Additive Manufacturing of Large-scale Metallic Components: Novel Applications I/Computation and Numerical Approaches
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee
Program Organizers: Sougata Roy, Iowa State University; Sneha Prabha Narra, Carnegie Mellon University; Andrzej Nycz, Oak Ridge National Laboratory; Yousub Lee, Oak Ridge National Laboratory; Chantal Sudbrack, National Energy Technology Laboratory; Albert To, University of Pittsburgh; Yashwanth Bandari, AddiTec Technologies LLC

Thursday 8:30 AM
March 23, 2023
Room: 25A
Location: SDCC

Session Chair: Yousub Lee, Oak Ridge National Laboratory


8:30 AM  
Rapid Qualification of Wire Feed Direct Energy Deposition Process Builds Using ICME Approach: Amit Verma1; Andrew Huck2; Rajib Halder2; Anthony Rollet2; 1Carnegie Mellon University; LLNL; 2Carnegie Mellon University
    While qualification is the end user prerogative, metal additive manufacturing (AM), in its current state, does present unique challenges that open up room for ICME (Integrated Computational Materials Engineering) tools. Finding the right set of parameters for a particular combination of feedstock, final geometry, AM platform, and other design requirements is still an iterative process. Currently, a suite of ICME tools in conjunction with in-situ process monitoring supported by artificial intelligence (AI) tools provides a range of opportunities. This talk will focus on the Wire feed Direct Energy Deposition AM process, applied to Ti-6Al-4V, for which we employed a host of modeling and simulation tools, along with in-situ process monitoring, to accelerate the qualification process. This includes, but is not limited to, thermodynamics & kinetics based microstructure evolution models, reduced order thermal models, constitutive models to predict mechanical properties, etc.

8:50 AM  
Process-Property Determination of Hot-Wire Laser DED Stainless Steel 316L Using Two Print Directions: Holly Martin1; Brandon Koenig1; Bharat Yelamanchi1; Andrew Prokop1; Brian Vuksanovich1; John Carballo1; Jackie Ruller1; Pedro Cortes1; 1Youngstown State University
    Hybrid manufacturing, which combines additive and subtractive manufacturing, allows for the complexities of additive manufacturing along with the finish and accuracies of subtractive manufacturing. Hot wire-laser direct energy deposition uses a metal wire, which can either be the same alloy or a different alloy as the base metal, to build the desired shape, or repair a damaged tool. Optimizing the printing process, to include direction of the wire in each layer, and examining the process-property relationships is important, especially if this technique is to be utilized to repair damage tools for continued use. The research presented here will compare SS316L specimens printed unidirectional, with the wire only moving along one axis, and bi-directional, with the wire moving along either the x or y axes. Mechanical properties, including tension and hardness, porosity, and coefficient of thermal expansion will be determined and compared to determine how print direction affects properties.

9:10 AM  
Dehydrogenation Model for Hydrogen-based Heat Treatments of Large Additively Manufactured Components: James Paramore1; Michael Hurst1; Matthew Dunstan1; Daniel Lewis2; Brady Butler1; 1DEVCOM Army Research Laboratory; 2Texas A&M University
    Thermo-Hydrogen Refinement of Microstructure (THRM) is a simple heat treatment, which has been shown to be an effective post-process for additively manufactured titanium alloys. During THRM, a component is charged with hydrogen to allow unique phase transformations and microstructural engineering, and then dehydrogenated to prevent hydrogen embrittlement. Predicting necessary dehydrogenation times is particularly problematic for large components, as the large amount of hydrogen evolved is constantly changing the partial pressure inside the furnace. Therefore, a Fickian diffusion model of the process has boundary conditions that are dependent on the instantaneous flux of hydrogen from the surface (i.e., dependent on the instantaneous concentration profile within the component). Modeling techniques for dealing with this challenge for components with > 5 cm cross-sections will be discussed. While this effort was focused on additively manufactured titanium components, the model and methods to experimentally identify model inputs are applicable to many diffusion-limited, gas-solid reactions.

9:30 AM  
Mitigating Large Distortion in Wire Arc Additive Manufacturing via Topology Optimization and Modified Inherent Strain Modeling: Wen Dong1; Xavier Jimenez1; Albert To1; 1University of Pittsburgh
    Applying wire arc additive manufacturing (WAAM) to manufacture large-scale metallic products is growing. However, due to the large part size and intensive energy input, the heat accumulation during the WAAM deposition is significant, resulting in extensive residual stress and distortion in the deposit and base plate. In the present work, an extra fixture is installed beneath the base plate to prevent structural distortion and ensure post-processing feasibility. The fixture design is based on topology optimization with the objective of compliance minimization. In each iteration, the temperature-dependent modified inherent strain (MIS) method is used to apply the load by simulating the deposition process. Using these methods, the fixture design produced is shown to reduce the distortion of the component by over 90%, demonstrating the effectiveness of the approach.

