UNT Theses and Dissertations - 10 Matching Results

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Corrosion Protection of Aerospace Grade Magnesium Alloy Elektron 43™ for Use in Aircraft Cabin Interiors

Description: Magnesium alloys exhibit desirable properties for use in transportation technology. In particular, the low density and high specific strength of these alloys is of interest to the aerospace community. However, the concerns of flammability and susceptibility to corrosion have limited the use of magnesium alloys within the aircraft cabin. This work studies a magnesium alloy containing rare earth elements designed to increase resistance to ignition while lowering rate of corrosion. The microst… more
Date: August 2013
Creator: Baillio, Sarah S.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Dislocation Dynamics Simulations of Plasticity in Cu Thin Films

Description: Strong size effects in plastic deformation of thin films have been experimentally observed, indicating non-traditional deformation mechanisms. These observations require improved understanding of the behavior of dislocation in small size materials, as they are the primary plastic deformation carrier. Dislocation dynamics (DD) is a computational method that is capable of directly simulating the motion and interaction of dislocations in crystalline materials. This provides a convenient approach t… more
Date: August 2013
Creator: Wu, Han
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Dynamic Precipitation of Second Phase Under Deformed Condition in Mg-nd Based Alloy

Description: Magnesium alloys are the lightweight structural materials with high strength to weigh ratio that permits their application in fuel economy sensitive automobile industries. Among the several flavors of of Mg-alloys, precipitation hardenable Mg-rare earth (RE) based alloys have shown good potential due to their favorable creep resistance within a wide window of operating temperatures ranging from 150°C to 300°C. A key aspect of Mg-RE alloys is the presence of precipitate phases that leads to str… more
Date: December 2013
Creator: Dendge, Nilesh Bajirao
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites

Description: Sustainability through replacement of non-renewable fibers with renewable fibers is an ecological need. Impact of transportation costs from South-east Asia on the life cycle analysis of the composite is detrimental. Kenaf is an easily grown crop in America. Farm based processing involves placing the harvested crop in rivers and ponds, where retting of the fibers from the plant (separation into fibers) can take 2 weeks or more. The objective of this thesis is to analyze industrially viable proce… more
Date: May 2013
Creator: Ramesh, Dinesh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Laser Deposition, Heat-treatment, and Characterization of the Binary Ti-xmn System

Description: The present research seeks to characterization of an additively manufactured and heat-treated Ti-xMn gradient alloy, a binary system that has largely been unexplored. In order to rapidly assess this binary system, compositionally graded Ti-xMn (0<x<15 wt%) specimens were fabricated using the LENS (Laser Engineered Net Shaping) and were subsequently heat-treated and characterized using a wide range of techniques. Microstructural changes with respect to the change in thermal treatments, hardness … more
Date: August 2013
Creator: Avasarala, Chandana
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Laser Surface Modification on Az31b Mg Alloy for Bio-wettability

Description: Laser surface modification of AZ31B Magnesium alloy changes surface composition and roughness to provide improved surface bio-wettability. Laser processing resulted in phase transformation and grain refinement due to rapid quenching effect. Furthermore, instantaneous heating and vaporization resulted in removal of material, leading the textured surface generation. A study was conducted on a continuum-wave diode-pumped ytterbium laser to create multiple tracks for determining the resulting bio-w… more
Date: December 2013
Creator: Ho, YeeHsien
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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A Study of Mechanisms to Engineer Fine Scale Alpha Phase Precipitation in Beta Titanium Alloy, Beta 21S

Description: Metastable b-Ti alloys are titanium alloys with sufficient b stabilizer alloying additions such that it's possible to retain single b phase at room temperature. These alloys are of great advantage compared to a/b alloys since they are easily cold rolled, strip produced and can attain excellent mechanical properties upon age hardening. Beta 21S, a relatively new b titanium alloy in addition to these general advantages is known to possess excellent oxidation and corrosion resistance at elevated t… more
Date: August 2013
Creator: Behera, Amit Kishan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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A Study of Power Generation From a Low-cost Hydrokinetic Energy System

Description: The kinetic energy in river streams, tidal currents, or other artificial water channels has been used as a feasible source of renewable power through different conversion systems. Thus, hydrokinetic energy conversion systems are attracting worldwide interest as another form of distributed alternative energy. Because these systems are still in early stages of development, the basic approaches need significant research. The main challenges are not only to have efficient systems, but also to conve… more
Date: August 2013
Creator: Davila Vilchis, Juana Mariel
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Surface Modifications to Enhance the Wear Resistance and the Osseo-integration Properties of Biomedical Ti-alloy

Description: The current study focuses on improving the wear resistance of femoral head component and enhancing the osseo-integration properties of femoral stem component of a hip implant made of a new generation low modulus alloy, Ti-35Nb-7Zr-5Ta or TNZT. Different techniques that were adopted to improve the wear resistance of low-modulus TNZT alloy included; (a) fabrication of graded TNZT-xB (x= 0, 1, 2 wt%) samples using LENS, (b) oxidation, and (c) LASER nitriding of TNZT. TNZT-1B and TNZT-O samples hav… more
Date: August 2013
Creator: Kami, Pavani
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Tribological Behavior of Spark Plasma Sintered Tic/graphite/nickel Composites and Cobalt Alloys

Description: Monolithic composites are needed that combine low friction and wear, high mechanical hardness, and high fracture toughness. Thin films and coatings are often unable to meet this engineering challenge as they can delaminate and fracture during operation ceasing to provide beneficial properties during service life. Two material systems were synthesized by spark plasma sintering (SPS) and were studied for their ability to meet these criteria. A dual hybrid composite was fabricated and consisted of… more
Date: December 2013
Creator: Kinkenon, Douglas
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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