071 - Production of Soft Magnetic Composite Material Using Cold Sintering Technique
Linsea Foster, Penn State University
Soft magnetic composites are materials under development for replacement of 2D laminates in electric motors. Maximization of the soft magnetic properties reduces the necessary volume and mass of material required, reducing cost and size in products such as electric vehicles. SMC production using electrically insulating coating poses an inherent tradeoff as retention of this coating is difficult while improving strength through annealing. This study investigates production of SMCs via cold sintering technique in the hopes to form insulating yet relatively strong SMC toroids. The technique, which utilizes surface modification of powders as an initial step towards strengthening of the material, is here used to also form an electrically insulating coating that gives the material its soft magnetic properties. Subsequently, powders are warm compacted to increase the strength of the material. Subsequent low-temperature heat treatment may also be utilized to further improve strength while minimizing breakdown of the insulating coating. Sample strength is tested using three-point bending tests, and microstructure is examined using scanning electron microscopy, transmission electron microscopy, and electron dispersive energy spectroscopy. Magnetic properties, including core losses, are measured through AC, DC, and permeability measurements.
072 - Implementation of Cold Sintering Technique for Green Phase Machining of Sinter Hardened Steel
Linsea Foster, Penn State University
Machining of green phase powder metal products is a technique which remains underdeveloped, particularly for sinter hardened steels. Sinter hardened steels possess high tool wear and damage compared to other powder metal products. Implementation of machining these powder products prior to the hardening process would significantly cut down on wear and damage, extending the life of tooling, and therefor reducing material use, cost, and environmental impact. Conventionally prepared green phase products possess low strength, making it extremely difficult, if not impossible, to machine without damage. Cold sintering is a technique under development for increasing green strength that may aid in the progression towards green phase machining for sinter hardened steels. This study focuses on use of hydrated phosphate coating for FLC-4608 steel. Three-point bending tests and hardness tests are performed, along with analysis of dimensional changes for machined samples of green phase versus sintered phase. Additionally, microstructure is viewed to ensure the retention of the typical sinter hardened FLC-4608 microstructure for cold sintered samples.
097 - Optimizing Binder Jetting Processes: A Comprehensive Study on the Development of Printing and Sintering Parameters with Simulation Validation
Kevin Caballero, University of Texas at El Paso
This study focuses on advancing binder jetting technology through a systematic investigation into printing and sintering parameters, complemented by simulation validation. Utilizing the Binder Jetting Innovent+ system, the research aims to optimize printing parameters for enhanced densities and geometric precision in components with diverse shapes.
The development of printing parameters involves a methodical exploration of variables like layer thickness and binder saturation. Following printing, a Gerolite tube furnace is employed for sintering, a crucial step in transforming green parts into fully dense components. Various atmospheres during sintering are explored to understand their impact on surface properties.
Coupled with experimental work, sintering simulations are conducted for result validation. This integrated approach seeks to provide insights into the optimization of binder jetting processes, contributing to advancements in density and geometric accuracy of printed components for diverse applications in additive manufacturing.
902 – Analytical Prediction of Texture of Multi-Phase Material in Laser Powder Bed Fusion
Wei Huang, Georgia Institute of Technology (Georgia Tech)
Laser powder bed fusion (LPBF) has been broadly employed in metal additive manufacturing to create geometrically complex parts, where heat transfer and its resulting temperature distribution significantly influence the parts' materials microstructure and the materials properties. In determining material properties, crystallographic orientations play one of the critical roles among all microstructure representations due to the influence on anisotropy, void growth, coalescence behaviors, etc. This paper first developed a physics-based analytical model to predict the multi-phase materials texture related to the 3D temperature distribution in LPBF, considering heat transfer boundary conditions, heat input using point-moving heat source solution, and heat loss due to heat conduction, convection, and radiation. The superposition principle was used to obtain temperature distribution based on linear heat input and linear heat loss solutions. Then, by utilizing temperature distribution, the texture grown on a substrate with random grain orientations was analytically acquired, taking into account the columnar-to-equiaxed transition (CET). The correlation between texture and process parameters has been effectively established using CET models and the second law of thermodynamics. Ti-6Al-4V was selected to demonstrate the capability of the analytical models in a multi-phase situation. With applied advanced thermal models, the accuracy of the texture prediction is evaluated based on the comparison to experimental data from literature and past analytical model results and shows higher accuracy achieved. In this work, there is no involvement of any finite element iterations. This study not only offers a quick and precise way of analyzing texture prediction in multi-phase mode for metallic materials but also lays the groundwork for future research on microstructure-affected or texture-affected materials' properties, both in academic and industrial settings. The accuracy and reliability of the results delivered through this approach make it a valuable tool for further research and development.
