Late News Poster Session: Additive Technologies
Program Organizers: TMS Administration
Monday 5:30 PM
March 20, 2023
Room: Exhibit Hall G
Location: SDCC
3-D Printed Storage Container for Nuclear Materials: Tyler Brunstein1; Nuggehalli Ravindra1; 1New Jersey Institute of Technology
This paper investigates the material behavior of commonly used 3D printed polymers and monomers when exposed to Beta and Gamma radiation. By utilizing a Torbernite mineral sample, the radiation shielding properties of various storage materials are explored. The materials tested in this paper are Nylon 6 30% glass fill, SLS Nylon 12, Polylactic Acid, ABS, Polyetheretherketone and photopolymer resins. By studying the impact of X-rays, a low cost alternative for radiation shielding, that does not require harmful materials such as lead or expensive machining, is presented. Preliminary testing has shown that polylactic acid and photopolymer resins provide significant radiation shielding. The study will also provide useful data on the radiation effects of 3D printed parts for use in surgery and medical storage.
A-61: Additive Manufacturing of Aluminum Alloys via Liquid Metal Jetting: Kellen Traxel1; Nicholas Watkins1; Eric Elton1; Viktor Sukhotskiy1; Alex Wilson-Heid1; Andrew Pascall1; Jason Jeffries1; 1Lawrence Livermore National Laboratory
Liquid metal jetting is an emerging metal additive manufacturing (AM) process requiring only solid metal feedstock to produce fully-dense parts through jetting molten metal droplets onto a moving platform. While opening a large application space due to a wide array of acceptable feedstock types, challenges related to part quality, processability, and limited understanding of printed properties limit industrial use. More specifically, droplet impingement on the build substrate, coalescence between adjacent droplets and solidification, as well as the chosen processing parameters can generate variations in both surface and bulk part characteristics which are not well understood. We present results of printing studies where aluminum alloy Al4008 was jetted onto metallic substrates at various processing parameters such as ejection frequency, spacing between droplets, hatch spacing, and the build plate surface temperature. Our results help manufacturers and researchers working to develop non-powder-based metal additive manufacturing methods. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-843103-DRAFT.
A-62: Additive Manufacturing of Functionally Graded Soft Magnetic Alloys: Jesse Adamczyk1; Erin Barrick1; Samad Firdosy2; Nichole Valdez1; Andrew Kustas1; 1Sandia National Laboratories; 2NASA Jet Propulsion Laboratory
Soft magnetic alloys produced by additive manufacturing can overcome many of the challenges associated with conventional metallurgical processing. Functional grading between brittle Fe-Co (BCC) and lower-saturation Ni-Fe (FCC) alloys through laser engineered net shaping (LENS) can enhance functional properties beyond those of the individual alloys. This work focuses on how grading between Fe49Co49V2 and Ni80Fe16Mo4 affects the microstructure, crystal structure, and magnetic properties. Grading results in a refined microstructure, however, post-build thermal treatments are found to promote recrystallization and grain growth, leading to improved magnetic properties. Analysis of the crystal structures provides an understanding of the solubility limits between the BCC and FCC structures. Success in functional grading of these soft magnets provides a pathway towards improved power conversion efficiency and application of multimaterial additive manufacturing.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
Additive Manufacturing of Nitinol Parts via Optimised Laser-powder Bed Fusion: Muhannad Ahmed Obeidi1; Dermot Brabazon1; 1Dublin City University
Nitinol alloys are widely used in biomedical and aerospace. They exhibit unique properties as super-elastic or shape-memory-alloys (SMA) which depend on their chemical composition and the Ni-Ti ratio. It is known that this ratio depends on the initial chemical composition of the alloy, but also the level of the input thermal energy because the latter can highly affect the evaporation of nickel in the final part. Producing mechanical parts from this alloy is more controlled when using traditional manufacturing techniques compared to Additive Manufacturing (AM). This study is focused on comparing the chemical composition of NiTi parts produced by using the laser continuous mode (CM) versus pulse mode (PM). The same metal printer and the metal powder batch were used. The parts produced by PM showed stable chemical composition with significant mechanical parts. Tough and brittle compression performance accompanied by catastrophic fracture was noted on the PM manufactured parts
A-63: Additive Manufacturing of TiNiSn Half-Heusler Thermoelectric Compound: Seoung-Ho Lim1; Pyuck-Pa Choi1; Chanwon Jung2; 1Korea Advanced Institute of Science and Technology; 2Max-Planck-Institut für Eisenforschung
Additive manufacturing (AM) has advantages for fabricating complex and customized parts with a single work step. Thus, it is expected to be a new technique to enhance the productivity of thermoelectric devices having diverse shapes. However, studies on producing the half-Heulser thermoelectric compound with AM are not developed well due to the printability issue. Severe thermal distortion from low thermal conductivity is the main obstacle for AM applications. This study describes producing TiNiSn half-Heusler compound with laser-aided directed energy deposition and blending pure Sn powder with pre-alloyed powder until the TiNiSn stoichiometric balance was a strategy to overcome printability issues. The phase and microstructure of the AM-produced specimens were analyzed to discuss the effect of Sn blending. Finally, thermoelectric properties were measured and discussed.
