Materials Science and Engineering Commons^™

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 …

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 …

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.

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 …

Effects Of Oxygen Content Of Admitted Gases In Sulfide Flotation, Brian J. Boyle

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Methods Of Studying The Effects Of Frothers, Frank L. Bazzanella

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Influence Of Quartz Particle Size And Concentration On The Fracture Stresses Of Triaxial Alumina Porcelain., John David Weyand

Masters Theses

"Quartz particles were introduced into a typical triaxial alumina porcelain. Three levels of particle size and three levels of concentration were studied. The strength sample sizes were large. A diametral- compression loading method was used for strength testing. It was found that the porcelain strength decreased with increasing grain size and concentration of quartz particles. A linear relationship existed between log quartz concentration and mean fracture stress"--Abstract, p. ii

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 …

A Study Of Crystallization Of Synthetic Fluor-Glaucophane Compositions, Kartini Tjokroatmodjo

Masters Theses

"The ability to form a stable glass and the crystallization properties of four compositions close to that of glaucophane, Na₂Mg₃Al₂Si₈O₂₂(OH)₂ studied. Three glasses were compared with a fourth glass containing no fluorine. The crystallization products of all four glasses were examined between the temperature range 600 - 1200°C. The crystallization products of the three fluorine containing glasses were similar, consisting of mica below 1000°C and of mica, fluor-glaucophane, enstatite and forsterite above 1000°C. In the fluorine free glass, enstatite was the only crystalline phase present below 1000°C, however, forsterite …

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

Densification Studies Of Three-Component Refractory Grog Systems., Jerome Dale Patterson

Masters Theses

"The bulk density and crushing strength properties of three-component refractory grog systems that were formed by mechanical impact or by mechanical vibration were determined.

Aqueous alkali silicate solutions of various types, concentrations, and amounts were investigated as room temperature binders for these grog systems. Compositions having maximum bulk densities were determined for each of six different three-component refractory grog systems. The densification rate curves for systems formed by mechanical impact were determined"--Abstract, p. ii

The Effects Of Surface Flaw Density And Configuration On Fracture Stresses Of A Triaxial Porcelain., William H. Daniels

Masters Theses

"The fracture behavior of a model brittle solid containing artificial surface flaws was studied. An industrial ceramic porcelain body was employed as the model brittle material. Sample groups of specimens containing 6, 11, 24, 49,. and 90 sharp surface notches uniformly distributed over a four inch length were broken under pure bending. The fracture data we-re compared to those of an identically treated control group containing no artificial flaws.

The mean strengths of the two groups of lowest flaw density were identical, both being significantly less than that for the control group. Further increases in flaw density resulted in increased …

Solid Solubility Of Sodium Oxide In Tricalcium Aluminate, Joel A. Conwicke

Masters Theses

"The tie line connecting the compounds 3CaO·Al₂O₃ and Na₂O·8CaO·3Al₂O₃ in the ternary system CaO-Al₂O₃-Na₂O was studied at 1250° Celsius.

It was determined that Na₂O can exist in crystalline solution with 3CaO·Al₂O₃ in percentages of about 2.3% or less without any apparent change in the structure of 3CaO·Al₂O₃. X-ray diffraction peaks in the back-reflection region shifted to lower d-spacing values on increasing Na₂O contents.

At a Na₂O content of about 2.7%, each major x-ray …

Mechanism Of Siliconizing Of Molybdenum And Tantalum By Vapor Deposition, Gordon Pu Kong Chu

Doctoral Dissertations

"Molybdenum and tantalum were siliconized in an enclosed system by the hydrogen reduction of silicon tetrachloride with induction heating between 900°C and 1450°C.

The siliconizing process was primarily influenced by the gaseous composition, temperature, time, molar flow ratio (SiCl₄/H₂), geometrical shape and ionization charges. The rate of siliconizing, measured as the weight gain by the fused quartz helix balance, generally follows a parabolic law, y = k t^1/2, where y = weight gain, t = time, and k = rate constant. The activation energy is estimated at 21.6 k cal/mole for siliconizing of molybdenum. …

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

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Habit Modification Of Naclo3 With Nai, William A. Coghlan

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.

Increased Corrosion Of A 304 Stainless Steel Upon Bending, William C. Tiddy

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Identification Of Nonmetallic Inclusions In Armco Ingot Iron With Polarized Light, Frank E. Panisko

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

The Hydrometallurgy Of Uranium, John E. Cesarani

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

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

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

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 …

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.