Additive Manufacturing: Materials Design and Alloy Development IV: Rapid Development: Other Alloys
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Behrang Poorganji, Morf3d; Hunter Martin, HRL Laboratories LLC; James Saal, Citrine Informatics; Orlando Rios, University of Tennessee; Atieh Moridi, Cornell University; Jiadong Gong, Questek Innovations LLC
Thursday 8:30 AM
March 3, 2022
Room: 261A
Location: Anaheim Convention Center
Session Chair: Orlando Rios, University of Tennessee
8:30 AM
Additive Manufacturing of AlCu0.5FeNiCoCr High-Entropy Alloy: Bandar AlMangour1; 1King Fahd University of Petroleum and Minerals
In the present research work, a high-entropy alloy of AlCu0.5FeNiCoCr was fabricated by selective laser melting. The samples were characterized by x-ray diffraction, scanning electron microscope, electron backscattered diffraction, CT scanning, and compression testing. The study showed the ability to tailor the microstructure and mechanical properties under various conditions. However, this study also demonstrates that not all alloys are designed for additive manufacturing.
8:50 AM
NOW ON-DEMAND ONLY - Laser Powder Bed Fusion Additive Manufacturing of Pure Copper (Cu) Metal: Maryam Sadeghilaridjani1; Leila Ladani1; 1Arizona State University
Copper is the common metal used as conductors in many applications such as structural aerospace or electrical components. These applications usually require parts with complex geometry which are challenging to get using conventional manufacturing techniques. Additive manufacturing (AM) as a disruptive technology allows the production of unique and complex custom-made part. However, there are limited study on AM of pure copper, particularly for laser powder bed fusion (LPBF) approaches due to challenges associated with its high thermal conductivity. Here, we studied the feasibility of fabrication of pure copper using LPBF-AM. The process parameter including scan speed, laser power, and hatch spacing were varied to find optimum condition to obtain high quality part. The surface roughness, microstructure, density, and thermal conductivity of parts were investigated. The results showed that the bulk copper sample with surface roughness below 20 µm and relative density of > 90% was successfully fabricated using LPBF-AM technique.
9:10 AM
Rapid Design and Evaluation of Compositionally Complex Alloys by Combining Additive Manufacturing with Machine Learning Methods: Phalgun Nelaturu1; Jason Hattrick-Simpers2; Michael Moorehead1; Santanu Chauduri3; Adrien Couet1; Dan Thoma1; 1University of Wisconsin; 2National Institute of Standards and Technology; 3Argonne National Laboratory
A framework was developed to rapidly explore any alloy system for any desired property by combining high-throughput experimental and computational techniques. We demonstrated this framework by designing materials with desired hardness in two quaternary alloy systems, Cr-Fe-Mn-Ni and Cr-Fe-Mo-Ni. In-situ alloying via directed energy deposition was used to rapidly synthesize more than 200 discrete, bulk samples of unique alloy compositions, exploring a vast portion of the composition space. Tight compositional control within ±10 at% and unmelted powder fraction <0.3% were achieved. The alloys were rapidly characterized via SEM, micro-hardness measurements, and automated XRD and EDS. This large dataset of experimentally measured properties was used to develop a predictive hardening model using active machine learning. The outcome of this effort was the discovery of a learned parameter, deltaLP, that was representative of the lattice distortion in these alloys. deltaLP was trained using the alloy compositions and was highly predictive of hardness.
9:30 AM
NOW ON-DEMAND ONLY - Site-specific Grain Boundary Engineering of Additively Manufactured Stainless Steel: Shubo Gao1; Matteo Seita1; 1Nanyang Technological University
Owing to the copious mechanical strain required, conventional grain boundary engineering (GBE) processing of metals and metal alloys is unfit to parts produced via additive manufacturing (AM). However, being able to control the grain boundary character distribution in AM would open the path to producing high-performance metal parts with complex geometry. We present a possible strategy to achieve this goal, which we term “additive grain boundary engineering” (AGBE). By tuning the process parameters during laser powder bed fusion (LPBF) of 316L stainless steel, we gain site-specific control of the solidification microstructure—including cell size and level of micro-segregation—which dictate the alloy thermal stability. Upon heat treatment, this controlled microstructure heterogeneity leads to site-specific recrystallization, which in turn enables engineering the grain boundary character distribution.
