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Articles 1 - 9 of 9
Full-Text Articles in Engineering
Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed
Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed
Masters Theses
Fusion energy has been said to be the solution to all the world’s energy problems. The International Thermonuclear Experimental Reactor (ITER) is the flagship project to demonstrate the feasibility of fusion energy. The Central Solenoid (CS), an important component of the reactor, is needed to induce plasma current, initiate, ramp-up, ramp-down, and sustain plasma in a very controlled manner. In order to achieve this, the CS coil packs must be manufactured under controlled conditions. The CS conductor is an advanced cable-in-conduit Nb3Sn superconductor. The CS cable will be made in long continuous sections but with thousands of meter of cable …
Comparative Corrosive Characteristics Of Petroleum Diesel And Palm Biodiesel For Automotive Materials
A.S. Md Abdul Haseeb
Corrosive characteristics of biodiesel are important for long term durability of engine parts. The present study aims to compare the corrosion behavior of aluminum, copper and stainless steel in both petroleum diesel and palm biodiesel. Immersion tests in biodiesel (B100) and diesel (B0) were carried out at 80 °C for 1200 h. At the end of the test, corrosion characteristic was investigated by weight loss measurements and changes on the exposed metal surface. Surface morphology was examined by optical microscope and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Fuels were analyzed by using TAN analyzer, FTIR, GCMS and …
Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary
Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary
Amy J. Moll
Novel die-stacking schema using through-wafer interconnects require vias to be filled with electroplated Cu, resulting in thick copper films, and requiring an aggressive first-step CMP. This work investigates the effects of microstructure on CMP of copper films, which are not presently well understood. Bulk and local removal rates were investigated for several different microstructures. Surface orientation maps were created and the orientations of individual grains were correlated with topographical data to elucidate local removal behavior. Cu removal depends on the details of the microstructure, and certain microstructures allowed for either faster or more uniform removal of thick Cu films.
Nanoscale Metal-Metal Contact Physics From Molecular Dynamics: The Strongest Contact Size, Hojin Kim, Alejandro Strachan
Nanoscale Metal-Metal Contact Physics From Molecular Dynamics: The Strongest Contact Size, Hojin Kim, Alejandro Strachan
PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems
Using molecular dynamics we find that the tensile strength of the contacts between two clean platinum surfaces with nanoscale asperities is strongly size dependent with a maximum strength for contact lengths of approximately 5 nm. This is the first time a strongest size is observed in single crystals. The strengthening with decreasing size down to 5 nm results from a decrease in the initial density of mobile dislocations available for plastic deformation and the subsequent weakening originates from a reduction in the constraint to mechanical deformation inside the contact by the bulk.
Development Of A Plasma Arc Manufacturing Process And Machine To Create Metal Oxide Particles In Water From Wire Feedstock, Jonathan Alan George
Development Of A Plasma Arc Manufacturing Process And Machine To Create Metal Oxide Particles In Water From Wire Feedstock, Jonathan Alan George
Theses and Dissertations
A plasma arc erosion process can be used to create metal and metal oxide particles in the ultra-fine size range (<70 µm). An electric arc is struck between two metallic electrodes, submerged in water, melting the surface of the electrodes. When the arc collapses a high energy pressure wave strikes the molten surface of the electrode. When the pressure wave strikes the molten metal, small metallic particles are created from the molten metal and are immediately cooled in the water. Previous research developed a process that used a constant current power supply and electrode motion to create ultra-fine particles. This research improves upon previous research by using a pulsed power supply similar to those used in Electrical Discharge Machining (EDM). The pulsed power supply eliminates the need for electrode motion and improves the rate of particle production, provides control over size of the particles created, and reduces the amount of energy needed to produce the particles. The new process improves the maximum particle production rate from 3.6 g/hr to 14 g/hr, provides a method to control the mean diameter of the particles produced, and reduces the amount of energy needed from 200 kWh/kg(previous constant current process) to 10.6 kWh/kg(using the pulsed power supply).
Corrosion Characteristics Of Copper And Leaded Bronze In Palm Biodiesel
Corrosion Characteristics Of Copper And Leaded Bronze In Palm Biodiesel
A.S. Md Abdul Haseeb
Biodiesel has become more attractive as alternative fuel for automobiles because of its environmental benefits and the fact that it is made from renewable sources. However, corrosion of metals in biodiesel is one of the concerns related to biodiesel compatibility issues. This study aims to characterize the corrosion behavior of commercial pure copper and leaded bronze commonly encountered in the automotive fuel system in diesel engine. Static immersion tests in B0, B50 and B100 fuels were carried out at room temperature for 2640 h. Similar immersion tests in B0, B100 and B100 (oxidized) fuels were also conducted at 60 °C …
Adhesion At Diamond /Metal Interfaces: A Density Functional Theory Study, Haibo Guo, Yue Qi, Xiaodong Li
Adhesion At Diamond /Metal Interfaces: A Density Functional Theory Study, Haibo Guo, Yue Qi, Xiaodong Li
Faculty Publications
To understand the basic material properties required in selecting a metallic interlayer for enhanced adhesion of diamondcoatings on the substrates, the interfaces between diamond and metals with different carbide formation enthalpies (Cu, Ti, and Al) are studied using density functional theory. It is found that the work of separation decreases, while the interface energy increases, with the carbide formation enthalpy ΔHf (Tiys (Ti>Cu>Al), is needed to achieve a higher overall interface strength. In addition, when the surface energy is larger than the interface energy, a wetted diamond/metal interface is formed during diamondnucleation, providing the strongest adhesion …
Mechanical, Microstructure And Texture Properties Of Interstitial-Free Steel And Copper Subjected To Equal Channel Angular Extrusion And Cold-Rolling, A A. Gazder, S S. Hazra, C F. Gu, W Q. Cao, C H J Davies, E V. Pereloma
Mechanical, Microstructure And Texture Properties Of Interstitial-Free Steel And Copper Subjected To Equal Channel Angular Extrusion And Cold-Rolling, A A. Gazder, S S. Hazra, C F. Gu, W Q. Cao, C H J Davies, E V. Pereloma
Faculty of Engineering - Papers (Archive)
Interstitial-free steel and OFHC copper were subjected to 8 passes, route BC room temperature ECAE followed by cold-rolling up to 97.5% thickness reduction. Uniaxial tensile tests and Electron Back-Scattering Diffraction were used to characterise the evolution in mechanical properties, microstructure refinement and micro-texture. IF-steel showed continuous increase in strength whereas Cu returned reduced strength and a small gain in ductility at 97.5% reduction. In both metals substructure refinement was accompanied by an increase in high-angle boundary fraction, average misorientation and a slight increase in Σ3 boundaries. An evolution of crystallographic orientations from negative shear to predominantly cold-rolled textures after …
Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary
Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary
Materials Science and Engineering Faculty Publications and Presentations
Novel die-stacking schema using through-wafer interconnects require vias to be filled with electroplated Cu, resulting in thick copper films, and requiring an aggressive first-step CMP. This work investigates the effects of microstructure on CMP of copper films, which are not presently well understood. Bulk and local removal rates were investigated for several different microstructures. Surface orientation maps were created and the orientations of individual grains were correlated with topographical data to elucidate local removal behavior. Cu removal depends on the details of the microstructure, and certain microstructures allowed for either faster or more uniform removal of thick Cu films.