Additive Manufacturing: Materials Design and Alloy Development II: Alloy Design-Aluminum Alloys and Composites
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Behrang Poorganji, Morf3d; James Saal, Citrine Informatics; Orlando Rios, University of Tennessee; Hunter Martin, HRL Laboratories LLC; Atieh Moridi, Cornell University
Tuesday 2:00 PM
February 25, 2020
Room: 6F
Location: San Diego Convention Ctr
2:00 PM Invited
Application of Direct Aluminothermic Reduction to the Production of Al-Ce-based Alloys for Additive Manufacturing: Scott McCall1; Alexander Baker1; Hunter Henderson2; Zachary Sims2; Orlando Rios2; David Weiss3; Corby Anderson4; 1Lawrence Livermore National Laboratory; 2Oak Ridge National Laboratory; 3Eck Industries; 4Colorado School of Mines
Recent advances in aluminum-cerium alloys have produced outstanding high temperature mechanical properties for an aluminum-based alloy, especially in additive manufacturing applications. Under rapid solidification conditions inherent to AM, the alloys exhibit a nanoscale architecture that is extremely resistant to coarsening. Despite these benefits, the suitability for commercial adaption of alloys depends heavily on its economic viability. A significant fraction of the expense in scaling production of Al-Ce alloys arises from the energy requirements to reduce Ce metal and the associated safety requirements for transporting the reactive pure cerium metal. These costs can be sharply mitigated by exploiting direct reduction of ceramic cerium precursors in molten aluminum. This presentation will focus on how the resulting alloys may offer additional mechanical property and economic benefits, especially when deployed in AM approaches.
2:30 PM
Additive Manufacturing of Al-10Ce Alloys by Laser Powder Bed Fusion of Gas Atomized Powders: Le Zhou1; Holden Hyer1; Sharon Park1; Thinh Huynh1; Brandon McWilliams2; Kyu Cho2; Yongho Sohn1; 1University of Central Florida; 2US Army Research Laboratory
The increasing demand for additive manufacturing (AM) continuously drives the development of AM-specific materials, including novel aluminum (Al) alloys. Cerium (Ce) is known to be beneficial to the corrosion resistance and high temperature strength of Al-alloys. Binary eutectic Al-10Ce alloys were manufactured by laser powder bed fusion (LPBF) using gas-atomized powders. Initial parametric investigation was carried out to determine the optimal parameter that yields near-full density. The phases and microstructural details of the as-cast, powders and as-built Al-10Ce were examined by optical and electron microscopes. The as-built Al-10Ce exhibited fine cellular microstructure due to the fast cooling rate, similar to that in LPBF AlSi10Mg alloys. The presence of fine eutectic Al+Al11Ce3 along the intercellular boundary was confirmed by transmission electron microscope. Various heat treatments were performed on the as-built Al-10Ce alloys and examined through hardness measurements. Tensile properties of the as-built and heat-treated Al-10Ce alloys will be reported.
2:50 PM
CALPHAD Aided Design of Aluminum Alloys for Additive Manufacturing: Emily Moore1; Zachary Sims2; Orlando Rios2; Scott McCall1; Aurélien Perron1; 1Lawrence Livermore National Laboratory; 2Oakridge National Laboratory
The development of new Aluminum alloys to include Cerium is currently being investigated to mitigate the mining-economics of rare earth elements. Thermochemical models using the CALPHAD (CALculation of PHAse Diagrams) method aid in alloy design for additive manufacturing by predicting the phase-behavior of multi-component systems to achieve the desired chemical makeup of an alloy. A thermodynamic database that covers the description of the multi-component Al-Ce-Cu-Fe-La-Mg-Ni-Si-Zn-Zr system has been developed. Equilibrium calculations and Scheil simulations are performed to elucidate phase relations for the development of two sets of alloys: the Al-Ce-Mg-Si (Ce-modified A-356) and Al-Ce-Cu-X, with X=Si,Fe,Mg alloy. In coupling thermochemical models with experiment, two newly developed Al-3.5Ce-0.4Mg-7Si and Al-19Ce-0.9Mg-1.1Si alloys that exhibit improved mechanical properties are presented. Prepared by LLNL under Contract DE-AC52-07NA27344. Research supported by CMI, an Energy Innovation Hub funded by the U.S. DOE, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office.LLNL-ABS-779577
3:10 PM
Design of Al-Fe-Si-based Additively Manufactured High Temperature Light Weight Alloys: Sujeily Soto-Medina1; Biswas Rijal1; Lilong Zhu1; Richard Hennig1; Michele Manuel1; 1University of Florida
Transportation industries are in constant search for low-cost lightweight, high-temperature materials. The Al-Fe-Si system provides an opportunity to develop such a material, as it comprises of the three low cost elements that are all abundant in nature. The intermetallic Al4Fe1.7Si (τ11) is of particular interest due to its low theoretical density, potential mechanical properties at high-temperatures and good corrosion resistance. Although this system displays promising properties, its small homogeneity range presents a limitation to potential applications in additive manufacturing. In order to increase its compositional range, quaternary additions are being explored. In the present work, we have determined the whole compositional range of Al4(Fe, Mn)1.7Si (τ11) using diffusion couples and equilibrated alloys. The composition was measured using EPMA, EDS and phase identification was carried out using XRD. This work was supported by U.S. Department of Energy under contract number DE-EE0007742.
