Dwell time low cycle fatigue (DLCF), low cycle fatigue (LCF), and creep tests were performed at ambient temperature on Ti-6Al-2Sn-4Zr-2Mo-0.1Si (Ti-6242Si). Test specimens were solution annealed at various temperatures below the beta transus to control the volume fraction of primary alpha. The influence of the changes in primary alpha phase...
Ti-6Al-2Sn-4Zr-2Mo-0.1Si specimens were shaped by repeated cycles of heating
(to 954 °C) and hammer or press forging followed by a solution anneal that varied from
968 to 998 °C. The coupons were originally extracted from billets forged below the beta
trans us ( 1009 °C) and slow cooled to ambient...
A series of TiNbHf alloys ranging from 0-40 atomic %
Nb and 0-15 atomic % Hf were evaluated to investigate
low-elastic modulus phenomena which occur in this ternary
system. The desirability of utilizing corrosion-resistant, biocompatible alloys with elastic modulus values
approaching that of human bone for medical prosthetic
implants provides...
Centrifugal casting has been a successful
technique for quickly filling molds, but little is
understood about the fluid flow characteristics that occur
during filling. The understanding of these flow
characteristics and the application of this knowledge
should improve the quality of metal parts cast by this
process. The subject of...
Mechanical properties of Nb-Ti composite superconducting wires were tested at
room temperature. The results were analysed using simple composite theory, the rule
of mixtures. The objective is to predict the mechanical properties of Nb-Ti
superconducting composite wires as a function of volume ratio and geometry of the
components, the composite...
In this thesis, I present studies in the field of terahertz (THz) spectroscopy. These studies are divided into three areas: Development of a narrowband THz source, the study of carrier transport in metal thin films, and the exploration of coherent dynamics of quasi-particles in semiconductor nanostructures with both broadband and...
Structurally efficient and cost-effective solutions are needed to extend the service-life of deficient and aging highway infrastructure around the world. One critical need is to increase the flexural strength of older reinforced concrete (RC) structures to carry heavier and more frequent loads. Titanium alloy bars (TiAB) offer a new opportunity...
Aging and deficient infrastructure has become a major problem throughout the world. This is particularly evident in the case of reinforced concrete (RC) bridges. The cost of replacing these bridges is often prohibitive, thus engineers must find ways to strengthen them. Many older RC bridges predate the modern understanding of...
Large numbers of reinforced concrete (RC) bridges were built in the past that are now considered seismically deficient. The structural members most likely to be considered deficient are the supporting columns. Typical deficient columns contain inadequate transverse reinforcement and poorly detailed lap splice lengths above the foundation. Insufficient lap splice...