Materials Science and Engineering Commons^™

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 …

The Anodic Dissolution And Disintegration Of Gallium And Aluminum And The Initial Valency Of The Ions Entering Aqueous Solutions., Kenneth Anderson Poush

Masters Theses

Gallium dissolved very slowly in dilute acids like HC1, H₂SO₄and HCIO₄. The rate was substantially accelerated if the metal was connected with a platinum electrode in the same solution. From the volume of the hydrogen developed the trivalency of gallium ions going into solution was calculated. This same ionic charge was obtained from coulometric measurements using gallium-amalgam as the anode. The initial ionic charge of aluminum dissolving from an aluminum amalgam anode was evidenced as being plus three by coulometric measurements.

Gallium and aluminum anodes were found to partially disintegrate while the current flowed. …

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

Properties And Perfection Of Zr-H Solid Solutions At Room Temperature., Dirk Heinrich Wiebe

Masters Theses

"The lattice constants of α. - Zr with 122 ppm H are a₂₅ = 3.23622 ± o. 00005 Å and c₂₅ = 5 .1526 ± 0. 0003 Å. The thermal expansion coefficients of α - Zr are found to be α_a =4.6 x 10^-6(⁰C^-1) and α_C =11,0 x 10^-6(⁰C^-1) in the range between 15 and 55°c.

The solid solubility limit in the Zr - H system at room temperature and independent of the H pressure was determined by the parametric x-ray method to be …

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 …

A Study Of The Crystallographic Orientation Dependence Of Electrical Resistivity In Zinc, Paul Frederic Becher

Masters Theses

"A potentiometer and galvanometer setup was used to obtain electrical resistivity data for polycrystalline zinc. Cold working textures were investigated by the reflection technique with a quadrant x-ray spectrometer.

Resistivity data were obtained for specimens that were reduced up to forty per cent from the as received condition, and the corresponding textures were studied. The results indicated that the resistivity change in the rolling direction is due to the reorientation of the c-axis in the rolling caused by cold working"--Abstract, page ii.

Study Of The Temperature Dependence Of The Haeffner Effect In Mercury, Charles George Arnold

Masters Theses

“In 1953, E. Haeffner (1) reported that after he had passed a direct electric current through a capillary tube filled with mercury, he obtained a separation of the isotopes of mercury. It was found that the heavier isotopes were enriched at the negative terminal and the lighter Isotopes at the positive terminal. This effect has since been referred to as the Haeffner Effect. Since this original experiment, other investigators have observed this effect in many other liquid and some solid metal systems.

The work of J. N. Baysden (2) showed that the separation of the isotopes in mercury could be …

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 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, …

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

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 …

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 …

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 …

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 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 …

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 …

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.

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 …

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 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 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 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 …

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. …