3:30 PM Break
3:45 PM Invited
Additive Manufacturing of Advanced Aluminum-cerium Alloys: David Weiss1; Orlando Rios2; Justen Schaefer3; Jessica Orr3; Hunter Henderson2; Zachary Sims2; Scott McCall4; Ryan Ott5; 1ECK Industries Inc.; 2Oak Ridge National Laboratory; 3University of Dayton Research Institute; 4Lawrence Livermore National Laboratory; 5Ames Laboratory
Aluminum alloys are ubiquitous in light-weighting applications due to an excellent combination of high specific-strength and corrosion resistance, but often face challenges at the highest performance levels, where more costly and denser materials are needed, such as Ti-alloys. Here we discuss fabrication of highly stable, intrinsically nanocrystalline Al-based powders that provide exceptional precipitate strengthening via powder production and subsequent fabrication of these powders using laser powder bed fusion and powder consolidation techniques. Additive manufacturing synthesis routes permit the production of structures otherwise impossible through conventional bulk processing routes. Al-Ce alloys exhibit an excellent combination of thermal stability, and high-temperature strength. These alloys contain a high-volume fraction of Al11Ce3 intermetallic (>20 vol%) that resists coarsening at high-temperature due to the near zero (<10-4%) solubility of Ce in solid Al. This extreme thermal stability enabled us to set up the nanostructure during gas atomization and preserve it during solidification.
4:10 PM
Selective Laser Melting and Mechanical Properties of Al-Ce-X Alloys: Alex Plotkowski1; Ryan Dehoff1; Kevin Sisco2; Amit Shyam1; Sumit Bahl1; Andres Rossy1; 1Oak Ridge National Laboratory; 2University of Tennessee
The selection of Al alloys for additive manufacturing is severely limited by the cracking tendencies of most conventional wrought compositions. Al alloy production by AM has therefore been limited to a small subset of highly weldable alloys that generally exhibit poor mechanical properties compared to desirable aerospace grade alloys. These poor properties are especially noticeable at elevated temperatures (between 200 and 500 C) where most Al alloys tend to lose a large fraction of their room temperature strength. This presentation will summarize recent research in Al-Ce-X alloys that are designed for both printability and high-temperature strength. The processing, microstructure, and properties of these alloys will be discussed, and implications for future design and selection of Al alloys for AM printability will be presented as well as the outlook for industrial adoption.
4:30 PM
Additive Manufacturing of Immiscible Alloy Systems: Brennan Yahata1; Julie Miller1; Justin Mayer1; Stan Dudinski1; Eric Clough2; Toby Schaedler1; Hunter Martin1; Jacob Hundley1; Tresa Pollock3; 1Hrl Laboratories, Llc; 2HRL Laboratories, Llc; 3Univesity of California, Santa Barbara
Maturation of metal additive manufacturing technology has drastically expanded access to prohibitively complex geometric design producing unprecedented levels of performance at the component scale. At the scale of the microstructure, design of alloy constituents and processing parameters dictate microstructural evolution to produce structure morphologies compatible with the process to broaden the availability of alloys beyond the commercially available to traditional, higher performing alloy systems. Beneath this length scale, the unique melt pool conditions encountered of high thermal gradients and solidification velocities provide opportunity to enable novel metastable nanoscale architectures unachievable in any other type of manufacturing. Particularly, the processing of immiscible metals to form bicontinuous metal networks with tailorable features from <1um to 1mm becomes possible. Here we will present on the control of microstructural evolution in selective laser melting of continuous biphase nano-architectures across several high and low temperature immiscible metal systems.
4:50 PM
Nano-structured NiAl-Cr(Mo) In-situ Composites Processed by Additive Manufacturing: Andreas Foerner1; Steffen Neumeier1; Abdullah Jamjoom1; Carolin Körner1; Mathias Göken1; 1Friedrich-Alexander-Universität Erlangen
NiAl-Cr and NiAl-Cr(Mo) eutectic in-situ composites are promising high temperature materials due to a high melting point, excellent oxidation behavior and their low density. To enhance the poor room temperature fracture toughness of these composites, high cooling rates are beneficial to obtain fine cellular-lamellar structures, which can be achieved by additive manufacturing. The influence of SEBM process parameters on the microstructure and the mechanical properties of NiAlCr(Mo) were analyzed. In this study the investigations reveal a very high hardness of the composites due to the fine microstructure according to Hall-Petch strengthening. The eutectic microstructure is required to get good high temperature strength and creep properties. The fracture toughness was determined by microcantilever bending tests and fracture surfaces were analyzed to find toughness increasing mechanisms like crack bridging, renucleation or deflection at NiAl-Cr(Mo) interfaces. The research shows that SEBM is suitable to process NiAl-Cr(Mo) in-situ composites with promising mechanical properties.
5:10 PM Cancelled
Nitrogen Solid-solution Strengthened Titanium Materials Fabricated by SLM Process: Katsuyoshi Kondoh1; Ammarueda Issariyapat1; Patama Visuttipitukul2; Tingting Song3; Junko Umeda1; Ma Qian3; 1Osaka University; 2Chulalongkorn University; 3RMIT
Titanium powder metallurgy materials with solid solution nitrogen elements were developed by using pure Ti powder with high nitrogen contents (Ti-(N)), which was prepared via heat treatment from 640 °C - 800 °C in a N2 gas atmosphere. Ti2N compound layers were formed at the Ti-(N) powder surface as a shell, and solid solution nitrogen elements were also detected in the matrix of this powder. The oxygen content of the powder was the same as the original one before heat treatment. Ti-(N) powder was consolidated by selective laser melting process, where Ti2N compounds were completely decomposed and nitrogen elements existed as solution atoms. Tensile test results revealed that SLM Ti-0.31%N material exhibited a 0.2% yield stress of 904 MPa and 21.7% elongation, which were remarkably superior to the strength-ductility balance of SLM CP-Ti materials with 350 MPa YS and 22% elongation.