bluuebunny/crossref_metadata_2025 huggingface dataset:
Segregation of Elements During the Crystallization of a Magma
Authors: OSBORN E. F.
Published: June 2006

The manner in which ions segregate during the long period of cooling and crystallization of a magma in the earth's crust, whereby rock bodies varying widely in composition are formed, is discussed from the standpoint of composition of liquid, temperature, and the properties of the ions. The initial magma composition taken is that of a basalt in which the quantitatively important cations are Si4+, AP, Ca2+, MgZ+, Fez+, Fe3+, Na+, and K+, and in which almost all of the remaining elements of the periodic table occur in minor amounts. The distribution of representative cations among early, intermediate, or late crystals formed from the liquid is considered from the standpoint of (e) ionic field strengths, (b) the noble‐gas or non‐noble‐gas character of the ions, and (c) the types of silicate or aluminosilicate frameworks which form as the temperature and compo1sition of the liquid change. An ion of low concentration in the initial magma may appear largely in early crystal structures (Sc3+), throughout the series of structures (Ge4+, Sr2+), or only in the late structures (Li+, U4+).
Stresses in Glass‐Metal Seals: I, The Cylindrical Seal
Authors: MARTIN F. W.
Published: June 2006

A consideration of the effects of viscous flow during cooling of a beaded wire seal following annealing treatment leads to a refinement of the theory of Hull and Burger. With the corrections provided, excellent correlation is obtained with experimental stress measurements. Cylindrical seals with metal as the external member are also considered. It is shown that the expansion necessary for the best match depends on the geometry of the seal. In general, metal‐glass seals should be annealed at a temperature above that used for the glass alone.
Improvement of the Stain Resistance of Lead Glasses
Authors: APOSHIAN MARY M. , KREIDL NORBERT J.
Published: June 2006

The development of a quarter‐wave‐length film in acidic media is taken as a measure of acid resistance of flint glasses improved by the introduction of relatively small percentages of ZrO2, TiO2, Ta2O5 (or Nb2O5). The time for the formation of this film may be increased one or more orders of magnitude by the addition of less than 10% of these oxides in a simple K2O–PbO–SiO2 base glass selected for this investigation.
Relation of Chemical Properties to the Bloating of Clays
Authors: RILEY CHARLES M.
Published: June 2006

Two conditions necessary for bloating which have long been recognized are (1) that a material must produce a high temperature glassy phase with a viscosity high enough to trap a gas and (2) that some substance must be present that will liberate a gas at a temperature at which a glassy phase has formed. By utilizing a large number of chemical analyses of bloating and nonbloating clays, the author was able to define the limits of bloating on a composition diagram. The “area of bloating” on this diagram showed the desirable compositions of clays which satisfy the first necessary condition for bloating. As a test of the area of bloating, silica and alumina were added to nonbloating clays to give them compositions conforming to paints within this area. When fired these mixtures bloated. Tests showed that of all the accessory minerals of the Decorah shale, hematite, pyrite, and dolomite are the only ones which could dissociate and produce a gas at the proper temperature. Fractions of the shale which apparently contain only illite also bloated. It was discovered that many igneous rocks whose compositions fall within the area of bloating on the composition diagram produced good bloats when ground and cast into briquettes. Aphanitic rocks such as rhyolites, trachytes, and dacites should be investigated as possible raw materials for lightweight aggregate.
Contribution to the Interpretation of Phase Diagrams by Ceramists
Authors: FOSTER WlLFRlD R.
Published: June 2006

An attempt is made to eliminate some of the difficulties which hamper the proper use of phase diagrams by ceramists. It is contended that equilibrium is more nearly approached in ceramic bodies than is generally realized. Accordingly, phase diagrams are believed to be capable of more general application than has been previously recognized. The significance of primary fields is discussed, and the harmful results of the overemphasis of these features of phase diagrams are illustrated with examples from the literature. The useful role of the much‐neglected compatibility triangles in the ceramic application of the diagrams is emphasized. The relation of invariant points, melting intervals, and courses of melting to the firing behavior of ceramic bodies is indicated. It is believed that the conclusions drawn largely from the consideration of the MgO–Al2O3–SiO2 diagram are of general application, except possibly in the case of the alkalialumina–silica systems.
A Study of the Refractory Borides
Authors: BREWER LEO , SAWYER DWIGHT L. , TEMPLETON D. H. , DAUBEN CAROL H.
Published: June 2006

The phases of the binary systems of boron with Ce, Ti, Zr, Nb, Ta, Mo, W, Th, and U were determined by X‐ray examination of samples prepared by heating various mixtures of boron and the respective metal to elevated temperatures in an atmosphere of argon. Data were obtained on the sintering behavior and stability at high temperatures of many of the phases. Several phases have promising refractory properties for use under inert or reducing conditions.
Temperature Distribution During Mineral Inversion and Its Significance in Differential Thermal Analysis
Authors: SMYTH HAROLD T.
Published: June 2006

Temperature distributions have been calculated in a thin slab of material for which the temperature of the outside faces was raised at a uniform rate. Calculations cover the entire period during which the material is transformed from one form to another with an endothermic reaction. Application of these calculations to the interpretation of thermal analysis data is discussed.
Thermal Expansion Properties of Some Synthetic Lithia Minerals
Authors: HUMMEL F. A.
Published: June 2006