A-64: As-Deposited Microstructure and Strain Rate Dependence of Aluminum Alloy 7020 Produced via Additive Friction Stir Deposition: Malcolm Williams1; Brian Jordon1; Paul Allison1; 1Baylor University
In this research, the feasibility of using the solid-state additive manufacturing (AM) process, additive friction stir deposition (AFSD), is studied as a suitable technology for creating components using aluminum alloy 7020. Using one set of the acceptable processing conditions, a large fully-dense 65 mm tall build was successful created. Tensile specimens were extracted from the as-deposited component to evaluate the quasi-static (0.001/s) and high-rate (1500/s) tensile strength and to characterize microstructure evolution. The AFSD AA7020 component exhibited a highly refined and equiaxed grain structure as compared to the feedstock material. In the quasi-static regime, the as-deposited AA7020 had a diminished YS and UTS when compared to the T651 feedstock material, however, in the high-rate regime the as-deposited material performed similar to the feedstock material. The present study indicates how AFSD technology can be implemented for the effective deposition of structural AA7020 components without hot-cracking or loss of alloying elements.
A-65: Challenges in the Production of Duplex and Martensitic Stainless Steels: Martina Koukolikova1; Pavel Podaný1; Sylwia Rzepa1; Michal Brázda1; Aleksandra Kocijan2; 1COMTES FHT a.s.; 2Institute of Metals and Technology (IMT)
Duplex and martensitic stainless steels are both excellent choices for materials with outstanding corrosion resistance and mechanical properties. However, there are still some challenges associated especially with their production. Functionally graded materials (FGMs) are a class of materials that have been developed to take advantage of the unique properties of individual metal components. Additive manufacturing of FGMs is a process that has been gaining popularity in recent years due to its ability to create components with multiple materials. One type of AM system that has shown promise for creating multi-material parts is SAF 2507 and 15-5PH steels. Recent advances in AM technology have made it possible to produce these materials with the required properties, without the use of filler materials, ensuring a high-quality metallurgical joint between dissimilar materials while minimizing thermal damage to the surrounding material.
A-84: Drop-on-demand Metal Jetting: Direct 3D Printing of Silver: Negar Gilani1; Nesma Aboulkhair1; Marco Simonelli1; Mark East1; Ian Ashcroft1; Richard Hague1; 1University of Nottingham
Drop-on-demand metal jetting promises new avenues in the direct fabrication of complex single- and multi-metal components at a resolution not achievable with more common AM metal techniques. Due to the droplet-by-droplet nature of the process, insights into the individual droplets’ behaviour are of fundamental importance since they define the consistency and quality of printed parts. Here, we present an integrated computational, analytical, and experimental approach to investigate the droplet’s dynamics and solidification during deposition, the microstructure evolution, and the interface formation. Our study shows that droplet morphology resulted from a complex interplay between impact hydrodynamics and solidification dynamics. Furthermore, the effects of substrate and droplet temperatures on the droplets’ morphology, microstructure, inter-droplet, and droplet-to-substrate bonding were investigated. Based on these findings, a solution was successfully employed to eradicate the previously-reported lack of consolidation between silver droplets. These results represent a step forward in the direct printing of functional multi-metal components.
