Materials Science and Engineering Commons^™

Corrosion Resistance Of Enamel Coating Modified By Calcium Silicate And Sand Particle For Steel Reinforcement In Concrete, Fujian Tang

Masters Theses

"Porcelain enamel has stable chemical property in harsh environments such as high temperature, acid and alkaline, and it can also chemically react with substrate reinforcing steel resulting in improved adherence strength. In this study, the corrosion resistances of enamel coating modified by calcium silicate and sand particles, which are designed for improved bond strength with surrounding concrete, were investigated in 3.5 wt% NaCl solution. It consists of two papers that describe the results of the study.

The first paper investigates the corrosion behavior of enamel coating modified by calcium silicate applied to reinforcing steel bar in 3.5 wt% NaCl solution …

Thermal Properties Of Zirconium Diboride - Transition Metal Boride Solid Solutions, Devon Lee Mcclane

Masters Theses

"This research focuses on the thermal properties of zirconium diboride (ZrB₂) based ceramics. The overall goal was to improve the understanding of how different transition metal (TM) additives influence thermal transport in ZrB₂. To achieve this, ZrB₂ with 0.5 wt% carbon, and 3 mol% of individual transition metal borides, was densified by hot-press sintering. The transition metals that were investigated were: Y, Ti, Hf, V, Nb, Ta, Cr, Mo, W, and Re. The room temperature thermal diffusivities of the compositions ranged from 0.331 cm²/s for nominally pure ZrB₂ to 0.105 cm²/s for (Zr,Cr)B₂ and converged around 0.155cm²/s at higher temperatures …

Development And Characterization Of Spiral Additions In A Ceramic Matrix, Andrea Lynn Els

Masters Theses

"A novel spiral architecture was formed using titanium diboride and silicon carbide ceramics as either the spiral or matrix phase. Particulate composites with the same compositions were fabricated to compare to the materials in this study. Spiral additions were formed using powder loaded polymers followed by a single and/or multi-filament co-extrusion. For 25 vol% SiC spiral additions to TiB₂, boron nitride was added to the SiC spiral to alter the bonding at the interface and reduce thermal residual stresses. All samples were hot-pressed to near full density at 1980 ⁰C. Hot pressed multi-filament co-extrusion of 2.4 mm / …

Effect And Interactions Of Commercial Additives And Chloride Ion In Copper Electrowinning, Wenyuan Cui

Masters Theses

"This thesis is to understand and compare the effects and interactions of modified polysaccharide (HydroStar), polyacrylamide (Cyquest N-900) and chloride ion on copper electrowinning. A study of the nucleation and growth was conducted in a synthetic electrolyte (40 g/L Cu, 160 g/L H₂SO₄, 20 mg/L Cl-) with the addition of HydroStar or Cyquest N-900 using potential step measurements. The current responses generated were compared to theoretical models of nucleation and growth mechanisms. The nucleation and growth mechanism changed as function of potential and the presence of organic additives. The nucleation and growth mechanisms were confirmed using scanning electron microscopy (SEM). …

Thermodynamics And Crystallography Of The Γ→Ε→Α' Transformation In Femnalsic Steels, Scott Thomas Pisarik

Masters Theses

"FeMnAlSiC steels which exhibit two-stage transformation induced plasticity (TRIP) behavior characterized by the γ→ε→α' dual stage martensitic transformation promise to take a leading role in the development of 3rd generation advanced high strength steels. The crystallographic orientation relationship of the γ→α' and γ→ε athermal martensitic transformations in these steels has been determined as the Kurdjumov-Sachs and the Shoji-Nishiyama, respectively. Six crystallographic variants of α-martensite consisting of three twin-related variant pairs were observed in ε- bands. A planar parallelism of {0001}ε || {110}α' and a directional relation of α' lying within 1⁰ of ε existed for these variants. Two regular solution …

Inorganic Biodegradable Devices For Temporary Implants, Kassan Unda

Masters Theses

"Implantable electronic devices have great potential to benefit many health care technologies. They comprise of two different categories. The first is permanent prosthetic devices like cardiac pacemakers or nerve stimulants. The other category includes temporary devices for interventional medical monitoring and control scenarios, which lose functionality and become unnecessary after their intended operational lifetime. This can cause serious electromagnetic and biomechanical safety concerns if not removed from the body by an additional surgical operation.

This thesis focuses on exploring the feasibility of implantable inorganic bioresorbable thin film resistive devices utilizing bioactive glass as the core structural material. This device will …