Materials Science and Engineering Commons^™

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The corrosion of structural materials is a major concern for the use of lead-bismuth eutectic (LBE) systems for nuclear applications such as in transmuter targets or fast reactors. Corrosion in liquid metal systems can occur through various processes, including, for example, dissolution, formation of inter-metallic compounds at the interface, and penetration of liquid metal along grain boundaries. Predicting the rate of these processes depends on numerous system operational factors: temperature, system geometry, thermal gradients, solid and liquid compositions, and velocity of the liquid metal, to name a few. Corrosion, along with mechanical and/or hydraulic factors, often contributes to component failure. …

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The focus of this work is to determine the effect of elevated temperatures on the tensile properties of Alloy EP-823 and other martensitic alloys having similar compositions. The information obtained through this work describing the mechanism of elevated-temperature deformation will assist in developing suitable target structural materials possessing enhanced LBE corrosion resistance at process temperatures, allowing the continued development and eventual deployment of these technologies.

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements, Ajit K. Roy

Transmutation Sciences Materials (TRP)

Metals and alloys, when subjected to tensile loading beyond a limiting value, can undergo plastic deformation resulting in lattice defects such as voids and dislocations. These imperfections may interact with the crystal lattice, producing a higher state of internal stresses characterized by reduced ductility. Residual stresses can also be generated in welded structures due to rapid rate of solidification, and dissimilar metallurgical microstructures between the weld and the base metals. Premature failures can be experienced in engineering metals and alloys due to the presence of these residual stresses. Specific thermal treatments commonly known as stress relief operations can relieve these …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications: Quaterly Report, Biswajit Das

Transmutation Sciences Materials (TRP)

During the past quarter, this project employed one graduate student and two undergraduate student researchers and made the following accomplishments :

• Acquisition of steel samples for experiments

• Design and fabrication of specialized anodization apparatus to accommodate steel samples

• Investigation of adhesiveness of aluminum on steel

• Investigation of effects of anodizing acids on steel to identify most appropriate acid and a suitable barrier material

Stress Corrosion Cracking Of Target Material, Mohammad K. Hossain

Transmutation Sciences Materials (TRP)

The primary objective of this paper is to evaluate the effect of hydrogen on environment assisted cracking of candidate target materials for transmutation applications. Transmutation refers to transformation of long-lived actinides and fission products from spent nuclear fuels (SNF), and occurs when the nucleus of an atom changes because of natural radioactive decay, nuclear fission, nuclear fusion, neutron capture, or other related processes. Martensitic Alloy EP 823 was selected to be the candidate alloy for this investigation. During the initial phase, the stress corrosion cracking (SCC) behavior of this alloy was evaluated in neutral (pH: 6-7) and acidic (pH: 2-3) …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion, Clemens Heske

Fuels Campaign (TRP)

The goal of this project is to elucidate the chemical bonding and interface formation of metal fission products with the coating materials used in state-of-the-art TRISO fuel particles. Particular emphasis is placed on an analysis of intermediate chemical phases at the interface, the intermixing/diffusion behavior, and the electronic interface structure as a function of material choice (metal and coating materials), temperature, and external stress. Furthermore, we intend to assess the chemical state of some of the metal fission products. The findings are expected to give valuable information about failure mechanisms of TRISO particles and fission product transport. Secondly, through simulating …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 3rd Quarter Report, 2004, Clemens Heske

Fuels Campaign (TRP)

The goal of this project, which started in May 2004, is to elucidate the chemical bonding and interface formation of metal fission products with the coating materials used in state-of-the-art TRISO fuel particles. Particular emphasis is placed on an analysis of intermediate chemical phases at the interface, the intermixing/diffusion behavior, and the electronic interface structure as a function of material choice (metal and coating materials), temperature, and external stress.

In detail, this project is devoted to studying the interface formation of Pd, Ag, and Cs with SiC and pyrolytic carbon. Using the TRISO coating materials and single crystal references as …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 4th Quarter Report, 2004, Clemens Heske

Fuels Campaign (TRP)

The goal of this project, which started in May 2004, is to elucidate the chemical bonding and interface formation of metal fission products with the coating materials used in state-of-the-art TRISO fuel particles. Particular emphasis is placed on an analysis of intermediate chemical phases at the interface, the intermixing/diffusion behavior, and the electronic interface structure as a function of material choice (metal and coating materials), temperature, and external stress. In detail, this project is devoted to studying the interface formation of Pd, Ag, and Cs with SiC and pyrolytic carbon. In order to study the properties of the relevant interfaces, …

Commissioning Of An Arc-Melting/Vacuum Quench Furnace Facility For Fabrication Of Ni-Ti-Fe Shape Memory Alloys, And The Characterization, Jagat Singh

Electronic Theses and Dissertations

Shape memory alloys when deformed can produce strains as high as 8%. Heating results in a phase transformation and associated recovery of all the accumulated strain, a phenomenon known as shape memory. This strain recovery can occur against large forces, resulting in their use as actuators. The goal of this project is to lower the operating temperature range of shape memory alloys in order for them to be used in cryogenic switches, seals, valves, fluid-line repair and self-healing gaskets for space related technologies. The Ni-Ti-Fe alloy system, previously used in Grumman F-14 aircrafts and activated at 120 K, is further …