Materials Science and Engineering Commons^™

A Thermodynamic Study Of The Zirconium-Sulfur, Titanium-Sulfur And Hafnium-Sulfur Systems In The Disulfide-Trisulfide Region, Norbert Achilles Vermaut

Doctoral Dissertations

"A static method was used to study the equilibria which exist between the higher sulfides of zirconium and sulfur at temperatures from 700° to 1000 °C. Both disulfide and trisulfide have been identified by chemical analysis and X-ray diffraction. There exists a two-phase region of 'ZrS₂' and 'ZrS₃'. The composition limit of the homogeneous disulfide phase appears to exist between ZrS_1.90 and ZrS_2.00. The lower composition limit of the homogeneous region of the trisulfide phase was established as ZrS_2.75.

An experimental method of Blitz and co-workers, i.e., the use of evacuated …

A Preliminary Study Of The Controlled Crystallization Of A Bottle Glass., Narayan M. Sedalia

Masters Theses

The effect of addition of Ti0₂ as a nucleating agent was studied with a bottle glass composition of 74 weight percent Si0₂, l percent Al₂O₃, 5.4 percent Cao, 3.7 percent MgO, 15. 3 percent Na₂O, and 0.6 percent K₂O as a base or original composition. The addition of titanium dioxide ii varied from 3 to 20 weight percent. The composition of this bottle glass was changed by increasing the following ingredients and keeping the other ingredients in the same ratios:

1. Increased 5 weight percent of Al₂O …

Development Of A Fluor-Mica Dielectric Using Glass-Ceramic Fabrication Methods., James Joseph Tuzzeo

Masters Theses

"A tetrasilicic fluor-mica, K₂Mg₅si₈o₂₀F₄, was synthesized using glass-ceramic fabrication methods. Bubbles, rods, and disks of glass-mica were formed, and heat treated at selected temperatures between 620°c and 1160°c for various time periods. Density changes were correlated to mica content to determine the relative amounts of crystalline mica phase precipitated after heat treatment. Dielectric losses and dielectric constants of the glass-mica disks were measured for correlation to mica content"--Abstract, p/ ii

Non-Ferrous Metal Mining And Smelting In Australia

School of Mines and Metallurgy Bulletins

Bulletin was published without an Abstract

Dissolution Rates Of Zone Refined Iron And Steel In Hydrochloric And Sulfuric Acids And In Sodium Chloride Solutions., Gary E. Welch

Masters Theses

"Dissolution rates for two carbon steels were deter­ mined in four concentrations of sulfuric acid at five temperatures and in four concentrations of hydrochloric acid at four temperatures.

No general relationship was found for the variation in activation energies in sulfuric and hydrochloric acid. An explanation of the difference in the reaction rates and a possible explanation of the activation energy is presented on the basis of chunk formation.

The results of this investigation indicate an electrochemical control mechanism for the dissolution reaction of steel in acid solutions.

Results of dissolution rate studies in sulfuric and hydrochloric acid solutions and …

A Study Of A Method For Determining Properties Of Metals At High Strain Rates., Warren Heidbreder

Masters Theses

"An experimental method has been developed for determining the tensile and other physical properties of metals under high loading rates. Experimental equipment was designed, fabricated and tested. It was desirable to keep the equipment simple and inexpensive so that it could be used by operators Lacking experience in electronics and high-speed photography which are required for some of the more sophisticated methods now in use. The energy for pulling the specimens is supplied by smokeless gun powder. The firing of a cartridge into a closed cylinder with movable piston accomplishes the breaking of the specimen. A record of the time, …

An Equilibrium Study Of The System Bi-S-H₂, Don Hie Lee

Masters Theses

"An experimental study has been conducted to determine the equilibrium behavior of the system Bi-S-H₂. The system was studied by equilibrating H₂-H₂S gas mixtures with Bi(l)- Bi₂S₃(s) two-phase mixtures at temperatures of 500°, 600°, 700° and 750°C in a circulating type equilibrium apparatus. The equilibrium gas mixtures were analyzed by a Fisher Gas Partitioner with a reproducibility of approximately 0.06 %.

A linear free energy equation has been derived from the results with an average deviation of ± 1 Kcal. This deviation is well within the accepted experimental accuracy for …

Determination Of The Standard Free Energy Of Formation Of Zr₃S₂, Peter E. Otten

Masters Theses

"The Knudsen effusion method was used to find the equilibrium magnesium pressure for the reaction

3 Zr (s) + 2 MgS (s) = 'Zr₃S₂' (s) + 2 Mg (v)

By using known standard free energy data for the formation of magnesium sulfide and by using the equilibrium magnesium pressure, the standard free energy of formation of Zr₃S₂ was calculated and could be expressed by the equation

Δ F° = -139,800 + 49.13 T cal/mole

in the temperature range 900 to 1100°C.

