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Lattice Constants, Thermal Expansion Coefficients, Densities, And Imperfections In Gold And The Alpha-Phase Of The Gold-Indium System, Vinayak Keshavlal Patel

Masters Theses

"An investigation of structure insensitive properties (lattice parameters, thermal expansion coefficients, densities, and imperfection) of gold and the alpha-phase of the gold-indium system was made. The gold-indium alloys were prepared from high purity (99.999%) gold and indium by melting both metals inside sealed quartz glass tubes which were first evacuated and then filled with helium gas. The solidified alloys were annealed and then examined by x-ray for homogeneity. The lattice constant of 99.999% pure gold at 25⁰C was found to be 4.07894 ł 0.00005 (corrected for refraction) Å. The coefficient of thermal expansion was 13.4 x 10⁻⁶⁰C⁻¹ between 15 and …

Relationships Among The Metallurgical Condition, Hardness, And The Electrical Conductivity Of Aluminum Alloys, Richard A. Mueller

Masters Theses

"Electrical conductivity measurements (eddy current determined) combined with indentation hardness measurements are now being used throughout the aerospace industry for nondestructive evaluation of the metallurgical condition of commercial precipitation hardenable aluminum alloys. The review of literature and experiments with two aluminum alloys, 7178 and a 5% Zn-Al binary, have shown that skilled interpretation of hardness-conductivity data depends not only upon a qualitative understanding of the modern wave mechanical theories of electron conduction, but also upon some knowledge of the precipitation reaction kinetics. In particular, the effects of "quenched-in" vacancies and retrogression upon the reaction kinetics must be considered. Studies of …

A Transmission Electron Microscopy Study Of Some High Strength Plain Carbon Steels, George Joseph Vytanovych

Masters Theses

"Methods of preparing foils of high strength, heat treated, plain carbon steels for examination in the electron microscope by the transmission technique were perfected and are described. Two processes for the initial thinning of a bulk sample were successful. A chemical process was found to be more rapid but not satisfactory for small samples. A mechanical process was slower, but was applicable to the smaller specimens. Electro-polishing the thinned material yielded acceptable foils from which photomicrographs of good quality were obtained. The microstructure of the high strength steel samples showed typical tempered martensite. No reasons for the differences in ductility …

Anodic Dissolution Of Zinc In Potassium Nitrate, Martin E. Straumanis, J. L. Reed, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

The apparent valence of pure zinc dissolving anodically in 3% KNO₃ was determined as a function of current density, temperature, and ultrasonic agitation. The apparent valence of zinc dissolving anodically at 24°C diminishes from 2.01 ± 0.01 at low current densities to 1.86 at about 50 ma and remains fairly constant up to about 80 ma cm−2. This valence is affected to some extent by the preparation, e.g., polishing of the electrode, but is independent of its structure (mono- or polycrystal). Ultrasonic vibrations do not influence the apparent valence at high current densities. In all cases a black film …

Thermal Expansion Coefficients And Lattice Parameters Between 10° And 65°C In The System Gap-Gaas, Martin E. Straumanis, J. P. Krumme, M. Rubenstein

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Compressive Creep Of High Alumina Refractories, Vernon Lee Burdick

Masters Theses

"The deformation of refractory materials consisting of 90% sintered or fused alumina plus 10% silica was measured at temperatures from 1450 to 1515⁰C and a compressive stress of 100 psi. Creep rates and activation energies were determined from the steady state portion of deformation vs. time data and correlated with the mineralogical composition. Supplemental measurements included x-ray diffraction, electron probe microanalysis, apparent porosity and tensile strength. conditions having an important effect upon the mineralolgical composition were: (1) duration of heat treatment, (2) amount of sodium oxide impurity, and (3) reactivity of the alumina grain. Prolonged heat treatment and sodium oxide …

8th Annual Meeting Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 8th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 8-9, 1966.

X-Ray Diffraction And Electron Microscopy Studies Of Glasses Containing Antimony, Sadek Momtaz Tadross

Archived Theses and Dissertations

No abstract provided.

A Study Of The Effect Of Magnetite Additions To Shell Molds On The Surface Quality Of Low Carbon Steel Castings, Robert C. Tooke

Masters Theses

"Shell molds containing additions of ten to fifty percent magnetite, Fe₃O₄, of various particle sizes were cured by induction heating. For comparison, regular shell molds were made using silica and zircon sand. Low carbon steel was cast into all of the molds.

Castings produced from the regular shell molds exhibited poor surfaces due to mold expansion. Magnetite additions eliminated the expansion defects from the casting surfaces.

