Metallurgy Commons^™

A Study Of High Strength, Heat Treated Plain Carbon Steels, Ing Shing Chien

Masters Theses

"This work was undertaken as the initial step in a program of studying brittleness in carbon steel that has been heat treated to high strength levels.

The trend in modern technology is toward higher tensile strengths. In practice, only alloy steels are commonly heat treated to very high strength levels. AISI 4340 is one of the more commonly used steels when high strength is desired. It is also becoming almost standard practice to use some of the tool steels or highly alloyed maraging steels for high strength structural components.

For this study high strength in a heat treated steel is …

The Thermodynamics Of The Zno-Fe₂O₃-Fe₃O₄ System, Dennis George Dreyer

Masters Theses

"A study was made of the ZnO-Fe₂O₃-Fe₃O₄ system at 1200ºC using oxygen pressures between 0.1 and 1x10⁻⁴ atmospheres. The results of this study were used to calculate the activities of ZnO, Fe₂O₄, and Fe₃O₄ in the spinel solid solution region of this ternary system. The activities of ZnFe₂O₄ and Fe₃O₄ across the pseudo-binary system were then calculated. The activities of the components in both the ternar and pseudo-binary systems exhibited large positive deviations from Raoult's Law, being more pronounced at the higher Fe₃O₄ content. The free energy, enthalpy, and entropy of mixing of the pseudo-binary system ZnFe₂O₄-Fe₃O₄ at 1200ºC were …

A Study Of The Effect Of Magnetite Additions To Shell Molds On The Surface Quality Of Low Carbon Steel Castings, Robert C. Tooke

Masters Theses

"Shell molds containing additions of ten to fifty percent magnetite, Fe₃O₄, of various particle sizes were cured by induction heating. For comparison, regular shell molds were made using silica and zircon sand. Low carbon steel was cast into all of the molds.

Castings produced from the regular shell molds exhibited poor surfaces due to mold expansion. Magnetite additions eliminated the expansion defects from the casting surfaces.

Excellent surfaces were obtained on the low carbon steel castings with proper selection of the magnetite particle size and the percent of magnetite added. Improper combinations of size and amount …

A Study Of The Photomechanical Effect In Silicon, Ronald M. Oglesbee

Masters Theses

"This paper presents the results of an experimental investigation into the photomechanical effect in silicon. The effect was found to be very similar to the electromechanical effect. In both cases the phenomena observed is the softening of a thin surface layer of the material when it is either illuminated or when a current is flowing through the material. An anisotropy was observed in both the hardness and the photomechanical effect. Increasing temperatures tended to "washout" the photomechanical effect. The surface hardness and the photomechanical effect were found to depend heavily on proper surface preparation of the samples, however little dependence …

Detection Of Stress Corrosion Cracking In U-Bend Brass Specimens By An Electro-Mechanical Method, Floyd Elwin Loftin

Masters Theses

"An apparatus was designed and built which held two u-bend specimens. When the specimens were exposed to a corrodent, losses in strength were detected as a result of stress corrosion cracking. The apparatus was used to study time to failure of cartridge brass u-bend specimens exposed to ammoniacal copper sulfate solutions which varied in pH. A minimum time to failure, 1.06 hours, was detected at pH 7.2. The maximum time to failure, for the range studied, was 28.36 hours at pH 7.7.

No useful data were obtained in the range from pH 6.6 - 6.8. thick, black surface coatings were …

The Effect Of Varying Sea Coal Fineness On Sea Coal Activity In Molding Sands, Laurence A. Cooley

Masters Theses

"An experiment was conducted in an attempt to establish a relation between sea coal activity in a facing sand and the particle size of the sea coal added to the sand. It was felt that if a sufficient difference in distribution of volatiles was detected, a correlation between particle size and activity of the sea coal within the test specimens might be established. The lack of positive evidence to support such a relationship is indicative that a variation in particle size does not promote volatile re-deposition within the range of particle sizes investigated for the particular weight per cent of …

A Study Of The Structural Rearrangements Accompanying Room Temperature Recovery Of High Purity Aluminum, Carlos Manuel Lago

Masters Theses

"X-ray methods (Laue back reflection and transmission) and etch pit studies were used in order to follow structural changes in the deformed metallic lattice during room temperature recovery. The accumulative evidence indicates that the deformed lattice undergoes subboundary movements and regrouping of fragments within a few days after stressing. On the basis of a superficial investigation, it was found that fast neutron bombardment increases the rate of room temperature recovery. Through the use of a new etchant, a finer substructure was revealed within the Lacombe subgrain. Glide strain values were determined for the series investigated, and a new approach was …

Anodic Dissolution And Disintegration Of Tin And Valency Of The Tin Ions Going Into Solution, Mrityunjoy Dutta

