Characterization of Minerals, Metals and Materials: Characterization of Mechanical Properties II
Sponsored by: TMS Extraction and Processing Division, TMS: Materials Characterization Committee
Program Organizers: Jian Li, CanmetMATERIALS; Mingming Zhang, Baowu Ouyeel Co. Ltd; Bowen Li, Michigan Technological University; Sergio Monteiro, Instituto Militar de Engenharia; Shadia Ikhmayies; Yunus Kalay, Middle East Technical University; Jiann-Yang Hwang, Michigan Technological University; Juan Escobedo-Diaz, University of New South Wales; John Carpenter, Los Alamos National Laboratory; Andrew Brown, Devcom Arl Army Research Office
Thursday 2:00 PM
February 27, 2020
Room: Theater A-5
Location: San Diego Convention Ctr
Session Chair: Juan Escobedo-Diaz, University of New South Wales; John Carpenter, Los Alamos National Laboratory
2:00 PM
Deformation Behavior of Mg-Al-Mn Sheets: Patrik Dobron1; Daria Drozdenko1; Michal Knapek1; Jan Bohlen2; Frantisek Chmelik1; 1Charles University; 2Helmholtz-Zentrum Geesthacht
The activity of individual deformation mechanisms which occur during tensile loading of Mg-Al-Mn sheets was investigated using the acoustic emission (AE) technique. The investigated sheets exhibited a typical basal texture with basal planes oriented nearly parallel to the rolling direction. Tensile tests were performed at room temperature and deformation behavior was analyzed by digital image correlation (DIC). The obtained results were supported by microstructure evolution analysis provided by electron backscattered diffraction (EBSD). The AE signal analysis correlated the microstructure and the stress-strain curves to the active deformation mechanisms quite well. To determine the dominant deformation mechanism in a given time period, the adaptive sequential k-means (ASK) clustering was applied.
2:20 PM
Investigation of Impact Toughness of Electron Beam Welded AISI 321 SS at Cryogenic Temperatures: Sandeep Sandhu1; Ajay Sharma1; Vineet Prabhakar2; 1Quest Engineering College; 2SUS Engineering College, Tangori
In this piece of research work, 18mm thick austenitic stainless steel AISI 321 was welded with Electron Beam Welding, to investigate the effect of welding parameters on the impact strength. Addition of Titanium in AISI 321, makes it resistant to intergranular corrosion at high temperature of 850°C approximately, thus it is used in exhaust of jet engines. In this paper single pass, square butt joint is fabricated using autogenous EBW at voltage 150 kV, current 90 mA and welding speed 600 mm/min. The metallographic studies were conducted using SEM and optical microscope. The microhardness and impact strength were investigated in as welded condition and after thermally ageing it at 750°C for 24 hours. The average impact toughness conducted using chary impact test at cryogenic temperature i.e. -40°C in as welded samples was recorded as 274J and it got reduced to 252 J after aging treatment of 750°C for 24 hours.
2:40 PM
The Influence Irradiation Conditions on the Microstructural Evolution of Irradiated U-Mo Fuels: Charlyne Smith1; Dennis Keiser2; Brandon Miller2; Assel Aitkaliyeva1; 1University of Florida; 2Idaho National Laboratory
Fission gas accumulation, and its eventual release, are one of the main causes of failure observed in irradiated U-Mo fuels. This work reports the impact of irradiation conditions on the microstructural behavior of two U-7wt%Mo dispersion fuel mini-plates. These two mini-plates were irradiated to similar conditions, with the exception of two parameters: fission power and U-235 burnup. Our data show that these irradiation conditions can significantly influence fuel recrystallization, creep, and pore size distribution. As expected, higher fission rate and burnup result in higher porosity and fuel recrystallization behavior. Both plates showed evidence of pore interconnection, which indicates that fission gas release may occur as early as 4.45×1021 fiss/cm3. Various image analysis tools were implemented to extract additional information, such as eccentricity, and correlate it to the stress-induced creep of the fuel plates.
