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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.

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. …

A Study Of Several Commercial Steels In The Red Short Range, Jorge Alberto Espana

Masters Theses

"The red short phenomenon present in steel, was studied by means of torsion tests at temperatures between 800 and 1200⁰C. Cold drawn bars of different compositions of steels were tested, and the number of turns to failure and maximum twisting torque were plotted versus temperature.

All the steels tested, exhibited to have a certain degree of red shortness. By comparing the curves and the respective chemical analyses, the detrimental effect of sulphur and lead and the beneficial effect of manganese, was established.

Microscopic examinations revealed the intergranular nature of the cracks in the red short range. Sulphur and oxide distribution …

The Effect Of The Rolling Load On The Micro-Structure Of Low Carbon Sheet Steel, Jerry Lee Cadden

Masters Theses

"A Stanat 315, two high-four high, combination rolling mill is used to cold roll annealed, low carbon steel strips. A method of measuring the rolling load was presented. The method consisted of constructing a load cell using SR-4 strain gages attached to a steel column. The load cell was placed under the hold down screw of the rolling mill and a known load was applied. The stresses from this load were transferred to the mill housing where another SR-4 strain gage was located. The strain in the mill housing was recorded at the corresponding applied load. During rolling, the strain …

Electrodeposition Of Antimony From Sulfide Melts, Mahendra N. Rana

Masters Theses

"A study of the current-potential relationships, and the electrodeposition of antimony metal was conducted for fused mixtures of Sb₂S₃-Na₂S, Sb₂S₃-Sb and Sb₂S₃-NaCl-KCl in the temperature range of 700° - 900°C. An attempt was made to determine the mutual solubility of molten antimony and Sb₂S₃-Na₂S melts. The microstructure of deposited metal was studied metallographically. Analysis of phases present in the matte mixture (Sb₂S₃-Na₂S) was made by x-ray diffraction patterns.

All investigations were carried out in …

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 …

New Genera And Species Of Myripristid Fishes, In The Gulf Coast Cenozoic, Known From Otoliths (Pisces, Beryciformes)

School of Mines and Metallurgy Bulletins

Studies of fossil and Recent otoliths (sagittae) supply an important line of evidence, bearing on classification of teleost fishes, supplementary to that of anatomy, osteology, and "phylogenetic" paleoichthyology.

Squirrelfishes ( " Holocentridae" of authors) are generalized forms in which evolutionary divergence of some mag nitude is reflected in unpreservable details of anatomy, inconspicuous skeletal structures, and striking differentiation of the sagittae. Otoliths show the holocentroid complex to consist of one homogeneous unit (l\fyripristidae, elevated) and another more heterogeneous group (Holocentridae, restricted). These lineages have been separate. at least since the middle Eocene.

A revised classification, based on available lines of …

4th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Abstracts of papers presented at the 4th 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 10-11, 1961.

Investigation Of The Platinum-Rich Portion Of The Platinum-Tantalum Phase Diagram, Bob Dean Browning

Theses and Dissertations

The Pt-Ta binary system was investigated at two isotherms;1000°C and 1500°C, and at eleven alloy compositions in the range of 50 to 100 atomic percent platinum. The alloys were examined by x-ray diffraction and metallography. Three intermetallic compounds, Pt₂Ta, Pt₃Ta, and Pt₄Ta were found to exist in this composition range. The Pt₄Ta intermetallic appeared only at the 1500°C isotherm. Platinum dissolved tantalum substitutionally to 90 atomic percent at 1500 °C and to approximately 80 atomic percent at 1000 °C.

Attempts To Grow Metal Single Crystals By Strain Anneal, Donald James Mcmillan

Bachelors Theses and Reports, 1928 - 1970

The growth of such crystals in the solid state eliminates these problems to a considerable degree. Therefore, the purpose of this study was to grow a metal single crystal of predetermined orientation in the solid state utilizing the strain-anneal method.