The binary compounds Li2O.5Al2O3 and Li2O.Al2O3 can be formed easily by reaction of pure materials at 1500°C. The ternary compounds βeucryptite and βT‐spodumene and solid solutions involving these two compounds can be prepared by reaction of Li2CO3, Al2O3, and SiO2 at 1300°C. The thermal expansions of the lithium aluminates are very high, but the expansions of β‐spodumene and β‐spodumene solid solutions are very low. The compound β‐eucryptite is unusual in that it shows a high thermal contraction to 1000°C. Some relations between the expansion data and the crystal structure of the phases given above are discussed.
Firing and Cooling Shrinkage Behavior of Structural Clay Bodies
Authors: VAN DER BECK ROLAND R. , EVERHART J. O.
Published: June 2006

Length change determinations on nineteen sewer pipe bodies were used to study the shrinkage of structural clays. Determinations over both heating and cooling cycles were included. Many of these materials are used in the production of other structural clay products and they represent mixes of shales and clays commonly used throughout the industry. The data consequently are of interest to all producers of structural clay products. A description of the techniques employed in securing the data, as well as a discussion and interpretation of the results, is given. Particular emphasis is placed on the possibility of conserving fuel and firing time, as well as reducing rejects, by applying information obtained. It was found that nearly all the shrinkage occurs in a very small portion of the total firing cycle, and that there are periods of slight volume change where considerations of shrinkage are of small consequence in firing.
X‐ray Diffraction Study of the Oxidation Characteristics of Nickel‐Pickled Sheet Iron as Related to Enamel Adherence
Authors: DOUGLAS G. S. , ZANDER J. M.
Published: June 2006

A systematic X‐ray diffraction study was made of the effect of nickel pickling on (1) the oxidation of bare enameling iron and (2) the reactions taking place under ground‐coat enamels. Nickel pickling reduces the amount of oxide formed during the heat‐up part of the firing cycle and favors the formation of Fe3O4, rather than of FeO. Since less oxide is formed on nickel pickled steel, the enamel can completely dissolve the initial oxide layer in a shorter time or at a lower temperature. With a typical high‐temperature ground coat, the time and temperature conditions required for adherence development can be correlated with the conditions required for removal of the oxide layer. With a low‐temperature ground coat, however, complete solution of the initial oxide layer does not insure adherence unless nickel pickling is used. Possible explanations for this latter effect exerted by nickel pickling are discussed. Metallic precipitates have been found in normal ground coats regardless of whether adherence is good or poor.
Anelasticity of Glass: I, Introduction
Authors: FITZGERALD J. V.
Published: June 2006

A vibrational energy absorption spectrum for glass has been assembled from elastic aftereffect data reported in the glass literature and also from internal friction and rigidity modulus measurements. The similarity of the anelasticity of glass to the anelasticity of metal is emphasized. Reference is made to possible applications of this powerful tool to glass technology.
Annealing of 517.645 Borosilicate Optical Glass: I, Refractive Index
Authors: BRANDT NEILL M.
Published: June 2006

The changes of the refractive index of the borosilicate crown BSC–2 (nD= 1.517, v= 64.5) with temperature and time were determined by the quenching method. From these findings and the equations concerning temperature distribution and strain release in glass by Adams and Williamson’were derived practical annealing schedules to predetermined index homogeneity for various thicknesses of glass. The data for this particular glass are compared graphically with similar and different types of glasses studied by other investigators.
Neutron‐Absorbing Glass: CdO‐SiO2‐B2O3 System
Authors: MELNICK LABEN M. , SAFFORD HURD W. , SUN KUAN‐HAN , SILVERMAN ALEXANDER
Published: June 2006

A large part of the glass‐forming region of the system CdO–SiO2–B2O3 has been investigated, and certain properties of representative glasses have been measured. Borate glasses high in cadmium oxide and containing lesser amounts of silica, together with small additions of calcium fluoride and alumina, are good slow‐neutron absorbers. These glasses are not only stable against moisture attack and devitrification, but axe easily made with ordinary glassmelting techniques. Equations have been developed to permit one to calculate, from composition, the neutron transmission and hence the neutron absorption of the glasses.
Ceramic Compositions Having Negative Linear Thermal Expansion
Authors: SMOKE EDWARD J.
Published: June 2006

Compositions having negative linear thermal expansions ranging from 0 to –0.38% have been obtained in two areas of the system lithia‐alumina‐silica. Petrographic and X‐ray examinations indicate the presence of three principal crystalline phases, each of which is a solid solution: β‐eucryptite, β‐spodumene, and an unidentified quartzlike phase. All compositions were prepared from lithium carbonate, clay, flint, and alumina. Some compositions have been prepared which, for all practical purposes, exhibit no change in length when heated from room temperature to as high as 600°C. Some of these compositions have excellent thermal endurance, withstanding repeated quenchings from a temperature of 1100°C. into water at room temperature.
Some Factors Affecting the Opacity, Color, and Color Stability of Titania‐Opacified Enamels
Authors: PATRICK ROBERT F.
Published: June 2006

X‐ray diffraction studies were made on a series of commercial titania‐opacified enamels. In all cases anatase was found to be the principal crystalline phase present; rutile and α‐silica were minor constituents. In comparing enamels with similar crystal size within each series, it was found that as the ratio of anatase to rutile increased, the reflectance increased and the color became bluer. When the relative amounts of anatase and rutile were held constant and the titania crystals decreased in size, the reflectance decreased and the relative amount of blue in the color increased. Minor amounts of niobium and antimony oxides which were smelted into the frit increased the relative amount of blue in the color of the fired enamel, simultaneously lowering the reflectance.
Limitations Imposed by Raw Materials on Firing Schedules
Authors: ROBINSON GILBERT C.
Published: June 2006

