Session Sheet - 2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Multi-Material Printing and Feedstock Considerations

2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Multi-Material Printing and Feedstock Considerations
Program Organizers: David Leigh, University of Texas at Austin

Tuesday 8:00 AM
August 4, 2026
Room: Zlotnick Ballroom 6
Location: AT&T Center

8:00 AM
Beyond the Melt Pool: Heterogeneous Behavior in Processing and Properties of Functionally Gradient Materials: Clayton Perbix¹; Maximalian Kephart¹; Leslie Lamberson¹; Samantha Webster¹; Joy Gockel¹; ¹Colorado School of Mines
    Directed energy deposition of functionally graded materials (FGMs) requires process control to ensure reproducibility. However, this study reveals that geometry-driven effects persist despite closed-loop melt pool control in a FGM of 316L stainless steel and nickel superalloy 625. Microhardness showed a 9% hardness decrease when reducing part size, while primary dendrite arm spacing remained constant. These results indicate that property variations are driven by part-scale thermal histories beyond the solidification front. To further interrogate the mechanical heterogeneity, we adopted a “Materials Testing 2.0” framework that combines nontraditional coupon geometries, full-field deformation measurements, and digital-twin-informed inverse analysis. Quasi-static full-field experiments provided strain maps that are processed using the Virtual Fields Method (VFM) to extract spatially resolved stiffness and yield properties. This integration of experimental and virtual testing decodes the heterogeneous behavior of FGM systems and establishes predictive relationships among composition, processing, and mechanical performance, enabling the design of next-generation multifunctional structures.

8:20 AM
Multi-Material Mixing Mechanisms Process Map: Zane Taylor¹; Tharun Reddy¹; Kamel Fezzaa²; Samuel Clark²; Leora Dresselhaus-Marais¹; ¹Stanford University; ²Advanced Photon Source
    Liquid-state mixing is a necessary prerequisite for in-situ alloying and multi-material printing in laser fusion-based additive manufacturing. We will present a mechanistic discussion of the fluid mixing process in the laser powder bed fusion of copper powder on a titanium substrate. In-situ synchrotron radiography and post-mortem X-ray computed tomography reveal the expected mixing improvement at high energy densities and low laser scan speeds due to slow Marangoni convection and diffusion, as well as an unexpected transition to high-velocity fluid-shear driven mixing mechanisms at higher scan speeds associated with the traditional balling regime. These results indicate fundamental tradeoffs between driving forces for mixing during the laser scanning process, and suggest that certain high-scan speed processing conditions may improve mixing and in-situ alloying without introducing more serious keyholing defects.

8:40 AM
Influence of Compositional Gradient Steps on Tensile Properties of Ti-6Al-4V and C103 Functionally Graded Materials via Laser Powder Direct Energy Deposition (LP-DED): Jesus De Haro Ruiz¹; Kurtis Watanabe¹; Diego Ariza¹; Clara Hofmeister Mock²; Lawrence Murr¹; Brandon McWilliams²; James Carney¹; Francisco Medina¹; ¹W.M. Keck Center for 3D Innovation, The University of Texas at El Paso; ²Army Research Directorate, DEVCOM Army Research Laboratory
    Multimaterial additive manufacturing allows combining dissimilar alloys into a single component. offering new possibilities for high-temperature and multifunctional structures. This study aims to investigate the mechanical properties of a functionally graded material composed of C103 refractory alloy and Ti-6Al-4V alpha-beta titanium alloy—both known for their high specific strength, suitable for aerospace and automotive applications. Using Laser Powder Direct Energy Deposition (LP-DED), five box-shaped thin-wall geometries were manufactured with three distinct material configurations: uniform Ti-6Al-4V at the top and bottom, and a center with five gradual transitions from 100 wt% C103 to 100 wt% Ti-6Al-4V in 25-wt% steps. Uniaxial tensile testing assessed strength and elongation based on geometric surface structure. SEM was used to characterize fracture surfaces and identify failure features, correlating fracture behavior to multilateral interfaces. Results indicated increased stress and reduced elongation as the gradient shifted toward Ti-6Al-4V. The impact of this work will be discussed in detail.

9:00 AM
Microstructural Evolution during Additive Manufacturing of Functionally Graded Materials from Structural to Refractory Alloys: Integrated Computational-Experimental Framework: Kaila Bertsch¹; Nicholas Ury¹; Brandon Bocklund¹; Jennifer Glerum¹; Benjamin Ellyson¹; Michael Juhasz¹; Aurelien Perron¹; ¹Lawrence Livermore National Laboratory
    Additive manufacturing (AM) of functionally graded materials (FGMs) enables novel design and joining capabilities for next-generation energy technologies. However, predicting microstructures and properties is challenging due to complex thermal histories, especially as material properties change spatially. To address this, we systematically investigated the microstructural evolution in AM FGMs from titanium to tantalum. Multiple builds with the same gradient step size were produced, each terminating at a different intermediate layer, then cross-sectioned perpendicular to the “terminal” melt pool to capture slices of microstructure in each layer development across build stages. Characterization using SEM, EDS, EPMA, and EBSD enabled tracking of phase formation, interdiffusion, and grain structure changes throughout the build. In situ thermocouple data was compared to analytical simulations to inform temperature-dependent property models to track phenomena. These insights provide a foundation for optimizing AM for FGMs to achieve precise spatial tailoring of properties for performance in advanced energy environments.

