Engineering Commons^™

The Effect Of Varying Sea Coal Fineness On Sea Coal Activity In Molding Sands, Laurence A. Cooley

Masters Theses

"An experiment was conducted in an attempt to establish a relation between sea coal activity in a facing sand and the particle size of the sea coal added to the sand. It was felt that if a sufficient difference in distribution of volatiles was detected, a correlation between particle size and activity of the sea coal within the test specimens might be established. The lack of positive evidence to support such a relationship is indicative that a variation in particle size does not promote volatile re-deposition within the range of particle sizes investigated for the particular weight per cent of …

The Thermodynamics Of The Zno-Fe₂O₃-Fe₃O₄ System, Robert Lee Benner

Doctoral Dissertations

"The purpose of this investigation was to (1) experimentally locate certain phase boundaries in three isothermal sections of the zinc oxide - ferric oxide - magnetite phase diagram, (2) to experimentally determine some of the thermodynamic properties of the zinc oxide - ferric oxide - magnetite system, (3) to use the thermodynamic properties of the zinc oxide - ferric oxide - magnetite system to evaluate the pseudo-binary system between zinc ferrite and magnetite, (4) to construct a compound stability diagram for the zinc-iron-oxygen-sulfer system"--Introduction, Statement of the Problem, page [1].

Internal Friction Of Mixed-Alkali Silicate Glasses, James E. Shelby

Doctoral Dissertations

"The mixed alkali effect in silicate glasses was examined from internal friction measurements made over the temperature range from -190 to 500⁰C and at a frequency of 0.4 Hz. Supplemental measurements of the activation energy for the different internal friction peaks, dynamic shear modulus, density, and index of refraction were also made. All measurements were confined to silicate glasses containing mixtures of Li-Na, Li-K, Li-Rb, Li-Cs, Na-K, Na-Rb, Na-Cs, and K-Rb. Rötger's interpretation of the internal friction of mixed-alkali silicate glasses is shown to be incorrect. A previously unreported internal friction peak was observed whenever two different alkali oxides were …

Detection Of Stress Corrosion Cracking In U-Bend Brass Specimens By An Electro-Mechanical Method, Floyd Elwin Loftin

Masters Theses

"An apparatus was designed and built which held two u-bend specimens. When the specimens were exposed to a corrodent, losses in strength were detected as a result of stress corrosion cracking. The apparatus was used to study time to failure of cartridge brass u-bend specimens exposed to ammoniacal copper sulfate solutions which varied in pH. A minimum time to failure, 1.06 hours, was detected at pH 7.2. The maximum time to failure, for the range studied, was 28.36 hours at pH 7.7.

No useful data were obtained in the range from pH 6.6 - 6.8. thick, black surface coatings were …

A Study Of Hot Shortness In Steels, Koang-Hwa Kung

Masters Theses

"In this investigation an attempt was made to study the deformation of a number of laboratory-melted and commercial steels. A compressive load was applied to the steels at constant temperature and also during heating. The amounts and rates of deformation in these two types of tests was not consistent: in the constant temperature tests the hot short steels deformed more than the others while they appeared to deform less during heating. Metallographic examination of the sulfides indicated that the sulfides in cast steel are not stable and that they change during heating and hot working"--Introduction, page 2.

The Effect Of Copper Upon The Eutectoid Reaction In The Zinc-Aluminum System, Paul Theodore Corcoran

Masters Theses

"A Leitz dilatometer was used to study the kinetics of the eutectoid reaction in the zinc-aluminum system and the effect of small additions of copper upon this reaction. Three alloys were investigated: a pure 78% zinc - 22% aluminum alloy; a 78% zinc - 21.9% aluminum - 0.1% copper alloy; a 78% zinc - 21% aluminum -1.0% copper alloy. It was found that this reaction was similar to the pearlite reaction in the iron-carbon system. The reaction occurred by diffusion processes and the products of the reaction looked similar to pearlite when examined under the microscope. Copper was found to …

Order-Disorder In Fe₃Al At Various Temperatures Induced By Neutron Irradiation, Robert F. Toma Jr.

Masters Theses

"Resistivity measurements were made on ordered and disordered Fe₃Al samples while irradiated by neutrons.

In the ordered as well as the disorder state, the different Fe₃Al samples were heated to 100, 150, 200, 250, and 300°C respectively, and were irradiated by a fast neutron flux of 0.534 x 10¹⁰ neutrons/cm²-sec. The ordered Fe₃Al measurements were characterized by an increase in resistivity denoting an advancement toward disorder. The disordered Fe₃Al measurements were characterized by a decrease in resistivity denoting an advancement toward order. In the Fe₃Al ordered and disordered samples …

A Feasibility Study Of The Haeffner Effect In Mercury, Paul Martin Machmeier

Masters Theses

"An investigation of the Haeffner Effect in mercury by the use of a decade scaler suggested the need for a comprehensive statistical analysis of the data to justify reporting the presence of an isotopic separation. It has also been shown that the temperature of the mercury column must be accurately calculated before a temperature dependent relationship with the Haeffner Effect can be cited"--Abstract, page ii.

