Engineering Commons^™

Oxidation Of Tetragonal Pbo In Air, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Isothermal oxidation of tetragonal PbO in air produced multiphase assemblages with apparent equilibrium compositions which varied linearly with temperature from PbO1.548 at 286°C to PbO1.333 at 351°C. Oxidation at each temperature was relatively rapid to PbO1.40 and very slow from PbO1.40 to apparent equilibrium values. Pseudocubic PbO1+x, with compositions between PbO1.41 and PbO1.57, was indexed on a cubic unit cell at the lower O/Pb ratios and on a tetragonal unit cell at the higher ratios. Linear changes in lattice parameters and deviation from cubic symmetry accompanied reversible oxidation and reduction of the phase. Pseudocubic PbO1+x was reduced irreversibly to Pb3O4 …

Polynary Silicon Arsenic Chalcogenide Glasses With High Softening Temperatures, H. E. Anthonis, N. J. Kreidl, W. H. Ratzenboeck

Materials Science and Engineering Faculty Research & Creative Works

The introduction of Ag in SiAsTe glasses permits the incorporation of Se, otherwise volatile and/or degradable as a constituent in Si-containing chalcogenide glasses. SiAsAgTeSe glasses exhibit much higher softening ranges and glass transition temperatures than encountered in known chalgogenide systems. A glass Si35As15Ag10Te20Se20 had the viscosity log ν = 13 at about 500°C, as compared to 370°C for the base glass Si35As25Te40, the viscosity of log ν = 9.8 at about 560°C, as compared to 442°C for the base glass. Phase separation occurs in the system SiAsAgTeSe and becomes manifest in two glass transitions indicated by changes in the slopes …

Oxidation State Control Of Volatile Species In Sintering, P. D. Ownby

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Initial Surface Reactions And Nucleation Kinetics Of Boron On Atomically Clean Molybdenum Substrates, Richard Eugene Moore

Doctoral Dissertations

"A study of the chemical vapor deposition (CVD) of boron from boron triiodide (BI₃) on molybdenum has been done with field emission microscopy (FEM) and low energy electron diffraction (LEED).

A correlation of the efficiency by which BI₃ is effectively dissociated to form adsorbed boron, and the temperature of the substrate has been shown through work function measurements on the boron covered molybdenum field emitter surfaces. The boron-induced work function change of molybdenum has been shown to be in agreement with a theoretical model which predicts positive, as well as negative work functions for adsorbate-substrate systems. It …

Premartensitic Elasticity Of Fe-Ni Invars, Bryce Linn Shriver

Doctoral Dissertations

"The premartensitic temperature dependence of ultrasonic wave propagation in Fe-30 pct Ni polycrystals and Fe-32 pct Ni single crystals was measured by using a continuous wave technique. As the temperature was lowered to within 10°C of the M_s, a nonlinear decrease of the relative shear velocity was observed. This effect is related to dislocation stacking fault instabilities which may trigger the martensitic phase transformation. In addition, the single crystals show a frequency dependence of the shear elastic constant C' well above the M_s. The dispersion is believed to be caused by fluctuations in the anisotropic molecular …

Prebainitic Phenomena In Aisi 86b80 And 0.8c-5.3ni Steels, Chung Lim

Doctoral Dissertations

"An ultrasonic investigation shows that the prebainitic kinetics of AISI 86B80 and 0.8C-5.3Ni steels follow t^2/3 and or t¹ time laws in the lower bainite temperature region. The data analysis indicates that these kinetics signal carbon segregation to dislocations. The simple time laws are interrupted at the bainite start time. It is shown that at this time the carbon depleted regions around dislocations transform martensitically. The lower bainite reaction is thus initiated by the formation of supersaturated ferrite through carbon segregation and the subsequent local martensitic transformation"--Abstract, page iii.

Powder Metallurgy, Harold L. Street

Graduate Research Papers

The purpose of the study is (1) to investigate pertinent literature and industries for the purpose of learning how the powder metallurgy process is carried out; (2) to construct a set of dies to press metal powder; (3) to use this equipment to press and sinter specimens; (4) to develop a unit of study on powder metallurgy suitable for use in an introductory metal class.

