Engineering Commons^™

Etch Patterns On Zone-Refined Fe, M. E. Straumonis, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Upon dissolution of zone-refined Fe in strong acids, mainly three kinds of corrosion patterns were observed in the crystallites of the sections. Regardless of the acids, the {110} plane always appeared on the three patterns in the form of smooth and even steps, ledges, or facets. The {112}, {122}, and {123} planes were also developed but to a much lesser degree. The {100} and {111} planes were not observed because grains of the respective orientation were missing on the sections. Attempts were made to explain the formation of the planes by taking into consideration the reticular density of the planes …

Exact Solution For A Model Of Dislocation Pipe Diffusion, J. Mimkes, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

The dislocations are treated as an ideal array of parallel pipes of radius and diffusivity Dp embedded in the bulk material of the diffusivity Db. The exact solution of this problem of diffusion along semi-infinite edge dislocations is presented for cubic, tetragonal, and hexagonal crystals. The solution makes it possible to evaluate the dislocation pipe radius a and the ratio of diffusivities from one experiment. It is applied to experimental data for self-diffusion in tellurium available in the literature. The results of the calculations are a dislocation pipe radius a=(1.5 0.5)x10-4 cm and an activation energy for the pipe diffusion …

Thermal Expansion Of Orthorhombic Pbo, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Thermal expansion of orthorhombic PbO was investigated by high‐temperature X‐ray diffraction. The coefficients in the a0, and c0 directions are equal and Pb–O chains extended in the a0 direction and bonded into layers in the b0 direction; appreciable Pb–Pb bonding is indicated. Coordination and bond distances observed in PbSiO3 and lead silicate glasses, which are similar to those of massicot, and PbnOn polymeric units reported in PbO vapor are interpreted as additional evidence of the importance of PbO chains as structural entities. Copyright © 1970, Wiley Blackwell. All rights reserved

Cation Grain-Boundary Diffusion In Sodium Chloride, K. R. Riggs, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Chemistry Of The Oxidant, Ferrate, Its Interaction With Specific Organics Found In Waste Water, Donald H. Williams, J. T. Riley

KWRRI Research Reports

It became obvious during this investigation that while much work has been done with ferrate (VI) chemistry, discrepancies existed in the literature and very little attention had been given possible engineering uses. This work attempted to fulfill these two needs in an exploratory manner.

The preparative techniques were reviewed and mechanical improvements made in one which allowed improved yields. Essentially what was done was to enlarge and improve the filtering technique of the product and use cooler temperatures throughout the preparation. This greatly shortened the time required. Then it was learned that the addition of ethyl alcohol to the final …

Additional Magnetic Disaccommodations In Ternary Iron Base Alloys, R. H. Graham, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Isotope Effect Of Carbon Diffusion In An Fe-Si Alloy, Manfred Wuttig, E. T. Yen

Materials Science and Engineering Faculty Research & Creative Works

The isotope effect of carbon diffusion in dilute iron silicon alloys containing 28Si and 30Si has been measured below room temperature using the Dis accommodation technique. The time dependence of the reluctivity has been analyzed in terms of two relaxation processes which are due to the reorientation of carbon interstitials in Fe-Fe and Fe-Si sites respectively. The ratio of the relaxation times of the two carbon isotopes 13C and 12C τ13/τ12 is 1.037 for the former and 1.007 for the latter process in the Fe+28Si alloy. The ratios of the relaxation times of the same carbon isotope 12C contained in …

On The Influence Of Surface Roughness On The Determination Of Diffusion Constants, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Cutting Nbs Budget, Norbert J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Age Hardening In A Mg-9 Wt.% Al Alloy, J. Beverley Clark

Materials Science and Engineering Faculty Research & Creative Works

The precipitation process and age hardening mechanism in a Mg-9 wt.% Al alloy were studied principally by transmission electron microscopy. This alloy age hardens by the general precipitation of plates of the equilibrium Mg₁₇Al₁₂ phase on the basal plane of the magnesium solid solution matrix. No evidence for the formation of either G.P. zones or a transition lattice of the Mg₁₇Al₁₂ precipitate was obtained. Cellular precipitation occurs competitively with the general precipitation at nearly all age hardening temperatures. In the solution treated condition, basal slip and {101̄2} twins are the principal deformation modes. Precipitation …

