Powder Materials for Energy Applications: Additive Manufacturing and Harsh Environment Materials
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Powder Materials Committee
Program Organizers: Kathy Lu, University of Alabama Birmingham; Eugene Olevsky, San Diego State University; Somayeh Pasebani, Oregon State University; Hang Yu, Virginia Polytechnic Institute And State University
Thursday 8:30 AM
February 27, 2020
Room: 17A
Location: San Diego Convention Ctr
Session Chair: Somayeh Pasebani, Oregon State University; Kathy Lu, Virginia Tech
8:30 AM Invited
Is Additive Manufacturing a Competition or Complimentary Technology to Current Processing of Metals?: Wojciech Misiolek1; 1Lehigh University
Analysis of Additive Manufacturing competitiveness will be performed using mechanical properties of 3D printed parts of selected metals and alloys. Copper has its prominent place among other metals as very good conductor. There is huge opportunity for copper and copper alloys to be used in electro-mechanical devices and machinery while fabricated by the additive manufacturing techniques. Selective Laser Melting (SLM) approach was used to fabricate samples in two copper systems, namely Cu-Si and Cu-Ni-Si. After optimization of the SLM process samples were printed under various conditions and their density, mechanical properties were evaluated. A heat treatment was used for Cu-Ni-Si alloy to strengthen it via precipitation hardening process to achieve comparable mechanical results to traditionally used today wrought alloys. Additional AM experiments were performed for Tungsten and Aluminum Alloys since these metal systems are very important for various applications and potential Additive Manufacturing could create new possibilities for these metals.
9:00 AM Invited
Novel Additive Manufacturing Process Design for U3Si2 Fuel: Isabella Van Rooyen1; 1Idaho National Laboratory
Adoption of additive manufacturing (AM) for energy applications are rapidly growing as the advantages within the flexible design domains and economic advantages. Specifically, new adopters within the nuclear industry are branching also to the fuel fabrication domain. An accident tolerant fuel concept by Westinghouse Electric Company LLC (WEC) includes U3Si2 fuel, chosen for its benefits in increased thermal conductivity. Shortened and consistent fabrication process exploration lead to the Idaho National Laboratory invention, AMAFT. The AMAFT process in combination with other hybrid advanced manufacturing processes, provides the unique capability to utilize multiple raw material sources, which yield commercial capabilities. Feasibility results will be discussed which includes thermodynamic and benchtop surrogate experimental results. Cerium, zirconium, and hafnium were down selected as surrogates based on their thermodynamic properties and crystal structure. Results from the surrogate compounds have provided microstructural data to design the experimental set-up to produce uranium compounds.
9:30 AM
Microstructural Evolution of a Nanostructured Ferritic Alloy Composite during In-situ Ion Irradiation: Kathy Lu1; Kaustubh Bawane1; David Bai1; Jing Hu2; Meimei Li2; 1Virginia Polytechnic Institute and State University; 2Argonne National Laboratory
Silicon carbide and carbon coated nanostructured ferritic alloy (SiC-C@NFA) composites are promising cladding materials for next-generation reactors. In this study, this material system was irradiated with Kr++ ions at 1 MeV energy up to 10 dpa at 300°C and 450°C. Microstructures and defect evolution were studied in-situ using the IVEM facility at Argonne National Laboratory. The effect of ion irradiation on various phases such as α-ferrite (NFA) matrix, (Fe,Cr)7C3, and (Ti,W)C precipitates were evaluated. The α-ferrite matrix showed a continuous increase in dislocation density along with spatial ordering (or loop string) of dislocations at >5 dpa irradiation. The size of the dislocation loops at 450°C was higher than that at 300°C. The nucleation and growth of new (Ti,W)C precipitate in α-ferrite grains increase with the ion dose at 450°C. This study provides an in-depth understanding of the ion irradiation resistance of the SiC-C@NFA system.