A-66: Fatigue Life Predictions of Additive Friction Stir Deposition Repairs using a Smooth Particle Hydrodynamic Model: Nick Palya1; 1Baylor
A Smooth Particle Hydrodynamic (SPH) simulation of an Additive Friction Stir Deposition (AFSD) repair was used to inform a multiscale approach to predicting the fatigue life of a high strength aluminum alloy. The AFSD process is a solid-state layer-by-layer additive manufacturing approach in which a hollow tool containing feedstock is used to deposit material. Elevated temperatures and strain rates associated with severe plastic deformation processes (SPDP) make accurate collection of experimental data within AFSD difficult. An understanding of the evolving microstructures is necessary to predict material performance. Without the ability to experimentally determine material history within the AFSD process, a smooth particle hydrodynamic (SPH) model was employed to predict the thermomechanical history. This SPH simulation of AFSD allowed material history predictions to be used in with existing microstructure and fatigue models to predict the fatigue life of an AFSD repair in a 7075 aluminum alloy.
A-67: Heat Treatment Effects on Microstructure and Mechanical Properties of Wire Arc Additively Manufactured (WAAM) and Electron Beam Additively Manufactured (EBAM) Ti-6Al-4V: Hannah Sims1; Jonathan Pegues2; Natalia Saiz2; Shaun Whetten2; Andrew Kustas2; 1Sandia National Laboratoriess; 2Sandia National Laboratories
Wire directed energy deposition (W-DED) is a common additive manufacturing (AM) process for large format titanium components. Two of the most common W-DED processes are Wire Arc Additive Manufacturing (WAAM) and Electron Beam Additive Manufacturing (EBAM). W-DED processes of Ti-6Al-4V have been shown to form large columnar prior beta grains that encourage continuous alpha grain formation along the grain boundaries which often results in severe anisotropy and low ductility. This work explores several heat treatments, including HIP, to understand if convincing benefits to the resulting microstructure and tensile properties of WAAM and EBAM Ti-6Al-4V could be obtained. Mechanical properties were found through a high throughput tensile testing procedure in order to generate statistically relevant data sets. Mechanical property results will be discussed in context of microstructural evolution and will be compared to conventionally processed Ti-6Al-4V.Sandia National Laboratories is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
Improved Cryogenic Tensile Properties of Additive Manufacturing-processed STS316L Steel by the Reuse of Powder: Chohyeon Lee1; Taekwan Koo1; Muhammad Ishtiaq1; Hyoungseop Kim2; Jaebok Seol1; 1Gyeongsang National University; 2Pohang University of Science and Engineering
Laser powder bed fusion (L-PBF) has attracted great interest in the aerospace sectors, because it can produce complex parts with high accuracy. In the L-PBF of metallic materials, costs and material yields strongly depend on the ability to reuse powder efficiently. However, some of the powders are exposed to high temperatures during the manufacturing process resulting in an alteration of the feedstock properties if it reused. Therefore, in order to investigate the change of the powder during the process and the effect of the powder on the laminated parts, we tried to investigate the effect of reused STS316L powders on the mechanical properties of their printed products under 298 and 77 K conditions. The powders were used, collected, sieved, and reused up to 6 times with all steps from the original powder.
A-68: Investigation of the Simple Layer Made by Additive Manufacturing on Forging Tools: Miroslav Urbánek1; 1COMTES FHT
Forging tools are loaded by temperature and mechanical press on their working surfaces, therefore these surfaces need to have higher resistance to external influences. A simple material layer made by Additive Manufacturing using Directed Energy Deposition (DED) can be used for increasing the service life of tools and dies. This paper focuses on protected layers made of nickel alloy Nimonic 80A, which appears suitable for these applications thanks to its properties. The price of Nimonic 80A is higher than tool steels, so it is advisable to apply this material in a small volume as a protected layer. The powder characterization, depositing parameters definition, mechanical properties measurement, hardness measurements, and microstructure evaluation was investigated. The forging processes were simulated using FE analysis in order to optimize the depth of the protected layer. The in-service fatigue tests were done in the production line in the forge.