903 – Validation of AF9628 Blown-Powder Direct Energy Deposition Parameters Through In-Process Monitoring and Mechanical Testing
Emmaline Hutchison, Ohio State University
AF9628 is a low-carbon, low-alloy steel developed by the United States Air Force with applications including additively manufactured munitions. This study examines the mechanical performance of AF9628 specimens manufactured using Blown-Powder Direct Energy Deposition after the completion of a parameter optimization investigation. In-process monitoring, and analysis were used to further optimize the process-parameter window. The chosen as-printed and heat-treated parameters were then validated through a combination of geometry builds, micro-hardness mapping, tensile testing, and charpy-impact testing, density measurements, and metallographic analysis.
904 – Strength, Microstructural Effects, and Stress Concentration Sensitivity in Green Metal Powder Compacts
Joseph Wright, Drexel University
Green metal powder compacts undergo fracture differently than their wrought counterparts due to the bonded particulate nature. While wrought components may exhibit fracture in an easily predictable manner, compacted powders may break at many particulate contacts and develop dynamic stress concentrations. Recent work has been done to understand powder compacts and their fracture behavior using side pressing of compacts with and without a hole. The ratio of the two strengths provides insight for the microstructure length scale related to distributed internal defects and related to the powder distribution. The ratio of the strength and the value of the strength of the specimen without a hole provides an estimate of the fracture toughness of the material. A review of the theoretical framework will be presented and experimental results related to FLNC-4408 (Ancorsteel 85HP + 2wt% Ni + 1.5wt% Cu + graphite) are presented and discussed.
905 – Scan Strategies and Texture Formation in Laser-Wire Directed Energy Deposition
Matthew Engquist, California State University, Los Angeles (Cal State LA)
Laser-Wire Directed Energy Deposition (LW-DED) is a novel technique that allows the production of large-scale metallic components with a relatively high deposition rate. The high cooling rates experienced in additive manufacturing processes create unique microstructures typically not seen in traditional manufacturing methods. Since the local solidification conditions are in part a result of the processing parameters selected, it follows that changing the printing parameters, in particular scan strategies, can lead to a change in microstructure and mechanical properties. In this study, the Meltio M450 LW-DED printer is used to prepare 316L samples with a variety of scan strategies by controlling attributes such as interpass delay and scan rotations. The resulting texture is evaluated with Electron Backscattered Diffraction and implications are discussed.
908 – Processing of NbTiZrTaV For Enhanced Mechanical Response
Nick Krienke, Colorado School of Mines
Refractory high entropy alloys (RHEAs) have gained attention due to their high temperature strength and phase stability. However, RHEAs often have ductile-brittle transition below room temperature making them less suitable for applications where toughness is needed. Recently, it has been seen that by introducing small amounts of oxygen, usually less than 3at%, both strength and ductility can be improved. The addition of oxygen creates ordered oxygen complexes (OOC’s) which enhances ductility through dislocation multiplication. Here, NbTiZrTaV was produced with powder metallurgy techniques to include various amounts of oxygen, and densified through either high pressure torsion or spark plasma sintering. The resulting microstructures and mechanical properties will be reported with the goal of exploring the effect of oxygen content on hardness, yield strength, and plasticity.
Outstanding PosterAward
909 – Graphene Impact on the Mechanical and Functional Properties of Composite Extruded Modeling Cordierite
Alvaro Garcia, University of Castilla-La Mancha
Graphene has shown substantial potential as a reinforcing material in ceramic composites due to its toughness, electrical conductivity, and potential modification of cordierite's resistance to thermal shock. Achieving optimal deagglomeration of platelets within the composite is crucial for maximizing its effectiveness. Composite extrusion modeling (CEM) emerges as a promising technique for fabricating graphene-reinforced cordierites with intricate geometries, particularly as a complement to ceramic injection molding (CIM). The incorporation of graphene into the binder system involved during processing facilitates nanoplatelet dispersion, leveraging intense shear forces during mixing. This study explores two methods of dispersing reduced graphene oxide. Moreover, the effect of different reinforcement loads on the mechanical and functional properties was examined. While much research has been focused on the study of nanoparticle dispersion in a matrix, this work succeeds in doing so in an industrially viable way by developing a scalable fabrication process to apply advances in specific aeronautic applications.
