Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Neutron diffraction (2)
- Amorphous (1)
- Bulk metallic glass (1)
- CN7M Stainless Steel (1)
- Carbides (1)
-
- Centrifugal Pump (1)
- Creep (1)
- Crystal plasticity (1)
- Fatigue crack (1)
- Ferritic alloy (1)
- First-principles (1)
- Intergranular Corrosion (1)
- Intergranular damage (1)
- Lattice misorientation (1)
- Lattice strain (1)
- Materials science (1)
- Mechanical behavior (1)
- Nanoindentation (1)
- Small angle X-ray scattering (1)
- Structure (1)
- Tennessee (1)
- X-ray (1)
Articles 1 - 6 of 6
Full-Text Articles in Engineering
Processing, Microstructures, And Properties Of Aluminide-Strengthened Ferritic Steels, Zhenke Teng
Processing, Microstructures, And Properties Of Aluminide-Strengthened Ferritic Steels, Zhenke Teng
Doctoral Dissertations
NiAl-strengthened ferritic steel is a material of interest for steam turbine applications due to their promising creep resistance, high thermal conductivity, low cost and thermal expansion coefficient. However, there are two critical issues restricting their applications: low room temperature ductility and limited creep resistance at temperatures higher than 600°C. The reasons for these behaviors have not been fully understood, especially the processing-microstructure-property relationship has not been clearly identified.
The alloys were designed, fabricated, and processed, according to the required microstructures and properties. The matrix and precipitates can be thoroughly characterized by a combination of techniques, including atom probe tomography, neutron …
Computational And Experimental Study Of Structure-Property Relationships In Nial Precipitate-Strengthened Ferritic Superalloys, Shenyan Huang
Computational And Experimental Study Of Structure-Property Relationships In Nial Precipitate-Strengthened Ferritic Superalloys, Shenyan Huang
Doctoral Dissertations
Ferritic superalloys strengthened by coherent ordered NiAl B2-type precipitates are promising candidates for ultra-supercritical steam-turbine applications, due to their superior resistance to creep, coarsening, oxidation, and steam corrosion as compared to Cr ferritic steels at high temperatures. Combined computational and experimental tools have been employed to investigate the interrelationships among the composition, microstructure, and mechanical behavior, and provide insight into deformation micromechanisms at elevated temperatures.
Self and impurity diffusivities in a body-centered-cubic (bcc) iron are calculated using first-principles methods. Calculated self and impurity diffusivities compare favorably with experimental measurements in both ferromagnetic and paramagnetic states of bcc Fe. The calculated …
Shear-Band Formation And Thermal Activation In Metallic Glasses, Lu Wang
Shear-Band Formation And Thermal Activation In Metallic Glasses, Lu Wang
Doctoral Dissertations
Metallic glasses (MGs) usually have high strength, high hardness and high elastic strain limit. However, the deformation mode and mechanism in metallic glasses are radically different from those in conventional crystalline materials with a long-range ordered structure. For crystalline materials, the intrinsic relationship between their mechanical properties and crystal structures has been well described by dislocation theory. In contrast, for amorphous materials, theories on the structures and controlling factors of localized shear-band formation are far from being complete.
In this thesis, shear-banding behavior of MGs under nanoindentation was first reviewed. The hardness of MGs was found to be independent on …
Micromechanical Studies Of Intergranular Strain And Lattice Misorientation Fields And Comparisons To Advanced Diffraction Measurements, Lili Zheng
Doctoral Dissertations
Inhomogeneous deformation fields arising from the grain-grain interactions in polycrystalline materials have been evaluated using a crystal plasticity finite element method and extensively compared to neutron diffraction measurements under fatigue crack growth conditions. The roles of intergranular deformation anisotropy, grain boundary damage, and non-common deformation mechanisms (such as twinning for hexagonal close packed crystals) are systematically evaluated. The lattice misorientation field can be used to determine the intragranular deformation behavior in polycrystals or to describe the deformation inhomogeneity due to dislocation plasticity in single crystals. The study of indentation-induced lattice misorientation fields in single crystals sheds lights on the understanding …
Failure Analysis Of Leaking Stainless Steel Pump Casing, Mary E. Parker
Failure Analysis Of Leaking Stainless Steel Pump Casing, Mary E. Parker
Chancellor’s Honors Program Projects
No abstract provided.
Study Of Mechanical Behaviors And Structures Of Bulk Metallic Glasses With High-Energy Synchrotron X-Ray Diffraction, Feng Jiang
Doctoral Dissertations
This dissertation addresses two critical issues in the mechanical behaviors and structures of bulk-metallic glasses (BMGs): (1) the effect of composition, fabrication method, and pretreatment of plastic deformation on mechanical properties and structures of BMGs; (2) the mechanical response and structural evolution of BMGs in the elastic and plastic region.
(Cu50Zr50)94Al6 and (Cu50Zr50)92Al8 amorphous alloys were used to study the effect of composition on mechanical properties and structures of BMGs. The (Cu50Zr50)94Al6 alloy exhibits lower yield stress and Young’s …