State-of-the-Art Speakers

Zackary Snow, Oak Ridge National Laboratory

Recent Advances on the Use of In Situ Monitoring as an NDE Tool for Additive Manufacturing Processes

In situ monitoring for additive manufacturing (AM) processes has become a hot bed of academic literature in recent years, as the promise of real time anomaly detection and feedback control encourages development of new sensors and analysis techniques. Machine learning is at the forefront of these developments, and recent advances in data fusion approaches have shown that ex situ characterization data, such as X-ray computed tomography, can effectively be used to provide object labels of material quality for process monitoring signals. In this way, in situ monitoring has an opportunity to transition from a process monitoring solution to a natural part of the non-destructive evaluation (NDE) pipeline for AM part qualification. This presentation will discuss recent advances, best practices, and limitations on using in situ monitoring as an NDE tool for AM processes. 

Zackary Snow is an associate research staff member at Oak Ridge National Lab in the Manufacturing Systems Analytics Group of the Manufacturing Science Division. His research interests include the use of process sensing and machine learning to understand and improve advanced manufacturing processes, non-destructive inspection, integration and utilization of material characterization data into digital manufacturing paradigms, and in situ material property prediction. Zackary received his PhD from The Pennsylvania State University in Engineering Science and Mechanics and has authored several publications in peer-reviewed journals related to flaw formation mechanisms in and in situ sensing of additive manufacturing processes. 

Paul Hooper, Imperial College London

Putting In-process Monitoring to Work: Towards Real-time Digital Quality Assurance

In-process monitoring has given us fantastic scientific insight into the physics of metal additive manufacturing processes. However, industrial use for quality assurance remains limited despite the availability of in-process sensors and software from machine manufactures. This talk will explore what we really want from in-process quality assurance, what is currently achievable, and recent progress to bring real-time digital quality assurance to fruition. It will detail different use cases for in-process monitoring, including the detection of specific defect causing mechanisms, generation of localised 3D porosity maps, and inspection to detect the presence of critical defects. Use of machine learning and evaluation of detection performance using non-destructive evaluation methodologies will be discussed, along with challenges associated with acceptance when considering replacement of conventional post-manufacture inspection techniques.

Paul Hooper is a Senior Lecturer in the Department of Mechanical Engineering at Imperial College London. His research focuses on additive manufacturing (AM) and he leads government and industry-funded projects focusing on certification of AM components. His specific interests include in-situ process monitoring, defect detection, process-microstructure-performance relationships, simulation of AM processes, machine learning, design for AM and new process development. He also has interests in high-strain rate material behaviour and structural integrity. He has authored over 50 journal publications and has an h-index of 32.

Brigid Mullany, University of North Carolina at Charlotte

Additive Manufacturing of Ceramics: Can Surface Measurements Provide Processing and Part Integrity Insights?

While a brief overview of ceramic additive manufacturing will be provided, the talk will focus on processing and part variances detectable via coherent scanning interferometric surface measurements. The talk will center on alumina parts printed via a stereolithography (SLA) process.

Brigid Mullany, PhD, received her bachelor’s degree and doctorate in mechanical engineering from the University College Dublin, Ireland. After graduation, she received a two-year EU Marie Curie postdoctoral research position at Carl Zeiss in Germany. In 2004, Mullany joined the Department of Mechanical Engineering and Engineering Science at the University of North Carolina at Charlotte where she is a professor working in the area of surface finishing and characterization, and additive manufacturing of metals and ceramics. Mullany received the SME Kuo K. Wang Outstanding Young Manufacturing Engineer Award in 2007 and the NSF CAREER Award in 2008. She is a fellow of the International Academy of Production Engineering (CIRP) and is currently the chair of CIRP’s Scientific Technical Committee on Surfaces. Mullany has previously served as the vice chair of the CIRP collaborative working group focused on Micro Production Process Chains (2012-14). From January 2017 to November 2019, she was a program director in the Advanced Manufacturing Program at the National Science Foundation.

Michael Cullinan, University of Texas at Austin

A Review of the State-of-the-Art and Precision Engineering Challenges in Micro/Nanoscale Additive Manufacturing

Microscale additive manufacturing is one of the fastest growing areas of research within the additive manufacturing community. However, there are still significant challenges that exist in terms of available materials, resolution, throughput, and ability to fabricate true three-dimensional geometries. These challenges render commercialization of currently available microscale additive manufacturing processes difficult. This talk will review the current state-of-the-art of microscale additive manufacturing technologies and investigate the factors that currently limit each microscale additive manufacturing technology in terms of materials, resolution, throughput, and ability to fabricate complex geometries. This talk will offer prognosis about the future viability and applications of each technology along with suggested future research directions that could be used to bring each process technology in line with its fundamental, physics-based limitations. This talk will also bring together the general design guidelines that must be followed while designing scalable microscale AM processes. Finally, this talk will conclude with an analysis of the role of precision engineering in the future advancement of microscale additive manufacturing technologies.

