2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Special Session: Wire-fed AM II
Program Organizers: Joseph Beaman, University of Texas at Austin
Tuesday 8:00 AM
August 13, 2024
Room: 400/402
Location: Hilton Austin
Session Chair: Bradley Jared, University of Tennessee, Knoxville
8:00 AM
High Deposition Rate Process Development for Wire-Arc Additive Manufacturing - 100lb/h: Andrzej Nycz1; Chris Masuo1; William Carter1; Luke Meyer1; Yukinori Yamamoto1; Nathan Lambert1; Michael Sebok1; Canhai Lai1; Alex Walters1; Jonathan Paul2; Jason Flamm2; 1Oak Ridge National Laboratory; 2Lincoln Electric
Wire-arc deposition process in one of the main technologies considered in replacement and augmentation of manufacturing large castings and forgings. Even though it is highly scalable, when it comes to creating objects weighing thousands of pounds, the time to produce the component may take weeks or months. ORNL partnered with Lincoln Electric to develop and test a system to break the barrier of 100lb/h. This work will present the unique challenges in developing a multi head system with prototype deposition torches using Inconel 625 as a test feedstock.
8:20 AM
Highly Productive Multi-Material Laser Wire DED: Frank Brueckner1; Marc Kaubisch2; Holger Hillig2; Irina Shakhverdova2; Francesco Bruzzo2; Elena Lopez2; Marko Seifert2; Christoph Leyens3; 1Fraunhofer Institute for Material and Beam Technology IWS/ Lulea University of Technology; 2Fraunhofer Institute for Material and Beam Technology IWS; 3Fraunhofer Institute for Material and Beam Technology IWS/ Institute of Materials Science
In order to achieve increased market penetration of laser-based DED, significantly greater process efficiency, consistently shorter process times and thus greatly reduced costs are required while keeping high quality. Market entry barriers can also be avoided by enabling new functionalities, e.g. simultaneous multi-material applications for composites or insitu alloying.In this contribution, the recently developed COAXquattro multi-wire process unit will be used to realize coatings, repair purposes as well as the production of complete new parts. With the help of this wire-based DED configuration, it is possible to easily achieve coating rates in the double-digit kilogram range per hour using up to eight simultaneously added materials. It can handle up to four wires and/or four powder materials at once while resulting in a finely dispersed material distribution after deposition. In addition to latest results of different material combinations, (potential) applications will also be shown.
8:40 AM
Implementation of Tool Shifts for 410 NiMo Overhang Structures in Wire-Arc Additive Manufacturing (WAAM): Michael Sebok1; Chris Masuo1; Nathan Lambert1; William Carter1; Alex Walters1; Andrzej Nycz1; Riley Wallace1; 1Oak Ridge National Laboratory
The wire-arc additive manufacturing (WAAM) process is highly sensitive to the spacing between deposited bead segments due to both the high thermal input of the process and inverted parabolic shape of beads. Perimeter beads deposited at high overhang angles with the same process parameters as a fully supported bead will fail due to gravitational effects. However, it is possible to modulate the bead spacing without adjusting other process settings to accurately deposit these overhang segments. This torch shift accounts for the gravitational effects on the melt pool in overhang segments so that the material will fill the desired geometrical bounds. In this work, a torch shift model is developed for printing overhangs in 410 NiMo Steel which improves surface finish of overhang segments across a selection of increasing overhang angles. Using this model, demonstration walls were printed with overhangs of ≥ 25 degrees without major degradation of the part geometry.
9:00 AM
Influence of Interlayer Mechanical Work on Microstructure and Mechanical Performance of Super Duplex Stainless Steel Deposited Using Wire Direct Energy Deposition Process: Paul Poulain1; Jun Wang2; Salima Bouvier3; Yao Lu2; Navid Niknafsabrbekooh2; Serhiy Budnyk4; Aleksandra Gavrilovic-Wohlmuther4; Stewart Williams2; 1Cranfield University; Université de technologie de Compiègne, Roberval (Mechanics, energy and electricity),; 2Cranfield University; 3University of Technology of Compiègne; 4Christof Group
Super Duplex Stainless Steels (SDSS) manufactured by Wire Direct Energy Deposition (WDED) often exhibit typical course columnar grain structures and undesirable phase balance, leading to anisotropy and detrimental mechanical performance. In this investigation, interlayer mechanical works, including High-Pressure Rolling (HPR) and Machine Hammer Peening (MHP), were applied during the WDED process of SDSS. Three single-pass walls were deposited using plasma transferred arc WDED process with different interlayer conditions: no interlayer deformation (control group); interlayer HPR with force of 75 kN; interlayer MHP with a frequency of 36 Hz and energy per impact of 6 J. Interlayer mechanical work changes the microstructure from coarse columnar to fine equiaxed. Interlayer mechanical work resulted in austenite grains dispersion and columnar ferrite grains fragmentation. Despite this, there was only a minor impact on the overall phase balance.These findings demonstrate the benefits of interlayer mechanical work in the WDED process of SDSS.
