Additive Manufacturing and Innovative Powder Processing of Functional and Magnetic Materials: Overcoming Build Challenges, Feedstock to Thermal Treatments
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
Thursday 2:00 PM
March 3, 2022
Room: 262C
Location: Anaheim Convention Center
Session Chair: Iver Anderson, Iowa State University Ames Laboratory
2:00 PM Introductory Comments
2:05 PM
Mechanical Alloying and Characterization of Al2Ni5Co6Fe6Sm0.2 High-entropy Alloy: Afsaneh Darvish Motevali1; Majid Vaseghi1; Mahmood Sameezadeh1; 1Shahid Beheshti University
Al2Ni5Co6Fe6Sm0.2 high-entropy alloy powders (HEAPs) were successfully manufactured via a mechanical alloying technique and the microstructure and magnetic properties were investigated. The predominant structure after 10 hours was the BCC phase with an intermetallic phase Fe3Al. After 20, 30 and 50 h of milling, supersaturated solid solution phases with an FCC predominant structure was formed in the Al2Ni5Co6Fe6Sm0.2 HEAP. In 50 h an intermetallic phase Fe3Al also formed in low angles. The 50 h ball milled Al2Ni5Co6Fe6Sm0.2 HEAP had high saturated magnetization (130 emu/g) and coercivity (103 Oe), indicating that the powder exhibited semi-hard magnetic properties. In addition, an asymmetrical displaced hysteresis loop was also observed in the Al2Ni5Co6Fe6Sm0.2 HEAP, and the shift ΔHs was about 212 Oe in 50h. With increasing milling time, the magnetic retentivity increases and the coercivity decreases from zero to 20 h then increases to 50 h. The magnetization decreases with increasing milling time.
2:25 PM
Improved Near-infrared Absorption for Additive Manufacturing Feedstock Using Reduced Graphene Oxide: Chu Lun Alex Leung1; Iuliia Elizarova2; Mark Isaacs1; Shashidhara Marathee3; Eduardo Saiz2; Peter D. Lee1; 1University College London; 2Imperial College London; 3Diamond Light Source Ltd
Additive Manufacturing (AM) makes components with complex geometry and unique design features, layer-by-layer. However, there are limited choices of commercial powders for AM, partly constrained by the laser absorbance, an area that is not well investigated. Carbon additives are commonly used to promote near infra-red (NIR) absorbance of the powders but their efficiency is low. Here, we combine synchrotron X-ray imaging with chemical characterisation techniques to explain the role of additives on NIR absorption, evolution mechanisms of melt track and defects during AM. We employ a reduced graphene oxide (rGO) additive that enables AM of low NIR absorbance powders, e.g. fused silica. The rGO increases the powder’s NIR absorbance 3 times greater than conventional carbon additives and enables printing of SiO2. This study reports a method to widen the palette of materials for laser based AM machines to process all classes of materials, unlocking their true potential.
2:45 PM
Additive Manufacturing of a Composite Made of Al 5083 Matrix and Encapsulated ZnAl Particles: Baolong Zheng1; David Svetlizky2; Sen Jiang1; Yizhang Zhou1; Lorenzo Valdevit1; Noam Eliaz2; Enrique Lavernia3; Julie Schoenung1; 1University of California, Irvine; 2Tel-Aviv University; 3National Academy of Engineering
The self-healing ability of materials allows mechanical behavior to be restored by healing cracks generated in the components. Aluminum alloy composites containing encapsulated Zn-Al particles were designed by Svetlizky and Eliaz as a metallic self-healing material. Here, we report on the additive manufacturing (AM) of Al 5083 based composites reinforced with core-shell ZnAl particles, using both directed energy deposition (DED) and powder bed fusion (PBF) modes. Different shell materials and various AM processing conditions are experimentally explored to overcome the challenge of the low evaporation temperature of Zn. The as-deposited composites are characterized by electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. The role of coating composition, coating thickness and particle size are also evaluated. The microstructure evolution is rationalized based on the thermal behavior during AM deposition.
3:05 PM
Growth Optimization of Single Crystal Fibers of Congruently and Incongruently Melting Garnets via Laser Heated Pedestal Growth Method: Dolendra Karki1; Edward Clover Hoffman1; Paul R. Ohodnicki1; 1University of Pittsburgh
Laser heated pedestal growth (LHPG) has been proven capable of growing high quality single crystal fibers of refractory oxides such as sapphire and YAG (Yttrium aluminum garnet) for applications spanning from high temperature sensing to lasing, from single crystalline feed-stock materials. Single crystal fibers of magneto-optical magnetic garnets can potentially enable magneto-optical field sensing. However, magnetic garnets such as Yttrium iron garnet (YIG) impose unique challenges for stable, high-quality single crystal growth due to incongruent melting resulting in tendency for compositional segregation within the liquid phase, as per the Y2O3-Fe2O3 phase diagram. Here we discuss growth process optimization of YAG (congruent melting) and YIG (incongruent melting) fibers via LHPG method from polycrystalline source materials prepared from their constituent powders using standard powder processing. The associated challenges inherent to the different thermodynamics involved is discussed. The impact on the quality of the fibers grown are analyzed upon optical and materials characterizations.