The raw material is the major factor in limiting the speed of firing when using tunnel kilns of small cross section, such as the Prouty‐type slab kiln. Raw materials vary greatly in the time required for water smoking, oxidation, and rapid shrinkage periods. The selection of materials that require small amounts of time can effect large reductions in firing time. Large reductions in firing time can be accomplished for slow‐firing materials through control of the grog particle size distribution or through the addition of other clays or shales to the material. Some reductions in firing time can be obtained through the elimination of hygroscopic water prior to firing and through apportioning the available firing time according to the needs of the raw material. Such scheduling permitted the firing of certain full‐size brick in 8° hours.
X‐Ray Study of the Reactions at the Steel Surface When Titania Enamel Is Applied Directly
Authors: DOUGLAS GORDON S. , ZANDER JASON M.
Published: June 2006

A detailed X‐ray diffraction study has been made of the reactions which occur at the enamel‐steel interface during the firing of a titania enamel directly on steel. The following crystalline compounds have been found near the interface under various conditions: (1) Fe3O4, (2) FeO, (3) FeTiO3, (4) anatase, (5) rutile, (6) nickel‐iron alloy, and (7) an unidentified compound designated “unknown X.” The Fe3O4 and FeO make up the initial oxide layer which forms on the steel before the enamel fuses. The FeTiO3 is formed by reaction between dissolving FeO and dissolved TiO2 in the enamel. Anatase is the primary opacifying crystal which precipitates because of supersaturation of the frit, but it is drawn back into solution as FeTiO3 precipitates. Rutile is a secondary opacifier which forms relatively slowly and apparently causes the re‐solution of the FeTiO3. The nickel‐iron alloy appears only as a trace and probably comes from reaction between FeO and a small amount of nickel oxide formed on the nickel‐flashed samples. The most important observable effect of nickel pickling is its drastic reduction of the amount of oxide initially formed. Increasing the firing temperature increases the rates of all the reactions, but most particularly the precipitation of rutile and the disappearance of FeTiO3. The adherence development of this enamel on Ti‐Namel steel is dependent to a great extent on the weight of nickel deposit and the firing temperature and time. The theory that adherence depends on the presence of an oxidizing agent in the enamel adjacent to the steel has been applied to this system, and a correlation has been obtained on the assumption that dissolved TiO2 is the adherence‐promoting oxidizing agent. The titania enamel does not develop adherence on a regular enameling iron under conditions where good adherence is developed on Ti‐Namel steel, although the reactions in the enamel are essentially the same. This may result from observed differences in crystal orientation or texture, behavior of the nickel deposit, or effects of hydrogen.
Thermal Stress Failure of Pure Refractory Oxides
Authors: SCHWARTZ BERNARD
Published: June 2006

An investigation was carried out to study the thermal stress failure of three pure, dense refractory oxides, namely alumina, stabilized zirconia, and magnesia. Thermal stress resistances were determined by means of a direct test and by calculation from the physical properties of the material. The properties measured included strength, elasticity, and thermal expansion. All the tests were conducted within the temperature range 25° to 1500°C. For hollow cylindrical specimens, heated uniformly from the inner surface, resistance to fracture was expressed quantitatively by the heat flow at steady state required to cause fracture. This resistance was found to be a function of (1) the physical properties of the material, (2) the temperature range of testing, and (3) the temperature distribution within the specimen.
Low‐Expansion Cordierite Porcelains
Authors: BEALS R. J. , COOK R. L.
Published: June 2006

The crystalline nature and expansion characteristics of compositions in the region surrounding the cordierite area of the system MgO–Al2O3–SO2 were investigated. The selected compositions were fired to temperatures of 1250°, 1300°, 1350°, and 1400°C., and the thermal expansion characteristics were determined with the interferometer. Coefficients of linear thermal expansion were determined in the temperature range of 20° to 300°C. and were found to lie between 9.8 ± 10–7 and 50.5 ± 10–7. The qualitative, as well as the quantitative, determination of crystalline constituents was made utilizing strontium fluoride as an internal standard in the X‐ray spectrometer. In the compositions studied crystalline cordierite ranged from 38 to 97%. There was a close correlation between the linear thermal expansion coefficient and the crystalline cordierite content of the bodies.
The Effect of Preparation Conditions on Tensile Strength of Soda‐Lime‐Silica Glass Rods
Authors: TOOLEY F. V. , STOCKDALE G. F.
Published: June 2006

A study has been made of the relationship between conditions of specimen preparation and the tensile strength of small constricted soda‐lime‐silica glass rods. The preparation and testing techniques were basically the same as those used in a previous investigation' except that the drawing loads were systematically varied. It was found that different loads under which specimens were drawn resulted in significant changes in tensile strength values. The average strength values varied from 62,800 lb. per sq. in. to 88,400 lb. per sq. in., depending on the drawing loads used. Maximum strength values were obtained with the highest loads. The limits of error of the strength values did not change appreciably with different drawing conditions. Rubbing the specimens with the fingers reduced the strength by approximately 32%.
Germania Glasses: The System Na2O–CaO–GeO2
Authors: PARIKH N. M. , SIMPSON H. E.
Published: June 2006