It was also found that Zr₃S₂ was the zirconium …

A Study Of The Solubility Of Gold In Aluminum And The Extent Of The Al₂Au Phase., Kuldip Singh Chopra

Masters Theses

"The lattice constant of pure aluminum (99.998%) at 25° C 0 was determined to be 4.04953 A and the limit of solubility of gold in aluminum at 58O° c was found to be about o.4 weight percent gold. The minimum of the lattice constant was observed at O.75 weight percent gold. No change in the lattice constant with time was found.

The Al₂Au phase has a range from 77.66 to 78.94 weight percent gold with the theoretical composition of Al₂Au nearly in the middle of the phase. The thermal coefficient of expansion, the density and the …

A Thermodynamic Study Of The Molybdenum-Sulfur System At 1100⁰C, Seth C. Schaefer

Masters Theses

"A static method was used to determine equilibrium sulfur pressure for molybdenum-sulfur mixtures at 1100°C.

The results obtained were:
(1) The molybdenum disulfide phase was stable in a sulfur pressure range of 1.023 x 10^-5 to 6.026 x 10^-1 atmospheres. A range of non-stoichiometry from MoS_2.00 to MoS_2.22 was determined under these conditions.
(2) The upper limit of sulfur content of molybdenum sesquisulfide (Mo₂S₃) is nearly stoichiometric.
(3) The extent of solid solution of sulfur in molybdenum is approximately 1.5 atomic % (0.5 wt %).
(4) Molybdenum sesqu-isulfide (Mo₂S_{3 …}

A New Method Of Making Stainless Steel Powder By Electrochemical Disintegration, Mohammed Maher Saad

Masters Theses

"This paper describes a new method of making austenitic stainless steel (18/8) powder by electrochemical disintegration. The method used an external direct current applied to a heat-treated stainless steel anode, and a platinum cathode in an electrolyte of an aqueous solution of 20% HNO₃ and 1% H₂SO₄ by weight respectively.

Special attention has been paid to the size distribution of sieve and sub-sieve sizes, and the following ranges were found: approximately one-half lies between the limits of 200 and 325 mesh, and one third is finer than 325 mesh, with the remainder about +200 mesh, average …

Liquid Mercury Embrittlement Of Thin-Walled 2024 Aluminum Tubes, Edward J. Beckemeyer

Masters Theses

"The dislocation theory, Zener-Stroh crack model, and the Petch relationship, which correlates fracture stress and grain size, were used to analyze the embrittlement of 2024 aluminum alloy tubes by liquid mercury.

Surface energy ratios, [formula], were determined for biaxial stress ratios of 1/2, 1, ∞. The values of the surface energy ratios considered were 4.24, 1.79, 1.46, respectively. As part of this study, an approximate Nabarro-Peierls frictional stress was calculated for each stress ratio"--Abstract, page 2.

A Preliminary Study Of The Dielectric Properties Of Bismuth Ferrate Ceramics., John Joseph Schwaller

Masters Theses

"In this investigation some of the results of Fedulov¹⁸ for a composition of 30 percent lead titanate - 70 percent bismuth ferrate were verified. The system of lead zirconatebismuth ferrate was studied with sintering data determined for the series. By X-ray and microscopic analysis the system was determined to be not a solid solution. The dielectric measurements show a linear relation between the dielectric constant and the percent lead zirconate from 100 percent BiFeo₃ to 10 percent BiFeo₃ - 90 percent PbZro₃"--Abstract, p. ii

Preliminary Investigation Of Acid Treatment For The Stabilization Of Doloma, Deward Pan

Masters Theses

"The work presented in this thesis is the result of an investigation to develop an economical and successful means for producing a stable, hydration resistant compound on the surface of doloma particles by an acid treatment, which does not significantly alter the refractoriness of the material. Granite, a commercial doloma, from Valley Dolomite Corporation, was treated with different concentrations of inorganic acid-water solutions and organic acid-alcohol solutions for varying time at atmospheric pressure and temperature. The treated doloma was examined by (l) X-ray diffraction and (2) the hydration test.

It was found that the organic acid acted as a coating …

Non-Ferrous Metal Mining And Smelting In Australia, H. R. Hanley

Missouri School of Mines and Metallurgy Bulletins

No abstract provided.