Interstitial Solute Trapping In Irradiated And Quenched Iron, M. (Manfred) Wuttig, J. T. Stanley, H. K. Birnbaum

Materials Science and Engineering Faculty Research & Creative Works

The interaction of interstitial carbon and nitrogen solutes with defects produced by low temperature neutron irradiation and by quenching was studied in high purity and Ferrovac E iron. Magnetic Dis accommodation techniques were applied to determine the interstitial solute content after irradiation and upon annealing. Doses of about 1017 neutrons/cm2 caused the trapping of about 20 ppm (atomic) interstitial solutes at 65 (carbon) and 40°C (nitrogen). Trapping of carbon in a Ferrovac E iron alloy occurred during a fast quench from 880°C. After trapping, the interstitial solutes reappeared in solid solution at 300 (carbon, neutron irradiation), 200 (nitrogen, neutron irradiation), …

Current Density-Anodic Potential Curves Of Single Crystal Gaas At Low Currents In Koh, Martin E. Straumanis, J. P. Krumme, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

Single p-type, GaAs crystals of high purity, Zn doped, were used to determine whether or not the inverse octahedral {111} faces show potential differences and various rates of anodic dissolution. The Ga{111}, As{111}, {110}, and {100} faces, were polished, etched, and etch-polished with concentrated H₂SO₄ + H₂O₂, and immersed in IN KOH. The Ga{111} faces were found to be the most noble with respect to rest and anodic dissolution potentials. The potential difference between the inverse {111} faces was as large as 0.14v for the rest and 0.123v for the dissolution potentials. The …

Zener Disaccommodation In Dilute F.C.C. Co-Ti Alloys, H. B. Aaron, M. (Manfred) Wuttig, H. K. Birnbaum

Materials Science and Engineering Faculty Research & Creative Works

The magnetic Dis accommodation, i.e., the time dependence of the low field magnetic permeability, was investigated in cobalt base alloys containing 0-5.1 at.% (0-4.2 wt.%) titanium in the temperature range 400-700°C. A strong temperature dependence of the Dis accommodation observed in the range 430-530°C could be accounted for predominantly by a single first order relaxation process. Analyzing the data in terms of (a) a single exponential relaxation, (b) a lognormal distribution of relaxation times, and (c) a sum of exponential relaxations, it was shown that the relaxation strength varies as the square of the titanium concentration and that the relaxation …

Influence Of Continuous Precipitation Upon The Growth Kinetics Of The Cellular Reaction In An Al-Ag Alloy, H. I. Aaronson, J. B. Clark

Materials Science and Engineering Faculty Research & Creative Works

The influence of the prior formation of a continuous precipitate upon the growth kinetics of the cellular reaction has been evaluated in an Al-17.9 wt. % Ag alloy. The continuous precipitate, in the form of intragranular plates of the γ′ transition phase, was shown to have reduced the upper bound of the driving force for the cellular reaction from the silver content of the untransformed alloy to that corresponding to the coherent solvus. When this reduction (≥ 98 %) is taken into account, the growth of cells is found to be controlled by cell boundary rather than by volume diffusion …

A Metallographic Study Of Solidification And Segregation In Cast Aluminum-Uranium Alloys, Bruce L. Bramfitt, Hollis P. Leighly

Materials Science and Engineering Faculty Research & Creative Works

The micromorphology and type of segregation in vacuum-cast ingots of aluminum-uranium alloys, ranging from 5 to 30 weight percent, were studied. The microstructural characteristics are similar to those of aluminum-silicon alloys of the same composition range, except that the aluminum-uranium eutectic was identified as having "chevron" and "rhombic spiral" types of morphology. © 1968.