The physical properties of some Na2O‐CaO‐GeO2 and Na2O‐CaO‐SiO2 glasses were compared. The glasses were compounded on a molecular basis with the RO2 held constant. Physical properties determined were softening point, viscosity, annealing point, density, and refractive index. The possible constitution of these glasses is discussed in brief on the basis of their physical properties. Their optical and transmissive properties, which were also determined, indicate possible new uses.
Stabilization of Zirconia with Calcia and Magnesia
Authors: DUWEZ POL , ODELL FRANCIS , BROWN FRANK H.
Published: June 2006

The minimum amount of calcia or magnesia required to stabilize zirconia into the cubic form is about 16 mole %. X‐ray diffraction studies show that both calcia and magnesia are in solid solution in cubic zirconia. This solid‐solution phase extends from 16 to 30 mole % in the case of calcia and from 16 to 25 mole % in the case of magnesia. These results are for specimens cooled from 2000°C. After heating at various temperatures between 815° and 1375°C., the calcia‐stabilized zirconia remains cubic, whereas the magnesia‐stabilized zirconia reverts to the monoclinic form. On the basis of the results obtained from X‐ray diffraction and dilatometric measurements, information was obtained on the phase relationships in the systems zirconia‐calcia and zirconia‐magnesia, and some modifications to the previously published phase diagrams of these systems are proposed.
The System Alumina‐Gallia‐Water
Authors: HILL V. G. , ROY RUSTUM , OSBORN E. F.
Published: June 2006

A study of the system Al2O3–Ga2O3–H2O has resulted in the determination of equilibrium diagrams for the systems Al2O3–Ga2O3 and Al2O3.‐H2O–Ga2O3.H2O. Extensive solid solution characterizes the α‐Al2O3 and β‐Ga2O3 structures at high temperatures, but it is shown that below 810°C. a compound, GaAlO3, and a new series of (Al, Ga)2O3 structures are stable. Among the hydrates, a complete series of diaspore solid solutions extends from Al2O3.H2O to Ga2O3.H2O. Boehmite solid solutions extend to approximately the composition 70Al2O3.H2O, 30Ga2O3.H2O.
Density, Expansivity, and Viscosity of Molten Alkali Silicates
Authors: SHARTSIS L. , SPINNER S. , CAPPS W.
Published: June 2006

The densities nd vi cositie of melts in the systems Li2O–SiO2, Na2O–SiO2, and K2O–SiO2 were measured with a restrained sphere apparatus over the temperature range 1000° to 1400°C. At the higher temperatures in this range the density in each system decreased with increasing alkali content. On a mole basis the thermal expansivity of the potassium silicates was greater than that of the sodium and lithium silicates. Comparisons on the basis of moles of alkali per unit volume of glass showed that to a first approximation the viscosity of the systems investigated was almost independent of the kind of alkali ion involved.
A Note on the Melting Point of Titanium Dioxide
Authors: PIERRE P. D. S. ST.
Published: June 2006

A new determination of the melting point of pure titanium dioxide has been made. The apparatus used and the conditions of experiment are described. It is concluded that some of the figures quoted in the literature are low because of reduction of the dioxide. The present results indicate a melting point of 1840°± 10°C.
Aging Changes in Clinical Thermometers
Authors: LIBERATORE LAURENCE C. , WILSON RAYMOND E.
Published: June 2006

In order to decrease the manufacturing time required to produce satisfactory clinical thermometers, heat‐treatment schedules have been developed to replace the aging period required to insure that the volumes of the thermometer bulbs will not change appreciably after the thermometers are placed in use. Two methods of heat treatment are reported, together with the results of a determination of the changes in the bulb volumes over a period of approximately 6 months after heat‐treating. Thermometers which had been heat‐treated showed average changes in reading of 0.03°F. or less, while the thermometers which had received no heat‐treatment changed by the equivalent of as much as 0.10°F.
Niobate and TantaIate Dielectrics
Authors: WAINER EUGENE , WENTWORTH CHANDLER
Published: June 2006

The ceramic and electrical properties of the niobates and tantalates of the elements of the first and second vertical groups of the periodic table have been examined. Included in the group are members of the perovskite crystal system which are ferroelectric and exhibit Curie points in the range 350° to 475°C. The NaNbO3 and NaTaO3 are of particular interest. It appears that Cd2Nb2O7 is the ceramic and dielectric analogue of SrTiO3. The binary NaNbO3.Cd2Nb2O7 is the evident analogue of BaTiO3 with the exception that its high dielectric constant and piezoelectric properties are maintained over a much broader range of temperature. A study of these compounds has indicated means for spreading the temperature range of usefulness of perovskite‐structure ceramics for capacitor and electromechanical application.
Binary Mixtures of UO2 and Other Oxides
Authors: EPSTEIN LEO F. , HOWLAND W. H.
Published: June 2006

The phase diagrams of the binary systems containing UO2 and the oxides MgO, Al2O3, and BeO have been constructed using (1) the laws of ideal solutions and (2) the approximation that the entropy of fusion of polyatomic molecules is N R, where N is the number of atoms per molecule. Reasonable values of the eutectic composition and temperature and satisfactory agreement with experiment have been obtained.
Determination of Strains Between Enamel and Iron by Means of Split Rings
Authors: WALTON J. D. , SWEO B. J.
Published: June 2006

