Metallurgy Commons^™

A Thermodynamic Study Of The System Pbo-Pbs, John P. Hager

Masters Theses

"An experimental investigation was conducted in order to determine the thermodynamic and kinetic behavior of the system PbO-PbS.

The thermodynamic behavior of the system PbO-PbS was studied by measuring the P_SO₂ in argon-SO₂ mixtures equilibrated with various PbO-PbS mixtures in a recirculating-type equilibrium apparatus, and analyzing the condensed phases by means of X-ray diffraction.

The effect of temperature and PbO/PbS ratio on the rate of SO₂ evolution was investigated in order to determine the reaction mechanisms involved in the approach to equilibrium.

A sodium hydroxide, hydrogen peroxide titration technique was employed in the analysis of SO_{2 …}

Preparation Of Casting Slips Containing Ferrous Powders And Alginates, Robert Eugene Newcomer

Masters Theses

"The preparation of casting slips containing ferrous powders dispersed by alginates was studied and an attempt was made to determine the mechanism by which suspension was attained. The colloidal aspects of preparing ceramic casting slips are discussed and an analogy is drawn to preparation of metallic slips suspended by alginates.

Sodium and ammonium alginates were used to suspend stainless steel and iron powders. The effect of NaOH, HC1, and various phosphate additions on the properties of slips and algin solutions was considered.

It was found that colloidal concepts can not be applied to explain observed behavior in the system studied. …

A Thermodynamic Study Of The Germanium Sulphides, Satya Prakash Jain

Masters Theses

"The experimental determination of some of the thermodynamic properties of germanium sulphide phases was conducted by a hydrogen reduction technique. The equilibrium H₂S/H₂ ratios were determined as a function of temperature for the two phase equilibria GeS₂-GeS and GeS-Ge. A Tutwiler analysis technique was used to analyze the equilibrated gas mixture for hydrogen sulphide content.

A detailed description is given for the process and the apparatus used in performing the experiments for equilibration of H₂S/H₂ gas mixture. The methods used for the preparation of germanium sulphide phases are also discussed.

The investigation …

A Thermodynamic Study Of Germanium Sulfides, Sham Lal Malhotra

Masters Theses

"The vapour pressure of germanium monosulfide (liquid) was determined by a boiling point method. An expression for the vapour pressure as a function of temperature was obtained and the heat of vapourization calculated. Using the heat of sublimation data obtained by other investigators, the heat of fusion was calculated.

The thermodynamic properties, change of standard free energy (Δ F°) heat content (Δ H°) and entropy (Δ S°); of germanium disulfide were determined by using an indirect method. The equilibrium H₂S/H₂O ratios are determined for the reaction:

GeS₂ (s) + 2H₂O(g) = GeO_{2 …}

A Dissolution Rate Study In Hydrofluoric Acid Of Titanium And The Alpha Solid Solutions Of Oxygen In Titanium, John L. Ratliff

Masters Theses

"The dissolution mechanism of titanium in hydrofluoric acid was studied by collecting the hydrogen evolved during the dissolution reaction. A concentration range of 0.05 N to 0.50 N and a temperature range of 15°C to 45°C were employed for the determination. Values of the reaction order and energy of activation were determined for both pure titanium and the alpha solid solutions of oxygen in titanium and found to be the same within experimental limits. This indicated that the reaction giving rise to hydrogen evolution on the surfaces of both pure titanium and the TiO_x alloys was the same. The …

The Effect Of Rare Earth Additions On Low Alloy Steel, Sukh Dev Sehgal

Masters Theses

"Rare earth metals have for some years been used as an inoculant in nonferrous foundry practice and lately in the production of nodular iron. It has been reported that addition of rare earth metal to certain grades of stainless steel so improve the hot malleability that reduction of large size ingots in the blooming mill is now possible. It has been reported that considerable improvement in soundness and mechanical properties of steel castings and wrought products have been attained as a result of small additions of rare earth metals and oxides. In practically all investigations, it has been reported that …

Mechanization Of First Stage Graphitization In Fe- C-Si- Alloys, Dildar S. Gill

Masters Theses

"The purpose of this investigation was to study the mechanism of first stage graphitization in iron-carbon-silicon alloys in the light of results obtained by Taub, and to propose a new mechanism of graphitization. The results of preliminary experiments confirmed the findings of Taub as regards the precipitation of secondary carbides. Therefore, it was decided to extend the investigation so as to include the study of growth of secondary carbides. In order to know the chief factor responsible for the growth of secondary carbides, the activation energy was calculated. Another factor which was investigated was the site of graphite nuclei formation”--Purpose …

X-Ray Diffraction Study Of The Metal Powder Compacts, Rajendra Sharan

Masters Theses

"Various theories have been put forward about the mechanism of compacting and sintering processes. None of these theories are confirmed. The reason is that most of these theories are based on observations on metallographic specimens, which is not a particularly good tool for such a study. Little data using xray diffraction analysis is available and there seems to be a great need of making a thorough investigation in this direction.