Zinc Sulfide-Sulfate Reaction Pressures, William L. Hallerberg

Masters Theses

"A static manometric method was used to find the equilibrium reaction pressure as a function of temperature for the reaction:

11 ZnSO₄ + ZnS → 4 (ZnO·2ZnSO₄) + 4 SO₂

From the reaction pressures, the standard free energy of the reaction was found to be:

ΔF⁰ = + 51,320 - 36.68 T

Using thermodynamic data for ZnSO₄, ZnS and SO₂ the standard free energy of formation of the basic salt ZnO·2ZnSO₄ was found to be:

ΔF⁰ = - 377,000 - 65.9 T cal/mole

in the temperature range 350 to 420⁰ C.

Above …

Phase Extent Of Gaas, Gasb, And Insb, And Solid Solubility In The System Gaas-Gasb Determined By The Lattice Constant-Density Method., Chang Don Kim

Masters Theses

"The lattice constant of the homogeneous gallium arsenide varies from 5.65298A⁰ to 5.65J26A⁰ at 25° c with a change of composition in the range from 49-935 to 50.015 atomic percent gallium. The lattice constants of g allium and indium antimonide are 6.09592A⁰ and 6.47876A⁰ at 25 ° c, respectively and the extent of the phases of gallium and indium antimonide could not be found in this work.

The thermal expansion coefficient of gallium arsenide is 6.4 x 10^-6/⁰ C in the range between 10 and 65° c regardless of composition, ar.d those of …

Influence Of Porosity On The Fracture Stresses Of Electrical Porcelain., Edward Anton Snajdr

Masters Theses

"Spherical pores were induced in a typical quartz electrical porcelain body. Three levels of pore size and four levels of concentration were studied. Large strength sample sizes were employed using a three-point loading and diametral loading method. Data for induced quartz particles is also included"--Abstract, p.ii

An Electrolytic Polishing And Recrystallization Study Of Zinc And Zinc Alloys., Roy Ashley Smith

Masters Theses

"A Unitron hot stage and polarized light were used to enable direct observation of recrystallization in high purity (99.99 per cent) zinc and high zinc content alloys. Electrolytic polishing was investigated in an attempt to prepare unetched surfaces which would show good structural contrast under polarized light and thus permit structural changes occurring during recrystallization to be observed.

Kinetic data obtained from a sequence of photographs during each recrystallization trial showed typical sigmoidal isothermal reaction curves characteristic of a nucleation and growth process. It was determined that rates of nucleation and grain growth are a maximum over the same time …

A Study Of The Relative Electric Resistance Of Commercial Steels And Pure Iron, William Eugene Wistehuff

Masters Theses

"The change in relative electric resistance of five commercial steels, Armco Ingot Iron and Pure Iron were studied over the temperature range of 800°C to 1100°C in an attempt to correlate the phenomena of hot or red shortness with a change in the Electric resistance .

The results from the above resistance measurements were compared with mechanical tests of the same steels to show that at the point at which the iron sulfide liquid forms there is a definite change in the slope of the electric resistance vs temperature curve.

Also studied was a discontinuity in the electric resistance vs …

A Dilatometric Study Of The Martensite Transformation And Maraging Behavior Of A Ni- Co- Mo Steel, Neal Matthias Griesenauer

Masters Theses

"An experimental investigation or the austenite to martensite transformation and the maraging behavior taking place in a nickel-cobalt-molybdenum steel was conducted for this project.

The austenite to martensite transformation was followed by the dilatometric method, being done on a Leitz Optical Dilatometer. An apparatus was constructed for the dilatometer in order to record dimensional changes at low temperatures, thus broadening the possible applications for the instrument.

The maraging behavior was investigated by means of metallographic analysis and hardness determinations"--Abstract, page i.

A Weight Loss Technique For The Determination Of Phase Boundaries, Robert Lee Benner

Masters Theses

"An apparatus has been designed and constructed that would continuously record the weight loss of a sample in a flowing inert atmosphere, at a constant temperature.

A technique has been developed to determine the phase boundaries of a binary phase diagram.

Alloys of the magnesium-nickel, cadmium-antimony, copper-cadmium, copper-zinc, and magnesium-zirconium systems were subjected to investigation to verify the operation and resolve a number of limitations of the equipment.

These investigations disclosed that the apparatus gave the best results with alloys having vapor pressures in the range between 1 and 35 millimeters of mercury"--Abstract, page 2.

A Study Of The Recrystallization And Polygonization Of High Purity Aluminum, Robert Leon Wright

Masters Theses

"Laue back reflection patterns were used along with visual examination in evaluating the characteristics of the annealed structure of high purity (99.99%) aluminum single crystals which had been deformed by elongation. It was found that the glide strain and annealing temperature are primary factors to be considered with respect to the structural changes occurring during annealing.

It was determined that the glide strain must be above a certain critical value to cause recrystallization; below the critical value polygonization will predominate in the annealed structure regardless of the annealing temperature.