A-69: Leveraging Spatial Gradation in Lattice Structure Development for Enhanced Energy Absorption from High Rate Loads: David Failla1; Haley Petersen1; Matthew Priddy1; Zackery McClelland2; 1Mississippi State University; 2U.S. Army Engineer Research and Development Center
This effort demonstrates the efficacy of strut diameter variation on the energy absorption capacity of additively manufactured (AM) body-centered cubic with Z-strut (BCCZ) stacked lattice structures for high-rate impact. By interchanging the internal geometry of a bulk part with lattice structures the failure mechanics of the lattice can be leveraged for stretch-dominated failure to increase energy absorption capacity or buckle-dominated failure for an increase in bulk strength with reduced weight. By combining finite element method predictions and results from experimental techniques, AM 316L BCCZ unit cell lattice structures fabricated via laser powder bed fusion are designed with independently varied strut diameters and characterized for high strain-rate applications. Down-selected unit cells were stacked to develop a column structure with functionally graded properties from increased strength to increased energy absorption through the height. The final optimized stack structure will demonstrate enhanced energy absorption for high rate loads with a favorable load-to-weight ratio.
A-70: Metal AM with Green Lasers is Propelling the Next Generation of Space Exploration: Eliana Fu1; Marco Goebel1; Ulli Kraske1; 1Trumpf
Recent exciting developments in rocket engine propulsion have included copper alloy engine component manufacturing by metal AM, whether it be in C18150 (CuCrZr) or GR Cop. Copper alloy combustion chambers allow exceptional thermal conductivity and 3D printing will allow improved design and shortened lead time for the manufactured product. Most typical AM processes involving lasers all use IR (infrared) wavelengths to rapidly melt powder either blown powder or on a powder bed but in fact, green laser light at 515nm, as opposed to infrared (1030-1064nm) is more effective for copper and other highly reflective materials.Combining a green wavelength in a laser AM process and copper alloy powder results in a printed part with higher as-printed density, less spatter and better surface finish. The production efficiencies obtained with green lasers translate to bigger and better engines, improved thrust output and bigger payload or higher orbit that can be achieved.
Microstructural Characterization of Electron Beam Additively Manufactured (EBAM) and Wire Arc Additively Manufactured (WAAM) Ti-6Al-4V: Luis Jauregui1; Joseph Boro1; John Williard1; Robert Craig1; Timothy Ruggles1; Hannah Sims1; Jonathan Pegues1; 1Sandia National Laboratories
Wire-based Direct Energy Deposition (W-DED) is an attractive additive manufacturing (AM) process to replace conventional casting and forging methods due to its net shaping capability and low machining waste. Two common W-DED processes are electron beam additive manufacturing (EBAM) and wire arc additive manufacturing (WAAM). Despite their similarities, several key processing variables unique to each technology often produce different chemical and microstructural characteristics, resulting in variable mechanical properties. Characterizing and understanding these differences and how they impact mechanical performance is vital for advancing the adoption of W-DED AM. In this poster, we present our efforts to characterize and assess the microstructural and chemical influences on the resulting tensile properties for EBAM and WAAM processed Ti-6Al-4V. Results are discussed in the context of the complex process-structure-property relationships for W-DED processed Ti-6Al-4V. Sandia National Laboratories is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
A-71: Microstructure Prediction in Powder Bed Metal Additive Manufacturing Using Coupled Nucleation and Monte Carlo Method: Aashique Rezwan1; Theron Rodgers1; Daniel Moser1; 1Sandia National Laboratories
The mechanical properties and as built geometries of components produced with the laser powder bed fusion (LPBF) process can have significant variation. Predicting mechanical properties and determining their uncertainties is necessary for component qualification. This work presents a probabilistic prediction of microstructure due to the variable laser input in LPBF. The melt pool behavior, i.e., temperature and phase, is first predicted by a high-fidelity thermal fluid model. The microstructure size, shape and crystallographic texture is predicted by using a coupled grain nucleation and kinetic Monte Carlo model for grain growth, considering the variability due to model parameters. This analysis will provide a tool for designers to predict a generalized margin of design for the mechanical properties of additively manufactured parts.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