The main object of this investigation is to study xray diffraction patterns of green compacts of aluminum, nickel and copper powders pressed under different compacting pressures to see if any …

The Vapor Pressures Of Pbo-Sb₂O₃-Sio₂ Mixtures., John Henry Smith

Masters Theses

"The removal of antimony is one of the important steps in the production of pure lead. The process of removing antimony from impure lead bullion is called "lead softening". The most common method used is to blow air into a bath of impure molten lead. The impurities, primarily antimony, arsenic and tin, if present, are oxidized and form a slag or "dross" which floats on the surface of the lead bath. A considerable amount of lead is oxidized in this step and joins the other oxidized compounds in the dross. This dross is skimmed from the bath of molten lead …

The Effect Of Heating Chill Cast Eutectics, Robert Lewis Dreshfield

Masters Theses

"This investigation is the result of the author's specific interest in two phase systems. In the past, considerable work has been done investigating the alteration of eutectoid structures; however, eutectic structures have been neglected to a great extent. Tammann did some work on the subject in 1937 as did Brown and Guy in more recent times. In both of the above cases the eutectic structure was altered by cold working and subsequent heating of the alloy.

Tammann also noted that eutectics chill cast in liquid air display a vastly different structure than those cast under equilibrium conditions and that there …

Lattice Constants, Thermal Expansion Coefficients And Perfection Of The Phase Tio, Hsiung Wei Li

Masters Theses

"TiO is one of the intermediate phases in the titanium - oxygen system with a crystal structure of the sodium chloride type. The phase extends from about 22 to 29 weight or about 46 to 55 atomic percent oxygen. A comprehensive survey of the physical properties of the phase has been made in previous investigations (see review of literature), but only impure titanium was available at that time. Therefore, some revision of the measurements had to be made. Also, neither the thermal expansion coefficients nor the temperature at which the lattice constants were measured were reported.

For precision determination of …

Imperfections Within Ti₂O₃ And Tio₂ Phases In The Titanium-Oxygen System, Tatsuhiko Ejima

Doctoral Dissertations

“The hexagonal-rhombohedral Ti₂O₃ phase in the Ti-O system extends from 32.5 to 34.5% oxygen b.w., with the exact composition of Ti₂O₃ nearly in the middle of the phase. Seven samples of different composition within that phase were made, and the lattice constants (a and c) and the density of each sample were determined.

The plots of the constants against the composition of the samples revealed a deviation from Vegard’s rule when approaching the exact composition of Ti₂O₃. The lattice constants of this compound, obtained by graphical interpolation were; a_{25 …}

A Study Of The Recrystallization And The Mechanical Properties Of Indium, Louis John Reitsma Jr.

Doctoral Dissertations

"The recrystallization temperature and the mechanical properties of tensile strength, elongation, reduction in area and hardness were determined for 99.97% indium. Metallographic techniques were developed and stress rupture data were obtained.

Single crystals of indium were grown in a horizontal furnace with a traveling temperature zone, and sectioned in a strain-free manner, with an etch-cutter. Because of the low recrystallization temperature of indium, no further work was done on the single crystals.

The effect of recrystallization on electrical resistance, thermoelectric force, hardness, bending strength, crystallographic orientation and microstructure was studied. The range of recrystallization temperature for small amounts of cold …

A Thermodynamic Study Of The Zirconium Sulfides, Andrew Hessler Larson

Doctoral Dissertations

"A hydrogen reduction technique was used to determine some thermodynamic properties of various zirconium sulfide phases. The equilibrium H₂S/H₂ ratios were determined as a function of temperature and composition of the condensed sulfide phases. The hydrogen sulfide content of the equilibrated gas mixtures was analyzed by an iodimetric titration procedure.

A detailed description is given for the method and apparatus used both in the preparation of the various sulfide phases and in their equilibration with a hydrogen-hydrogen sulfide gas mixture.

The composition ranger 59 to 67 atomic per cent sulfur was studied over a temperature range of …

Methods To Improve The Metallurgy Of Bolivian Tin Ores, Oscar Davila-Michel

Masters Theses

"Tin is a rare element; among the base metals it is one of the rarest. Although it was one of the first metals used by man and has been used since prehistoric time, the ore-dressing and metallurgical methods of tin are inefficient and very wasteful.

