Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development: Ni-based Alloys
Program Organizers: Prashanth Konda Gokuldoss, Tallinn University of Technology; Juergen Eckert, Erich Schmid Institute of Materials Science; Zhi Wang, South China University of Technology
Monday 2:00 PM
October 18, 2021
Room: A115
Location: Greater Columbus Convention Center
Session Chair: Ian Nettleship, University of Pittsburg
2:00 PM
Creation of Process Representative Flaws and Their Impact on the Mechanical Properties L-PBF Inconel 718: Jacob Rindler1; David Schick2; Peter Daum3; Adam Sutton4; Michael Groeber1; 1Ohio State University; 2Proto Precision Additive; 3Rolls Royce; 4Lockheed Martin
Laser powder bed fusion additive manufacturing (L-PBF AM) has become increasingly popular for rapidly manufacturing complex light weight components. Highly regulated industries such as aerospace and energy require rigorous characterization to understand material properties and the effect of flaws. These are the major factors that drive the design of the component, qualification requirements, inspection technique, and inspection interval. In order to prove inspection techniques are capable of reliably detecting flaws within AM components a method to precisely seed flaws is required. This presentation will share methodologies for intentionally seeding process representative flaws with a known morphology, size, and location into otherwise nominally printed parts. The authors will also present low-cycle fatigue and tensile test results from specimens with and without the seeded flaws. Attendees of this talk will learn about methods for intentionally seeding realistic process flaws that will aid them in AM part and process qualification efforts.
2:20 PM
The Material Quality of Samples Obtained by Selective Laser Melting Method from IN718 Alloy Powder: Vladimir Klochikhin1; Pavel Kasay1; Konstantin Balushok1; Valeriy Shilo1; Valeriy Naumyk2; 1JSC «Motor Sich»; 2NU "Zaporizhzhya Polytechnic"
It was studied the material quality of the IN718 alloy samples made by the method of selective laser melting (SLM) in different directions from the powder obtained by the centrifugal sputtering method. It was found that the mechanical (at all temperatures) and heat-resistant properties of the IN718 alloy samples (both vertical and horizontal) meet the requirements of AMS 5662M and significantly exceed the requirements to the ЭП718-ВД alloy.The microstructure of samples is a γ-solid solution with the presence of carbides and carbonitrides. In the microstructure there is a structural inhomogeneity. Heat treatment leads to obtaining a more uniform structure due to the equalization of the chemical composition between the zones of layer-by-layer melting.
2:40 PM
Heat Treatment Design of Haynes 282 Alloy Prepared by Wire-arc Additive Manufacturing: Yuankang Wang1; Rafael Rodriguez De Vecchis1; Wei Xiong1; 1University of Pittsburgh
Haynes 282 is a nickel-based gamma-prime strengthened superalloy with the unique combination of creep strength, thermal stability, and weldability among other desirable properties making it a great candidate for advanced ultra-supercritical applications. Wire arc additive manufacturing (WAAM) can be used to produce large metallic parts with high deposition rates holding potential for large-scale additive manufacturing applications using weldable metal alloys in wire form. By coupling high-throughput experiments and ICME (Integrated Computational Materials Engineering) modeling, the post-heat treatment impact on microstructure-property relationships have been studied, including precipitation strengthening effect, and oxidation behavior of WAAM Haynes 282 under different heat treatment conditions. This study explores an effective pathway to further enhance the mechanical performance of alloy components prepared by WAAM.
3:00 PM
Microstructure Development of Additively Manufactured Gamma Prime Strengthened Ni-based Superalloy Rene65: Colleen Hilla1; Andrew Wessman2; Alber Sadek3; Hyeyun Song4; Wei Zhang1; Michael Mills1; 1Ohio State University; 2University of Arizona; 3Edison Welding Institute ; 4Edison Welding Institute
Grain and precipitate structure, influenced by location specific thermal history during AM, have important effects on mechanical behavior. This study aims to understand the role that spot size plays in microstructure development and subsequent mechanical behavior of Rene65, a γ’ strengthened Ni-based superalloy. Segregation across the melt pool, and melt pool characteristics, were analyzed on single-track samples using EDS and optical analysis. The effect of overlap of adjacent passes on a single build layer and the effect of thermal cycling due to subsequent build layers were analyzed on overlapping tracks and small builds using SEM and EBSD. As-built microstructures were altered using various heat treatment schedules. The effect of these microstructural changes on tensile strength and creep behavior was tested. Changes in spot size and heat treatment schedule lead to variations in the segregation profile, texture development, and mechanical behavior due to changes in thermal history validated through thermal modeling.
3:20 PM Break
3:40 PM
Print Defects, Microstructure Evolution and Remnant Porosity for Binder-jet Printed 625 Alloy: Chuyuan Zheng1; Ian Nettleship1; Markus Chmielus1; 1University of Pittsburgh
Unlike beam-based additive manufacturing technologies, binder-jet printing offers distinct advantages in production rate and microstructure homogeneity. However, printing defects such as inter-layer spacings and printing lines caused by jetting will easily cause remnant porosities in sintered parts and degrade their mechanical properties. In this work, the effects of powder layer spreading and binder jetting on microstructure evolution in pressureless sintering were investigated for 625 alloy. Green and sintered microstructures were characterized by traditional 2D microscopy and also 3D computer tomography. The relationship between the print defects, the evolution of the microstructure and the remnant porosity were quantified.
4:00 PM
Mechanical Behavior of Ni-based Superalloy Single Crystals Produced via Electron Beam Melting AM: Patxi Fernandez-Zelai1; Quinn Campbell1; Chris Ledford1; Michael Kirka1; Sebastien Dryepondt1; 1Oak Ridge National Laboratory
In recent years a number of groups have demonstrated the feasibility of printing Ni-based superalloy single crystals via electron beam melting (EBM) AM. In all cases the crystallographic orientation of the single crystal is deterministic with a precise secondary orientation preference. This control offers the possibility of producing components with desired orientation without the need for seed crystals. Optimizing such systems requires detailed knowledge of the deformation behavior of these single crystals. In this work we present properties of these single crystals produced via EBM AM. Mechanical tests are performed at various orientations to capture the crystal-scale behavior of the material. We demonstrate that the behavior coincides with established crystal plasticity theory.