9:20 AM
Designing & Printing Dispersion Strengthened Ti-6Al-4V via Laser Powder Bed Fusion Additive Manufacturing: Amaranth Karra¹; Tirthesh Ingale¹; Sivaji Karna¹; Shreya Mukherjee¹; Ravisankar Haridas²; Rajarshi Banerjee¹; Anthony Rollett³; Rajiv Mishra¹; Hector Siller¹; ¹University of North Texas; ²Enabled Engineering; ³Carnegie Mellon University
    The anisotropy of the mechanical properties of Ti-6Al-4V additively manufactured (AM) via laser powder bed fusion (PBF-LB) is increased by the long and textured columnar prior β grains that typically occur despite the high cooling rates. This work explores the designing and printing of yttria (Y2O3) dispersion hardened Ti-6Al-4V with minimal powder feedstock preparation. A uniformly dispersed bimodal distribution of Y2O3 in the Ti-6Al-4V matrix decreases the transverse size of the prior β grains. Furthermore, STEM bright field micrographs reveal dispersoid pinning of dislocations and STEM EDS confirms that the dispersoids are Y2O3 as expected. A modest increase in room temperature microhardness is observed and room temperature nanoindentation creep results show a ∼ 64% lower mean creep rate compared to standard PBF-LB Ti-6Al-4V. This work successfully demonstrates the use of PBF-LB to fabricate ODS Ti-6Al-4V with minimal feedstock preparation enabling refinement of the prior β grain and improved mechanical properties.

9:40 AM Break

10:00 AM
Thin Wall Microstructure and Mechanical Behavior of GRX-810 ODS Alloy Fabricated Across Multiple Laser Powder Bed Fusion Systems: Patricio Sebastian Rodriguez Beltran¹; Jimena Coello¹; Paul Gradl²; Colton Katsarelis²; Sohail Mohammed¹; Timothy Smith³; Francisco Medina¹; James Carney¹; ¹W.M. Keck Center for 3D Innovation, Department of Aerospace and Mechanical Engineering, College of Engineering, The University of Texas at El Paso; ²NASA Marshall Space Flight Center; ³NASA Glenn Research Center
    This study investigates the microstructural characteristics and mechanical performance of the NASA GRX-810 Oxide Dispersion Strengthened (ODS) NiCoCr alloy with a 0.4% Y2O3 fabricated via Laser Powder Bed Fusion (L-PBF) across multiple commercial systems. All specimens underwent Hot Isostatic Pressing (HIP) post-processing to evaluate its effect on densification and microstructural evolution. Thin-wall and bulk coupons are characterized to assess defect content, geometry, grain morphology, grain boundary character, precipitate dispersion as a function of machine parameters and wall thickness. Preliminary results suggest that microstructural features, including grain size and boundary angle distribution, are sensitive to machine-dependent processing parameters, highlighting the importance of platform selection in GRX-810 fabrication. The effect of build orientation on tensile properties is evaluated using ASTM E8 sub-sized specimens printed at multiple angles, with Yield Strength (YS), Ultimate Tensile Strength (UTS), elongation, and Young’s modulus measured at room temperature.

10:20 AM
Effect of Oxygen Contamination in Shielding Environment on Laser Metal Deposited Ti-5Al-5Mo-5V-3Cr alloy: Ranjit Joy¹; Sung-Heng Wu¹; Sriram Isanaka¹; Ben Brown²; Patrick Thomas²; Frank Liou¹; Joseph Newkirk¹; ¹Missouri University of Science and Technology; ²Kansas City National Security Campus
    Laser Metal Deposition (LMD) can promote oxygen pickup from the shielding environment, causing variation in tensile behavior of β Ti-5553 deposits. Ti-5553 powder was deposited in an enclosed volume having different oxygen concentrations and by conventional Localized Shielding Gas (LSG) strategy. The critical oxygen concentration that causes ductile-to-brittle transition was systematically investigated using tensile testing. Oxygen pickup in LMD processed thin walls increased with increasing oxygen concentration. Tensile testing revealed only incremental increase in yield, and ultimate tensile strengths with corresponding increase in oxygen pickup, primarily due to solid solution strengthening. However, the post-yield ductility was significantly influenced by oxygen pickup. Gradual reduction in total elongation was registered from 1 PPM to 1000 PPM while exhibiting significant ductility, which was followed by a transition to mixed mode at an oxygen concentration of 5000 PPM. Interestingly, LSG processing induced a fully brittle failure, attributed to increased α precipitation at grain boundaries.