The only tin deposits of importance in the Americas are located in Bolivia, South America, and it is in Bolivia that the problems of tin metallurgy are greatest. More than 50% of the tin that is mined in Bolivia is lost in the tailing dumps of the beneficiation plants. In a country where the export …

Influence Of Some Metals On The Rate Of Corrosion And Deposition Of Titanium In Molten Salt Baths, Yu-Pu Huang

Masters Theses

"2. The purpose of this investigation. The substances obtained by corrosion of titanium in fused salts, if leached with water and dried, are composed of three kinds of products, namely of black, gray and yellowish ones. The black product was identified by X-ray diffraction as titanium-oxygen alloy with 9-10% by weight oxygen which later was used as coating material instead of the titanium sheet for deposition experiments described previously. The yellowish product was identified as rutile. The grayish product was also rutile but containing some titanium powder. Of these three products only the black one possessed the ability to deposit …

Separation Of Iron-Tin Alloys Using Gas-Solid Reactions, Carl Richard Bieling

Masters Theses

"For years it has been a problem to the tin smelting, plating, and detinning industries to be able to separate iron from tin once they were associated together as described above. Due to the lack of a tin smelter in the United States in the past, and the abundance of tin scrap available, which had little value either for the iron content or the tin content in their untreated state, most interest was concentrated on seeking methods of separating this tin scrap into its two useful components, iron and tin, rather than deal with the problems of smelting tin from …

An Investigation Of The Dissolution Of Hafnium-Free Zirconium In Hydrofluoric Acid And The Effect Of Fluoride Additions, Alfred S. Neiman

Masters Theses

"Hafnium-free zirconium has assumed great importance in commercial use in recent years. When economical methods were developed in 1950 to remove hafnium from Zr, a metal was produced which not only exhibited good corrosion resistance and desirable physical properties, but also had a very low absorption cross section for thermal neutrons. Such a metal could obviously be utilized to advantage as a structural material for nuclear reactors. This application is the most important one for Zr at present.

Good corrosion resistance to most mineral acids is one of the outstanding non-nuclear properties of Zr. Hf-free Zr has good corrosion resistance …

Statistical Analysis Of X-40 (Stellite-31) Production Blends., Edward P. Patterson

Masters Theses

"An investigation was undertaken to statistically analyze the data obtained on X-40 (Stellite 31) production blends which were tested to the requirements of AMS 5382. For our purpose a blend is one or more furnace heats, the shot of which has been thoroughly mixed to produce greater uniformity of product. The mixed shot is charged to the arc furnaces and cast into parts, and test specimens. A great range of test results have been obtained in testing blends, and it was felt that a statistical analysis of a few of the variables might yield information which could be applied toward …

Determination Of Lattice Constants, And Thermal Expansion Coefficients Of Ti₂O₃ And Of Its Solid Solutions With Ti, Tatsuhiko Ejima

Masters Theses

"For the determination of the precise lattice constants of Ti₂O₃, it is very important to use a Ti₂O₃ as pure as possible.

Due to the formation of solid solution with titanium or oxygen, ranging from 32.5 to. 34.5% O₂ by weight in the Ti-O binary system, it is very difficult to get a pure Ti₂O₃ (33.8% O₂ by weight) in the laboratory.

To determine the precise lattice constants of pure Ti₂O₃, therefore, the extrapolation method was used.

This method computes the respective constants for pure Ti₂O₃ from the values obtained With Ti₂O₃-Ti solid solutions by extrapolation. To carry out such …

An Experimental And Theoretical Investigation Of The Preferred Orientation In Deformed And Recrystallized Hafnium, David S. Gould

Doctoral Dissertations

"The research problem, as presented, therefore became two-fold; first to investigate and determine the feasibility of fabrication of hafnium and secondly to study the deformation characteristics of the material in light of the overall study of hexagonal metals aimed at the development of an overall general theory of plastic deformation. This appeared to envolve a study of the operating deformation systems in hafnium and the theoretical and experimental study of the textures resulting from plastic deformation. These were to be analyzed in comparison with the other hexagonal metals.

It became evident immediately that the research techniques which must be evolved …

A Thermodynamic Study Of The Titanium Sulfides, Reinhard Paul Abendroth

Doctoral Dissertations

"The determination of the thermodynamic properties of chemical compounds is in essence an experimental one. The purpose of this investigation was (1) to make an experimental determination of the thermodynamic properties of the titanium sulfides (2) to determine what sulfide phases are present in the titanium-sulfur system (3) to show the relationships between the various phases present"--The Problem, Statement of the Problem, page 3.

