Session Sheet - 2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Metal Jetting and Droplet Deposition Processes

2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Metal Jetting and Droplet Deposition Processes
Program Organizers: David Leigh, University of Texas at Austin

Tuesday 1:30 PM
August 4, 2026
Room: Brazos
Location: AT&T Center

1:30 PM
Thermal Modeling of Drop Placement Strategies for Multi-Nozzle Molten Metal Jetting: Denis Cormier¹; Kareem Tawil¹; Christopher Chungbin¹; Irtaza Razvi¹; David Trauernicht¹; ¹Rochester Institute of Technology
    Multi-nozzle molten metal jetting has the potential to significantly increase material deposition rates in metal additive manufacturing. However, concurrent deposition of molten metal tracks by an array of adjacent nozzles presents challenges with regards to heat management and surface tension related geometric distortion. This talk will present preliminary findings from Flow3D simulations of different multi-nozzle drop placement strategies. Specifically, strategies involving track spacing, drop spacing, unidirectional vs. bidirectional printing, and interlayer pause times will be explored.

1:50 PM
Towards Microstructure Control in Molten Metal Jetting Using Airborne Ultrasound: Alexander Martinez-Marchese¹; Tao Liu¹; Chinedum Okwudire¹; ¹University of Michigan
    Molten metal jetting (MMJ) or Liquid metal drop-on-demand is a recently developed AM process in which an actuator releases individual droplets of molten metal to build a component layer-by-layer. This process has many advantages, including higher build rates and lower part-level residual stresses. In this work, we investigate the effect of a focused airborne ultrasound field from a phased array on the molten metal droplets as they reach the part being built, as well as changes in grain refinement, morphology, and texture in the resulting component.

2:10 PM
Influence of Droplet Parameters on Porosity in Metal Parts Manufactured with Droplet-On-Demand Metal Jetting: Viktor Sukhotskiy¹; Laura Marquez¹; Kellen Traxel²; Andrew Pascall¹; Jason Jeffries¹; ¹Lawrence Livermore National Laboratory; ²Pacific Northwest National Laboratory
     Liquid metal jetting (LMJ) is a molten metal droplet-based additive manufacturing method, which has great potential as a low-cost high-performance alternative to established technologies. As with many AM methods, minimizing porosity in LMJ is key to ensuring strong mechanical properties. To date, several perspectives have been proposed on minimization of porosity in LMJ, most of which center on the thermal and fluid properties of the metal droplet as the voxel of LMJ. We extend the work to date by experimentally and computationally showing that the droplet Weber number, the Freezing number, along with a new dimensionless thermal deposition rate metric can together enable process maps that track solidified droplet shape, degree of remelting and porosity trends. The improved processing map presented here will enable higher quality part production across material systems by enabling reduced porosity, ensuring droplet-droplet bonding and improving resolution.Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-2019000

2:30 PM
Metal Extrusion Additive Manufacturing of Thin-Walled Aluminum Alloys.: Zefang Li¹; Rohit Berlia¹; Colin Goodman¹; Mark Foster¹; Timothy Weihs¹; Jochen Mueller¹; ¹Johns Hopkins University
    Metal extrusion additive manufacturing (MEAM) directly extrudes molten metal from wire feedstock to produce near-net-shape parts, offering simple feedstock handling and reduced system complexity, which are advantageous for aluminum and other reactive alloys. However, nozzle clogging and part collapse, especially for higher-melting temperature alloys, limit reliable implementation. Here, we analyze thermal mechanisms driving these failures in thin-walled aluminum structures and identify the nozzle and the top of the previously deposited layer as critical thermal states for stability. We develop a thermally informed, simulation-guided framework that combines layer-wise print bed temperature control with practical time-based thermal criteria to prevent under- and over-heating during deposition. Applying this framework yields thin-walled aluminum parts with improved geometric fidelity and repeatability across build height. Microstructural characterization, mechanical testing, and demonstrations across multiple length scales and complex geometries illustrate the method’s effectiveness and limitations.

2:50 PM
Creating a Custom Optical Diagnostic for Advancing Liquid Metal Jetting: Dylan Levine¹; Viktor Sukhotskiy¹; Eric Elton¹; Nicholas Watkins¹; Jason Jeffries¹; Andrew Pascall¹; ¹Lawrence Livermore National Labratory
     Liquid metal jetting is a metal additive manufacturing technique that involves jetting molten metal droplets at high frequencies to build solid metal parts. Real-time diagnostics are essential to ensure consistency and quality in the metal jetting process. As such, we are developing a high-speed optical diagnostic system to identify the following jetting performance metrics down to the level of individual ejections on a custom pneumatic printhead: droplet volume and diameter, mass flow rate, and droplet velocity. By connecting these measurements to crucible pressure, wire feed rate, and other process control parameters, we aim to enable real-time in-line process control. A key advantage of this approach over commercial systems is its flexibility for custom optomechanical and software integration with any jetting platform. Future work will focus on improved processing throughput and expanding measurement capabilities.Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-CFPRES-2019022

3:10 PM
Preliminary Experimental Results Using An Eight Nozzle Molten Metal Jetting Print Head: Christopher Chungbin¹; Kareem Tawil¹; Irtaza Razvi¹; David Trauernicht¹; Denis Cormier¹; ¹Rochester Institute of Technology
    The throughput of a single nozzle Molten Metal Jetting (MMJ) printhead is limited by the drop size and maximum frequency. We developed an 8 nozzle printhead which allows much higher throughput than a similar single nozzle. This talk will present preliminary results of experimental printing using the printhead. We compare print times between single and multi-nozzle printheads and analyze deposited layers to show how jetting conditions and print strategy affect the characteristics of layers printed in a multi-nozzle system. The possibility of scaling throughput without sacrificing minimum feature size makes multi-nozzle MMJ a promising area for future development.