14th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 14th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 31 - August 1, 1972.

The Use Of Hardboard And Particleboard For Composition Panels In Furniture Construction, Jerry Dean De Penning

Graduate Research Papers

This study is concerned with the investigation of lamination using particleboard and hardboard as substrates for overlays. The purpose of the research includes the following:

1. To acquire information about the history and construction processes of particleboard, hardboard, and plastic laminates.

2. To investigate the procedural application of plastic laminates and vinyl overlays to particleboard and hardboard substrates.

3. To relate to the industrial arts students the industrial use of overlays laminated to a substrate.

4. To develop an instructional unit to be used in the industrial arts program.

5. To construct a school shop project in the area of …

Crystal Growth And Electrical Properties Of Some Pbte-Snte Alloys, Adel Fayez Seif

Archived Theses and Dissertations

No abstract provided.

Photo Chemical Milling, Terry R. Smith

Graduate Research Papers

This study is concerned with the techniques used in the production of metal parts by the use of photofabrication. Included will be a research of the historical background of the industry, and the production processes used by the photofabrication industry that apply to this project. Information will include careers, education, current status of the industry, as well as methods for implementing the processes into the industrial arts curriculum.

Electrostatic Fluidized Bed Plastic Powder Coating Process, Richard H. Florer

Graduate Research Papers

The overall objective is the fabrication of a functional electrostatic fluidized bed dry plastic powder coating apparatus which can be utilized in an Industrial Arts laboratory.

Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang

Masters Theses

"Thermal expansion, thermal hysteresis, and the monoclinic tetragonal phase transformation of ZrO₂ have been studied with high temperature x-ray diffractometry. The initial transformation temperature in pure ZrO₂, on heating, is about 1150ºC. The transformation occurs over a 100ºC temperature range and thermal hysteresis occurs on heating and cooling. The mechanism of the transformation is related to preferred vibrational modes of atoms on the A_O -C_O plane of the monoclinic structure. Because the monoclinic B_O axis is parallel with the tetragonal [110] axis, structural relationships can be seen to be a controlling factor in the transformation. Initiation of …

A Mass Spectrometric Characterization Of Positive Ions Created In Simple Vacuum Diodes Incorporating Oxide Cathodes With Supplementary Analysis Of Background Gases, Larry A. Addington

Masters Theses

"Simple diodes were constructed utilizing oxide cathodes and nickel anodes. The cathodes were obtained by applying a mixture of barium, strontium, and calcium carbonates to a nickel filament and decomposing them to yield the oxides. The products of decomposition were analyzed by monitoring the composition of the background gases in the vacuum chamber. A portion of the flux of positive ions bombarding the cathode during diode operation was analyzed. It was possible to determine the region of origin of the ions and their potential energy at the time of formation. Positive ions of chlorine, fluorine, sodium, potassium, and rubidium were …

A Study Of The System Lithia - Silica, Roy Richard Ramey

Masters Theses

"X-ray intensity and d-spacing measurements were performed upon samples in the system Li₂O-SiO₂. Samples ranged from 0.0 to 28.0 mole percent lithia and were fired for 72 hours at temperatures from 920ºC to 1400ºC. Atomic absorption analyses were made upon the fired samples. Non-equilibrium conditions were prevalent and results are inclusive. Quartz is the stable phase in the high silica field at temperatures below 1050ºC with cristobalite stable above that. The quartz - cristobalite transformation occurs at 950ºC with the cristobalite transforming into tridymite at 1010ºC. There was wide scattering of data at 1000ºC and below. There was no correlation …

Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang

Masters Theses

"By precise X-ray measurements, the lattice parameter of pure nickel (Fisher Co., reagent grade) was found to be 3.52389 Å at 25ºC. At the same temperature, the lattice parameters of iron samples were found to be: 2.86621 Å, 2.86624 Å and 2.86614 Å for purities of 99.999%, 99.985% and 99.9%, respectively. By measuring high angle back reflection lines, the linear coefficients of thermal expansion of both nickel and iron were precisely determined. Both, high purity nickel and iron, exhibited anomalies in their expansion coefficients near their Curie points. This is in agreement with some of the previously reported data. Some …