911 – Densification and Microstructural Evolution of Binder Jet Printed and Sintered Porous Ni-Mn-Ga Magnetic Shape-Memory Alloys
Pierangeli Rodriguez De Vecchis, University of Pittsburgh
Binder Jet 3D Printing (BJP) of polycrystalline magnetic shape-memory alloys (MSMAs) allow creating complex geometries from pre-alloyed powders. Porous and large-grained microstructures can help increase functionality of polycrystalline MSMAs by decreasing internal constraints to twin boundary motion. This study focuses on the microstructural evolution of BJPed porous Ni-Mn-Ga during isothermal sintering to determine the densification mechanisms taking place over temperature (1070, 1080 and 1090 °C) and time (0-8 h) to tailor the microstructure. Stereology was used to determine the grain and pore size, and sintering mechanisms as defined by Coble’s model for intermediate stage sintering. Sintering at 1070 °C resulted in an interplay of densifying and coarsening mechanisms, while at 1080 °C the dominating mechanism was volume diffusion and at 1090 °C grain boundary diffusion.
912 – A Novel Approach to Printing Soft Magnetic Composites
Hope Spuck, Pennsylvania State University, DuBois
As the electrification of our world continues to grow, the world will begin to look to the application of electric motors; but they will also look for ways to make the motors in a more efficient way. Soft Magnetic Composites (SMC) bring efficiencies in performance, size and design flexibility to electric motors; however, the processing of these components can be challenging. The current method with heated compaction, very green densities, and long lubricant removal times makes the process very costly and challenging especially for larger components.
In this work, we look at the application of a novel approach to producing SMC's. In previous work, it was demonstrated that typical water-atomized, add-mixed FC-0208 powder can be printed and sintered to 7.56g/cc without the need for a lubricant. Using similar technology, we will investigate the 3D printing of SMC's and consider a new processing approach to improve the processing efficiencies, increase design flexibility, and enhance the properties of the SMC's, while using commercially available powders.
917 – Implementation of Solidification Modeling Towards Tailorable Refractory Microstructures in Additive Manufacturing
Megan Le Corre, Colorado School of Mines
Additive manufacturing (AM) of traditional refractory alloys and refractory multi-principal element alloys (RMPEAs) promises to circumvent potential fabrication challenges associated with traditional manufacturing processes. While recent studies of refractory alloys produced by AM have revealed promising results, more work remains to evaluate the foundational solidification behavior associated with and responsible for the resulting microstructures and properties. Thermocalc (i.e., CALPHAD) modeling was first implemented to determine relevant thermodynamic parameters. Thermal gradients and solidification velocities produced by laser single track melts of refractory alloys were determined using heat transfer modeling. Microstructural morphologies are then correlated to predicted ones using the Ivantsov Marginal Stability model and Hunt modification to the Gaümann columnar to equiaxed transition model. Agreement or discrepancy between microstructural predictions and experimentally observed microstructures can be used to calibrate solidification models, ultimately enabling tailorable microstructures and properties in additively manufactured refractory alloys.
Poster of Merit Award
919 – A Comparative Study on the Tensile Deformation Behavior of Inconel 718 Fabricated via L-PBF, LP-DED, and AW-DED: From Cryogenic to Elevated Temperatures
Alireza Bidar, Auburn University
This study compared the tensile behavior of laser powder bed fused (L-PBF), laser powder directed energy deposited (LP-DED), and arc wire directed energy deposited (AW-DED) Inconel 718 over a wide range of temperatures (from -195°C to 870°C). For all above-mentioned additive manufacturing processes, the tensile strength gradually decreased from -195°C to 650°C, and sharply declined from 650°C to 870°C. The tensile strength of L-PBF specimens was higher than that of LP-DED and AW-DED ones at all tested temperatures except 870°C, which could be ascribed to its smaller grain size. The ductility was similar among all three AM processes from -195°C to 425°C. At 650°C, L-PBF specimens showed slightly higher ductility than their LP-DED and AW-DED counterparts. At 870°C, while L-PBF and LP-DED specimens exhibited comparable ductility, AW-DED specimens showed notably higher ductility compared to L-PBF and LP-DED ones.