9:50 AM Break
10:05 AM
Versatile Additive Manufacturing of Metals and Alloys via Hydrogel Infusion: Max Saccone1; Daryl Yee2; Rebecca Gallivan1; Kai Narita1; Julia Greer1; 1Caltech; 2MIT
We report a streamlined technique for the additive manufacturing (AM) of a variety of metals and alloys. Hydrogels are formed via vat polymerization, then infused with appropriate metal precursors. Calcination and reduction convert the hydrogel into the target metal or alloy. Unlike previous vat polymerization strategies which incorporate target materials or precursors into the resin, our method does not require re-optimization of resins and curing parameters when the target material is changed and therefore enables quick iteration and compositional tuning. As proof of concept, we fabricated octet lattice architectures with ~50 µm feature size from several materials including copper, nickel, silver, cupronickel alloys, copper-silver alloys, and tungsten. We characterized these materials to show the unique microstructures enabled by our technique and demonstrate the link to mechanical properties measured by nanoindentation. This work represents a powerful new tool for the rapid and facile development of AM metals and alloys.
10:25 AM
Comparison of Multiple Rapid Solidification Techniques to Accelerate Stainless Steel Alloy Development in Additive Manufacturing: Zachary Hasenbusch1; Johnathan Roze1; Andy Deal2; Ben Brown2; Davis Wilson2; Laurentiu Nastac1; Luke Brewer1; 1University of Alabama; 2Honeywell FM&T
This presentation will discuss the use of multiple rapid solidification processing (RSP) techniques for two different alloys within the AISI 240 spec for 316L to observe the effects of composition and rapid solidification rate on the solidification microstructure. The alloys have similar compositions, except the Ni concentration is either 10.5 wt% or 13.5 wt%. The three RSP techniques (two-piston splat quenching, gas atomization, and laser powder bed fusion) cover a wide range of cooling rates between 103 K/s – 107 K/s. A combination of optical microscopy, electron microscopy, quantitative x-ray spectroscopy, electron backscatter diffraction, and vibratory sample magnetometry is used to observe microstructural features such as phase content, cell size, and nano segregation. This work was funded by the Department of Energy’s Kansas City National Security Campus which is operated and managed by Honeywell Federal Manufacturing Technologies, LLC under contract number DE-NA0002839.
10:45 AM
Mechanical Behavior of Functionally Integrated Materials Produced by Directed Energy Deposition: Benjamin MacDonald1; Baolong Zheng1; Sen Jiang1; Penghui Cao1; Lorenzo Valdevit1; Enrique Lavernia2; Julie Schoenung1; 1University of California, Irvine; 2National Academy of Engineering
Injected powder directed energy deposition additive manufacturing (DED-AM) enables the precise control of composition as a function of location in the built part. This control has enabled the field of research in so-called functionally integrated materials (FIMs) where this control allows for the development of site-specific functionality in both mechanical and physical properties. In this work, gradients of 316L stainless steel and Haynes 282 nickel-based superalloy are deposited through the manipulation of two independent powder delivery systems of a DED-AM system. Deposits containing no gradient interlayer, a 50% increment interlayer, a 25% increment interlayer, and a 10% increment interlayer are synthesized to determine the effects of resolution on joining the two feedstock materials. Through microstructural and mechanical characterization, the role of local compositional changes on the printability and mechanical behavior is elucidated. The experimental results are compared to predictions of phase stability and solidification behavior calculated using Thermo-Calc software.
11:05 AM
Efficacy of Elemental Mixing for In Situ Alloyed Al-33wt%Cu during Laser Powder Bed Fusion: Jonathan Skelton1; Eli Sullivan1; James Fitz-Gerald1; Jerrold Floro1; 1University of Virginia
Alloy development for laser powder bed fusion (LPBF) is hindered by lack of access to custom powder feedstocks. To circumvent this, in situ alloying of elemental powder during LPBF processing is investigated for rapid prototyping of new alloy compositions. The effect that powder size distribution in elemental powder blends has on the compositional homogeneity of built samples is studied with respect to the laser processing parameters. The microstructure of the Al-Cu eutectic system serves here as an indicator of the mixing efficacy during laser melting, where deviations of the solute concentration from the eutectic composition can be observed through hypo- or hypereutectic regions that form. These composition deviations arise when the melt pool size encompasses insufficient particles to be a stochastic representation of the blend, suggesting that liquid phase intermixing limitations are less important than the melt pool volume itself. Support of the NSF under grant DMR-1663085 is gratefully acknowledged.