9:50 AM Break

10:10 AM  
Analysis of Bead Geometry and Solidification Behavior during Laser-Wire Directed Energy Deposition: Mohsen Eshraghi1; Matthew Engquist1; Amir Shakibi1; 1California State University-Los Angeles
    Direct energy deposition (DED) is a type of additive manufacturing process utilizing powder, wire or a combination of the two as feedstock. DED is notable for its high deposition rate and is capable of producing large-scale complex functional parts and thin walls. Typically, a set of optimized processing parameters is provided on a material or 3D printer basis. It is crucial to understand the effects of different process parameters on the bead geometry and solidification behavior to be able to minimize the defects and improve the mechanical properties of the additively manufactured products. In this study, 316L stainless steel samples are manufactured using a laser-wire DED system equipped with a six-beam laser head with coaxial wire feed. The influence of processing parameters on the bead geometry and solidification microstructure is analyzed and discussed.

10:30 AM  
Steel-copper Functionally Graded Material Produced by Twin-wire and Arc Additive Manufacturing (T-WAAM): Joao Oliveira1; 1FCT-UNL
    A functionally graded material (FGM) based on a Cu-based alloy and HSLA steel was fabricated by twin-wire and arc additive manufacturing (T-WAAM) . Copper and steel parts are of interest in many industries since they can combine high thermal/electrical conductivity with excellent mechanical properties. Mixing copper with steel is difficult due to mismatches in the coefficient of thermal expansion, in the melting temperature, and crystal structure. Moreover, the existence of a miscibility gap during solidification, when the melt is undercooled, causes serious phase separation and segregation during solidification which affects the mechanical properties. Copper and steel control samples and the FGM were fabricated and investigated using optical microscopy, scanning electron microscopy, and high energy synchrotron X-ray diffraction. A smooth gradient of hardness and electric conductivity along the FGM was obtained. An ultimate tensile strength of 690 MPa and an elongation at fracture of 16.6% were measured in the FGM part.

10:50 AM  
Structure-property-processing Relationship of 3D Printed Metals via Hot Wire Direct Energy Deposition: Bharat Yelamanchi1; Andrew Prokop1; Brian Vuksanovich1; John Carballo1; Jackie Ruller1; Brandon Koenig1; Holly Martin1; Pedro Cortes1; 1Youngstown State University
    The present work has explored the use of a hot wire-laser direct energy deposition process to produce metallic parts based on a hybrid manufacturing. This hybrid approach combines the simultaneous benefits of additive manufacturing (complex geometries, part consolidation, and mass customization) with the advantages of subtractive manufacturing (superior surface finish and enhanced dimensional accuracies) by integrating a suite of complementary traditional processes. This research program has studied the fundamental processing-property relationships of printed metals, with a particular interest on Invar-36 due to its low coefficient of thermal expansion performance, which is a feature of great interest on the production of composite tooling. Here, the effect of its printing parameters and tool paths have been investigated in terms of its mechanical-thermal properties. These results have provided the basic understanding of hybrid manufacturing, which is being expanded on the production of tooling parts for the automotive and aerospace sector.

11:10 AM  
Wire Arc Additive Manufacturing (WAAM) of Nano-Treated High Strength Aluminum Alloys: Yitian Chi1; Shuaihang Pan1; Maximillian Liese1; Narayanan Murali1; Jingke Liu1; Xiaochun Li1; 1University of California Los Angeles
    High-strength aluminum alloys such as AA7075 and AA2024 have drawn enormous attention from both industry and academia owing to their high specific strength and good fatigue resistance. Additive manufacturing (AM) can achieve significant weight savings with only minor compromises in strength if high-performance wrought aluminum alloys are used as feedstock. Despite the advantages in strength that aluminum alloys offer, they cannot be manufactured via fusion-based printing because of hot cracking and other solidification problems. Nano-treating is an emerging nanotech metallurgy method that uses a small fraction of nanoparticles to enhance alloy manufacturability and properties. This work successfully used wire-arc additive manufacturing to print nano-treated AA7075 and AA2024 components. The resulting parts were crack-free with exceptional grain morphology and superior mechanical properties. Due to the excellent size control capabilities with nanoparticles, a homogeneous distribution of small grains was maintained in all deposited layers even during the repeated thermal cycles.