2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Process Development: Wire Arc AM
Program Organizers: Joseph Beaman, University of Texas at Austin
Wednesday 8:00 AM
August 14, 2024
Room: 415 AB
Location: Hilton Austin
Session Chair: Joseph Beaman, University of Texas at Austin
8:00 AM
In-Situ Print Layer Height Correction Framework for Wire Arc Additive Manufacturing: Wei Sheng Lim1; Siddharth Ganesh1; Gim Song Soh1; 1Singapore University of Technology and Design
Wire arc additive manufacturing (WAAM) is a form of layered manufacturing method which relies on predictable deposition of weld beads layers upon layers to form a final part. Within a layer, utilization of variable bead width toolpath planning has been shown to produce geometrically accurate void free shape. However, due to the inherit variability of the WAAM process, print height deviations can still occur which causes uneven surface deposition within a layer. Without intervention, this error would stack with each layer and lead to print failure. To overcome this issue, a variable bead width and height process control framework was developed. This approach utilizes a profile sensor to determine the height variation of a print layer and correct for the height difference at the next layer toolpath using a regression based bead-width process parameter model. An example part is printed to test and verify the feasibility of the framework.
8:20 AM
Design of a Novel TZM Alloy Tool for use in the Additive Friction Stir Deposition of 7XXX Series Aluminum Alloys: Matthew Patterson1; 1University of Tennessee
Additive friction stir deposition is an emerging solid state metal additive manufacturing process which feeds a consumable material through a spinning tool. The friction generated at the tool surface plasticizes the material allowing it to be deposited layer by layer. Each material undergoes a unique thermal-mechanical process during plasticization, making tool design essential for the development of AFSD for new materials. Parameters such as material strength, diffusion rate, oxidation, and thermal conductivity are critical for maximizing tool lifespan and material compatibility. Depositing 7XXX aluminum alloys with current tools requires the use of a lubricate which contaminates the deposited material. Without the lubricant, the deposit material will bind inside of the tool. This work investigates the use of TZM molybdenum alloy to increase tool cooling and eliminate material binding. Additionally, a tungsten disulfide coating inside the tool was also employed to prevent the oxidation of TZM and increase tool life.
8:40 AM
Optimizing Molten Metal Deposition (MMD) for Aluminum Alloys: A Synergetic Approach of Finite Element and Experimental Study: Jan De Pauw1; Chola Elangeswaran1; Jonas Galle1; Ellard Hoekstra2; Davoud Jafari2; 1ValCUN; 2UTwente
Molten Metal Deposition (MMD) is a novel wire-based metal additive manufacturing (AM) technique with an initial focus on aluminium. MMD involves the direct liquefaction and deposition of wire feedstock onto a heated substrate. This method eliminates the need for auxiliary energy sources like lasers, binders, or support structures, thereby reducing thermal stress and enhancing process efficiency. MMD is particularly suited for the production of high-strength aluminium alloys in the 6xxx and 7xxx series. To optimize the parameters of this process, a detailed finite element analysis (FEA) is performed using an element-birth technique to accurately simulate the dynamic conditions during deposition. Following this, experimental validation of the thermal profiles of the components is carried out to ensure consistency with the simulated results. An extensive design of experiments is performed to obtain the optimum process parameters. The study demonstrates the potential of MMD to fabricate components with diverse geometrical configurations effectively.
9:00 AM
In-Situ Layer-Wise Generation of 3D Thermal Point Clouds for AM via Embedded 3D Scanning and Thermal Data Fusion: Tadeusz Kosmal1; Bemnet Molla1; Henry Claesson1; Samuel Pratt1; Christopher Williams1; 1Virginia Tech DREAMS Lab
Additive Manufacturing (AM) processes pattern heat and/or material to construct part geometries in a layer-wise manner. Understanding heat location and its flux throughout a build process is critical because it affects deposition geometry, final material properties, and throughput. In-situ metrology of thermal history in AM is important; however, existing thermal measurement techniques rely on single point measurements (e.g., thermocouple) or a planar thermography of the part, which limit spatial understanding of a part’s thermal history. To capture a complete “thermal” Digital Twin of a part during construction, the authors combine in-situ 3D scanning and thermography to form layer-wise “thermal point clouds”. A novel calibration methodology is presented that fuses thermography results with high resolution (< 0.3mm) Structured Light scans to obtain part thermal history at resolutions (< 3mm) required in manufacturing. The proposed methodology is integrated in wire-arc directed energy deposition and validated against single point measurements from embedded thermocouples.