A Study Of Gas Porosity In Aluminum Casting Alloys Using Radioactive Hydrogen As A Tracer, Osborne Milton

Professional Degree Theses

"A method will be described wherein the absorption of hydrogen by aluminum is evaluated using hydrogen 3 as a tracer element. Results show that hydrogen gas is readily absorbed into the melt when it is injected directly, but is not taken on from the combustion products, that quantities of it are released when the metal freezes, and that the commonly used methods of fluxing with chlorine and nitrogen gas are of value for degassing"--Preface, page iii.

A Study Of The Deleading Of Zinc Sulfide Concentrates, Larry Leroy Gidley

Masters Theses

"The object of this research was to study the basic principles and optimum conditions for the deleading of commercial zinc sulfide concentrates by sublimation of the lead in the form of a sulfide. Present commercial practice conducts this sublimation in hearth roasters. This research considered only the variables affecting sublimation of the lead sulfide, not the types of applicable equipment, or other possible processes. However, the laboratory conditions were at least partially similar to those that could be obtained in commercial practice"--Object, page 1.

The Properties Of Cold Rolled - Stress Relief Annealed 70-30 Cartridge Brass, Robert F. Hartmann

Professional Degree Theses

"Because of the possible commercial application of the proposed treatment of 70-30 brass, this work was undertaken. In addition, the data resulting from this work will result in a better understanding of the treatment of brass.

The objectives of this work were as follows:

1. Determine if higher strength and better spring properties can be realized from a process for commercial 70-30 cartridge brass wherein the regular recrystallizing anneals between rolling reductions are replaced by stress relief anneals.
2. Determine if it is possible, using the above process, to produce essentially fully recrystallized metal with an average grain size below that usually …

The Experimental Fabrication Of Titanium Magazines For 3 Inch 50 Caliber Twin And Single Gun Mounts, John Marshall Thorp

Professional Degree Theses

"The element titanium was discovered in 1790 by the Reverend William Gregor an Englishman from Cornwall England. Titanium is ninth in abundance or o.62 percent of the total of the elements making up the lithosphere. It is exceeded in amount only by oxygen, silicon, aluminum, iron, magnesium, calcium, sodium and potassium. Titanium is a constituent of practically all crystalline rocks and of sediments derived from them. Its chief mineralogical occurrence is as oxides in such minerals as ilmenite and rutile, which are the chief ores of titanium metal….

The titanium metal used in the project discussed in this thesis was …

A Study Of Titanium Diffusion Coatings By X-Ray Fluorescent Methods, Alan Bernard Burgess

Masters Theses

"As the only previous determinations of the chemical composition of the titanium coatings had been analyses of the average composition of the entire coating, the determination of the variation in chemical composition throughout the coating was suggested. From this information, it was proposed that a better insight might be gained as to the extent and mechanism of diffusion in the coatings. It was also hoped to correlate the results with concurrent work being done on the phases present in the titanium coatings. From this correlation, it might be possible to show which phases are responsible for the desirable properties of …

Deposition Of Titanium By Gaseous Reaction, Louis John Reitsma Jr.

Masters Theses

"Previous investigations undertaken at the Missouri School of Mines and Metallurgy on the deposition of titanium involved the use of fused salt baths, aqueous solutions, and cementation processes. The fused salt baths produced satisfactory coatings on small metal parts. Some difficulty was encountered however, when the coating of large articles was attempted.

For this reason, it was decided to investigate the possibility of titanium deposition by the reaction of a volatile titanium compound with a metal surface. Two different compounds were proposed for investigation, (1) a lower chloride of titanium and (2) an iodide of titanium. The reaction with the …

The Preparation Of Titanium Tetrachloride From Rutile, Nalin Sen

Masters Theses

"In recent years, considerable interest has been shown in the manufacture of titanium metal because of its outstanding properties both physical and chemical. The commercial process for the preparation of metallic titanium, known as the Kroll process, consists essentially of the reduction of titanium tetrachloride with magnesium in an inert atmosphere to produce titanium metal with magnesium chloride as a by-product.

Since, titanium tetrachloride is the basic compound from which to prepare metallic titanium by the Kroll process, much thought has been given to the preparation of titanium tetrachloride from titanium ores such as rutile or ilmenite.

The present work …

A Study Of The Structure Of Titanium Diffusion Coatings On Iron And Steel, Pao-Jen Chao

Masters Theses

"The Problem of the Thesis: A series of experiments have been made in the Metallurgical. Engineering Department of the Missouri School of Mines and Metallurgy for the investigation of titanium diffusion coatings. The technique of applying the titanium diffusion coatings on iron and steel is still in the experimental stage. A few of the physical properties and chemical compositions of such coatings have been determined, but the structures have not yet been extensively studied. As the correlations of the structures and the desirable properties are valuable for improving the quality or titanium diffusion coatings on iron and steel, an investigation …