A modified split‐ring test has been devised whereby it is possible to measure strains produced between porcelain enamel and iron from room temperature to the softening point of the enamel. A correlation of data obtained by this test is made with warpage and expansion data to determine the accuracy and validity of the test. A description of the apparatus used and the method of determining strains is presented.
Synthetic Mica Investigations: II, Role of Fluorides in Mica Batch Reactions
Authors: EITEL WILHELM , HATCH R. A. , DENNY M. V.
Published: June 2006

Various fluorides were studied to determine which might be suitable for the synthesis of fluor‐phlogopite mica (K2Mg6Al2Si6O20F4). K2SiF6, MgF2, K2AlF5, and K3AlF6 are preferred in that order. KF, KMgF3, AlF3, KAlF4, and MgSiF6· 6H2O are less suitable for the purpose. Solid‐state reaction studies were made on the following binary partial systems of the mica batch: MgF2+ MgO, 3MgF2+ Al2O3, 2MgF2+ SiO2, 3MgF2+ KAlSi3O8, K2SiF6+ 3MgO, K2SiF6+ Al2O3, K3AlF6+ 3MgO, and K3AlF6+ 3SiO2. Solid‐state reaction studies on various types of fluor‐phlogopite batches showed that this mica compound can be synthesized at temperatures as low as 750°C. For best results, however, it should be done at 1000° to 1300°C. in closed containers, using anhydrous batch materials to minimize hydrolysis of the fluorides and loss of HF. Many of the mica batches expand as they react in the solid state, and there is danger in large‐scale experiments that the container may break unless heating is rapid between 750° and 1200°C.
Thermal Conductivity of Refractory Insulating Concrete
Authors: HANSEN W. C. , LIVOVICH A. F.
Published: June 2006

The thermal conductivities and unit weights of seventeen refractory insulating Lumnite cement concretes were determined over the approximate temperature range 500° to 2000°F. The thermal conductivities of all the concretes increased with an increase in temperature, which is usual for amorphous bodies. The aggregates used with Lumnite cement were vermiculite, perlite, pumice, calcined diatomaceous earth, and expanded shale. A graph is given of the thermal conductivities at a mean temperature of 1000°F. for a range of fired unit weights which should be useful in estimating the thermal conductivity of a concrete from its fired unit weight.
Metal‐Ceramic Interactions: I, Factors Affecting Fabrication and Properties of Cermet Bodies
Authors: KINGERY W. D.
Published: June 2006

The fundamentals of cermet fabrication and properties of cermet bodies are considered. These include metal‐ceramic reactions, surface and interfacial energies, constituent properties, and the effect of the dispersed state on the properties. These factors affect metal‐ceramic bonding, body composition, and phase distribution, which are important in fabrication and to properties. Strength, oxidation resistance, thermal conductivity, and thermal‐shock resistance also are considered.
Uranium Oxide Phase Equilibrium Systems: III, UO2–ZrO2
Authors: LAMBERTSON W. A. , MUELLER M. H.
Published: June 2006

The UO2–ZrO2 phase equilibrium system contained no new compounds but was found to contain extensive solid solution. The UO2 solid solution was cubic and extended up to 52 mole % ZrO2. Its lattice parameter varied from 5.46 to 5.32 a.u. with an increasing percentage of ZrO2. The zirconia solid solution when examined by quenching techniques was tetragonal and extended from 53 to 100% ZrO2. There were some indications that ZrO2 transformed to a polymorphic form other than monoclinic or tetragonal at approximately 1900°C.
Relation of Bubble Structure of Porcelain Enamel to Fish‐Scaling
Authors: BERGERON C. G.
Published: June 2006

A technique is described for making angular cross sections of enameled steel in order to study the bubble structure of a porcelain enamel. This technique involves cutting a section so that the width of the glass layer is extended, allowing easier observation of bubble size and distribution. Plates of low‐carbon steel 1/8 in. thick were enameled and then made to fish‐scale by cathodic pickling, thus giving a measure of the fish‐scale resistance. The relative cross‐sectional area and the relative volume of the bubbles were calculated from photomicrographs of polished sections of the test plates and were correlated statistically with their fish‐scale resistance. Results indicate that the bubbles which were effective in inhibiting fish‐scaling were contained approximately in the 1‐mil layer of glass adjacent to the steel.
Effect of Heat‐Treatment on Color of Amber Bottle Glass
Authors: SPIX WILLIAM L. , BACON FRANK R.
Published: June 2006

It is demonstrated that the color and transmittance of carbon‐sulfur amber glasses are affected reversibly by heat‐treatment. If a specimen is soaked at a given temperature between 1150° and 950°F. for a sufficient period and air‐quenched, the transmittance is characteristic of that temperature. If the same specimen is then soaked at a lower temperature, the transmittance decreases to a value characteristic of the lower temperature. The soaking time required to establish an equilibrium condition as evidenced by attainment of the characteristic transmittance increases from less than 10 minutes at 1100°F. to more than 15 days at 950°F. A change in transmittance at 650 mμ from 54 to 27% was attained in one sample.
Reactions in the System Li2O–MgO–Al2O3–SiO2: I, The Cordierite‐Spodumene Join
Authors: KARKHANAVALA M. D. , HUMMEL F. A.
Published: June 2006

