Additive Manufacturing: An Industrial, Academic and Governmental Perspective: Session I
Program Organizers: Navin Manjooran, Solve; Gary Pickrell, Virginia Tech
Monday 8:00 AM
October 10, 2022
Room: 306
Location: David L. Lawrence Convention Center
Session Chair: Anthony Rollett, Carnegie Mellon University; Allison Beese, Pennsylvania State University; Navin Manjooran, Chairman, Solve; Gary Pickrell, Virginia Tech
8:00 AM Invited
A Viewpoint on the Roles of Academia, National Laboratories, Government and Industry: Anthony Rollett1; 1Carnegie Mellon University
Academics are most effective when they adopt a hypothesis, implement the experiment (physical or numerical) to test it and generate new understanding of a problem. Generation of intellectual property from such understanding is a welcome add-on. Education of scientist/engineers, especially to the level of independent researchers is equally important. National laboratories are most effective when they coordinate disparate disciplines to solve a major problem. Government (research) agencies are most effective when they distill the opinions of the research community about gaps in knowledge into new thrusts with funding attached. Notwithstanding such an orderly view of how research and development advances areas such as additive manufacturing (AM), actual progress is sporadic and dependent on culture shifts and risk taking. Examples are taken from the author’s recent experience of AM projects to understand the fundamentals of laser melting, define processing-microstructure-properties, build high temperature heat exchangers and implement artificial intelligence in AM.
8:40 AM Invited
Additive Manufacturing of Zirconia Ceramics by Digital Light Processing and Laser Engineered Net Shaping: Bai Cui1; Nathan Snyder1; Fei Wang2; Xueliang Yan3; Yan Chen4; 1University of Nebraska–Lincoln; 2University of Nebraska Lincoln; 3University of Nebraska-Lincoln; 4Oak Ridge National Laboratory
Novel additive manufacturing (AM) processes for creating ceramic parts have significant benefits such as the ability to create complex 3D shapes in a short processing time. AM of yttria–stabilized zirconia (YSZ) ceramics has recently become a spotlight for biomedical applications and shown promising results in mechanical properties and visual aesthetics. This presentation will report our progress in 3D printing of YSZ ceramics by two AM processes, digital light processing (DLP) and laser engineered net shaping (LENS), and discuss the related technical challenges and solutions. The DLP process involves the methods of forming ceramic slurries, designing 3D models, 3D printing, and heat treatment to remove the binder and sinter the ceramic body. The LENS process uses a high-power laser beam to directly sinter the feedstock of YSZ powders. The microstructure formation and phase transformation during these AM processes have been characterized by electron microscopy and neutron diffraction and correlated with the mechanical and optical properties. These studies show the feasibility of 3D printing of YSZ ceramics and the possibility to achieve similar properties to those of traditional ceramic manufacturing processes.
9:20 AM Invited
Use of Nondestructive Evaluation to Link Defects to Properties in Additive Manufacturing: Allison Beese1; Andrea Arguelles2; 1Pennsylvania State University ; 2Pennsylvania State University
Defects, or pores and pore networks, encountered in additive manufacturing (AM) processes impact the resultant properties. In particular, lack of fusion pores are often found in laser powder bed fusion, while irregular pore networks are found in metal samples fabricated using binder jet AM. This talk will describe our efforts toward using nondestructive methods of X-ray computed tomography and ultrasound measurements to identify linkages between internal defects and mechanical properties in metals processed with laser powder bed fusion and binder jet AM.
10:00 AM Break
10:20 AM
The Effects of Powder Recycling in LPBF AM of Al-Sc-Mg Alloy on Powder Quality: Junwon Seo1; Srujana Rao Yarasi1; Sandra DeVincent Wolf1; Bryan Webler1; Anthony Rollett1; 1Carnegie Mellon University
Recycling the powder in laser powder bed fusion (L-PBF) additive manufacturing can significantly reduce the cost of the overall process. However, laser interactions with powder can potentially degrade recycled powder quality and the printability of the material made with recycled powder. In this research, we investigate the effects of powder recycling on L-PBF additive manufacturing of Al-Sc-Mg alloy. Ten consecutive L-PBF builds are run, first using virgin Al-Sc-Mg powder and then using recycled powder from the previous build. Virgin powder and ten batches of recycled powder collected after each build are sampled and imaged using a scanning electron microscope to check the surface and the cross-sections. Computer Vision is used to extract features such as powder size distribution, the number of satellite particles, and particle morphology of the powder batches. Also, the bulk flowability of the powder batches is measured, which is linked with features extracted from powder images.
10:40 AM
Additive Manufacturing Research with Mission Intent: JHU/APL’s Research toward Solving Critical Defense Challenge Problems: Morgana Trexler1; Michael Presley1; Steven Storck1; Gianna Valentino1; Li Ma1; Brendan Croom1; Sal Nimer1; Drew Seker1; 1Johns Hopkins University Applied Physics Laboratory
As the Nation’s largest University Affiliated Research Center, the Johns Hopkins University Applied Physics Laboratory (JHU/APL) maintains a long-term, trusted relationship with the DoD and contributes greatly to the nation’s defense needs. JHU/APL conducts scientific research and engineering in the national interest, with additive manufacturing (AM) work focused on inventing new alloys, understanding solidification and defect formation mechanisms, and creating unique structures to enable new capabilities. Custom-tailored alloys are designed using computational insights and produced for sponsor-defined applications. Topology optimization and lattice design are coupled with AM to enable enhanced thermostructural capabilities. In situ monitoring, statistical design sampling, high-throughput testing and nondestructive evaluation, and machine learning are leveraged to understand and predict properties. Mission-driven AM research will be presented, providing examples of rapid material development for high temperature or corrosive environments, topology optimized structures for structural enhancement or thermal mitigation for aerospace applications, and novel actuation devices for spacecraft deployables.