2023 Technical Division Student Poster Contest: SMD 2023 Technical Division Undergraduate Student Poster Contest
Program Organizers: TMS Administration

Monday 5:30 PM
March 20, 2023
Room: Exhibit Hall G
Location: SDCC

SPU-13: An In-situ Radiography Study on Meltpool Dynamics and Fluid Flow as a Function of Laser Power in Ti-6Al-4V Raster Melts: Garrett Fields¹; Rakesh Kamath¹; Gerry Knapp²; John Coleman²; Stuart Slattery²; Sam Reeve²; Hahn Choo²; ¹The University of Tennessee-Knoxville; ²Oak Ridge National Laboratory
    Understanding melt pool dynamics and fluid flow during melting and solidification is key to improving metal additive manufacturing (AM) processes. This study performed single line melts on Ti-6Al-4V alloy substrates with varying laser powers (76.5 W to 437 W) at a constant scan speed of 0.4 m/s in a laser-AM simulator at the 32-ID-B beamline, Advanced Photon Source, Argonne National Laboratory. The transient evolution of the melt pool dynamics was observed in-situ using a high-speed, high-resolution synchrotron x-ray radiography technique. The meltpool and vapor cavity dimensions, interface velocity, dynamics, and fluid flow were analyzed using radiography images. The dimensional evolution provided by radiography and microscopy guided current meltpool models to better understand the transition between melting modes which will show the influence of keyholing on meltpool geometry. These findings will further validate and improve finite volume meltpool simulations, like OpenFOAM-based solvers, which contribute to optimizing the metal AM process.

SPU-14: Understanding the Microstructure-Property Relationship in the Additive Manufactured Titanium Alloy for Aerospace Applications: Sydney Fields¹; Dian Li¹; Yufeng Zheng¹; ¹University of Nevada, Reno
    Titanium alloys are critical structural materials with excellent comprehensive properties such as high specific strength, excellent toughness, and high corrosion resistance. These properties of titanium alloys can be tuned by the manipulation of microstructure evolution during a variety of heat treatment. In this work, we used the advanced scanning electron microscopy (SEM) and MIPAR image analysis software to quantitatively study the microstructural evolution during the post-heat treatment for the additively manufactured Ti-5Al-5V-5Mo-3Cr (wt.%, Ti-5553) alloy. The influence of the aging temperature and cooling rate on the ⍺ microstructure during the post heat treatment was systematically investigated. Refined, more-refined, and super-refined ⍺ microstructure with different number densities were successfully generated. We will introduce the critical roles of post heat treatment on tuning the microstructure in additive manufactured Ti-5553. This work is supported by the Nevada Undergraduate Research Award and National Science Foundation, grant CMMI-2122272.

SPU-15: Using Microstructural Modifications to Influence Intense Strain Localization in Inconel 718Plus: Olivia Egbers¹; Jenna Benko¹; Nathan Heniken¹; Michael Mills¹; Semanti Mukhopadhyay¹; ¹Ohio State University
    Allvac®718Plus™ is a novel Nickel-based superalloy with superior mechanical properties, good creep resistance, and high-temperature capability. The superior properties of this superalloy are heavily influenced by its microstructure, which comprises g’ (Ni3Al) precipitates in a Ni solid solution matrix. Under external loading, this superalloy exhibits intense strain localization adjacent to annealing twin boundaries (ATBs), which can be sites for crack initiation. Recent findings suggest that strain localization in some superalloys may be caused by precipitate-free zones (PFZ) near ATBs. In the present work, we attempted to investigate the role of heat treatments on PFZ adjacent to annealing twin boundaries. We designed several novel heat treatments using ThermoCalc’s TC Prisma module to minimize or eliminate PFZs. Then we characterized the heat-treated samples using scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). Finally, we assessed strain localization in the newly designed microstructures using in-situ tensile testing and digital image correlations.