Additive Manufacturing of Metals: Post Processing: Poster Session
Program Organizers: Ola Harrysson, North Carolina State University; Ulf Ackelid, Freemelt AB; Andrzej Wojcieszynski, ATI Metals; Sudarsanam Babu, University of Tennessee, Knoxville

Tuesday 4:45 PM
October 1, 2019
Room: Exhibit Hall CD
Location: Oregon Convention Center

P3-24: Comparative Study between the Processed and Unprocessed TIG Welded Joints: Sipokazi Mabuwa1; Velaphi Msomi1; 1Cape Peninsula University of Technology
    This paper presents the mechanical properties of the friction stir processed and unprocessed TIG welded joints. The processed and unprocessed plates were cut into dimensions relevant to bending, tensile, microstructure, macrostructure, SEM and microhardness tests. The results showed a clear improvement on the processed joint compared to unprocessed ones and were also notable higher than the commercial ones. There is a good correlation observed between the bending and the tensile results. This confirms that the friction stir processing improved the mechanical properties of the TIG welded joints. The good correlation observed between the macroscopic and microscopic results suggest FSP as the weld joint enhancement technique.

P3-25: Hot Isostatic Pressing of High Volume Fraction Gamma Prime Nickel-base Superalloys: Brian Welk1; Kevin Chaput2; Hamish Fraser1; 1Ohio State University; 2Air Force Research Laboratory
    Hot isostatic pressing powder metallurgy (HIP-PM) is an alternative to additive manufacturing (AM) for producing near net-shape or net-shape components. In this work, high volume fraction gamma prime nickel-base superalloys, which are difficult to process with AM, were studied to determine the influence of the HIP cycle parameters and post-HIP heat-treatments on the microstructure and mechanical properties. This effort included optimizing the process to reduce the number of prior particle boundary (ppb) particles, a known defect in HIP’d nickel-base superalloys. The microstructure of HIP’d coarse powder (i.e. larger than AM specification and lower in cost) was compared to standard size powder. Local property enhancement, a unique advantage of HIP where a different alloy and/or powder size can be placed at a particular location in the HIP tooling, was also investigated. Characterization of the microstructure included SEM, EBSD and TEM. Tensile and fatigue properties were evaluated.