Dr. Cullinan is an Associate Professor in the Walker Department of Mechanical Engineering The University of Texas at Austin. Prior to joining The University of Texas, Dr. Cullinan was a National Research Council Postdoctoral Associate at the National Institute of Standards and Technology in Gaithersburg, Maryland. Dr. Cullinan received his Ph.D. in Mechanical Engineering from the Massachusetts Institute of Technology (MIT) in 2011. Dr. Cullinan also holds an MS (2008) in Mechanical Engineering from MIT as well as a BS in Engineering and a BA in Economics from Swarthmore College (2006). Dr. Cullinan’s research focuses on the development of novel nanomanufacturing systems and on finding ways to exploit nanoscale physical phenomena in order to improve existing macroscale devices and to create novel micro- and nanoscale devices for energy and sensing applications. Dr. Cullinan has received many awards for his research and teaching including American Society for Precision Engineering Early Career Award (2021), the Outstanding Young Manufacturing Engineer Award from the Society of Manufacturing Engineers (2016), the Rising Star Award from the Sensors Expo and conference (2017), multiple Best Poster Awards from the American Society for Precision Engineering (2017, 2018), and the Outstanding Teaching by an Assistant Professor Award from the Department of Mechanical Engineering at The University of Texas at Austin (2017). Dr. Cullinan is also an associate editor for both Precision Engineering and the ASME Journal of Micro and Nanomanufacturing. In addition, he is also the co-chair of the Micro and Nanotechnology Technical Leadership Committee for the American Society for Precision Engineering.

Orion Kafka, National Institute of Standards and Technology

In-situ 2D and 3D Measurements of Process and Performance in Additive Manufacturing: Applications in Metals and Polymers

This talk will summarize recent outcomes of my research across a range of materials (photopolymer plastics and hydrogels, metals such as Ti64 and IN718) using advanced characterization methods and computational image analysis to measure, generally in 3D, both how AM systems work and how parts made with AM perform in load-bearing service conditions. Examples include direct measurements of the photocure process (e.g., revealing striking dependency of critical cure energy on pattern area), and of the laser-melting process of Ti-6Al-4V and the impact powder size distribution may have. On the performance side, demonstrator examples include in-situ observation of strut deformation during compressive loading of an polymer TPMS gyroid structure, pore deformation during tensile loading of a IN718 sample, and ex-situ measurements highlighting the complex interactions between as-built surface and microstructure in the fatigue performance of IN718.

Orion Landauer Kafka is a staff researcher in the Applied Chemicals and Materials Division, in the Material Measurement Laboratory at the National Institute of Standards and Technology. He holds degrees in Mechanical Engineering from Clarkson University (B.S., 2014) and Northwestern University (Ph.D., 2020). His research interests are in solid mechanics, at the interface of mechanical engineering and materials science. Much of his recent work has been focused on the 3D characterization and mechanical performance of additively manufactured materials. Orion’s scholarly work includes some 40+ journal articles and two pending patents.

Joy Gockel, Colorado School of Mines

Additive Manufacturing Research and Education at Mines

An interdisciplinary approach is required for advancement of additive manufacturing (AM). The Alliance for the Development of Additive Processing Technologies (ADAPT) is a multi-disciplinary research center and industry-academic consortium at Colorado School of Mines dedicated to the development and optimization of technologies associated with AM. Through research, education, and technology transfer, ADAPT aims to advance the application of additive manufacturing, while educating the next generation of engineers. This talk will highlight the additive manufacturing research and education in ADAPT. Research expertise includes materials development for metals and ceramics, fundamental AM processing understanding, processing-structure-properties-performance relationships, AM process control and qualification leveraging in-situ monitoring and machine learning. Educational activities in AM include many forms including formal degree programs, outreach, training, credentials, webinars, coursework and more.

Joy Gockel is an associate professor of Mechanical Engineering at Colorado School of Mines and the Executive Director of the ADAPT Center. Her research spans several aspects of additive manufacturing by connecting the processing-structure-properties-performance relationships using modeling, in-situ monitoring, materials characterization and mechanical testing. She joined Mines from Wright State University where she was an assistant professor in the Mechanical and Materials Engineering Department. Prior to her faculty positions, she was a lead engineer at GE Aviation’s Additive Technology Center. Joy earned her PhD in Mechanical Engineering from Carnegie Mellon University. For her professional and research contributions, she has received the 2020 ASTM International Additive Manufacturing Young Professional Award, the 2021 TMS Young Leader Professional Development Award and the 2021 International Outstanding Young Researcher in Freeform and Additive Manufacturing Award and is part of the 2022 class of America Makes Ambassadors.