924 – Multi-Material Fabrication and Part Repair With Powder Direct Energy Deposition Additive Manufacturing
Justin Gillham, University of Louisville
The Additive Manufacturing Institute of Science and Technology (AMIST) at the University of Louisville recently acquired a BeAM Modulo 400 direct energy deposition (DED) metal additive manufacturing machine. The Modulo 400 uses metal powder as its feedstock and runs as a 5-axis CNC mill with a deposition head in place of the spindle. There are various use cases that are better suited to this technology rather than traditional metal additive manufacturing methods like laser powder bed fusion (LPBF) or metal filled filament fused deposition modelling. A use of powder DED that has been investigated is multi-material fabrication and part repair. In this study, the DED system is used to build upon existing geometries and add material to broken parts. The Modulo 400 uses 316L stainless steel powder to build upon pre-fabricated LPBF parts and mechanical testing specimens. The test specimens are then used to test the bond quality between materials.
927 – Investigation of Residual Stresses in Laser Powder Bed Fusion Manufactured Ti64 Specimens after Machining using X-ray Diffraction
Cristian Banuelos, University of Texas at El Paso
This study focuses on the characterization and analysis of residual stresses in Titanium alloy Ti64 samples produced via Laser Powder Bed Fusion (LPBF) technology and subsequently machined. Residual stresses play a critical role in determining the mechanical performance and dimensional stability of additively manufactured components. Understanding and mitigating these stresses is imperative for ensuring the reliability and structural integrity of parts in aerospace and biomedical applications. A series of Ti64 specimens were manufactured using LPBF, followed by precision machining to simulate post-processing conditions commonly encountered in aerospace components. X-ray Diffraction (XRD) was employed to assess the distribution and magnitude of residual stresses induced during the machining process. The study utilized non-destructive techniques to evaluate the depth and spatial variations of the residual stress fields.
928 – Exploring the Effect of Different Scanning Strategies on the Microstructure in IN718 Fabrication via Electron Beam Powder Bed Fusion
Shadman Tahsin Nabil, University of Texas at El Paso
Additive Manufacturing (AM) of metals is gaining popularity in the aerospace and defense sectors due to its ability to reduce weight and make unique parts. One significant challenge in the metal AM process is anisotropy, which refers to the variation in material properties in different directions. Sometimes this can require extra post-processing techniques like Hot Isostatic Pressing (HIP) or Heat Treatments (HT) to fix. This research aims to minimize anisotropy in the popular Ni-based superalloy IN718 during the Electron Beam Powder Bed Fusion fabrication process itself by implementing specific scanning strategies during the melt step of the metal. The results suggest the possibility of different scanning strategies to influence the microstructure, enhancing control over the transition from columnar to equiaxed structures in the build direction.
931 – A Study on the Influence of Process Parameters on the Microstructure and Mechanical Properties of LPBF Manufactured Ti-6Al-4V Components
Runlin Pu, University of Utah
This research focuses on Laser Powder Bed Fusion (LPBF), an advanced manufacturing technique for producing Ti-6Al-4V components with complex geometries, leveraging the alloy's notable strength and lightweight characteristics. It explores the critical influence of LPBF parameters—laser power, scan speed, and thermal cycles—on the microstructure of Ti-6Al-4V parts, which directly affects their mechanical properties. The study examines the effects of part orientation, surface strategies (including down-skin and up-skin), and geometric intricacies on the microstructure at specific locations, underscoring the necessity of microstructural understanding to predict component performance accurately. By characterizing the microstructure of a Ti-6Al-4V impeller produced via LPBF, the research demonstrates how layer-by-layer heating impacts microstructural characteristics. It further investigates heat treatment's role in altering the microstructure of LPBF-produced Ti-6Al-4V, aiming to refine manufacturing processes for improved material performance.
