ni-Mn-Ga Alloys: Effect of Rapid Solidification on Microstructure and Phase Transformation Characteristics: Emily Flitcraft1; Jakub Toman2; Markus Chmielus2; Carolin Fink1; 1Ohio State University; 2University of Pittsburgh
    Laser-based additive manufacturing holds the promise of enabling complex geometries for shape memory alloy components. However, rapid melting, resolidification and multiple reheating create challenging microstructures characteristic of non- or low-functional alloys. We investigate how non-equilibrium processing and complex thermal cycling effect microstructural evolution and functional properties in Ni-Mn-Ga magnetic shape memory alloys. This talk gives insight into our efforts to establish cooling rate-microstructure-magnetic property relations that will help identify processing conditions for laser metal deposition (LMD) of functional Ni-Mn-Ga alloy. Physical simulation of rapid solidification achieved cooling rates that resemble what is seen in LMD (102-104 K/s). Microstructure characterization was performed as a function of cooling rate using scanning electron microscopy, electron dispersive spectroscopy, and X-ray diffraction. The effect of cooling rate on phase transformation characteristics was investigated using differential scanning calorimetry. If available at time of presentation, results from magnetic property measurements using vibrating-sample magnetometer will also be included.