The single crystals used in the investigation were grown by the …

A Study Of The Chemical Kinetics, Activation Energy And Difference Effect On Beryllium Dissolving In Mineral Acids, Daniel Santhamurthi Gnanamuthu

Masters Theses

"The rate of dissolution of polycrystalline beryllium was studied in hydrofluoric, hydrochloric and sulfuric acids. Two samples of beryllium containing different amounts of beryllium oxide were used. The experiments were performed at temperatures ranging from 20 to 50°C, and at various acid concentrations. The kinetics of these heterogeneous processes conformed to a reaction order of approximately one in all the cases. Since the conditions of the surface were complex during dissolution, these might complicate the reaction. This might be due to the oxide layer, which is present as impurity.

The difference effect was determined at various acid concentrations at 25°C …

Statistical Analysis Of Fracture Stresses Of Triaxial Porcelain Bodies, Robert E. Moore

Doctoral Dissertations

"Triaxial porcelain bodies containing various forms of silica, quartz, cristobalite and fused silica, were strength tested in bending. Significance tests were employed to discern real differences in the strength sample statistics caused by the various forms of silica. Firings were performed at three temperature levels. The differences in strength sample statistics were correlated to the microstructures of these silica porcelains.

A triaxial alumina porcelain body was employed as a model brittle solid for a study of the effect of flaw density on mean fracture stress. The flaws were introduced in the form of large diameter (d̄ = 115 microns) rounded …

Preliminary Investigation Of The Effects Of Seeding Fusion Cast Refractories, Thomas Spencer Montgomery

Masters Theses

"The crystallization process in a zirconia-alumina- silica melt of high viscosity was studied, A system was used of the same composition found in commercial electrocast glass tank refractories. Artificial nucleation was tried in an attempt to control the process of crystallization; the method involved the addition of suitable "seeding" material.

It was found that introduction of nucleation agents consisting of the major component oxides of the system had noted effect upon the course of crystallization. Preferred orientation normally found in unseeded electrocast refractories was diminished with the addition of zirconia grains and amplified with particles of tabular alumina.

Results obtained …

A Determination Of Vapor Pressure Of Barium In The Thermal Production Of Barium Metal, Thomas A. Theobald

Masters Theses

The Knudsen effusion method was used to find the equilibrium reaction pressure of barium for the following reactions:
4BaO + 2Al - 3Ba + BaO·Al₂O₃ (l)
4BaO + Si - 2Ba + 2BaO·SiO₂ (2).
The resulting barium pressure for reaction (l) ranged from 0.27 mm. Hg to 1.77 mm. Hg in a temperature range of 940°C to 1086°C. The barium pressures for reaction (2) varied from 0.38 mm. Hg to 1.94 mm. Hg in a temperature range of 1000°C to 1086°C. The free energies of formation of BaO·Al₂O₃ and 2BaO·SiO₂ at 1087°C …

An Investigation Of The Deformation Textures Of Cobalt, Roy Carl Wilcox

Doctoral Dissertations

"Deformation textures of various cobalt structures as a result of cold rolling together with some annealing textures were studied. The textures of cobalt were determined using a modification of the Schulz-Decker Geiger counter technique. Pole figures of the (1011), (0001) and (1010) planes were constructed. Also, a study of the microhardness of cobalt was made.

Microhardness tests were performed on various cobalt structures, in both the cold rolled and unworked conditions. The microhardness was found to vary with the source of the cobalt, the crystal orientation, and the amount of deformation and twinning. Deformation lines about the hardness impressions diffused …

A Study Of Segregation In Cast Aluminum-Uranium Alloys, B. L. Bramfitt

Masters Theses

"This investigation involves a photomicrographic study of the segregation resulting from the eutectic solidification characteristics of aluminum-uranium alloys, ranging from 5 to 30 weight percent uranium. The segregation can occur in either of two manners; the first, due to the gravitational forces acting upon the growing particles which nucleate in the melt and the second, due to the mode and rate of heat transfer through the material. It was found that segregation occurred only as the result of the latter factor due to the small volume of the ingot and the rapid rate of heat transfer. The segregation was measured …

A Preliminary Study Of The Effect Of Heat Treatment On The Strength And Microstructure Of A Glass-Ceramic Material, P. D. Ownby

Masters Theses

"The strength and microstructure of a glass-ceramic material of the composition 53 percent SiO₂, 19 percent Al₂O₃, 15 percent MgO, and 13 percent Li₂O were studied. Cylindrical specimens of glass were formed and heat-treated to six different temperature levels for various time periods. The method of strength testing used was a diametral compression loading technique. It was found that the strength of this material increased initially with heat-treatment but then decreased. The strength characteristics of the completely crystallized glass ceramic material were found to be dependent on the initial nucleation period. Some factors which influenced anomalous crystal growth are described. …