A-72: Neutron Diffraction Measurement of Residual Stresses in AFSD AA6061 Deposits: Ning Zhu1; Luke Brewer2; Brian Jordon1; Paul Allison1; 1Baylor University; 2The University of Alabama
This poster presents the correlation between processing parameters and residual stresses in AA6061 produced by additive friction stir deposition (AFSD). Although the distortion from solid-state additively manufacturing processes may be low due to substantial clamping of the workpiece, but this mechanical constraint may only serve to increase the residual stresses. In this study, three AFSD AA6061 deposits were built with varied traverse speeds and the residual stress distributions were analyzed via neutron diffraction method using the VULCAN instrument at Oak Ridge National Lab. In the deposit built with medium traverse speed (127 mm/min), the residual stresses were generally tensile between -5 and 91 MPa at the starting end and center region of the deposit, and the balancing compressive residual stresses were between 127 and -46 MPa at the finishing end. The measured residual stresses are still significant in light of the low yield strength of the AFSD deposits.
Cancelled
A-73: Physics-based Analytical Modeling of Defects Formation in Metal Additive Manufacturing: Wenjia Wang1; Oladayo Ariyo1; Wei Huang2; Aixi Zhou1; Steven Liang2; 1North Carolina Agricultural and Technical State University; 2Georgia Institute of Technology
Laser powder bed fusion (LPBF) can fabricate complex metallic products directly from digital models, which is superior to most traditional manufacturing technologies. However, it is still very challenging to avoid the defects formation and control part quality in LPBF. In this work, physics-based analytical modeling methods are developed to predict the formation of common defects (i.e., lack-of-fusion-induced void, keyhole-induced porosity) in laser powder bed fusion metal additive manufacturing. The influence of powder packing behavior, temperature-dependent material properties, process-dependent laser absorptivity, complex part geometry, complex scan strategies, and preheating temperature are all considered in the modeling process. The proposed models have been experimentally validated and show very good predictive accuracy and very high computational efficiency. Thus, they can work as efficient tools to conduct process optimization of LPBF to fabricate defects-free products.
A-74: Powder Particle Impact and Pore Release Behavior in Laser, Powder-blown Directed Energy Deposition: Samantha Webster1; Shuheng Liao2; Sanjana Subramaniam2; Jihoon Jeong2; Anchen Tong2; Rujing Zha2; Jian Cao2; 1NIST; 2Northwestern University
Process defects currently limit the use of additive manufacturing (AM) components in industry due to shorter fatigue life, potential for catastrophic failure, and lower strength. Conditions under which these defects form, and their mechanisms, are starting to be analyzed through in-situ, high-speed X-ray imaging of both laser powder bed fusion (LPBF) and directed energy deposition (DED). It is evident that the melt pool surface in powder blown DED will exhibit very dynamic behavior due to stochastic, violent powder delivery. In this study, highspeed X-ray imaging at the Advanced Photon Source was utilized in conjunction with a high through-put DED set-up to observe particle impact behavior and pore release at the melt pool surface. Initial observations of these phenomena and their potential implications on build quality will be presented.
A-75: Powder Spreading Mechanism in Laser Powder Bed Fusion Additive Manufacturing: Experiments and Computational Approach Using Discrete Element Method: Ummay Habiba1; Michael Fazzino1; Serge Nakhmanson1; Rainer Hebert1; 1University of Connecticut
Laser powder bed fusion (LPBF) additive manufacturing (AM) has been adopted by various industries as a novel manufacturing technology. Powder spreading is a crucial part of LPBF AM process that defines the quality of the fabricated objects. In this study, the impacts of various input parameters on the spread powder density and particle distribution during the powder spreading process are investigated using the DEM (discrete element method) simulation tool. The DEM simulations extend over several powder layers and are used to analyze the powder particle packing density variation in different layers and at different points along the longitudinal spreading direction. Additionally, this research covers experimental measurements of the density of the powder packing and the powder particle size distribution on the construction plate.
