Engineering Commons^™

Phase Equilibrium And Thermodynamic Study Of The Iron-Copper-Carbon System, Krishna Parameswaran

Masters Theses

"Gas carburization experiments were conducted at 950ºC in order to study the phase relations and to determine the activity of carbon in the iron-rich corner of the iron-copper-carbon system. The solubility of graphite in equilibrium with iron-copper alloys was determined at 950º, 1000º, and 1050ºC. The results of gas carburization and graphite solubility experiments at 950ºC were used in constructing an isothermal section of the iron-rich end of the iron-copper-carbon phase diagram, on which are superimposed carbon isoactivity lines. Graphite solubility data at 1000º and 1050ºC were used to construct similar diagrams without the isoactivity lines. The effect of carbon …

High Temperature Compressive Creep In Mullite, Peter C. Smith

Masters Theses

"Compressive creep measurements were made on two groups of mullites at temperatures between 1455ºC and 1520ºC. The first group consisted of commercially manufactured mullites. The second group was made up of 7 different mullite compositions spanning the alumina-silica solid solution range from 3Al₂O₃ • 2SiO₂ to 2Al₂O₃ • SiO₂ . Thermal activation energies and stress exponents were calculated for the mullites in the second group. Steady state strain rates taken at 1460ºC under loads of 100 and 110 psi varied between 1.3x10⁻⁴ in/in/hr and 15.4x10⁻⁴ in/in/hr. Activation energies were between 109 Kcal/mole and 204 Kcal/mole. Stress exponents calculated from data …

Mechanical Properties Of Low Carbon Martensite, Allen L. Affolter

Masters Theses

"Steels of three different compositions were heat treated and tensile tested in order to determine their mechanical properties after heat treatment. All samples had near 0.20 per cent carbon and two manganese levels 0.90 per cent and 1.35 per cent. One group containing the higher manganese level also had small additions of columbium and vanadium. The specimens were too brittle in the as-quenched condition to be loaded to full strength. Maximum strength and ductility were found after short time tempering at low tempering temperatures -- 2 to 15 minutes at 200º to 300ºF. Higher strengths were found at the low …

Anodic Dissolution Of Beryllium In Anhydrous Media, William Joseph James, Martin E. Straumanis

Chemistry Faculty Research & Creative Works

No abstract provided.

Stored Energy Of Room Temperature Deformed Copper, G. J. Filatovs, Hollis P. Leighly

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Thermal Expansion Of Pb3o4, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Thermal expansion of Pb₃O₄ was investigated by high‐temperature X‐ray diffraction. The coefficient in the a0 direction is 14.6x10−6/°C. Expansion in the c0 direction is 32% greater, with a coefficient of 19.3x10−6/°C. Coefficients of expansion are linear from 25° to 490°C and are comparable with those of tetragonal and orthorhombic PbO. Copyright © 1971, Wiley Blackwell. All rights reserved

Activation Volumes Of Interstitial Diffusion In Ferromagnetic Metals And Alloys, Manfred Wuttig, J. Keiser

Materials Science and Engineering Faculty Research & Creative Works

The Dis accommodation technique was used to determine the activation volumes of carbon diffusion ΔV of a Fe-1.4 wt% Si alloy, of hcp cobalt, and of nickel at the temperatures of -21, 75, and 110°C, respectively. The obtained values of ΔV are +0.3 ± 0.3 and -0.6 ± 0.9 cm3 mole-1 for the two relaxations observed in hcp cobalt, and 1.2 ± 0.1 cm3 mole-1 for nickel. These results are discussed in terms of a continuum model that interprets the activation energy of diffusion as a sum of the strain and exchange energies. It is found that in ferromagnetic solids …

Mixed‐Cation Effect In Silver Borate Glasses, E. N. Boulos, N. J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Liquid Viscosity Measurement Using A Buret: An Instructional Technique, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Structure And Properties Of Silver Borate Glasses, E. N. Boulos, N. J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

Clear glasses form in the system Ag₂O‐B₂O₃ up to about 35 mol% (65 wt%) Ag2O. Infrared absorption, thermal expansion, and density data indicated an analogy to the Na₂O‐B₂O₃ system. Pentaborate‐triborate group pairs appear to be formed on addition of Ag₂O to B₂O3 up to 20 mol% Ag2O and diborate groups from 20 to 33 mol% Ag₂O. This interpretation is supported by the comparison of the infrared absorption spectra of quenched and crystallized glasses. One crystallization product, Ag₂O‐4B₂O₃, was …

On The Activation Entropy Of Interstitial Diffusion In B.C.C. Iron, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Structure And Properties Of Silver Borate Glasses, Edward Nashed Boulos

