Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Investigating Typical Additive Manufacturing Defects and Generation of Hot Spots Under Shock Loading" By Caitlin H. O'Grady Purdue MSE Preliminary Exam Advisors: Professor Steven F. Son and Professor Weinong W. Chen ABSTRACT Additive Manufacturing (AM) techniques are increasingly being utilized for energetic material processes and research. The downside to utilizing current AM techniques is that samples fabricated using these techniques often develop artifacts or defects during the manufacturing process. This work reviews current literature on the topics of hot spot formation and current AM techniques of Robocasting (aka Direct Ink Write). Robocasting is a type of direct ink writing AM technique that consists of extruding cylindrically-shaped beads with high solids loading that are suspended in a paste-like mixture into layers that are used to build 3D structures. The technique has been utilized for different mixtures of high explosives (HE). The technique is currently being developed for different HE materials. Robocasting techniques can result in samples with natural defects like cracking, delamination, conglomerates, and voids. My research will focus on three proposed detonation experiments that consist of testing samples created via robocasting techniques and other samples created via Physical Vapor Deposition (PVD) techniques. Samples created via robocasting techniques will be chosen because they can have artifacts and defects in the material that are a natural result of the Robocasting process. PVD explosive samples will be used as a model system to investigate the effects of these typical AM artifacts or defects on explosive samples. PVD techniques allow for precise control of geometry to simulate typical AM artifacts or defects embedded into explosive samples. These experiments will attempt to explore the mechanisms that govern the formation of hot spots by experimentally testing the interactions of detonation/shock front with typical material artifacts or defects that can result from robocasting techniques. An ultra-high-speed framing camera and streak camera will be used to view the samples under dynamic shock loading. Date: Thursday, May 9, 2019 Time: 1:00 P.M. Place: Chaffee Auditorium