Mechanism Of Ual₃ To Ual₄ Transformation, Ling Ping Lee

Masters Theses

"The UAl₄ compound which forms during the peritectic reaction, Liquid + UAl₃ - UAl₄ , has a long needle-like shape and a characteristic morphology of fish-tail when cut along the long axis. It has an internal core of another phase when cut perpendicular to the needle axis. Because of the interesting similarity between UAl₃ and UAl₄ crystal structures, the peculiar UAl₄ morphology could be explained. The mechanism of UAl₃ to UAl₄ transformation is identified as shear and diffusion controlled transformation"--Abstract, page ii.

An Investigation Of Stage I Fatigue Crack Growth In Fcc, Bcc, And Hcp Metals, Marion Anthony Russo

Masters Theses

"The objectives of this investigation were to 1) determine if Stage I mode or fatigue crack growth could be extended beyond the 45 degree maximum shear plane in metals having a face-centered, body-centered and hexagonal close pack crystal structure; 2) identify the crystallographic planes or crack propagation in Stage I growth in each crystal structure; 3) characterize the fracture surface topography or Stage I growth in each crystal structure. The test material used for this investigation consisted of alpha brass (70% Cu, 30% Zn), Armco iron and commercially pure titanium which are representative of FCC, BCC, and HCP crystal structures …

A Tensi-Volumetric Apparatus: Theory, Calibration, And Use In An Investigation Of The Oxygen Non-Stoichiometry Of Pure Batio₃, Glenn Jon Conger

Masters Theses

"The development of the tensi-volumetric apparatus has been traced to its current position of significance in studies relating to oxide non-stoichiometry. Components of the tensi-volumetric apparatus, especially the capacitance membrane manometer, were examined in detail as were the parameters affecting the performance of such an apparatus. Based on a careful consideration of components and performance, a tensi-volumetric apparatus has been designed, built, and its operation theoretically justified for its particular physical configuration. Results of existing studies of the oxygen non-stoichiometry of barium titanate have been used to predict its behavior during a tensi-volumetric study. Specific analytical procedures developed for use …

Equilibria Between Moo₂ And Liquid Molybdenum Oxide, Prakash Bakhru

Masters Theses

"The oxygen pressure over solid molybdenum dioxide in equilibrium with liquid molybdenum oxide was determined by transpiration and solid electrolytic galvanic cell methods at 950ºC and 900º, 950º and 1000ºC respectively. The results were compared to those expected from thermodynamic data on the Mo-O system. Possible reactions between MoO₂ and SiO₂ were studied at different oxygen pressures up to 1550ºC. No compound formation or solid solution between MoO₂ and SiO₂ was detected by x-ray diffraction techniques. The phase boundary between MoO₂ and liquid molybdenum oxide was checked by microscopic examination of quenched samples. Equilibration runs were carried out in silica …

The Electric Field Strength Dependence Of Neutron-Induced Defects In Silicon P-N Junctions, Paul Edward Johnson

Masters Theses

"The effect of high electric field strengths (10⁴ to 10⁵ V/cm) present during neutron radiation on the neutron-induced defects is determined by utilizing the high electric field strength inherent in the emitter-base transistion region of an n-p-n transistor. A method is presented for the separation of neutron and gamma effects. Previous theoretical work on the ratio of base current increase to collector current decrease is applied to experimental data. The variations of the space-charge region volume damage introduction rate with neutron fluence and the average electric field strength are determined experimentally in order to obtain a measure of this effect. …

Concentration By Sorting : Feasibility Determination By Radial Distribution Analysis, Robert M. Doerr

Masters Theses

"A method was developed for determining certain factors for assessing the feasibility of sorting fragments of an inhomogeneous solid to concentrate a species. These factors are the typical size of zones in which the grade exceeds a selected value, and the recovery potentially achievable by sorting fragments of such size"--Abstract, page iii.

