Additive manufacturing news at the University of Louisville
Tim Gornet (Manager of AMIST Core Facility), Kate Schneidau (UofL Graduate Student), Kathy C. Chuang (NASA Glenn Research Center) and Hilmar Koerner (Wright-Patterson Air Force Base) recently published a paper that has been highlighted in 3DPrint.com (https://3dprint.com/258500/3d-printing-thermoset-composites-at-high-temperatures-aerospace-applications/?fbclid=IwAR3Crg8oDDYkx55piyfaBHvW_Rd4LY1z7M1Ti2tr5j4egqxqaaF3mVSBFEI).
Selective Laser Sintering (SLS) is an additive manufacturing technique that builds 3D models layer by layer using a laser to selectively melt cross sections in powdered polymeric materials, following sequential slices of the CAD model. SLS generally uses thermoplastic polymeric powders, such as polyamides (i.e. Nylon), and the resultant 3D objects are often weaker in their strength compared to traditionally processed materials, due to the lack of polymer inter-chain connection in the z-direction. Our previous effort showed the challenges of printing a melt-processable RTM370 imide resin powder terminated with reactive 4-phenylethynylphthalic anhydride by LS, due to its inherently low viscosity of these oligomers. This paper presented the first successful 3D printing of high temperature carbon fiber filled thermoset polyimide composites, followed by post cure cycles to promote additional crosslinking for achieving higher temperature (Tg = 370 °C) capability. The processes to build tensile specimens and a component by LS, and the characterization of RTM370 imide resin by DSC and rheology as well as evaluation of the LS printed polyimide composite specimens by SEM and mechanical tests will be discussed.
Stephanie Hendrixson (Senior Editor, Additive Manufacturing) sat in metal AM training class at AMIST, offered by Ed Tackett (Director, Workforce Development, AMIST). Stephanie shares what she learned in an article, titled "6 Things I Learned about Metal 3D Printing at the AMIST" in Additive Manufacturing (https://www.additivemanufacturing.media/)
Aug. 28, 2017
Dr. Keng Hsu joined the University of Louisville in August 2017 as Associate Professor in Speed School's Mechanical Engineering Department. Prior to this post, Dr. Hsu was an assistant professor of Mechanical Engineering at Arizona State University.
Dr. Keng Hsu has over 25 years of experience in Manufacturing, Mechanical Engineering, and Materials Science. He received his Ph.D. in Mechanical Science and Engineering from the University of Illinois at Urbana-Champaign in 2009. His work revolves around physics-based advanced manufacturing research at multiple scales in both top-down (subtractive) and bottom-up (additive) approach. Specifically, scalable nanomanufacturing process development, metal/semiconductor/metal-semiconductor hybrid nanomaterials for energy conversion and storage, additive manufacturing process development, engineered anisotropic materials by additive processes, meso-structure materials, metamaterials, plasmonics, solid-state electrochemistry are some of his research areas. His research work in these areas has been funded by NSF, ARPA-E, Intel, Orbital ATK, SRP, NASA, and DoD.
June 13, 2017
Drs. Kevin Chou and Tom Starr are leading a new NSF award “Pore Formation Mechanisms in Laser Powder-Bed Fusion Additive Manufacturing.”
Pores generated during the additive manufacturing (AM) process can degrade part mechanical performance. Pore formation in metal AM is complex and difficult to predict and control. The objectives of this research are to identify pore formation mechanisms in selective laser melting (SLM) and to predict, analyze and characterize porosity in SLM parts. A hybrid numerical modeling technique will produce particle-resolved simulations of various pore formation mechanisms. SLM experiments to be conducted in the Additive Manufacturing Research Center will validate the model using in-situ thermal imaging to capture process temperatures and melt-pool dynamics and post-build characterization to identify and quantify porosity using a high resolution micro-CT scanner.
This collaborative research project also includes Dr. Alexey Volkov from the University of Alabama.
Feb. 27, 2017
Prof. Thomas Starr gives invited keynote presentation at TMS2017 meeting.
Dr. Starr's presentation The New Metallurgy of Additive Manufacturing kicked off the Additive Manufacturing: Past, Present, and Future session at the TMS2017 meeting in San Diego, Feb. 26-Mar. 2, 2017. His talk reviewed research results illustrating the challenge and opportunity created by additive technology. These include the challenge of creating metal structures with material properties comparable to those obtained with traditional processing and the opportunity to create new materials with unique performance characteristics.
