Materials Science and Engineering Commons^™

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 …

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 …

Some Properties Of Chrome-Magnesite Mixtures And Calcium Aluminate Cement-Magnesite Mixtures, Edward Charles Duderstadt

Masters Theses

"The knowledge of the physical and chemical properties of refractories is of great importance in determining their usefulness and application. The thermal expansion of refractories is of particular importance in that it affects the thermal stability of the product. A high coefficient of thermal expansion leads to greater spalling and destruction of the bricks in use. It is, therefore, desirable to develop compositions having low coefficients of thermal expansion. This investigation was undertaken (1) to determine some of the properties of chromite-magnesite refractory mixtures in an attempt to determine the optimum composition of these mixtures, the specific properties including thermal …

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 …

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 …

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 …

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 …

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 …

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 …

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 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 …

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 …

A Fundamental Study Of Clay Drying Using Ware Of Large Cross Section, Robert F. Grady Iii

Masters Theses

"The drying of clay has been studied extensively in the past by many investigators, some of whom attempted to relate this information to the structure of clay and thereby develop a more vivid picture, while others studied the mechanism of drying in its own right in order to present a useable theory that would allow improvements in the drying operation.

At present the literature is unable to present a theory of the mechanism of drying that is sufficiently general to cover the observed aspects of clay drying. Many and varied mechanisms are presented, but correlation is seldom completely evident between …

Mechanism And Measurement Of First Stage Graphitization In White Cast Iron, David S. Gould

Masters Theses

"The original object of this thesis was to ascertain if coercive force measurements could be used for the determination of degree of malleablization in malleable iron. Since first stage graphitization was involved, it was only natural that an interest in the mechanism of first stage graphitization developed. The investigation which resulted from this interest was done primarily for the edification of the author, however it was subsequently deemed of enough importance to be included in this thesis. For this reason the thesis may appear at times to deviate from the original objective"--Preface, page iii.

Effect Of Carbon Content In Steels Upon The Deposition Of Titanium From A Fused Salt Bath, Reinhard Paul Abendroth

Masters Theses

"STATEMENT OF PROBLEM Previous work done at the Missouri School of Mines and Metallurgy on the deposition of titanium upon various metals, especially iron and steel, bas shown that titanium can be deposited upon ingot iron and. low carbon steels with comparitive ease. Difficulty was encountered in attempts to deposit titanium upon steels of higher carbon content and upon cast irons.

For this reason, it was decided to investigate more thoroughly the relationship between the carbon content of various steels and the quality of titanium coatings deposited on these steels. Once this relationship had been established, a suitable theoretical explanation …

Deposition Of Metallic Coatings From Fused Salt Baths, Andrew Hessler Larson

Masters Theses

"This thesis is the result of an investigation undertaken to study some of the important factors affecting the deposition of metallic diffusion coatings on other metals immersed in a fused salt bath….

There are many methods which have been devised to obtain diffusion coatings on various metals. One which is quite well known and used commercially is the process of “chromizing” which produces a diffusion layer if chromium on another metal. One method of “chromizing” consists of immersing the specimen to be coated in a mixed chloride fused bath containing chromium metal flakes. Another method consists of packing a low …

Corrosion Products Of Titanium In Fused Salt Baths, Kai-Chai Chiou

Masters Theses

"Titanium is gaining great interest in the modern metal industry because of its natural abundance and its desirable physical and chemical properties. Among them, its excellent corrosion resistance, such as the resistance to normal atmosphere attack, humid and saline atmosphere attack, sea water attack, and nitric acid attack, is the most prominent characteristic being welcomed by the engineers. The usefulness of titanium would be greatly increased if it were possible to plate titanium on other metals, thus increasing the corrosion resistance of these other metals.

Much concern, at present, has been given to the possibilities of the electrodeposition of titanium …

Testing Of Missouri Shales For Light Weight Aggregate Production, Jerry D. Plunkett

Masters Theses

"The original objective of this investigation was to determine by testing those clays, shales, and loesses occuring in Missouri in large deposits (over 15 feet in thickness with little overburden), which would be suitable for the production of light weight aggregate. The second objective was to investigate the mechanism of bloating as related to the physical and chemical properties of the above materials, and by using these relationships cause clays which do not naturally bloat, to bloat using some addition. The use of additives would permit the economical use of material closer to the market in many instances.

After the …

The Lattice Constant And Coefficient Of Expansion Of Chromium, Chao-Ching Weng

Masters Theses

"The most important use of chromium, other than as an alloying element in the manufacture of stainless steel, is for electroplating; to form a coating on other metals for corrosion prevention in order to procure longer life, and to achieve a decorative effect.

The physical properties of chromium are important in the effectiveness of its uses, and its lattice constant, as well as coefficient of thermal expansion, seem worthy of exact determination.

A number of research workers, over a span of thirty years, have spent considerable effort in determining the aforementioned constants. However, their results do not check, and the …

The Bloating Of Missouri's Shales, Peter Kurtz Jr.

Masters Theses

"The first objective of this investigation was to determine which deposits of clays, shales, and loesses in Missouri are suitable for use in the production of lightweight aggregate by virtue of their expanding characteristics upon heating. The second objective was to determine, if possible, commercially feasible additions that will produce the bloating property in shales that do not naturally bloat.

There are two conditions which must be met in firing in order to bloat a clay or shale. First, a gas must be formed and evolved during firing. Second, enough glass of the proper viscosity must be formed to trap …

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

Masters Theses

"The present work is a continuation of the previous investigations of Gross and Warrington and Liu in which the effect of various reducing agents on the vacuum reduction of zinc sulfide was studied. The author became interested in this topic while reading the papers by these investigators in which they recommended that further work be performed in an attempt to prevent zinc sulfide from distilling over during reduction, thereby contaminating the zinc condensate. The original plan was to perform a few runs for the purpose of duplicating the results that were reported by Liu, and from this point carry on …

Autographic Determination Of Thermally-Induced Linear Changes In Ceramic Bodies, William Dean Mckee Jr.

Masters Theses

"The determination of changes in length of ceramic compositions as a function of temperature is frequently required in ceramic research and testing. With the use of an observer, excellent means are available for determination of changes in length over moderate ranges of temperature. However, the extended period required for some tests makes desirable the automatic recording of length change as a function of temperature.

There has been in use in the Ceramic Engineering Department a furnace arranged for determination of length changes; this furnace, shown in Figure 1, is so arranged that change in sample length causes linear displacement of …

Dissociation And Relative Stability Of Sodium Fluotitanate, Walter L. Gage

Masters Theses

"Titanium is urgently needed in the armament industry especially as a substitute for 18-8 stainless steel. There would be an almost inexhaustible supply of ores of titanium if high-purity titanium metal could be produced economically in large quantities. The use of titanium would permit much of the scarce nickel and chromium to be made available for other important uses.

It has been found by H. C. Kawecki and E. J. Bielecki that high-purity Na₂TiF₆, K₂TiF₆, and (NH4)₂TiF₆ can be produced from iron-bearing titaniferous raw material, ilmenite ores, or a …

Activation Energy For Recrystallization In Rolled Silver, Krishan Kumar Tangri

Masters Theses

"In several metals the process of recrystallization is accompanied by a change in the orientation of the recrystallized material with respect to the cold rolled material. If the change is sufficiently large, the changing position of the crystals can be determined by measuring the change in the intensity of the characteristic Bragg-reflection with a Geiger counter x-ray spectrometer. Recent determinations of the activation energies of copper and a 50/50 iron-nickel alloy have been made by using this x-ray technique. Both of these metals show a decided shift in the orientation as the material is recrystallized.

Silver was examined to find …