3:00 PM
Microstructural Evolution of γ'-Ni3Al Precipitates Affecting Mechanical Properties of Nickel-based Superalloys: Rasim Eris1; M. Vedat Akdeniz1; Amdulla O. Mekhrabov1; 1Middle East Technical University
Nickel-based superalloys are exceptional materials due to their novel two phase (γ-γ') microstructures. In this study, the effects of ternary alloying X element additions and heat treatment procedures on the microstructural evolution of γ'-Ni3Al precipitates and mechanical properties of Ni80Al15X5 alloy systems (i.e. X = Cr, Co, Nb or Ti) will be presented. Furthermore, the results of the experimental studies will be supported by modelling and theoretical first-principles calculations via charge density difference (CDD), electron localization function (ELF) and density of states (DOS) simulations which demonstrate site preferences and bonding characteristics of alloying X element atoms with their next neighbour atoms.
3:20 PM
Influence of PWHT on Impact Toughness of Electron Beam Welded AISI 409 Stainless Steel: Akash Doomra1; Sandeep Sandhu1; Beant Singh2; 1Quest Engineering College; 2PCET Lalru
Ferritic stainless steel are considered as an alternative to SS and CS as it possess desirable mechanical properties at low price however it has poor weld ability. Ferritic steels suffer from fall in mechanical properties due to high grain growth in the HAZ during welding. In this piece of research 409 ferritic steel plates of 18mm thickness are welded with single pass electron beam welding. The joint was subjected to metallurgical examination in as welded condition and after PWHT at 500°C for 75 minutes (furnace cooled). Due to rapid solidification, ferrite grains in the HAZ changed the morphology from equiaxed to columnar. The charpy impact test was done at both at room temperature and cryogenic temperature (-40°C). The material showed nearly equal to zero impact toughness at -40°C in both as welded and after PWHT. It possessed acceptable toughness of 28 J when tested at room temperature.
3:40 PM Break
3:55 PM
Calibrating Yield Criteria in 6 Dimensions: A Collection of Analytic and Experimental Case Studies: Zachary Brunson1; Aaron Stebner1; 1Colorado School of Mines
More anisotropic materials than ever before are being used as technological and material developments continue to advance the field of solid mechanics; everything from Magnesium sheet and NiTi tubes to additively manufactured Inconel and fiber reinforced composites possess anisotropy. As recently brought to light in ‘New Perspectives on Elastic Limit Hypersurfaces: The Need for Six Dimensions in Modeling Anisotropic Materials,’ the elastic limit of a material describes a bounding hypersurface in six dimensions, and when considering anisotropic materials all six dimensions are necessary. Classical approaches to calibrating yield criteria have hinged on graphical techniques which were limited to at most a three-dimensional platform. This presentation explores how to extend these graphical techniques to appropriately address all six dimensions, introduces equation-based calibration approaches, and presents a collection of analytic and experimental case studies for calibrating a complete six-dimensional yield hypersurface.
4:15 PM Cancelled
The Evolution of Precipitates in a Novel Heat-resistant Martensitic Steel During Creep: Pengyu Wen1; Haiwen Luo1; Zhengdong Liu2; Zhengzong Chen2; 1University of Science and Technology Beijing; 2China Irons & Steel Research Institute Group
In the past decades, several 9-12 wt.% Cr containing martensitic steels have been researched for the application in ultra-supercritical power plants at 650 ℃, which is still a worldwide challenge. Among them, G115 martensitic steel, which was developed in China, is one of promising candidates. It has the basic composition of 9% Cr-3% W-3% Co and also contains 1% Cu and the optimized contents of B and N, leading to much better creep strength and creep ductility than P92. Both M23C6 carbides and ε-Cu particles were found during the tempering of G115, and the former have finer size than those in P92, which results in Laves phase to form with the refined size too during the latter creep stage but no BN found. All these formed precipitates shall contribute to improved creep performance of G115 since they dominate the recovery kinetics of tempered martensitic lath structure.