Jan. 2, 2017
Dr. Kevin Chou joined the University of Louisville in January 2017 as the Edward R. Clark Chair of Advanced Manufacturing in Speed School's Industrial Engineering Department.
Prior to this post, Dr. Chou was a professor of Mechanical Engineering at The University of Alabama. Dr. Chou received his Ph.D. in Industrial Engineering from Purdue University, followed by a post-doctoral training at National Institute Standards and Technology (NIST). He brings over fifteen years of experiences in manufacturing research, higher educations and public services to the University. Among his broad experiences, Dr. Chou has been a Faculty Fellow at NASA's Marshall Space Flight Center, a Visiting Professor at National Chung Cheng University (Taiwan), and a Guest Researcher at NIST. Most recently, Dr. Chou served as an Assistant Director for Technology in the Advanced Manufacturing National Program Office (AMNPO) of U. S. Department of Commerce, supporting the newly established Manufacturing USA program (formerly National Network for Manufacturing Innovation.)
Dr. Chou's research and teaching interests include design and manufacturing, CAD/CAM, mechanics, metrology and materials. His recent study fields have been focused on integrated materials, design and manufacturing innovations, including metal additive manufacturing, metal matrix composite machining, and diamond coatings, supported by NASA, NSF, DoC, and DoD, etc., as well as private sectors and foundations including GM, Vista Engineering, CFD Research Corp., and Society of Manufacturing Engineers (SME). A recipient of the Dick Aubin Distinguished Paper Award from SME's Rapid Technologies & Additive Manufacturing Community, Dr. Chou's group has published over 130 refereed articles and made about 100 technical presentations, plus over 40 invited seminars. Dr. Chou is a Fellow of American Society of Mechanical Engineers (ASME) and currently serves on the Executive Committee of ASME's Manufacturing Engineering Division. In 2011 he chaired the Technical Program of the International Manufacturing Science and Engineering Conference (MSEC), ASME's flagship manufacturing conference. In addition, Dr. Chou serves as an Adviser of SME's Additive Manufacturing Certificate Program.
In his capacity as the Edward R. Clark Chair, Dr. Chou will work closely with different groups on campus involved in additive manufacturing (AM) research and education, including the Rapid Prototyping Center, to collaboratively promote and grow the AM programs in the University.
Aug. 15, 2016
The winner of the 2016 SFF Symposium International Outstanding Young Researcher in Freeform and Additive Manufacturing Award (FAME Jr) is Dr. Li Yang.
This award is given annually to recognize an outstanding young researcher in the field of freeform/additive fabrication early in their career. Dr. Yang was recognized for his research in design methods for additive manufacturing with emphasis on the design and fabrication of 3D cellular structures.
July 1, 2016
Harish Irrinki, a PhD student from the University of Louisville is a winner of the 2016 Axel Madsen Award from the Center for Powder Metallurgy Technology and the Metal Powder Industries Federation.
Mr. Irrinki does his research in the Materials Innovation Guild.
Aug. 9, 2018
Dr. Li Yang won this year's 3D Printing Design Contest at the Additive Manufacturing Users Group (AMUG) meeting in St. Louis. Dr. Yang's entry was a Layered Cellular Padding used to absorb energy and reduce intensity of impacts. While demonstrated in a football helmet this lattice design can be tailored for other types of helmets or pads or any other impact application.Sponsored by BASF the contest prize is a one week trip to work at the BASF Application Technology Center in Heidelberg, Germany. Additional description of the contest and Dr. Yang's design can be seen in the presentation ceremony video.
Drs. Li Yang and Lihui Bai published a quantitative model and analysis of how AM could be used for on-demand spare parts production. Using AM as a spare parts supply instead of traditional inventory is a decision faced by many manufacturers. The paper describes a performance model for a powder bed fusion AM system in a spare parts supply chain and provides insight into a question that has very little prior reporting in the open literature.
Zhang Y, Jedeck S, Yang L, Bai L. Modeling and analysis of the on-demand spare parts supply using additive manufacturing. Rapid Prototyping Journal. 2018 Nov 26.