933 – Numerical Modeling of Laser-Wire Directed Energy Deposition Process
Nathan Stoetzel, California State University, Los Angeles (Cal State LA)
Directed Energy Deposition (DED) is an Additive Manufacturing (AM) method that has opened new possibilities for metal additive manufacturing due to its emergence in recent years. Laser-Wire DED uses high powered lasers to deposit a wire feed material onto a substrate in a prescribed pattern. Numerical modeling of this process is a valuable tool which can be used to predict the effects of various process parameters, reducing the burden on experimental testing. In this study, single bead samples of stainless steel 316L alloy produced by this process are analyzed and a numerical model is developed to simulate how process parameters affect the melt pool geometry and deposition behavior. The numerical model is developed in the computational fluid dynamics (CFD) software, Flow-3D. The model replicates a co-axial wire feed with six off-axis lasers focused to a single point, akin to Meltio M450 laser wire DED system. The simulation results are validated against the the experimental measurements within a reasonable level of accuracy. This model can then be applied to samples with more complex geometry, creating a valuable tool for predicting the outcomes of this process.
935 – Investigation of Microstructural Alignment Utilizing Engineered Cooling during Additive Manufacturing of Powder-Based Alnico Magnets
Luke Gaydos, Iowa State University
Alnico is an anisotropic, rare-earth free, permanent magnet (PM) which maintains its saturation magnetization while at temperatures up to 550oC but lacks the coercivity and energy product needed for a wide range of demanding applications. With an optimal set of processing and manufacturing techniques, alnico could replace Dy-free Nd-Fe B magnets in certain applications if the microstructure is textured in a 〈001〉 direction. Additive manufacturing (AM) of near-net-shape magnets may provide such texture. To investigate the possibility, directed-energy deposition (DED) in conjunction with an actively cooled substrate was used to build samples with a compositionally modified, gas-atomized, alnico 8 alloy. The resulting samples were solutionized and quenched, followed by magnetic annealing and a heat treatment. Magnetic properties and microstructures are compared to previous work. Funded by KCNSC through Ames Lab contract no. DE-AC02-07CH11358. Honeywell Federal Manufacturing & Technologies, LLC operates the KCNSC for USDOE/NNSA under contract number DE-NA0002839
936 – Extrusion-Based Metal Additive Manufacturing of 316L Using Highly Loaded Feedstock
John Reidy, Northwestern University
Powders with high tap density are of interest in extrusion-based metal additive manufacturing (AM) for their potential to produce highly loaded feedstocks. This paper reports the results of a high tap density 316L powder compounded into a feedstock at a loading of 70 vol.% and subsequently printed by bound metal deposition (BMD) on the Desktop Metal Studio System. The critical solids loading of the powder was determined by dynamic viscosity measurements at a range of solids loadings. Sintering of printed parts achieved densities of ~99%, at just ~11% shrinkage. Mechanical properties measured on the sintered samples were compared to values reported by MPIF Standard 35 for typical 316L produced by metal injection molding (MIM). The work presented shows the capability of high volume loading feedstocks in extrusion-based AM to reduce shrinkage compared with typical feedstocks, without deleterious effects to mechanical properties.
937 – Optimizing Surface Quality in Powder Bed Fusion of 316SS: Remedial Role of Shot Peening
Sivasubramanian Chandramouli, Purdue University
With the growing adoption of additive manufacturing (AM), especially laser-powder-bed-fusion (LPBF), in automobile and aerospace industries, process optimization is necessary to comply with existing industry standards of surface and mechanical properties. LPBF, as a layered manufacturing technique, surface roughness is a major issue that stems from powder characteristics with added influence of gravity in complex oriented parts. High surface roughness significantly affects product performance, especially fatigue properties due to the formation of stress-concentration points. The potential for enhancing surface topology and roughness solely through LPBF process parameter optimization is constrained, necessitating post-processing techniques. In this work, we investigated the effect of shot peening on roughness variations on LPBF-manufactured 316SS, considering surface orientations from 0-90°. Shot peening effectively reduced surface roughness by approximately 50% under optimized conditions, inducing a tensile to compressive residual stress transition. These results provide a pathway for improving the surface and component performance of AM parts through standardized industry post-processing surface modification techniques.
941 – Improved Design of a Customized Inkjet 3D Printer
Andrew Gillespie, Indiana University-Purdue University Indianapolis (IUPUI)
This study presents the construction and enhancement of an open-source binder-ink jet 3D printer called Plan B, designed by Ytech3d, despite the original designer's discontinued support and future upgrades in 2017. Our efforts focused on leveraging the open-source design to construct improvements for modernization, maintenance, operations, and printer safety for the user while keeping the cost and essential factors within the process. This paper outlines the technical improvements made to the printer while demonstrating how the open-source initiative can dive into future research and development within the powder-based additive manufacturing community while keeping it within a cost-effective range.