Engineering Commons^™

Studies In Modulation Of Interfacial Reactions For Certain Sulphide Minerals, Robert Owen Beyaert

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Production Of Standard-Grade Ferromanganese In An Electric Arc Furnace, Force F. Baney Jr.

Bachelors Theses and Reports, 1928 - 1970

The investigations conducted in this project were essentially concerned with the effects of various compositions of two different slag systems upon the increased recovery of manganese in a standard-grade ferromanganese.

Investigation Of The Ternary System Silver-Aluminum-Indium (Ag-Al-In), Elvin H. Beardslee

Bachelors Theses and Reports, 1928 - 1970

This thesis paper contains material pertaining to & preliminary investigation of the ternary system Ag-Al-In. Procedures in this preliminary investigation are discussed in detail.

Preliminary Examination Of The Aluminum Corner Of The Ternary System Aluminum-Silver-Indium (A1-Ag-In), Jerome J. Blake

Bachelors Theses and Reports, 1928 - 1970

In this paper the author attempts to lay the groundwork for future work on the Al-Ag-In system.

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 …

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 …

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

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 …

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 …

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, …

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

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 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 …

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 …

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 …

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 …

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.

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 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 …

Crystal Habit Modification Of Sodium Chlorate, Michael R. Keegan

Bachelors Theses and Reports, 1928 - 1970

All single crystals have a particular habit or morphology. The crystal habit refers to the relative degree of development of crystallographic planes into surfaces which make up the external appearance of the single crystal.

In this paper, NaClO3 is used as a parent crystal. Its simple cubic habit is modified to tetrahedral by the use of impurities of SO4=, S2O3=, Cr2O7=, and NO3-. The degree of habit change is studied as a function of impurity concentration and temperature. The problem and phenomena are explained in terms of surface chemistry and thermodynamics.

Physico-Chemical Principles Of Sixteenth Century Metallurgy, Robert E. Johnson

Bachelors Theses and Reports, 1928 - 1970

Following a review of sixteenth century metallurgical literature and a discussion of Gibbs free energy, this thesis discusses thermodynamic considerations of galena (PbS) reduction by iron from a lead assay of this period. The importance of fluxes in this assay is emphasized. The discussion covers both equilibrium and non-equilibrium conditions at 1100 degrees Celsius. Possible substitutes for iron are also covered.

Information from twenty-one small controlled lead assays is correlated with the thermodynamic discussion to determine the purpose of each constituent in the assay.

The Beneficiation Of Titaniferous-Magnetite Sands, Ronald Lloyd Nordwick

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation of beneficiation methods is to develop and study possible economic methods for recovering an iron-titanium concentrate of sufficient purity to meet metallurgical requirements for subsequent direct reduction to pig iron and a high titanium slag.

Stress-Corrosion Cracking Of Brass, Paul A. Fossey

Bachelors Theses and Reports, 1928 - 1970

the mechanism of stress-corrosion cracking of brass has been sought for many years. Investigators have proposed many mechanisms, but each of these mechanisms has always had several drawbacks. This paper presents an account of experimental work done in the laboratory on this subject and compares it to the work of previous investigations. It evaluates the mechanisms presented by investigators and shows the failures of these mechanisms. A theory of Nitrogen Embrittlement is presented and an evaluation of this theory with experimental work follows.

Experimental Arc Furnace Smelting Of Titaniferous Iron Sands From The Northern Oregon Coast, Allan P. Herring

Bachelors Theses and Reports, 1928 - 1970

This investigation is an attempt to experimentally smelt titaniferous iron sands from the Northern Oregon Coast in a laboratory arc furnace.

The Effect Of Ph Upon Chelation Reactions In Montmorillonite Clays, Joseph Michael Keane

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to investigate several chelation reactions and determine the effect of variable pH upon these reactions.

An Investigation Of The Sintering Of Iron-Wire Compacts, George L. Vivian

Bachelors Theses and Reports, 1928 - 1970

A study of the sintering of iron has been made by observing the rate of bonding of iron wires wound on iron spools. The specimens were sintered at a constant temperature of 850c in vacuum furnaces capable of producing pressures of 10-5 to 10-4 mm of mercury, and the growth of the bond between wires was observed as a function of time.

It has been concluded that the volume-diffusion mechanism is strongly operating in the sintering of iron at 850c, but in an evacuated system, the evaporation-condensation mechanism also contributes to the sintering process.

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 …

A Survey Of The Influence Of Selected Sulfides On The Thermal Decomposition Rate Of Zinc Sulfate, L. G. Twidwell

Masters Theses

"The influence which ZnS, CdS, Cu₂S, PbS, and FeS has on the thermal decomposition rate of ZnSO₄ was studied by measuring the SO₂ gas evolved per unit of time for various ZnSO₄-MeS mixtures at 600°C, and analyzing the solid phases by means of X-ray diffraction patterns.

The SO₂ gas evolved upon heating the pellets was analyzed as a function of time by absorbing the gas in a solution of distilled water, H₂O₂, and NaOH, and measuring the time required for the SO₂ to neutralize the NaOH. The gas …

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 …