Excellent surfaces were obtained on the low carbon steel castings with proper selection of the magnetite particle size and the percent of magnetite added. Improper combinations of size and amount …

Tensile Strength Of Prereacted Porcelain Compositions, Chester Lee Hill

Masters Theses

"The tensile strengths of two porcelain compositions containing prereacted silica and feldspar have been determined with the diametral loading technique. A comparison was made between the strength of the prereacted samples and the strength of samples of the same compositions, but prepared in the conventional manner. At the optimum firing temperature, no significant differences in tensile strengths were observed between the prereacted and control samples for the two compositions studied. At temperatures below and above the optimum firing temperature, the prereacted samples had the higher tensile strengths. The tensile strengths are correlated with the average size of the quartz particles …

An Investigation Of The Induction Heating Characteristics Of Powdered Susceptors Dispersed In A Non-Conducting Medium, Robert Leon Wright

Doctoral Dissertations

"This investigation determined some of the induction heating characteristics of powdered magnetite, iron and ferrosilicon susceptor dispersed in silica sand which had been coated with thermosetting resin. The powdered susceptor particles in the mixture were heated by the field of an induction coil, consequently heating the resin coated sand and bonding the sand grains together.

It was found that the type, relative amount,and particle size of the susceptor were important variables to be considered in the induction heating characteristics. Hysteresis losses in the susceptor particles, which are a function of the coil current, frequency, and permeability, appear to be the …

Hydrogen Absorption And Corrosion Studies Of Zone-Refined Iron, Chang Don Kim

Doctoral Dissertations

"The lattice constants of zone-refined iron filings and iron whiskers are 2.86623 and 2.86626 Å at 25°C respectively. Their thermal expansion coefficients are both the same, 12.1 x 10⁻⁶ /°C at temperatures 10 - 65°C.

The influence of hydrogen on the lattice constant of iron was investigated and it was found that hydrogen has no effect (within the limits of errors) on the lattice constant of iron at room temperature regardless of the charging methods. However, at elevated temperatures hydrogen expands the iron lattice due to increased solubility of the gas. The lattice constant of iron in vacuum and in …

The Statistical Mechanics Of Kink Interactions, Michael Brewer Mcneil

Doctoral Dissertations

"Using a potential derived from continuum elasticity, the interactions between kinks on a dislocation line are studied as special cases of the problem of a one-dimensional system of interacting particles. By the use of constant pressure ensembles, the principal kink-interaction problems of physical interest are solved. The application of these solutions to the theoretical analyses of work hardening and internal friction is explored and comparisons made to previous work in which kink interactions were neglected; it is found that, as would be expected, variations of equilibrium kink populations with external stress cannot account for the Bordoni peak, which must therefore …

A Study Of High Strength, Heat Treated Plain Carbon Steels, Ing Shing Chien

Masters Theses

"This work was undertaken as the initial step in a program of studying brittleness in carbon steel that has been heat treated to high strength levels.

The trend in modern technology is toward higher tensile strengths. In practice, only alloy steels are commonly heat treated to very high strength levels. AISI 4340 is one of the more commonly used steels when high strength is desired. It is also becoming almost standard practice to use some of the tool steels or highly alloyed maraging steels for high strength structural components.

For this study high strength in a heat treated steel is …

Synthesis And Structural Determination Of Intermetallic Compounds In The Fe-Ho System, Gerald J. Roe

Masters Theses

"The intermediate phases in the holmium-iron system were investigated by means of X-ray diffraction and metallographic examination. The intermediate phases identified by X-ray diffraction data were HoFe₂ , HoFe₃ , HoFe₅, and Ho₂Fe₁₇.

A new intermediate phase, HoFe₃, was found. HoFe₃ was indexed as hexagonal with lattice parameters of a = 5.084 Å and c = 24.45 Å, and was thought to be of the space group R3̄̄m.

HoFe₂ was formed by a peritectic reaction and its solidus was estimated to be between 1325°C and 1340°C. suggested to be a congruent melting intermetallic compound with a melting point below 1340°C. …

The Thermodynamics Of The Zno-Fe₂O₃-Fe₃O₄ System, Dennis George Dreyer

Masters Theses

"A study was made of the ZnO-Fe₂O₃-Fe₃O₄ system at 1200ºC using oxygen pressures between 0.1 and 1x10⁻⁴ atmospheres. The results of this study were used to calculate the activities of ZnO, Fe₂O₄, and Fe₃O₄ in the spinel solid solution region of this ternary system. The activities of ZnFe₂O₄ and Fe₃O₄ across the pseudo-binary system were then calculated. The activities of the components in both the ternar and pseudo-binary systems exhibited large positive deviations from Raoult's Law, being more pronounced at the higher Fe₃O₄ content. The free energy, enthalpy, and entropy of mixing of the pseudo-binary system ZnFe₂O₄-Fe₃O₄ at 1200ºC were …

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 …

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 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 …

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 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 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.

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 …

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.

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 …

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 …

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.

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 …

Hot Isostatic Compaction Of Graphite, Donald C. Carmichael, P. D. Ownby, Edwin S. Hodge

Materials Science and Engineering Faculty Research & Creative Works

The effects of temperature, pressure, and graphite starting material on the density, isotropy, and strength of dense graphite material prepared by hot isostatic compaction of graphite powders were examined. Process equipment was developed to permit operation at temperatures up to 2700 C under a 1600-atom isostatic pressure of inert gas . The isotropy of graphite compacts was determined by neutron diffraction. Relatively isotropic, high-purity graphites were produced having modest isotropic tensile strength and extremely high density (up to 2.24 g per cm³, or 99 per cent of theoretical).