10:40 AM
Effect of Alloy Composition on Liquid-Phase Sintering in Additive Manufacturing of W-Ni-Fe Alloys: Jianming Zhou¹; Fuda Ning¹; ¹Binghamton University
    Extrusion-based additive manufacturing enables the fabrication of complex W-Ni-Fe parts, yet the final density and microstructure are largely determined by liquid-phase sintering and its dependence on alloy composition, which remains insufficiently understood. This work compares two printed alloys, 90W-7Ni-3Fe and 93W-4.6Ni-2.4Fe, to clarify how chemistry affects sintering behavior. A combined CALPHAD-based and kinetics-informed framework was used to analyze liquid formation, W solubility difference between phases, and Fe redistribution during thermal processing. The results show clear composition-related differences in liquid evolution, γ-phase chemistry, and elemental partitioning. XRD confirms that both alloys remain primarily composed of W and γ phases after sintering. Comparative SEM/EDS reveals distinct redistribution behavior in the two alloys, whereas TEM observations in the 93W alloy further identify nanoscale W/γ coexistence and heterogeneous interfacial strain. A composition-process map for 88-95 wt.% W is further proposed to support alloy and sintering design.

11:00 AM
Influence of Elevated Chromium Levels on the Corrosion and Mechanical Behaviors of Directed Energy Deposited H13 Tool Steel: Seyed Mohammad Hosseini¹; Chang-Hwan Choi¹; ¹Stevens Institute of Technology
    H13 tool steel is used in die-casting and hot-work applications but exhibits corrosion and oxidation resistance. Traditional post-processing methods can improve these properties, although they increase complexity. This study evaluates chromium enrichment, up to 11 wt.%, in laser powder directed energy deposition (DED)-fabricated H13 as an alloy-design strategy. Four conditions were investigated: annealed H13 substrate and DED-processed H13 containing 5, 8, and 11 wt.% Cr. Potentiodynamic polarization, cyclic corrosion exposure, high-temperature oxidation, and Vickers hardness testing were conducted. Results show that 8 wt.% Cr achieves the best balance of properties, providing corrosion resistance comparable to conventionally processed H13 while maintaining hardness at 621 HV. The 11 wt.% Cr condition produced corrosion and oxidation resistance through enhanced Cr2O3 passive layer formation, while retaining hardness above the annealed baseline. These findings demonstrate that targeted chromium enrichment through DED can extend H13 tooling life in chemically aggressive environments.

11:20 AM
Development of Laser Based Modification Process for Water‑Atomized Powders for Additive Manufacturing Applications: Taisei Yachi¹; Ayahito Saikai¹; Yuta Mizuguchi¹; Yoshinori Funada¹; Tsukasa Nakamura²; Kazuki Makinoshima²; Yu Sakon²; Keisuke Takenaka³; Yuji Sato³; Masahiro Tsukamoto³; ¹Industrial Research Institute of Ishikawa; ²Muratani Machine Manufacture Co., Ltd.; ³Joining and Welding Research Institute, The University of Osaka.
     Powders used in metal additive manufacturing (AM) require high flowability, therefore, spherical gas‑atomized powders are generally employed. However, gas‑atomization suffers from low production yield and high manufacturing cost. As a means of addressing these issues, the use of low‑cost water‑atomized powders has gained attention. Nevertheless, water‑atomized powders exhibit poor flowability due to their irregular particle shapes and also contain higher oxygen levels.In this study, a laser-based modification process for water‑atomized powders was developed. In this process, the powders were heated and melted in-flight using a laser with precisely controllable heat input, thereby promoting spheroidization driven by surface tension. As a result, the treated powders exhibited a fraction of spherical particles comparable to that of gas‑atomized powders, and an improvement in flowability was confirmed.

11:40 AM
Assessment of Manufacturing Process Variability in LP-DED JBK-75 Alloy for Structural Applications: Anannya Doris¹; Luis Munoz¹; Kurtis Watanabe¹; Edel Arrieta¹; Lawrence E. Murr¹; Colton Katsarelis²; Paul R. Gradl²; James P. Carney¹; Francisco Medina¹; ¹University of Texas El Paso; ²NASA, Marshall Space Flight Center
    This study investigated the mechanical and fracture behavior of Laser Power Directed Energy Deposition (LP-DED) additively manufactured JBK-75 as a function of geometry, temperature, and powder production. Bulk bar and thin plate tensile specimens fabricated from powders using different production methods, rotary and gas atomization, were tested over a range of temperatures. The resulting tensile properties were correlated with fractographic observations. Strength decreased systematically with increasing temperature in both specimens, while thin-wall samples showed lower overall strength, indicating greater sensitivity to geometry. Multivariate statistical analysis identified temperature as the primary factor influencing the overall mechanical response, with powder production method having a smaller secondary effect. SEM fractography showed predominantly ductile failure through microvoid coalescence, with dimple morphology evolving from finer, uniform features at lower temperatures to coarser, irregular void structures at higher temperatures. These results indicate that temperature-driven softening and void growth dominate the deformation and fracture response of JBK-75.