Doctoral Dissertations

"Clear glasses form in the system Ag₂O-B₂O₃ up to about 35 mol.% (65 wt.%) Ag₂O. Infrared absorption, thermal expansion and density data indicated an analogy to the Na₂O-B₂O₃ system. Pentaborate-triborate group pairs appear to be formed upon the addition of Ag₂O to B₂O₃ up to 20 mol.% Ag₂O and diborate groups from 20 to 33 mol.% Ag₂O. This interpretation is supported by the comparison of the infrared absorption spectra of quenched and crystallized glasses. One crystallization product ,Ag₂O.4B₂O₃, has been identified previously. A new compound starts to appear at 28 mol.% Ag₂O. Silver is generally present as a network modifier …

The Genesis Of Cellular Precipitation In Copper Rich Copper-Indium Alloys, Raymond Albert Fournelle

Doctoral Dissertations

"The morphology of cellular precipitation in a Cu-9.5at.%In alloy has been investigated by light and electron microscopy and x-ray and electron diffraction. Both cellular and general precipitation were observed to occur simultaneously in quenched and aged alloys while only cellular precipitation was observed to occur in isothermally aged alloys. Because of the presence of wide, vacancy depleted precipitate free zones in the vicinity of grain boundaries, general precipitation was observed to have no effect on the early development of cellular precipitation. Hence, the early development of cellular precipitation was found to be identical for both types of heat treatment. By …

Thermal Lattice Expansion Of Various Types Of Solids, Jayantkumar Shantilal Shah

Doctoral Dissertations

"Thermal lattice expansion studies of various types of solids were carried out in this investigation and were corelated to their crystallographic and various other properties. The advantages and limitations of various methods of studying thermal expansion are discussed in detail. A new design for a versatile low temperature camera to study expansion by an X-ray method is proposed. The thermal lattice expansion of silicon was negative below 119ºK. This behavior is discussed in terms of crystal structure and interatomic bonding. Diamond exhibits no anomalous thermal expansion. Lattice parameter data for many metals at low temperatures are reported for the first …

Activation Volumes Of Carbon Diffusion In F.C.C. Iron-Nickel Alloys, James Raymond Keiser

Doctoral Dissertations

"The disaccommodation technique was used to determine the activation volume of carbon diffusion, ΔV, in six fcc iron-nickel alloys. Measurements were made at temperatures ranging from 68ºC to 90ºC and pressures up to six kilobars on samples having a nickel content between 31 and 63 at. %. A maximum activation volume of 3.9 cm³/mole was found at 34 at. % nickel. The compositional dependence of ΔV is satisfactorily reproduced by a magnetic energy continuum model in which it is assumed that the activation free energy of diffusion is essentially ferromagnetic in origin "--Abstract, page iii.

An Age Hardening Study Of Magnesium-Thorium-Manganese Alloys, Kuldip Singh Chopra

Doctoral Dissertations

"The age hardening processes in Mg-3.5 wt.% Th-1.0 wt.% Mn and Mg-1.0 wt.% Th-1.0 wt.% Mn alloys have been studied by light and electron microscopy, and by electron and X-ray diffraction. At aging temperatures of 300ºC and below, G.P. zone formation rapidly hardens these alloys followed by the precipitation of disc shaped plates during averaging. During aging above 300ºC, no G.P. zones form and the disc shaped precipitate grows to very large sizes. The combined results of X-ray and electron diffraction indicate that the disc shaped precipitate has a Mg₃Cd (DO₁₉) type structure. The basal plane of the Mg₃Th discs …

Internal Friction Of Ion Exchanged Li₂O•Al₂O₃•2sio₂ Glasses, A. Ismail A. Abdel-Latif

Doctoral Dissertations

"Li₂O•Al₂O₂•2SiO₂ glass fibers were ion-exchanged from 1 to 300 minutes in a sodium nitrate bath at 366ºC. The internal friction was measured along with the lithium and sodium concentration profiles. As sodium progressively replaced lithium, the alkali internal friction peak became smaller while a new peak (mixed alkali peak) appeared and increased in magnitude. These changes in the internal friction are similar to those that occur upon the addition of a second alkali to glasses prepared by conventional melting. The magnitude of both internal friction peaks in ion exchanged glasses was dependent on the overall glass composition. The magnitude of …

Surface Reactions Of Boron With Clean Tungsten Substrates, Thomas A. Flaim

Doctoral Dissertations

"A model developed to predict adsorbate-induced work-function changes for thermionic emitters is shown here to apply to a more general class of electron emission phenomena and a much broader range of adsorbates. This model predicts that chemically, vapor-deposited boron will increase the work function of a clean tungsten substrate at coverages between 0 and 1 monolayer. This is the first time that a single model has been shown to predict both positive and negative work function changes for different adsorbates. The reactions of chemically, vapor-deposited (CVD) boron with clean tungsten substrates were studied using field emission microscopy (FEM) and low …