Phase equilibria along the nonbinary join between cordierite (2MgO · 2Al2O3· 5SiO2) and spodumene (Li2O · Al2O3· 4SiO2) were investigated in the temperature range 800° to 1550°C. using the quench technique on fourteen compositions. The phase diagram at high temperatures is characterized by a very small region of solid solution on the cordierite side, appreciable solid solution on the spodumene side, and regions of three and four phases toward the center of the system, including liquid, α‐cordierite, mullite, spinel, corundum, and β‐spodumene and its solid solutions. The liquidus has a flat minimum between 40 and 50% cordierite at 1347°, and rises on one side to the congruent melting point of β‐spodumene (1421°) and on the other side to the temperature of complete melting of cordierite (1530°). The lowest temperature at which liquid appears is 1325°. At low temperatures a complete series of metastable solid solutions exists between μ‐cordierite and β‐spodumene. The significance of the data in the preparation of thermal‐shock‐resisting bodies is discussed.
Uranium Oxide Phase Equilibrium Systems: IV, UO2–ThO2
Authors: LAMBERTSON W. A. , MUELLER M. H. , GUNZEL F. H.
Published: June 2006

UO2 and ThO2 form a continuous series of solid solutions with the solidus‐liquidus extended from 2875°C. for UO2 to above 3200°C. for ThO2.
Compression Strength of Porous Sintered Alumina and Zirconia
Authors: RYSHKEWITCH EUGENE
Published: June 2006

The influence of controlled porosity on the compression strength of sintered pure alumina and of partly magnesia‐stabilized zirconia was investigated. Bodies with porosities ranging from approximately 3 to 60% by volume were prepared utilizing hydrogen peroxide to induce pore formation. Cubes of approximately 1.2‐cm, unit length were used in testing for compression strength at room temperature. The spatial arrangement of pores in sintered alumina was found to exert an influence, inasmuch as bodies with pores lined parallel to the pressure direction revealed a higher strength than bodies of the same porosity but with pores lined mainly perpendicular to this direction. It was found that an increase of porosity by 10 volume % decreased the strength of both sintered alumina and sintered zirconia by half of their initial respective values.
Fundamentals of Glass‐to‐Metal Bonding: I, Wettability of Some Group I and Group VIII Metals by Sodium Silicate Glass
Authors: ZACKAY VICTOR F. , MITCHELL DAVID W. , MITOFF STEPHAN P. , PASK JOSEPH A.
Published: June 2006

The degree of wetting of Cu, Ag, Au, Pd, Pt, and Ni by three sodium silicate glasses having 30.8, 33.6, and 36.9% Na2O was observed in vacuum, helium, hydrogen, oxygen, and air atmospheres. No apparent correlation of the contact angles of the three sodium silicate glasses with the metals studied in the various atmospheres was observed with the position of the metals in the periodic system of elements. It was found that within the range of glass compositions studied, there is no appreciable difference in contact angle for identical conditions. In pure helium no chemical effect of atmosphere itself is possible. The observed variations in contact angle from metal to metal may be related to the polarizing power of the metal, which may be presumed to have the effect of lowering the interfacial tension. At present it is felt that no reaction between pure metal and glass occurs in an inert atmosphere. In oxygen and hydrogen atmospheres chemical reactions are possible, and these reactions result in phenomena that favor spreading. Results are reviewed on a theoretical basis.
Modification of a Fixed‐Range Potentiometer Recorder into a Variable‐Range Recorder
Authors: KANDA FRANK A. , SHAVER RICHARD C.
Published: June 2006

The circuit of a Brown Electronik strip chart recording potentiometer was easily and inexpensively modified to enable rapid selection of ranges and spans by means of variable precision resistors. Variable zero‐point suppression combined with an adjustable span makes the instrument ideal for the study of continuous phenomena. The modified instrument possesses good reproducibility and stability. Data are presented to show the effects of settings of the modified components on the spans and ranges of the instrument.
Relation Between Bond and the Surface Physics of Masonry Units
Authors: THORNTON JOHN C.
Published: June 2006

While the author and his colleagues were doing research work with mortars, it was noticed that many brick had high capillarity on rough or sanded surfaces and little or none on others. This led to bond tests during which it became evident that there was a relation between the kind of surface on a unit and the amount of bond. Further experiments with chimneys or wells showed that (1) leakage and extent of dye penetration coincided closely with the previous laboratory bond tests, (2) there was excellent bond and practically no dye penetration with smooth brick, which had little or no capillarity, (3) bond decreased and dye penetration increased according to the surface, and (4) as the capillarity of the surface increased, the bond decreased. It became apparent that while there are differences in mortars in respect to bond, these differences are rather small when compared with the effect caused by the surfaces of masonry units.
Study of Some Binary Silicate Glasses by Means of Reflection in Infrared
Authors: ŠIMON I. , McMAHON H. O.
Published: June 2006

The reflection method provides means of studying the 10‐micron infrared region that contains the fundamental vibration of the silica lattice. Structural changes produced by introduction of various amounts of alkali or alkaline‐earth network modifiers can be conveniently followed. A series of soda‐silica glasses was studied in an interval of 0 to 46 mole %; other binary glasses containing Li, K, Ca, Sr, and Ba oxides also were investigated.
Investigation of the Thermal Dissociation, Reassociation, and Synthesis of Zircon
Authors: CURTIS C. E. , SOWMAN H. G.
Published: June 2006

The amount of dissociation present in zircon after 2‐hour heating periods at temperatures between 2800° and 3600°F. was determined by X‐ray analysis of quenched specimens. The course of dissociation was followed in the same manner during 8‐ to 10‐hour heating periods at temperatures of 2800°, 3000°, and 3200°F., respectively. Data are included that pertain to the synthesis of zircon from its constituent oxides at temperatures from 2100° to 2800°F. The results indicate that zircon is the stable phase up to about 2800°F.; above that temperature it becomes unstable, the degree of instability increasing with temperature, especially above 3200°F. On the basis of the results obtained from this investigation, a revision of the present phase diagram of the system zirconia–silica is proposed.
Ceramic and Dielectric Properties of the Stannates
Authors: COFFEEN WILLIAM W.
Published: June 2006