A-76: Recyclability Study of APO-BMI: Alexander Hatmaker1; 1Los Alamos National Laboratory
Selective laser sintering/melting is a powder and laser based additive manufacturing process. It can process many types of materials such as polymer, metal, ceramic, and composite and can make complex parts. This study will analyze the recyclability of APO-BMI powder to see how it degrades after multiple prints and how to best recycle it for multiple uses. It will utilize an EOS P450 to execute prints and a suite of TA instruments for thermal/powder analysis. Flowability of the powder will be a large factor of print quality, which is why conditioned powder is normally mixed with virgin at a 50/50 ratio. Different ratios will be mixed and examined to determine how much each affects the print quality.
A-77: Tooling Influence on Deposition Width in Additive Friction Stir Deposition of AA 6061: Isaac Liu1; Paul Allison1; Brian Jordon1; 1Baylor University
Additive friction stir deposition (AFSD) is a solid-state additive manufacturing process in which a rotating tool deposits a center-fed feedstock onto a substrate via plastic deformation. Tool geometry can affect the properties of the deposition. Previous studies in friction-stir welding suggest an increase in tool diameter leads to a larger contact area and thus larger deposition width. Furthermore, tool pin profile in friction-stir welding affect both the tensile properties and the size of the friction stir processed zone, as pin profile regulates material flow. Additive friction stir deposition, as opposed to friction stir welding, does not have pin profiles but can have tool protrusions. Minimal research has been done on the effect of tool geometry in additive friction stir deposition (AFSD). This research investigates that effect, specifically in the deposition of AA6061. Three different tool diameters are used, and the deposition width measured and compared normalized to input power.
A-78: Understanding Material Flow Behavior of Additive Friction Stir Deposition Using Smoothed Particle Hydrodynamics: Jacob Hoarston1; Kirk Fraser2; Brian Jordon1; Paul Allison1; 1Baylor University; 2National Reserach Council Canada
In this study, simulations of varying tool geometries were conducted through smoothed particle hydrodynamics (SPH) simulations of additive friction stir depositions (AFSD) in-order to elucidate deposition mechanics for AA6061. The simulations compared influence of tool face diameter changes, and the resulting thermo-mechanical behavior with a focus on material flow behavior and heat generation resulting from frictional forces and plastic deformation. The simulation results revealed a relative difference in resulting heat generation beneath the tool face from diameter changes. Additionally, results from the SPH simulations showed that changes in tool geometry and resulting heat generation produce different flash generation and deposition behaviors. The rotational, radial, and traverse flow interactions visualized by AFSD simulations explained the resulting changes in thermal heat generation and subsequent material flow changes during material deposition. The resulting simulations show how the meshless computational tools are able to elucidate material behavior in this solid-state thermomechanical AM process.
A-79: The Effect of Beam Shaping Strategies on Additively Manufactured Microstructures: Giovanni Orlandi1; Robert Moore1; Theron Rodgers2; Fadi Abdeljawad1; 1Clemson University; 2Sandia National Labs
In Laser Powder-Bed Fusion Additive Manufacturing (LPBF AM), Gaussian beams are known to result in narrow AM processing windows, outside of which undesired AM microstructures are commonly observed. Recent experimental evidence in beam shaping strategies points to new routes of manipulating the spatial distribution of temperatures, allowing for direct control over AM microstructures. Using a coupled thermal diffusion-Potts Monte Carlo model, we examined the impact of Gaussian, Ring, and Bessel-like laser beam types on the evolution of thermal profiles and grain microstructures. It is shown that Ring and Bessel-like beams extend the AM processing window, resulting in a higher diversity of melt pool geometries, spatial distribution of thermal gradients, and resultant microstructures. High throughput simulations are used to develop design maps relating laser beam shapes to temperature profiles and resultant microstructures. Our modeling framework provides an approach to rapidly screen the AM design space for the optimal processing windows.