Pioneers in Additive Manufacturing: Poster Session
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Powder Materials Committee
Program Organizers: James Foley, Los Alamos National Laboratory; Paul Prichard, Kennametal Inc; Iver Anderson, Iowa State University/Ames Laboratory; David Bourell, University of Texas

Monday 6:00 PM
February 27, 2017
Room: Hall B1
Location: San Diego Convention Ctr

A-94: 3D Additive Manufacturing of Metals at Micro/Nanoscale Using Localized Electrodeposition: Majid Minary1; 1University of Texas at Dallas
    We present an additive manufacturing technique for deposition of pure metallic micro/nanostructures. This research is supported by US Navy under Young Investigator program (ONR-YIP). In this technique a glass capillary with a few micron to sub-micron tip is filled with the electrolyte of a metal of interest. A liquid capillary formed between the tip of the pipette and the conductive substrate completes the electronic-ionic circuit. Upon application an appropriate electric potential metal ions reduce and get deposited on the substrate. The pipette is steered precisely in 3D using precision nano-positioners, which results in formation of desired 3D objects from a CAD file. The process is mainly driven by evaporation of the liquid in the meniscus bridge. We present fabrication of various metallic structures, as well as characterization of their materials, mechanical an electrical properties. A Multiphysics computational model will be also presented to explain the detailed mechanisms governing the process.

A-95: Direct Metal Write Additive Manufacturing of Rare-earth Modified Aluminum Alloys Using Electromagnetic Heating Systems: William Carter1; Zachary Sims1; Orlando Rios1; Lonnie Love1; Brian Post1; Randall Lind1; Max Neveau1; 1Oak Ridge National Laboratory
    Structural direct-write additive-manufacturing is a layered filament based metal manufacturing technology wherein liquid material is deposited from a print head directly onto a print bed, where it solidifies, retaining an intended shape and bonding with a layer of the same material upon which it is deposited. This process has been enabled for metals by the unique rheological properties of rare-earth modified aluminum alloys to create a scalable direct metal write system. Tailoring the rheology of the alloy has allowed for a system that is capable of direct write additive manufacturing of metal parts at room temperature in air. Removing the requirement for large ovens and tailored atmospheres significantly increases the accessibility of metal additive manufacturing. The system can also be used to create large and small scale parts with faster build rates than traditional metal additive manufacturing methods.

A-96: FEM Modeling of Steel Additive Manufacturing Using Laser Hot-Wire Process: Zhenguo Nie1; Gang Wang1; James McGuffin-Cawley2; Badri Narayanan3; Yiming (Kevin) Rong1; 1Tsinghua University; 2Case Western Reserve University; 3The Lincoln Electric Company
    The laser hot-wire (LHW) process has the potential to deposit material at high rates using low laser power. Numerical simulation of LHW was conducted to obtain the temperature, stress and strain fields, and the distortion. The outstanding features for numerical simulation are additive geometry and numerous analysis steps. The INP files of ABAQUS are compiled by a Matlab program because of a great deal of step and element definitions. Temperature and distortion were both measured to validate the FEA model. The verification result indicates that the model is accurate. Calculations show that the maximum residual stress is located in the junction between the deposit and substrate. The junction area becomes the most likely crack position. The processing window of stable hot-wire deposition was mapped via numerical computation method. It is shown that the stable deposition has top and bottom limitations under a certain current intensity and wire feed speed.

A-97: Microstructure Evolution and Galling Properties of Hard Facing Coatings Deposited Using Laser Directed Energy Deposition: Niyanth Sridharan1; Brian Jordan2; Ryan Dehoff2; Sudarsanam Babu1; 1University of Tennessee Knoxville; 2Oak Ridge National laboratory
    Surface engineering is a topic of great relevance today from the standpoint of enhanced wear and corrosion resistance. In this work we attempt to deposit and evaluate the galling resistance of a new hard facing alloy. The alloy based out of a stainless steel composition is designed to solidify as a nano crystalline material during laser deposition. The hard facing material was deposited on a maraging steel substrate and characterized using electron microscopy and X-Ray diffraction. Characterization using X-Ray diffraction showed that on solidification the material partially amorphized though the bulk of the deposit was crystalline with hardness in excess of 800 VHN. A detailed microstructure evolution performed using multi scale characterization coupled with computational thermodynamics showed complex boride phases in the matrix leading to significant increase in the hardness and wear performance of the deposited alloy. The galling performance of these alloys was evaluated using a custom designed jig.

A-98: Novel High Temperature Drop on Demand Liquid Metal-jetting for the Production of Complex 2D and 3D objects: Marco Simonelli1; Mark East1; Nesma Aboulkhair1; Richard Hague1; 1University of Nottingham
    This research work presents a novel drop-on-demand (DoD) technology for the spatially controlled deposition of high-temperature droplets of molten metal for the production of 3D objects in both single and multiple high temperature metallic materials. The key aspects of the printing process will be presented. Firstly the authors will discuss the stability of the jetting of two example materials, namely tin and silver. It will then be shown that by jetting metal droplets on a movable substrate with 5micron positional accuracy, it is possible to realise accurate tin and silver 2D structures. The adhesion of the droplets on the target substrates (Cu and dielectric materials) and the drop-on-drop bonding of tin and silver will be then discussed. Finally, it will be shown that by printing multiple different layers, complex, low to medium volume 3D structures for a wide variety of applications can be created.