The hydrated stannates of barium, calcium, strontium, magnesium, bismuth, lead, cobalt, nickel, zinc, copper, cadmium, iron, and manganese were prepared and their thermal behavior was studied by differential thermal analyses coupled with X‐ray diffraction patterns of calcines. Ceramic bodies were prepared from each of the individual stannates and their dielectric properties were measured. Bodies prepared from the stannates of zinc, copper, cadmium, ferrous and ferric iron, and manganese are semiconductors. The remaining stannates have dielectric constants at 1 mc. ranging from 12 (SrSnO3) to 101 (NiSnO3) and power factors from nearly zero (CaSnO3) to 0.0456 (NiSnO3). Suggestions are made for the utilization of the stannates in barium titanate bodies.
Investigation of Gases Evolved During Firing of Porcelain Enamels
Authors: MOORE DWIGHT G. , MASON MARY A.
Published: June 2006

An investigation was made of the gases evolved during the firing of porcelain enamels. The investigation included (1) examination of gas evolution with a microscope while specimens were being fired, (2) examination of fired specimens for changes in bubble structure with firing time, (3) examination of the changes in the normal gas evolution when water‐free enamels were used, (4) analysis with the mass spectrometer of the gases trapped in the bubble structure after varying firing times, (5) determination of the source of the carbon gases in the bubble structure using radioactive C14 as a tracer, and (6) determination of the effect of various pretreatments of the clay used for suspending the coating slip on the resulting bubble structure of the fired specimens. The results showed that the principal gases evolved during the firing were carbon monoxide, carbon dioxide, and hydrogen. The blistering that is often observed in the early stage of firing when porcelain enamels are applied to low‐carbon steel was found to be caused by evolution of the carbon gases formed by the oxidation of the carbon in the steel. Evidence was obtained that the hydrogen formed from the reaction between the dissolved water in the coating and the hot‐iron base slowly diffuses into the coating as the firing continues. Some of the hydrogen also diffuses into the metal. On fast cooling this hydrogen is expelled, causing bubbles to form in the coating at the interface. It was found that a considerable portion of the bubble structure in an enamel fired for a normal time is due to some impurity in the clay mill addition. The impurity is probably organic matter adsorbed on the clay particles.
Relationship of Surface Structure of Glass to Residual Laminar Stresses
Authors: LEVENGOOD W. C. , BUTLER E. B.
Published: June 2006

The force necessary to detach a glass test block from a sample of tempered glass to which it is glued is shown to be linearly related to the stress in the tempered glass. Fine microscopic glue lines left on the tempered glass after detachment of the test block are suggested as Griffith cracks by comparison of the glue lines with the pattern made visible by treatment of tempered samples with sodium vapor. A linear relationship between the square root of the total crack length on a sample and the stress in the glass is demonstrated. The linear relationship between the square root of the crack length and stress is derived theoretically.
Chemical Analyses, Surface Area, and Thermal Reactions of Natural Graphite, and Refractoriness of the Ashes
Authors: MACKLES L. , HEINDL R. A. , MONG L. E.
Published: June 2006

Spectrochemical data, differential thermal analysis data, and surface area were determined for eleven natural graphites from different foreign and domestic sources, and the chemical analyses and refractoriness of their ashes were obtained. The assortment of elements, other than carbon, was essentially the same for all the graphites regardless of the source. Differential thermal analyses did not indicate any thermal reactions in the range from room temperature to 1000°C. with the exception of one graphite that had 35% ash which was partly kaolin. The surface areas ranged from 0.3 to 4.8 m.2 per gm. for ten of the graphites, but the eleventh graphite had a value of 26.5 m.2 per gm. For the ashes, the silica–alumina ratios ranged from 2 to 11, the total alkali from 0.4 to 7.8 mole %, and the total alkaline earth from 0.6 to 43.6 mole %. The percentage of the remainder of the nine major constituents also varied from one ash to another. The refractoriness of the ashes ranged from cone 5 to cone 27.
Hydrothermal Synthesis
Authors: MOREY GEORGE W.
Published: June 2006

The underlying theory of hydrothermal synthesis is presented and the apparatus used is described. By way of illustration the determination of the solubility of quartz in superheated steam at high pressures and the determination of the compositions of coexisting gas and liquid phases in the system H2O–Na2O–SiO2 at 400°C. are discussed.
Synthetic Mica Investigations: I, A Hot‐Pressed Machinable Ceramic Dielectric
Authors: COMEFORO J. E. , HATCH R. A. , HUMPHREY R. A. , EITEL WILHELM
Published: June 2006

A new ceramic composed entirely of synthetic fluorine mica manufactured by the hot‐pressing technique is described. Its chemical, physical, and electrical properties are given. As the extensive isomorphism possible in the mica structure permits the variation and control of properties over a wide range, the characteristics of several different synthetic mica compositions are included. Hot‐pressed mica is soft (2+ to 4+, Mohs' scale) and machinable, yet has a transverse strength of more than 8000 lb. per sq. in. As an electrical insulator, it compares with fused silica and ultra‐low‐loss steatite. With a rise in temperature, the dielectric constant remains essentially unchanged up to 300°C.; some synthetic mica compositions show an increase of less than 3% when they are heated to 400°C. The power factor of several synthetic mica compositions remains less than 2% at 400°C., being 0.05% at room temperature.
Studies on the Lime‐Rich Crystalline Solid Phases in the System Lime—Silica—Water
Authors: Kalousek G. L. , Logiudice J. S. , Dodson V. H.
Published: June 2006

