Engineering Commons^™

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 …

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 …

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 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 …

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 …

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 …

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 …

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 …}