Additive Manufacturing: Advanced Characterization for Industrial Applications: Structures and Material Properties
Sponsored by: TMS Advanced Characterization, Testing, and Simulation Committee, TMS Additive Manufacturing Bridge Committee
Program Organizers: Nadia Kouraytem, Utah State University; Fan Zhang, National Institute of Standards and Technology; Lianyi Chen, University of Wisconsin-Madison
Monday 2:00 PM
October 18, 2021
Room: A121
Location: Greater Columbus Convention Center
2:00 PM Invited
Synchrotron Characterization of Hot Cracking and Related Topics: Anthony Rollett1; Guannan Tang1; Nadia Kouraytem2; Benjamin Gould3; Joseph Pauza1; Ziheng Wu1; Joseph Aroh1; Runbo Jiang1; Seunghee Oh1; Srujana Yarasi1; Ann Choi1; Amit Verma1; Rajib Halder1; Andrew Huck1; Zhening Yang1; Amaranth Karra1; 1Carnegie Mellon University; 2Utah State University; 3Argonne National Laboratory
Hot Cracking is a challenge for the use of many alloys, especially with respect to additive manufacturing (AM). Notwithstanding the extensive literature on the topic, we lack a criterion for susceptibility to hot cracking. We have used high-speed visualization with high energy x-rays to quantify the phenomenon in different Al and Ni-based alloys, supplemented by ex situ microscopy and cross-sections. We report on comparisons between the synchrotron-based characterization and the various methods used in the literature, as well as a heuristic approach to correlating susceptibility to hot cracking to various material properties. Preliminary results suggest that freezing range by itself is a poor predictor, for example. Additionally, we review progress in: automating the analysis of keyhole behavior; occurrence of stray grains (new orientations) in AM; orientation gradients in AM metals; microstructures in 3D printed heat exchangers; solid state transformation in AM; microstructures in laser-DED Ti-6Al-4V.
2:30 PM
Moisture Impacts in AM Metal Powders Characterized by Karl Fischer Oven Titration and Avalanche Rheometry: Dave van der Wiel1; Ethan Pawlak1; Tyler Gutzky1; 1NSL Analytical
Metal powders exhibit native oxide surface films which readily interact with ambient moisture to varying degrees. A series of typical metal powders used in AM powder bed fusion processes were exposed to various environmental conditions in order to control their moisture content. The bulk flow properties of the powders were then characterized using a drum-style avalanche powder flow analyzer. Precision moisture content was measured using oven desorption/evaporation coupled with Karl Fischer coulometric titration. The results of this study have implications on powder handling, recycling and AM process control.
2:50 PM
Investigation of the Protective Mixture Influence on the Heat Input Meaning for the Layered Electric Arc Surfacing of Aluminum Alloys AlSi5 and AlMg5: Mikhail Gnatenko1; Valeriy Naumyk2; Maria Matkovska2; Vadim Shalomeev2; 1JSK Motor Sich; 2NU "Zaporizhzhya Polytechnic"
It was studied the dependences of the protective argon-helium mixture influence on the heat input meaning for the process of layer-by-layer electric arc surfacing with wire, and the effect of parameters changes in this process on composition, properties and structure of AlSi5 and AlMg5 aluminum alloys. Helium contain in argon was at a ratio of 10% to 50% in 10% increments. It was found, that with the amount increase of helium the concentration of the arc increases and the amperage required to melt the metal decreases.It was found that the heat input meaning increasing provides the improvement of metal structure and properties for both of studied aluminum alloys. The addition of helium can reduce the amount of heat input required to obtain higher mechanical properties.
3:10 PM
Gradient Alloy Heat Exchanger Manufacturing for Energy Applications: Kevin Luo1; Bob Markley2; Nadia Kouraytem3; Hailei Wang3; Michael Juhasz4; 1Formalloy Technologies, Inc.; 23rd Dimension Industrial 3D Printing Co; 3Utah State University; 4FormAlloy Technologies, Inc.