Anodic Dissolution Of Zinc In Potassium Nitrate, Martin E. Straumanis, J. L. Reed, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

The apparent valence of pure zinc dissolving anodically in 3% KNO₃ was determined as a function of current density, temperature, and ultrasonic agitation. The apparent valence of zinc dissolving anodically at 24°C diminishes from 2.01 ± 0.01 at low current densities to 1.86 at about 50 ma and remains fairly constant up to about 80 ma cm−2. This valence is affected to some extent by the preparation, e.g., polishing of the electrode, but is independent of its structure (mono- or polycrystal). Ultrasonic vibrations do not influence the apparent valence at high current densities. In all cases a black film …

Thermal Expansion Coefficients And Lattice Parameters Between 10° And 65°C In The System Gap-Gaas, Martin E. Straumanis, J. P. Krumme, M. Rubenstein

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Hot Isostatic Compaction Of Graphite, Donald C. Carmichael, P. D. Ownby, Edwin S. Hodge

Materials Science and Engineering Faculty Research & Creative Works

The effects of temperature, pressure, and graphite starting material on the density, isotropy, and strength of dense graphite material prepared by hot isostatic compaction of graphite powders were examined. Process equipment was developed to permit operation at temperatures up to 2700 C under a 1600-atom isostatic pressure of inert gas . The isotropy of graphite compacts was determined by neutron diffraction. Relatively isotropic, high-purity graphites were produced having modest isotropic tensile strength and extremely high density (up to 2.24 g per cm³, or 99 per cent of theoretical).

Effects Of Calcining Temperature On The Physical Properties Of Zirconate Ceramics, P. D. Ownby

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Vapor Pressures & Relative Stabilities Of Certain Double Flourides, Walter L. Gage

Missouri School of Mines and Metallurgy Reports

The vapor pressures and relative stabilities of certain double fluorides such as sodium titanium fluoride and strontium titanium fluoride will be investigated by heating them under vacuum to determine the extent of evaporation or decomposition.

Direct Reduction Of Zinc Sulfide Under Vacuum -- Course Work, Merritt E. Langston

Missouri School of Mines and Metallurgy Reports

A study of the reduction of zinc sulfide under vacuum by such reducing agents as iron, calcium oxide and carbon, graphite, and iron and carbon.

An attempt to refine the impure zinc metal condensates obtained from the above reductions under under by the mechanism of a differential displacement of the volatile constituents.

Progress Report: Reduction Of Zinc Sulfide, Merritt E. Langston

Missouri School of Mines and Metallurgy Reports

To date the work which has been completed has been concerned with an attempt to duplicate the results reported by Liu in his thesis. In short, little can be said in comparing the two separate investigations because there does not seem to be any apparent similarity, even though the operating conditions were kept as nearly the same as possible. Figure 1 shows the lack of agreement for the amount of total zinc distilled, expressed as weight percent....

Stabilization Studies On Soil-Cement Mixtures For Experimental Lining--Logan Experimental Section--Logan, Utah, United States Department Of The Interior, Bureau Of Reclamation

Elusive Documents

Earth Materials Laboratory Report No. EM-170 covers the laboratory tests made on one type of soil from Logan, Utah, for the purpose of using the soil in soil-cement canal lining experiments. The intention was that two types of soil would be used for experimental linings at Logan, Utah; a fine sandy soil, poorly graded with little or no silt (Classification Symbol SP) and a fine sandy soil with excess silt (Classification Symbol SF-silty). These field test sections which will provide durability and permeability information gathered under natural conditions were carried out as part of a joint lower-cost canal lining experiment …

A Report On The Reduction Of Sphalerite Under Reduced Pressure, John H. Fuqua, William H. Magruder

Missouri School of Mines and Metallurgy Reports

During the last war, with the increased demand for magnesium metal and the general disregard for costs, a number of plants were constructed for the production of magnesium by vacuum metallurgical methods. (Both the Carbothermic Process and the Pidgeon Ferrosilicon Process employ vacuum systems for the production of metallic Mg.)

At the close of the war several of the government built plants were forced to suspend operations because of the economic impossibility of producing magnesium in competition with the Dow Chemical Company. It was with the availability of these plants in mind that experimentation with the possibilities of producing metallic …

Aircraft Quality Casting Standards, Robert Katz, Robert Bolin , Depositor

Robert Katz Publications

These standards are to be used in connection with the Handbook for Instructions for Aircraft Designers, 8^th Edition …

In the radiography of aircraft castings, markings appearing on the film may be attributed to either the condition of the castings examined, or to some details of the radiographic process entirely unrelated to the quality of the castings, These latter patterns must be recognized and related to the radiographic process so that sound castings will not be unnecessarily rejected. Radiographs must be carefully compared with the surface irregularities of the casting they represent before an attempt is made to …