Masters Theses

"The increased demand for protective coatings on metals and for non-corrosive alloys has stimulated extensive research on the fundamental behavior of metals in corrosive media. One of the problems still unsolved is the nature of the mechanism of the anodic dissolution of metals like beryllium, zinc, magnesium, cadmium, tin, aluminum, iron in aqueous salt solutions. It has been reported in the literature that these metals show discrepancies which often arise between coulometric data and the weight loss of metal electrodes in various media. Several investigators have proposed different and opposing theories to explain the above deviation. The purpose of the …

A Study Of Sulfide Inclusions In Medium Carbon Steels, Shane Shiang Yen

Masters Theses

"Sulfur is a very important component in steel. Usually is it present as an impurity in commercial steels. In these materials the sulfur content is 0.05 percent maximum but may be higher or lower than this in some steels...It is generally believed that sulfur has a deleterious effect on the mechanical properties of steels. Originally this investigation was to deal with this aspect of sulfur in steels but the work did not progress to this stage. An effort was made to vary the nature of the sulfides in several experimental heats of steel by controlling their composition. Variation in the …

The Effect Of Copper Upon The Eutectoid Reaction In The Zinc-Aluminum System, Paul Theodore Corcoran

Masters Theses

"A Leitz dilatometer was used to study the kinetics of the eutectoid reaction in the zinc-aluminum system and the effect of small additions of copper upon this reaction. Three alloys were investigated: a pure 78% zinc - 22% aluminum alloy; a 78% zinc - 21.9% aluminum - 0.1% copper alloy; a 78% zinc - 21% aluminum -1.0% copper alloy. It was found that this reaction was similar to the pearlite reaction in the iron-carbon system. The reaction occurred by diffusion processes and the products of the reaction looked similar to pearlite when examined under the microscope. Copper was found to …

A Feasibility Study Of The Haeffner Effect In Mercury, Paul Martin Machmeier

Masters Theses

"An investigation of the Haeffner Effect in mercury by the use of a decade scaler suggested the need for a comprehensive statistical analysis of the data to justify reporting the presence of an isotopic separation. It has also been shown that the temperature of the mercury column must be accurately calculated before a temperature dependent relationship with the Haeffner Effect can be cited"--Abstract, page ii.

Order-Disorder In Fe₃Al At Various Temperatures Induced By Neutron Irradiation, Robert F. Toma Jr.

Masters Theses

"Resistivity measurements were made on ordered and disordered Fe₃Al samples while irradiated by neutrons.

In the ordered as well as the disorder state, the different Fe₃Al samples were heated to 100, 150, 200, 250, and 300°C respectively, and were irradiated by a fast neutron flux of 0.534 x 10¹⁰ neutrons/cm²-sec. The ordered Fe₃Al measurements were characterized by an increase in resistivity denoting an advancement toward disorder. The disordered Fe₃Al measurements were characterized by a decrease in resistivity denoting an advancement toward order. In the Fe₃Al ordered and disordered samples …

Solid Solubility Of Sulfur, Selenium, And Tellurium In Molybdenum At 1100°C, Lattice Constants Thermal Expansion Coefficients, And Densities Of Molybdenum And The Molybdenum-Base Alloys, Ramesh Purushottamdas Shodhan

Masters Theses

"With the ever increasing requirement for engineering materials having adequate mechanical properties at ever higher temperatures there has been, in quite recent years, a considerable increase in the study of molybdenum and molybdenum-rich alloys. Since 1945 extensive information on the engineering properties of molybdenum and molybdenum-base alloys has gradually become more available ... The present work involves the determination of solid solubility of elements with large atoms such as sulfur, selenium, and tellurium in molybdenum at 1100°C using the parametric method. Furthermore, the thermal expansion coefficients of pure molybdenum and of molybdenum-base solid solutions containing the elements just mentioned were …

A Study Of Hot Shortness In Steels, Koang-Hwa Kung

Masters Theses

"In this investigation an attempt was made to study the deformation of a number of laboratory-melted and commercial steels. A compressive load was applied to the steels at constant temperature and also during heating. The amounts and rates of deformation in these two types of tests was not consistent: in the constant temperature tests the hot short steels deformed more than the others while they appeared to deform less during heating. Metallographic examination of the sulfides indicated that the sulfides in cast steel are not stable and that they change during heating and hot working"--Introduction, page 2.