A study was carried out to ascertain the effects of two forms of silica, quartz and silicic acid, the methods of mixing, and autoclaving conditions on the formation of the lime–rich crystalline hydrous calcium silicates designated as alpha–, beta–, and gamma–type hydrates. The alpha–type hydrates were synthesized from mixtures of lime slurry and quartz in compositions of 1.8 to 2.4 CaO/SiO2 molar ratios (C/S ratios). This series of compounds, free of all contaminants, showed X–ray patterns containing many or nearly all lines of crystalline Ca(OH)2. The beta‐type hydrates, of which synthetic hillebrandite is a member, were prepared in 1.8 to 2.4 C/S ratios from mixes of CaO and silicic acid dispersed in water. This series of phases or closely related phases may extend in composition from 1.5 to 3.0 C/S and includes minerals and other synthetic solids previously believed to be distinctly separate phases. The gamma‐type hydrates having compositions of about 1.5 to 2.25 C/S were prepared from mixes of quartz and CaO dispersed in water and autoclaved at somewhat higher temperatures than the alpha‐type hydrates. The gamma‐type hydrates contained about 0.3 to 0.4 mol. of water per mol, of compound compared with values of 1.00 to about 1.25 for the other two types of hydrates.
Metal‐Ceramic Interactions: III, Surface Tension and Wettability of Metal‐Ceramic Systems
Authors: HUMENIK MICHAEL , KINGERY WILLIAM D.
Published: June 2006

The wettability and adherence of metal–ceramic systems were investigated, using a precise sessile–drop method. The surface tension and wettability of silicon, iron, and nickel in contact with various refractory materials were evaluated at elevated temperatures. Measurements were carried out in vacuo, in hydrogen, and in helium. Generally, nonwetting contact angles were observed for iron and nickel with oxides, whereas silicon was found to wet the oxides partially. In all cases the wettability was greater for the metal‐graphite and beryllium carbide systems than for the metal‐oxide systems. The nature of the atmosphere was found to have a significant effect on the wettability and surface tension of the metal. Wettability results are interpreted on the basis of surface tension and by the consideration of free‐energy changes.
Properties of a Tin Oxide‐Base Ceramic Body
Authors: QUIRK JOHN , HARMAN C. G.
Published: June 2006

Some thermal and mechanical properties were measured for tin oxide‐matrix compacts which nominally were composed of 99% by weight tin oxide (SnO2) and 1% zinc oxide (ZnO). The sintered compacts were similar in strength to high–fire mullite porcelains, had superior resistance to thermal shock, and had high thermal conductivity. The tin oxide body might be expected to give good service under conditions of severe thermal shock and in an oxidizing atmosphere at temperatures up to 1500°F.
Phase Equilibria in the System MgO‐Cr2O3‐SiO2
Authors: KEITH M. L.
Published: June 2006

Studies of phase equilibria by the method of quenching show that there are no ternary compounds at liquidus temperatures in the system MgO‐Cr2O3‐SiO2. There is an extensive two‐liquid region, and the stability fields of periclase, picrochromite, and chromic oxide extend across most of the diagram. Temperatures of liquid formation are sufficiently high that a number of different compositions can be suggested for refractory purposes. Fundamental explanations are brought out for the improvement of chromite and chromite‐forsterite refractories by the addition of MgO and for the improvement of chromite‐silica refractories by the addition of chromic oxide or some other high‐chromium compound.
Sintering of Zinc Oxide
Authors: GRAY T. J.
Published: June 2006

The fundamental processes involved in the sintering of ionic solids are highly complex. Of particular significance are the initial stages of sintering during which surface effects are of prime importance. The sintering of zinc oxide has been studied by the method of changes in surface area at temperatures from 300° to 1000°C. and with varying oxygen pressures (from 10‐5 to 760 mm. of Hg). It has been demonstrated that significant sintering occurs at temperatures far below the Tammann temperature. It also has been shown that under specific conditions a very high defect concentration may exist in the surface of the material and that this is closely related to the phenomenon of sintering. Correlation has been made with an electron‐microscope investigation. Detailed X‐ray studies on single‐crystal specimens of zinc oxide have shown that interstitial zinc constitutes the defects. Activation energies have been deduced for the sintering process which suggest that the rate‐controlling step is diffusion in the surface zone in the low‐temperature region which changes to lattice or complex diffusion and viscous‐flow mechanisms about the Tammann temperature.
Structural and Dielectric Studies in the System (Ba, Ca) (Ti, Zr)O3
Authors: McQUARRIE MALCOLM , BEHNKE FRED W.
Published: June 2006

The crystalline phases in the system (Ba, Ca) (Ti, Zr)O3 were identified and their lattice dimensions were determined from X‐ray powder patterns of fired ceramic disks. Compositions near the BaTiO3‐BaZrO3 and CaTiO3‐CaZrO3 sides of the composition square gave evidence of complete solid solution, whereas all intermediate compositions contained two separate phases. Variations in the temperature of the Curie point and in aging rate were found to correlate reasonably well with variations in the character of the crystal structure.