9:50 AM Break
10:10 AM Invited
Materials for Nuclear Applications Produced by Powder-based Techniques: Stuart Maloy1; Ben Eftink1; Tarik Saleh1; Osman El-Atwani1; John Carpenter1; Eda Aydogan2; Thomas Lienert3; Mychailo Toloczko4; Thak Sang Byun4; Curt Lavender4; George Odette5; David Hoelzer6; 1Los Alamos National Laboratory; 2Sabanci University; 3Optomec Corporation; 4Pacific Northwest National Laboratory; 5University of California, Santa Barbara; 6Oak Ridge National Laboratory
The Nuclear Technology R&D program is investigating improved fuels for advanced reactors. These new fuels and cladding materials must be developed and tested to high burnup levels (e.g. >20%) requiring cladding to withstand very high doses (greater than 200 dpa) while in contact with the coolant and the fuel. New ferritic/martensitic and ferritic Oxide Dispersion Strengthened (ODS) alloys are being developed with improved radiation tolerance. These advanced materials are being produced through powder-based techniques. Ferritic/martensitic (F/M) steels (e.g. grade 91) are being produced through additive manufacturing (AM) while ferritic ODS alloys are being processed through powder metallurgy (PM) techniques. The AM produced F/M steels show very high strength up to 650C while maintaining excellent ductility while the ferritic ODS steels show good high temperature strength and excellent radiation tolerance. Recent progress in these two new alloys will be presented.
10:40 AM Invited
Processing and Characteristics of Nanostructured Ferritic Alloys for Nuclear Reactor Applications: Thak Sang Byun1; David Hoelzer1; 1Oak Ridge National Laboratory
The powder-metallurgy based nanostructured ferritic alloys (NFAs) have been considered as prominent materials for future fission and fusion reactor core components because of their excellent creep strength and resistance to radiation-induced degradation of mechanical properties. Special milling and consolidation processes have been developed for improving the mechanical properties of NFAs as their nanocluster-strengthened microstructures often show high-temperature embrittlement and poor ductility. This talk is to summarize the processing routes and practices that have been developed to produce advanced NFAs with excellent high-temperature mechanical properties, as well as with uniquely-high defect sink efficiencies. The discussion will focus on the processing development efforts for improving the fracture toughness and fabricability of the phase-transformable 9Cr and 12Cr NFAs and the 14Cr NFAs with highly stabilized microstructures. It was demonstrated that a carefully designed milling process combined with a low temperature consolidation and/or a thermomechanical treatment could lead to significant improvement in mechanical properties.
11:10 AM
Microstructural Evolution of NFA and Cr3C2@SiC-NFA Composite during Ion Irradiation: Kathy Lu1; Kaustubh Bawane1; David Bai1; Meimei Li2; 1Virginia Polytechnic Institute and State University; 2Argonne National Laboratory
Ion irradiation responses of a Fe-based nanostructured ferritic alloy or ‘NFA’ (Fe-9Cr-2W-0.2V-0.4Ti-0.3Y3C2) and a Cr3C2@SiC-NFA composite were assessed. In-situ ion irradiation with TEM observation was carried out using 1 MeV Kr++ ions at doses of 0, 1, 3, 5, and 10 dpa and temperatures of 300°C and 450°C. Both the NFA and Cr3C2@SiC-NFA samples showed significant dislocation density after 10 dpa at 300°C. However, the Cr3C2@SiC-NFA composite showed a lower dislocation loop density and a smaller average loop size during the irradiation at 450°C as opposed to the NFA. Interestingly, at 450°C, <100> type loops were dominant in the NFA sample while 1/2<111> type loops were still dominant in the Cr3C2@SiC-NFA sample. The results were discussed based on the large surface sink effects and enhanced interstitial-vacancy recombination at higher temperatures. The additional Si element in the Cr3C2@SiC-NFA sample might have played a significant role in determining the dominant loop types.
11:30 AM Cancelled
Synthesis and Characterization of Lanthana Based ODS Steel for Nuclear Reactor Applications: Ashwani Kumar1; Krishanu Biswas1; Sudhanshu Singh1; 1IIT Kanpur
Oxide dispersed strengthened (ODS) ferritic steels have emerged as promising material for the core of nuclear reactors due to a good combination of resistance to radiation and high temperature strength. The most commonly used oxide in ODS steels is yttria (Y2O3). Although extensive studies have been carried out with yittria in ODS steels, other rare earth oxides have not been explored. In the present study, tungsten containing ODS steel (Fe-14Cr-1Ti-xW-0.5L2O3) has been fabricated by mechanical alloying followed by spark plasma sintering. The variation of tungsten (W) content and temperature (1050oC and 1100oC) on the microstructure and mechanical properties of lanthana based ODS steel have also been studied. Microstructural characterization was performed using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The quantification of mechanical properties using nano-indentation and compression testing indicated that 14LWT ODS steels exhibit equivalent or better mechanical properties than the conventional 14YWT ODS steels.