2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Plenary Session
Program Organizers: Joseph Beaman, University of Texas at Austin
Monday 8:00 AM
August 12, 2024
Room: Salon HJK
Location: Hilton Austin
Session Chair: Joseph Beaman, University of Texas at Austin
8:00 AM Introductory Comments
8:15 AM Plenary
Fatigue Performance of Fiberglass Reinforced 3D Printed Thermoplastic Materials for Wind Blade Internal Shell Structures: James Tobin1; Adam Stevens1; Nadim Hmeidat1; Tyler Smith1; Julian Charron1; Alex Roschli1; Wendy Lin2; Michael Schuster3; Pascal Meyer3; Vlastimil Kunc1; Ahmed Hassen1; 1Oak Ridge National Laboratory (ORNL); 2GE Aerospace; 3GE Research
Additive manufacturing methods have been investigated for use in utility scale wind turbine structures for production wind turbine blades. This talk will discuss the challenges and opportunities associated to fatigue performance needs of wind turbine structures. Fatigue performance in wind turbine blades is a critical-to-quality performance metric of wind blade structural materials. An overview of strain-controlled fatigue performance of 3D printed materials and S-N curves will be shared. Materials tested include glass reinforced PETG and also a new thermoplastic poly(hydroxy amino ether) resin reinforced with glass fiber from L&L Products. Comparisons between fatigue tests run on injection molded bars compared to 3D printed bars with the same materials will also be shared. An overview of a large scale pilot demonstration of multihead 3D printing to produce a 12 meter blade tip for structural testing will also be shared.
8:40 AM Plenary
Investigating Deviations from NAVSEA LPBF Qual-Cert Requirements on the Microstructure and Mechanical Properties of 316L Stainless Steel Components: Keegan Muller1; Katherine Fowler2; Jennifer Semple2; Evan Handler2; Shawn Robinson2; 1Vision Point Systems; 2NSWCCD
Technical data packages developed by NAVSEA for Laser Powder Bed Fusion (LPBF) components currently do not allow manufacturers to alter the qualified build file in any way without requalification due to concern over how small changes can alter the component’s thermal history, microstructure, and mechanical properties. To allow for greater manufacturing flexibility and inform decision-making on proposed build file alterations, common build file changes on LPBF components were investigated through the manufacturing of a representative component and generic test specimens under various test conditions. Common build file alterations to be investigated included the addition of multiple parts to the build plate, mid-production pauses, part location, and the distance between adjacent parts. Characterization of microstructure, tensile properties, and fracture toughness was conducted to quantify the impact of these common build file alterations and establish guidance for future qualification efforts.
9:05 AM Plenary
Developing a Practical In-situ AM Process Monitoring Framework to Reduce Qualification Burdens: Michael Heiden1; Dan Bolintineanu1; Anthony Garland1; David Moore1; David Saiz1; Tyler LeBrun1; Ben Brown2; Nick Calta3; 1Sandia National Laboratories; 2Kansas City National Security Campus; 3Lawrence Livermore National Laboratory
In-situ monitoring’s ability to evaluate metal AM processes for abnormal build events and detect detrimental defects have been demonstrated in laboratory settings. However, the challenge remains to convert these high-fidelity research and development frameworks into production-ready environments with deployable sensor hardware. The slow, resource-intensive nature associated with acquiring/analyzing large datasets with complex outputs remains a barrier toward reducing burdensome testing/inspection for qualification. There is also a need for software solutions that provide manageable amounts of practical data for decision-making. This presentation highlights an ongoing, multi-year effort within the DOE labs to develop a resource-effective in-situ instrumentation toolset for AM production environments, which leverages machine learning to form a common data processing framework. Discussion will cover how this framework aims to assist AM process development, ensure process consistency, and contribute to part acceptance for metal AM production.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
9:30 AM Plenary
Development of a Geometrically Based Methodology for Local Process Control in Powder Bed Fusion: Holger Merschroth1; Julius van der Kuip1; Jana Harbig1; Michael Kniepkamp1; 1Technical University Darmstadt
Laser powder bed fusion is a widely used additive manufacturing process, which is dependent on various influences. Layer-wise melting of powder generates successive heating and cooling, which affects the local microstructure of the manufactured part. Especially geometry-dependent heat distribution leads to inhomogeneous local solidification and microstructure. Therefore, control strategies are required which locally adapt the process parameter depending on the part geometry and building process. In this paper, a voxel-based control strategy for the laser power is designed. A voxel size of 100 μm considers the local heat distribution of each point’s vicinity and adjusts the parameter voxel-wise. In addition, a machine-independent methodology is developed to execute the voxel-based parameters in vectors for the laser powder bed fusion process. Furthermore, the limits of the laser power adaption are identified experimentally. The presented results demonstrate an improved part geometry, surface roughness, and homogenization of the material properties.