The Effect Of Small Alloy Additions On The Quench Induced Texture Of Alpha Uranium, Kenneth Ray Riggs

Masters Theses

"The preferential orientations produced in binary alloys of U-Si and U-Cr on plane sections perpendicular to the direction of heat flow by cooling from beta-phase temperatures were determined. The experimentally determined textures were presented using inverse pole figures. A definite and reproducible relationship was found to exist between the preferred orientation present at any position and the cooling rate which material at the position had experienced. It was found that the concentration of the alloying elements within the ranges studied had little detectable effect upon the observed relationship between the cooling rate and the resulting preferential orientation. It was postulated …

Zirconium Chloride Nuclear Battery, Lonnie J. Shalton

Masters Theses

"An investigation of the neutron absorption characteristics of zirconium chloride was made to verify the reports of Chicago Development Corporation (5810 47th Ave., Riverdale, Md.) that ZrCl Blight be used as a power source for a nuclear battery. The company detected what they believed to be a beta current when the ZrCl was bombarded with neutrons from a slightly enriched uranium source. Investigation using higher powered neutron sources revealed that such a current was highly improbable and the company incorrectly interpeted the phenomena. Reports in the literature also confirmed that an electric current from the ZrCl using a low powered …

Investigation Of Inoculant Effect On Cast Iron, Darrell W. Donis

Masters Theses

"An assumption was made that extensive holding time of an inoculated gray iron melt would result in a loss of physical properties of castings poured from this melt. This theory was examined in both a literature search and by testing and conclusions drawn from these findings are presented and discussed. Although there is a great deal of data available which discusses inoculants and their effects, very little mention is made of the effect of holding time in any of this material. The results indicate that holding time is of considerable importance when dealing with inoculated iron, and that calcium silicon …

The Effect Of Cation Size Of Xanthate Collectors In Sulphide Flotation., R. W. Bourne

Masters Theses

"Batch flotation tests on Utah Copper ore were used to show the effect of collector cation size.

The results obtained were:

(1) Recovery of copper in the concentrate decreases with increase in the size of the collector cation.

(2) Increased recovery with ethyl over that for amyl with a given cation.

(3) No beneficial recovery with sulphur enriched xanthates.

Statistical techniques were used to ascertain if significant differences in results were present"--Abstract, p. i

The Effect Of Moisture Content On The Action Of Sea Coal In Molding Sands., Robert J. Endres

Masters Theses

"An assumption was made that an increase in moisture content in the sand would result in an increase in the amount of volatile matter retained in a sand, clay, water, and sea coal mixture which had been subjected to the heat of molten iron. Because of a lack of positive evidence to support this assumption, it was concluded that the volatile matter retained within the sample is independent of the moisture content.

It was also shown that the volatile products do not travel back through the sand, away from the mold-metal interface. Rather, the volatiles escape from the sand and …

The Imperfect Structure Of Ti-, Zr-, And Hf- Nitrides Containing An Excess Of Nitrogen., Chester A. Faunce

Masters Theses

"Chemical analyses were made on all three nitrides using oxidation, Kjeldahl, dissolution and gas evolution techniques, and the chemical formulae were calculated. They are as follows: Ti_0•931^N, Zr_0•970^N, and Hf_0•792^N.

The lattice constant of all the nitride samples was determined at 25°C. The Ti_0•931^N sample obtained from Union Carbide Company had a lattice parameter of 4.23986± 0.00007A⁰, while the sample from W. Germany, Ti_1.0^N in the as received condition had a lattice parameter of 4.24027 t 0.00003A⁰• A second lattice parameter determination was …

Sonic Flow Meter., Daniel E. Wilson

Masters Theses

"The purpose of this thesis was to construct a device to measure the velocity of air employing sound waves. The principle of operation of the device is that the time interval required for the sound wave to travel between two points in the duct is a function of the fluid velocity. This time interval was measured both with the air flowing and with the air stationary. An equation was derived such that the mean velocity of the flowing air could be calculated by knowing the two-time intervals.

The mean velocity determined by this device was compared to the mean velocity …

Microscopic Observations On Etched Surfaces Of Zinc Single Crystals And On Anodic Disintegration., Yun Wang

Masters Theses

"The technique used to grow single zinc crystals was based on the Bridgman method. Zinc-gold, zinc-aluminum, and zinc-magnesium alloys were prepared and their single crystals were grown. Four crystallographic planes of the single zinc crystals were used for both chemical and anodic etching. The zinc alloys were etched more easily by acids than the purest (99.999%) zinc. The etching patterns changed for the different crystallographic planes of the single zinc crystals.

The appearance of particles during anodic dissolution of the single zinc crystals depended on time, acid concentration and current density. The partial disintegration of single zinc crystals is promoted …

Anodic Dissolution And Disintegration Of Indium, Thallium, And Indium-Cadmium Solid Solutions And Valency Of The Ions Going Into Solution., Richard Lloyd Martin

Masters Theses

"Indium was found to form only In⁺³ ions when dissolving anodically in aqueous acid solutions. Thallium dissolves anodically in acid solutions giving Tl⁺¹ ions only. The reason why Faraday's law is not being formed is that the anode undergoes partial disintegration producing small metallic particles.

Disintegration of these anodes depends on several factors: the nature and concentration of the corrosive medium, the surface condition of the anode, the current density, and the temperature of the corrosive solution. Disintegration may be due to different mechanisms depending on the nature of the electrolyte" -- Abstract, p. ii

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. …

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 …

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, …

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 …