9:20 AM
Wire Feed Speed Based Layer Height Controller for Wire Arc Additive Manufacturing: Zaky Hussein1; Kyle Saleeby2; Christopher Saldana1; 1Georgia Institute of Technology; 2Georgia Tech Manufacturing Institute
This work investigates the implementation and performance of a wire feed speed-based layer height controller to minimize error in Z-direction and thus the contact tip to work piece distance (CTWD) and associated changes in arc characteristics. A wire feed speed-based controller only requires changes to welding parameters to mitigate over-building or under-building and there is no need to change motion platform parameters allowing for simpler implementation. Single weld tracks were deposited with known height errors at various wire feed speeds and a regression model was trained to predict the current CTWD and part height from arc data and a given wire feed speed. A series of experiments were performed to tune a proportional-integral controller to modify the wire feed speed based off feedback from arc data. Controller performance was evaluated by comparing the variation in CTWD, average layer height, surface waviness and peak-to-valley surface roughness.
9:40 AM Break
10:00 AM
Geometric Repeatability Study for Robotic WAAM of Aluminum: Kamren Sargent1; Hutchison Peter1; Joshua Penney1; Tony Schmitz1; 1University of Tennessee
This paper evaluates the geometric and property repeatability of components printed by robotic wire arc additive manufacturing (WAAM). The WAAM system includes a KUKA KR 50 R2500 robot with a Fronius TPS 4000 welder. Gas metal arc welding (GMAW) is used for layer-by-layer deposition of ER4943-aluminum wire. A single geometry is printed five times using the same part plan, weld settings, and wire. The repeatability of the geometry and mechanical properties are then evaluated. For geometry, each component is measured using structured light scanning, 3D models are generated, and the deviations between each print are determined. For mechanical properties, tensile specimens are extracted using the ASTM E8 subsize tensile specimen standard. Tensile testing is then performed to determine the tensile strength, yield strength, and elongation. Experimental results are provided, and comparisons are drawn.
10:20 AM
Symmetric Build Plate Deposition: A Strategy to Mitigate Solidification-Induced Residual Stresses in DED-Arc Additive Manufacturing: Henry Claesson1; Isaac Rogers1; Tadek Kosmal1; Christopher Williams1; 1Virginia Tech
Directed Energy Deposition (DED-arc) additive manufacturing (AM) provides an economical approach for fabricating near-net-shaped, large metal components. Due to high-heat input and rapid solidification, DED-Arc processes can induce residual stresses during printing, which often result in build failures characterized by build plate warping and layer delamination. These failures predominantly arise from asymmetric stresses imposed on the build plate and on the part, given that only the active printing (top) surface experiences melting and solidification. To address these challenges, this study investigates residual stress propagation when parts are designed with symmetric geometric features on both sides of the build plate. Specifically, an 8-DOF multi-axis DED-arc toolpath is used to symmetrically complete the layerwise printing process; build plate strain measurements, temporal evolution of part temperature profiles, and in-situ 3D scanning of the printed part during printing are used to analyze the approach.
10:40 AM
Titanium Wire Arc Additive Manufacturing Inert Enclosure and Material Handling Safety Considerations: Harold Walters1; Kat Brand1; Brittany Herman1; Dan Johnson1; Brian Gibson1; Andrzej Nycz1; Chris Masuo1; William Carter1; Michael Sebok1; Nathan Lambert1; Riley Wallace1; 1Oak Ridge National Laboratory
Metal inert gas (MIG) wire arc additive manufacturing (WAAM) is a well-established process that uses MIG welders mounted on robotic arms to deposit weld beads along a given toolpath and stack layer-over-layer of weld to create a 3D geometry. Titanium WAAM requires an inert enclosure be utilized to protect the weld deposit from oxygen entrainment. The welding process creates a pyrophoric titanium soot residue around the deposit. This soot must be contained by a soot collection system that is paired with the inert enclosure system; residual soot must be accounted for during the part cleaning and removal procedure. This presentation will address the additional hardware and operational safety procedures specific to the titanium WAAM process.
11:00 AM
Weave or Not to Weave in Wire Arc Additive Manufacturing: Stevens Hill1; Bishal Silwal1; Hossein Taheri1; Jared Seals1; 1Georgia Southern University
Wire-Arc-Additive-Manufacturing shows promise as a manufacturing method for large structures. However, careful control of material properties is required due to the number of process variables involved. Traditional welding techniques employ many different weaving methods to produce various weld properties in different situations. The effect of these weave patterns on the porosity and tensile strength of the produced prints is studied to determine if a relationship exists been print weave settings and the porosity of printed samples. Walls which have been manufactured using Wire-Arc-Additive-Manufacturing are analyzed using SEM and image analysis software to quantify sample porosity. Similar samples undergo tension testing to determine if the yield point of the samples is affected by weave conditions.
11:20 AM
Wire Arc Additive Manufacturing of Multi-material Parts Using H-13 Tool Steel: Nathan Lambert1; Andrzej Nycz1; Chris Masuo1; William Carter1; Riley Wallace1; Alex Walters1; 1Oak Ridge National Laboratory
H-13 tools steel’s relative hardness, resistance to thermal fatigue, and high tolerance of thermal shock, make it very desirable for use in forging, pressing, and extrusion processes. H-13 is however typically very expensive when compared to other steel compositions making it desirable to encase a lower cost alloy with H-13. This configuration allows for the benefits of H-13 tooling to be realized, at a considerably reduced cost. To demonstrate the viability of this concept, a pressing tool was fabricated using a Wire Arc Additive Manufacturing (WAAM) process. Initial materials testing was conducted on a multi-material wall consisting of one section of H-13 tool steel, and one section of 410NiNo. This testing generated favorable results and subsequently a pressing tool was fabricated for evaluation. Utilization of a Multi-Material WAAM process to fabricate large tooling in this manner could yield significant improvements in material cost, manufacturing agility, and supply chain complexity.