Chelation Reactions In Montmorillonite Clays, Donald Edward Mahagin

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation was the study of reactions between the cations which are absorbed between the basal planes of montmorillonite clay and certain commercially-available organic reagents.

Crustacean Gastroliths From The Jackson Eocene Of Louisiana

School of Mines and Metallurgy Bulletins

Wechesia louisianae, n. sp., is described from upper Eocene beds at Montgomery, Louisiana. Second species of the genus, it extends the range of Wechesia Frizzell and Exline from Claiborne (middle) Eocene and validates the generic diagnosis.

A Resistivity Study Of Hot Short Ferrous Alloys, Harold Alfred Koelling

Masters Theses

"Resistivity measurements were performed at elevated temperatures on four special ferrous alloys and one commercial iron. The alloys were pure iron, iron with .023 per cent sulfur, iron with .33 copper, iron with .32 copper and .024 sulfur. Other elements were held to the minimum amounts possible in order to determine the actual effects of sulfur and copper. The commercial alloy was Armco Iron.

Measurements of resistivity versus temperature were taken at slow heating rates to determine if the iron sulphide liquid film formed in the grain boundaries of red-short steels had any effect on the electrical resistivity"--Abstract, page 7.

The Effects Of Sulphur And Copper On Hot-Workability Of Pure Iron, Hung-Chi Chao

Masters Theses

"The independent effects of sulphur, copper and their combinations on the hot-workability of pure iron free from other elements was studied, with special emphasis on the red-short phenomenon. Electrolytic pure iron with the addition of 0.023 cent sulphur, 0.33 per cent copper and 0.024 per cent sulphur plus 0.032 per cent copper along with a heat of only electrolytic pure iron was melted under vacuum, and cast under helium pressure. The specimens machined from the forged bars were tested at various temperatures by the hot twist-test and by the constant energy single blow drop forging test to evaluate the hot-workability …

A Dissolution Rate Study Of Beryllium In Hydrofluoric Acid, Donald Lee Mathis

Masters Theses

"Beryllium was shown to react stoichiometrically with HF, HCl, and H₂SO₄ acids in accordance with a plus two valence. These reactions were investigated by the hydrogen evolution method.

Dissolution rates were determined in five concentrations, 0.01, 0.05, 0.10, 0.50, and 0,75 N, of HF acid at 10, 20, 30, 40 and 50°C, This was accomplished by the hydrogen evolution method and the results were based on the tested stoichiometry. Beryllium has a high dissolution rate in HF acid, which approximates the following under similar conditions: 10 times Al, 4 times Ti, and 1.5 times Zr. A kinetic …

A Study Of The Difference Effects On Alpha Solid Solutions Of Oxygen In Titanium Dissolving In Hydrofluoric Acid, Kuo-Chin Chuang

Masters Theses

"Alpha solid solutions of oxygen in titanium dissolving in hydrofluoric acid exhibited a positive difference effect with k values of 5.7, being independent of the concentration of HF, within the compositional range studied 0 to 5 w/o oxygen. This indicates that various TiO_x alloys are polarizable to the same extent by the same strength of anodic current in hydrofluoric acid.

The difference effect observed on TiO_x alloys dissolving in HF-HCl revealed that the effect is dependent on the oxygen content of the solid solution as well as on the concentration of HCl. The presence of HCl results in …

A Preferred Orientation Study Of Sheet Formed By Rolling Copper, Nickel, Titanium And Tungsten Metal Powders, Martin Franklin Marchbanks

Masters Theses

"Pole figure scans of strip rolled from copper, nickel, titanium, and tungsten metal powders were made on samples taken across the width of the strip, and with various amounts of surface material removed, to determine if any preferred orientation existed. No preferred orientation was found in any of the samples examined.

The method used was a modification of the Schultz technique, using the Norelco Pole Figure Fixture, whose geometry and operation is described, in conjunction with the Norelco diffractometer.

Defocusing resulting during the run of a pole figure is discussed and a method for reducing this defocusing is described.

The …