Additive manufacturing (AM) has been revolutionizing part manufacturing, design optimization, sustainability, and new applications. Specifically, directed energy deposition (DED) enables the possibility of printing gradient alloys. Additively manufactured gradient alloy parts are manufactured with multiple fractions of dissimilar metals. In this work, we present the potential of using a combination of DED and laser powder bed fusion (L-PBF) to fabricate gradient alloy parts with superior device functional performance. The combined AM approach is used to manufacture high-temperature heat exchangers for concentrated solar power applications. By leveraging the unique capabilities of the combined technologies, it provides an opportunity to use lower cost materials such as stainless steel in lower temperature sections and higher temperature materials in other regions in the heat exchanger designs. The thermal-fluid modeling shall utilize its unique manufacturing processes to conduct topology optimization. This work is expected to support advancements in the AM area for various energy applications.
3:30 PM Break
3:50 PM
Tensile Behavior of Metal AM Lattice Structures: Ben Dimarco1; Jeremy Seidt1; Ariel Gluck; Jacob Rindler1; Edward Herderick1; 1The Ohio State University
Complex cellular and lattice structures offer an exciting opportunity for tailored mechanical properties. Additive manufacturing (AM) is uniquely suited to produce complex lattice structures. There is an unmet need for a standard approach to mechanical testing and evaluation of these lattice structures in order to support their adoption into demanding sectors such as defense, biomedical and commercial applications. The key objective of this work is to define a tensile test geometry appropriate for a range of different metal printed lattice designs and still provide repeatable mechanical property measurement. This presentation will include results for laser powder bed fusion printing of 316L lattice tensile bars and their static tensile testing using 3D Direct Image Correlation (3D DIC). Failure analysis is also included in the results. Designs tested include fluorite, bcc, TPMS, kelvin, and auxetic structures. The presentation will conclude with a perspective on future developments for metal printing testing standards. Acknowledgement: This effort was performed through the National Center for Defense Manufacturing and Machining under the America Makes Program entitled “Tensile Behavior of AM Lattice Structures” and is based on research sponsored by Air Force Research Laboratory under agreement FA8650-20-2-5700. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon.Disclaimer: The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the Government. Distribution authorized to U.S. Government Agencies and America Makes Members. Other request for this document shall be referred to AFRL/RXMS, Wright-Patterson Air Force Base, OH 45433-7750.
4:10 PM
The Effect of the Cross-sectional Area on the Microstructure and Mechanical Properties of AlSi10Mg Parts Manufactured by Laser Powder Bed Fusion (L-PBF): Nujood Alshehhi1; Lewis Kindleyside2; Nesma Aboulkhair1; 1TII; 2Khalifa University
Defects’ formation in parts produced by Laser Powder Bed Fusion (L-PBF) is one of the biggest challenges facing the wider adoption of additive manufacturing. Extensive research effort is invested in optimising the process parameters to produce defect-free parts. These studies primarily optimise the process parameters for a fixed size sample. Recent studies on Ti- and Ni-alloys have shown that an optimised set of process parameters might not be as effective if the sample size changes beyond a specific range. Not only does the content of defects change with the sample size but also the microstructure and mechanical properties. Therefore, in this study we investigate the correlation between the samples’ sizes and an ‘optimised’ set of process parameters in the case of L-PBF of AlSi10Mg alloy, evaluating the effect on the microstructure and mechanical properties.
4:30 PM
The Influence of the Characteristic Microstructure of Additively Manufactured AlSi10Mg on the Mechanical Behaviour at Various Strain Rates: Natalia Ghisi1; Henrique Ramos1; Rafael Santiago1; Lewis Kindleyside2; Wesley Cantwell2; Nesma Aboulkhair3; 1TII; 2Khalifa University; 3University of Nottingham
The capability of additive manufacturing to fabricate complex geometries enables engineering the mechanical performance and failure modes of components through controlled-porosity in the form of lattice structures. The energy absorption field, among other sectors, is largely benefitting from this. Understanding the mechanical behavior of these designs under various strain rates is imperative for designing energy absorption structures, such as protective panels and impact-shielding. Thus, this research presents a study on the influence of the microstructure and anisotropy of AlSi10Mg lattice structures produced by Laser Powder Bed Fusion (L-PBF) on their mechanical behaviour when tested under various strain rates. The samples were built using various build directions and scan strategies. Metallography was used to study the microstructure and the fracture surfaces. These results were analyzed together with mechanical testing results obtained using Digital Image Correlation (DIC) technique to develop a full understanding of the process-structure-property relationships in L-PBF produced lattice structures.
4:50 PM Concluding Comments