Engineering Commons^™

Nonlinear Anelasticity Of Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

An approximate solution of the equation of motion of a nonlinear anelastic reed at or near resonance is presented. The steady state solution reproduces the well-known nonlinear resonances. The solution also predicts the existence of auto modulations, i.e., self-excited modulations of the amplitude and phase at constant power of excitation of the reed. Numerical examples of such auto modulations are presented for an antisymmetric deformation potential. Experimental studies of finite amplitude oscillations of a magnesium reed vibrating at 72 and 431 Hz at room temperature confirm the existence of auto modulations. The experimental results can be semi quantitatively described in …

Factors Influencing The Production Rate And Quality Of Lead Sinter, John R. Knoepke, Hung Yang Tsai, Arthur E. Morris

Materials Science and Engineering Faculty Research & Creative Works

The sintering characteristics of a typical Missouri lead concentrate were determined for two types of raw sinter mix: conventionally prepared and pelletized. The important sintering characteristics are sulfur elimination, sinter strength, production rate of sinter, permeability of the sinter bed, and bed temperature. These characteristics were analyzed statistically, and are described by an empirical model, in which proportion of returns, moisture content, air flow, bed height, size distribution of returns, and ignition time are the independent variables. The characteristics of a conventionally prepared sinter mix are most strongly affected by the moisture content of the raw mix. The characteristics of …

Drawing Characteristics Of Electrogalvanized Steel Wires., Chi-Yuan Tsao

Masters Theses

"As a means of investigating the often adverse drawing behavior of electrogalvanized steel wire, drawing experiments were conducted on a variety of industrially-supplied and laboratory-prepared electroplated steel wires. Back-flow and shaving appeared to be the mechanisms by which sizeable zinc losses occurred. Performance during drawing and the quality of the product depended upon both the characteristics of the plating and the drawing process variables. Grain size, grain texture, and surface 'flatness' can affect the required drawing force, surface finish and level of zinc retention. Low die angles and large reductions offered greatest efficiencies with minimum zinc loss"--Abstract p. ii

The Influence Of Manganese Oxide On Sintering Of A Commercial Natural Magnesite., Alamar Kasan Duarte

Masters Theses

"Sintering studies on a commercial natural magnesite have been done to investigate the influence of MnO doping (MnO concentration from 0.16 to 2.50 wt.%) on the densification process over the temperature range 1520 to 1760°C , over periods of time from 3,600 to 57,600s in both oxidizing and reducing atmospheres (Air and P_O2 = 10^-7 KPa. In an air atmosphere the additions of MnO enhances the densification process. This fact may be associated with an increase in lattice diffusion of Mg ions due to an increase in cation vacancies in the MgO lattice from the presence of …

Sessile Drop Studies Of Gallium On Alumina, Timothy John Snyder

Masters Theses

"The liquid-vapor and solid-vapor interfacial energies of the system Ga-Al₂O₃ were determined by the sessile drop technique. The interfacial energies were found to decrease with increasing temperature and P₀₂.

A maximum liquid-vapor interfacial energy of 581 ergs/cm² was found for a clean sessile drop at 1227°C. Values for Γ₀, the excess concentration of oxygen, were calculated for both the liquid-vapor and solid-liquid interfaces. The work of adhesion between molten Ga and Al₂O₃ was found to increase with decreasing P₀₂ with a maximum of 576 ergs/cm² occurring …

Phaseautomodulation In Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

No abstract provided.

Chemical Corrosion Of Ag Films On Glass, Hyun Soo Park

Doctoral Dissertations

"The chemical corrosion of chemically, vacuum and sputter deposited Ag films on an aluminoborosilicate and a soda lime glass was investigated in wet HCl and saturated water vapor as a function of concentration, temperature and time. The higher corrosion resistance of chemically deposited Ag films in comparison to evaporated or sputtered Ag films is attributed to their lower microvoid density and higher adhesion strength. Ag films on the more chemically durable aluminoborosilicate glass had a higher corrosion resistance. Furthermore, films which received a moderate thermal annealing (80 to 140° C) or were deposited on a glass surface washed with HN0 …

Effects Of Varying Oxygen Partial Pressure On Molten Silicon-Ceramic Substrate Interactions, And Oxygen Partial Pressure Measurements Of Silicon Sheet Production Facilities, P. D. Ownby, Harold V. Romero

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Measurement Of The Wear Properties Of Metallic Solids With A Falex Lubricant Testing Machine, Edward Boyd Hale, Chun-Ping John Meng, Ronald A. Kohser

Physics Faculty Research & Creative Works

A modified Falex Lubricant Testing Machine has been used to determine wear properties of metallic solids. In particular, wear mass loss, wear volume loss, wear rates, and other parameters have been determined for a basic steel, as heat treated and after ion implantation. Wear rate improvements of more than an order of magnitude were found in a nickel-chrome steel (SAE 3135) implanted with 2.5x10¹⁷ N⁺₂/cm². Wear tests were conducted with a cylinder-in-groove geometry in a mild lubricating oil with loads greater than 540 N, which corresponded to pressures which exceeded 10⁸N/m^{2 …}

Glass Surfaces Then And Now, Norbert J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

A reservoir of efficient instrumentation capable of detailed and quantitative exploration of glass surface features is now available in the face of the recognition of their crucial importance for both surface and bulk properties as well as performance. Yet it may be instructive to glance at what had been learned about glass surfaces by investigators before the advent of these intricate tools. Among such earlier findings are the recognition of the altered composition and structure of the surface layer, the extension of this disturbance to considerable depth, the effect of surface structure on adsorption, adhesion, wetting, finishing, etc. and on …

Anomalous Diffusion Of Carbon In A 70/30 Iron-Nickel Alloy, L. R. Chapman, D. A. Powers, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.