The Morphology Of The Cellular Precipitation Reaction In A Pb-3.0 Wt% Sn Alloy, Federico Sequeda Osorio

Masters Theses

"The complete development of the cellular precipitation structure at selected grain boundaries in a Pb-3.0 wt% Sn alloy during aging at 34°C and 23°C was investigated by light microscopy. The cellular structure in this alloy consists of lamellae of solute depleted lead solid solution and lamellae of ß tin precipitate. The cellular precipitation reaction begins by local migration of a grain boundary with concomitant grain boundary precipitation of ß tin. The grain boundary bows around the ß tin grain boundary precipitates which then begin to lengthen in the direction of boundary migration thus forming the precipitate lamellae of the cell. …

Polynary Silicon Tellurium Glasses, Henry Edward Anthonis

Masters Theses

"The introduction of Ag into Si-As-Te glasses permits the incorporation of Se, otherwise volatile and/or degradable as a constituent in Si-containing chalcogenide glasses. Si-As-Ag-Te-Se glasses exhibit much higher softening ranges and glass transition temperatures than encountered in known chalcogenide systems. A glass Si₃₅As₁₅Ag₁₀Te₂₀Se₂₀ had the viscosity log η =13 at about 500°C, as compared to 370°C for the base glass Si₃₅As₂₅Te₄₀, the viscosity of log η = 9.8 at about 560°C, as compared to 442°C for the base glass Si₃₅As₂₅Te_{40 …}

Radiation Induced Centers In Silver Doped Glasses And Application In Phototropy, Perihan Soliman Tawfik

Archived Theses and Dissertations

No abstract provided.

Dissolution Potentials And Activation Energies Of Insb Single Crystals, Martin E. Straumanis, Lih Da Hu

Materials Science and Engineering Faculty Research & Creative Works

The rest (or corrosion) and dissolution potentials of InSb single crystals in HC1 were determined. There is no potential difference (within error limits) between the inverse {111} faces in pure HC1. A difference of up to 44 mV and more develops as soon as the InSb electrode is anodically dissolved. The potential becomes less noble in the sequence In{111}, {100}, {110}, Sb{111}. The Tafel relationship is observed over three decades of current density. With additions of FeCl3, FeCl2, K3Fe(CN)6, K4Fe(CN)6, H2C4H4O6 to 2N HC1, the anodic potentials of both inverse {111} faces are shifted to more active values; the e'H …

Irradiation Enhanced Decomposition Of A Nickel-Carbon Solid Solution, B. L. Shriver, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

This investigation was performed to determine the effects of room temperature neutron irradiation on the distribution of carbon in a nickel-0.3 wt.% carbon alloy. The experiment consisted of comparing the amount of carbon in solid solution and the internal stresses of both unirradiated and irradiated (1013 fn-cm-2 < ΦF < 1018 fn-cm-2) samples following isochronal anneals between 100 and 1200°C by using the magnetic Dis accommodation technique. The results indicate that the amount of carbon remaining in solid solution decreases with increasing neutron dose. At temperatures below 200°C this is due to the trapping of carbon by mobile irradiation-produced defects. Between 200 and 600°C the formation of metastable carbides is enhanced by the presence of irradiation-produced defects. No differences are observed in irradiated and unirradiated samples above 600°C. © 1972.

Activation Volumes Of Carbon Diffusion In Fcc Iron-Nickel Alloys, J. Keiser, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

The Dis accommodation 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 68 to 90 °C and pressures up to 6 kbar 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. © 1972 The American Physical Society.

Nonstoichiometry In Batio3, G. J. Conger, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Low Temperature Lattice Parameters And Expansion Coefficients Of Ai2au And Lif Gruneisen Constants Of Lif, Martin E. Straumanis, Jayant S. Shah

Materials Science and Engineering Faculty Research & Creative Works

There is no difference in the thermal expansion behavior of an intermetallic compound (Al2Au) and of an ionic (LiF), except in the magnitude of the expansion coefficients, which for both compounds upon cooling below 40°K approach zero. The lattice parameters of the two compounds mentioned decrease uniformly and without anomalies with lowering the temperature, approaching a constant value below 40°K. The a–T relationship between 40 and 180° is given in form of equations. A pump working on the Joule‐Thomson principle was used for cooling. The GRÜNEISEN parameter, γ, of LiF between 40 and 180°K is a constant, contrary to theoretical …