A Study Of The Photomechanical Effect In Silicon, Ronald M. Oglesbee

Masters Theses

"This paper presents the results of an experimental investigation into the photomechanical effect in silicon. The effect was found to be very similar to the electromechanical effect. In both cases the phenomena observed is the softening of a thin surface layer of the material when it is either illuminated or when a current is flowing through the material. An anisotropy was observed in both the hardness and the photomechanical effect. Increasing temperatures tended to "washout" the photomechanical effect. The surface hardness and the photomechanical effect were found to depend heavily on proper surface preparation of the samples, however little dependence …

The Elastic And Anelastic Constants Of A Synthetic Fluor-Mica Formed By Glass-Ceramic Fabrication Techniques, John H. Ainsworth

Masters Theses

"A tetrasilicic fluor mica, K₂Mg₅Si₈O₂₀F₄, was synthesized using glass forming techniques. Density changes, weight losses, and shrinkage, as well as elastic and anelastic properties, were measured on bars heat-treated at selected temperatures between 500°C and 1150°C to determine the characteristics of this material. Phase changes were followed by determining thermal expansion, logarithmic decrement, and modulus of elasticity from room temperature to 800°C.

It was found that the elastic and anelastic constants decreased gradually with heat treatments from 600°C to 1000°C. This indicated progressively increased structural ordering. Heat treatments above 1000°C …

A Study Of The Structural Rearrangements Accompanying Room Temperature Recovery Of High Purity Aluminum, Carlos Manuel Lago

Masters Theses

"X-ray methods (Laue back reflection and transmission) and etch pit studies were used in order to follow structural changes in the deformed metallic lattice during room temperature recovery. The accumulative evidence indicates that the deformed lattice undergoes subboundary movements and regrouping of fragments within a few days after stressing. On the basis of a superficial investigation, it was found that fast neutron bombardment increases the rate of room temperature recovery. Through the use of a new etchant, a finer substructure was revealed within the Lacombe subgrain. Glide strain values were determined for the series investigated, and a new approach was …

Solid Solubility Of Sulfur, Selenium, And Tellurium In Molybdenum At 1100°C, Lattice Constants Thermal Expansion Coefficients, And Densities Of Molybdenum And The Molybdenum-Base Alloys, Ramesh Purushottamdas Shodhan

Masters Theses

"With the ever increasing requirement for engineering materials having adequate mechanical properties at ever higher temperatures there has been, in quite recent years, a considerable increase in the study of molybdenum and molybdenum-rich alloys. Since 1945 extensive information on the engineering properties of molybdenum and molybdenum-base alloys has gradually become more available ... The present work involves the determination of solid solubility of elements with large atoms such as sulfur, selenium, and tellurium in molybdenum at 1100°C using the parametric method. Furthermore, the thermal expansion coefficients of pure molybdenum and of molybdenum-base solid solutions containing the elements just mentioned were …

Anodic Dissolution And Disintegration Of Tin And Valency Of The Tin Ions Going Into Solution, Mrityunjoy Dutta

Masters Theses

"The increased demand for protective coatings on metals and for non-corrosive alloys has stimulated extensive research on the fundamental behavior of metals in corrosive media. One of the problems still unsolved is the nature of the mechanism of the anodic dissolution of metals like beryllium, zinc, magnesium, cadmium, tin, aluminum, iron in aqueous salt solutions. It has been reported in the literature that these metals show discrepancies which often arise between coulometric data and the weight loss of metal electrodes in various media. Several investigators have proposed different and opposing theories to explain the above deviation. The purpose of the …

A Study Of Sulfide Inclusions In Medium Carbon Steels, Shane Shiang Yen

Masters Theses

"Sulfur is a very important component in steel. Usually is it present as an impurity in commercial steels. In these materials the sulfur content is 0.05 percent maximum but may be higher or lower than this in some steels...It is generally believed that sulfur has a deleterious effect on the mechanical properties of steels. Originally this investigation was to deal with this aspect of sulfur in steels but the work did not progress to this stage. An effort was made to vary the nature of the sulfides in several experimental heats of steel by controlling their composition. Variation in the …

The Effect Of Small Alloy Additions On The Quench Induced Texture Of Alpha Uranium, Kenneth Ray Riggs

Masters Theses

"The preferential orientations produced in binary alloys of U-Si and U-Cr on plane sections perpendicular to the direction of heat flow by cooling from beta-phase temperatures were determined. The experimentally determined textures were presented using inverse pole figures. A definite and reproducible relationship was found to exist between the preferred orientation present at any position and the cooling rate which material at the position had experienced. It was found that the concentration of the alloying elements within the ranges studied had little detectable effect upon the observed relationship between the cooling rate and the resulting preferential orientation. It was postulated …

The Dielectric Properties Of A Synthetic Fluor-Mica Formed By Glass-Ceramic Fabrication Techniques, Ray Fred Schumacher

Masters Theses

"A tetrasilicic fluor-mica, K₂Mg₅Si₈O₂₀F₄, was synthesized, utilizing glass forming techniques and subsequent heat treating of the mica glass. Discs, approximately two inches in diameter, were formed and heat-treated at selected temperatures between 700⁰C. and 1150⁰C. for various time periods. Density change, weight loss, shrinkage, and dielectric properties were measured to determine the characteristics of this material"--Abstract, page ii.