9:55 AM Plenary
Re-Defining Catheter Care with Multi-Material Additive Manufacturing: James Caruana1; Geoffrey Rivers1; Adam Dundas1; Karina de Almeida Lins1; Cameron Devine1; Richard Hague1; Derek Irvine1; 1The University of Nottingham
Catheter-related bloodstream infections (CRBSIs) and chronic bacterial biofilm formation pose persistent healthcare challenges, contributing to significant morbidity and mortality rates. Neonatal and low-birth-weight infants are especially vulnerable due to heightened susceptibility to CRBSI, exacerbated by misplaced routine catheters and inadequate tracking structures and sizing. This study showcases stereolithography (SLA) as a method for developing functionalized multi-material and multi-lumen catheter structures. Critical to our investigation was the systematic evaluation of candidate monomers: Tetrahydrofurfuryl Acrylate (THFuA) and Tricyclodecane-dimethanol Diacrylate (TCDMDA). These materials presented non-eluting anti-biofilm effects, effectively mitigating Pseudomonas aeruginosa biofilm formation on printed components. Incorporation contrast agents into these formulations using novel nanoparticles encapsulated in polymeric microparticles allowed for functionalised catheters with echogenicity in Ultrasound imaging. Removing the requirement for external coatings or eluting antibiotics. By amalgamating precision nano-engineering with bioactive polymeric formulations, our approach offers a paradigm shift towards mitigating CRBSIs and enhancing patient outcomes in neonatal and low-birth-weight populations.
10:20 AM Plenary
Improving Additive Manufacturing with AI-Powered Robots: Satyandra Gupta1; 1University of Southern California
This presentation will describe how robots can be used to realize the next generation of AM technologies. The first part of this presentation will describe how performing material deposition using articulated robot arms can significantly expand capabilities of AM processes by enabling material deposition on non-planar surfaces. Many composite parts have thin three-dimensional shell structures. Achieving the right fiber orientation is critical to the functioning of these parts. Printing them using conventional planar-layer AM processes leads to fibers being oriented in the plane of the layer. The capability to deposit the material using non-planar conformal layers can increase part strength in the desired direction and hence produce parts with improved properties. Robots can be used to perform multi-resolution printing that finds the best trade-off between build speed and surface finish. Robots can also be used to realize of supportless AM. The use of robots also enables the insertion of externally fabricated components such as sensors, actuators, and energy harvesting devices during the AM process. The second part of this presentation will describe artificial intelligence techniques needed for generating and executing robot trajectories to build high quality parts using AM.
10:45 AM Break
11:15 AM Keynote
Local Microstructural Control with Synchronized Dual Laser Scan Strategies: Fantasy or Reality?: Michele Vanini1; Samuel Searle1; Lars Vanmunster1; Kim Vanmeensel1; Bey Vrancken1; 1KU Leuven
It has long been known that it is possible to manipulate the local thermomechanical conditions during laser powder bed fusion by locally adapting the process parameters. A major limitation has been that the primary function of the laser is to consolidate the material into fully dense parts, which inherently limits the range of parameter variation that can be leveraged for microstructural control. In dual laser systems, the consolidation and tailoring of the thermal conditions can be decoupled across both lasers, which increases the opportunity for microstructural control. This talk will explore the possibilities, but also the limits of dual laser scan strategies to locally manipulate the microstructure using simulations as a guide, with verification from experimental examples for Ti6Al4V and super duplex stainless steel.
11:40 AM Keynote
Towards High Resolution and High Speed Metal AM with Molten Metal Droplet Jetting: Denis Cormier1; David Trauernicht1; Chris Chungbin1; Kareem Tawil1; Irtaza Razvi1; Usama Rifat1; Paarth Mehta1; Khushbu Zope1; Gabriel Stash1; Daniel Cormier1; 1Rochester Institute of Technology
Industrial adoption of mainstream metal AM technologies, including PBF and binder jetting, has primarily focused on high value and low production volume aerospace and medical components. This is largely due to the high cost of metal AM equipment and powder, powder safety concerns, and low production speeds relative to conventional manufacturing processes. This talk will present a promising new (sort of) technology known as molten metal jetting (MMJ). MMJ jets droplets of molten metal on-demand towards a moving substrate where they spread and solidify following impact. The push towards high frequency multi-nozzle molten metal jetting opens up possibilities for high material deposition rates without any loss of feature resolution, multi-material deposition, highly conductive printed electronics, and other exciting research activities. The talk will describe state-of-the-art and future developments in MMJ research at RIT and other leading research laboratories around the world.