X-Ray And Neutron Diffraction Study Of The Holmium-Iron System, Michael Fred Simmons

Doctoral Dissertations

"Neutron diffraction and x-ray powder studies have been made of holmium-iron intermetallic compounds. The magnetic moments of Ho and Fe are in good agreement with measured spontaneous magnetization assuming a ferrimagnetic model with the Ho moments antiparallel to the Fe moments. The magnetic moments of the Fe atoms are found to be localized and thus independent of the rare earth content in the alloys. In contrast to HoCo₃, (00ℓ) type magnetic peaks in the neutron diffraction patterns are still prevalent at room temperature and gradually decrease as the Curie temperature is approached. This fact indicates that the easy direction of …

Diffusion In Wide Grain Boundaries, J. Mimkes, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

The rigorous solution of the grain-boundary diffusion problem has been approximated by a series expansion method. The calculations show that higher-order terms may be neglected in the bulk adjacent to the grain boundary. Thus, in this region Whipple's and Suzuoka's solutions represent a close approximation to the problem. Inside the grain boundary, however, higher-order approximations have to be taken into account. These approximations gain importance in the case of wide grain boundaries. The solutions obtained for an instantaneous source have been fitted to available grain-boundary diffusion data of Ni2+ in MgO at 1200°C. Numerical calculations give for the bulk diffusion …

Thermal Expansion Of Tungsten At Low Temperatures, Jayant S. Shah, Martin E. Straumanis

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Phase Equilibria And Thermodynamic Studies In The System Cao-Feo-Fe2o3-Sio2, M. Timucin, Arthur E. Morris

Materials Science and Engineering Faculty Research & Creative Works

Phase equilibria and thermodynamic properties of the system CaO-FeO-Fe₂O₃-SiO₂ were studied at 1450° and 1550°C, over a range of pO₂ from 1 to about 10-11 atm. Isothermal phase diagrams and activity-composition diagrams were constructed for 0, 5, 10, 20, and 30 wt pct SiO₂ sections. The data are applicable to further understanding the behavior of simple BOF steelmaking slags. © 1970 The Minerals, Metals & Materials Society - ASM International - The Materials Information Society.

The Fe-Ho Binary System, G. J. Roe, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

The Fe-Ho phase diagram was determined on the basis of data obtained by X-ray diffraction, metallographic and differential thermal analysis techniques. Since emphasis was centered in the region where intermetallic compounds predominate, neither the iron nor holmium terminal regions were included in this study. Eutectic reactions were found to occur at 16.5 wt pct Fe and 875° C, 61 wt pct Fe and 1284° C, and 79 wt pct Fe and 1338° C. The congruent melting points of the compounds Ho6Fe23 and Ho2Fe17 were found to be 1332° and 1343° C, respectively. Two other intermetallic compounds were found, HoFe2 and …

12th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 12th 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 3-4, 1970.

An Experimental Study Of Lateral Soil Pressures And Moments On Flexible Sheet Piles, James H. Donahue

Civil & Environmental Engineering Theses & Dissertations

In order to study the effect compaction has on lateral earth pressures exerted on and bending moments in steel sheet pile bulkheads, an experimental study was undertaken which employed the placement of a non-cohesive soil at two specific densities against three model piles of varying thicknesses. The soil was placed both in a loose and a dense state and the bending strains and deflections of the sheet piles were measured at various stages of backfill. Surface loadings were then placed after completion of the backfilling to observe the effects these loads had on the bending moments. The results of the …

The Microstructure Of Hardened Gypsum Pastes, Raafat Ishak Abdel Malek

Archived Theses and Dissertations

No abstract provided.

Traps And Trap Distribution In Commercial Zinc Sulphides Phosphors Silver Activated And Poisoned With Cobalt, Zohra Safinaz El Calamawy

Archived Theses and Dissertations

No abstract provided.

Switching Characteristics Of Calcium Borate Glasses Containing Iron, Mahmoud Aly El Hamamsy

Archived Theses and Dissertations

No abstract provided.

A Comparative Study Of The Inorganic Composition In Body Fluids Of Four Egyptian Tick Species, Samir Fouad Araman

Archived Theses and Dissertations

No abstract provided.

Wood Flour Molding, Charles Reed Snyder

Graduate Research Papers

The purposes of this research are briefly stated in the following:

1. Develop an understanding of the values of an industrial process through the use of raw materials and laboratory equipment.

2. Investigate wood flour molding and its relation to industry.

3. Experiment with materials, laboratory equipment, and wood flour mixtures to produce a molded article.

4. Develop an instructional unit for use in an industrial arts curriculum.