bluuebunny/crossref_metadata_2025 huggingface dataset:
Volume Expansion of Glass at High Temperatures
Authors: JOHNSON A. G. , SCHOLES S. R. , SIMPSON H. E.
Published: June 2006

The determination of the volume expansion of glass at high temperatures required the development of a technique or method that would give reproducible results. The considerations necessary in developing such a technique are discussed, and the design and construction of the apparatus used are described. The volume expansion of a glass was determined by the change in buoyancy of a hollow platinum plummet over the temperature range 925° to 1300°C. Although no density measurements were made in the annealing range, previous findings which indicated that glass does not attain complete equilibrium when cooled by normal procedures are confirmed.
Warpage and Cross‐Bending Tests as Criteria of Resistance of Enamels Under Stress in Service
Authors: GOETCHIUS D. R. , BRYANT E. E.
Published: June 2006

Various commercial finish‐coat enamels of widely different compositions were evaluated using the warpage test and the cross‐bending test. Values obtained in the two tests were compared with known service data. The working ranges of these test values that meet specific requirements in a porcelain enamel coating are indicated. Cross‐bending and warpage measurements can be used to predict the performance of porcelain enamels when subjected to various types of stresses.
Differential Thermal‐Analysis Studies of Ceramic Materials: II, Transition of Aragonite to Calcite
Authors: GRUVER R. M.
Published: June 2006

Published differential thermal‐analysis curves for aragonite have not shown the transition to calcite near 450 °C. This inversion is clearly seen in curves presented for six samples of aragonite, and the transition is confirmed by X‐ray diffraction patterns.
Determination of Calcium, Sodium, and Silicate Ions in Extracts from Chemical Durability Tests on Glass
Authors: SEN SUDHIR , TOOLEY F. V.
Published: June 2006

This study was undertaken to establish a method of determining the calcium ion that would be suitable for application to extracts obtained from glass durability tests. The oxalate‐perman‐ganate method proved to be satisfactory. It consisted essentially of precipitating tpe calcium ion as oxalate at a suitable pH and filtering, washing, and dissolving the precipitate in 9 N sulfuric acid. Standard potassium permanganate solution was added and the excess was determined photometrically after proper dilution. The sodium zinc uranyl acetate method of determining the sodium ion and the molybdenum blue method of determining the silicttte ion were also studied in order to permit their application to smaller volumes of extracts. Several determinations of Na20, CaO, and SiOz were made on extracts from soda‐lime‐silica glass.
Effect of K2O and Li2O on Properties of Soda‐Dolomite Lime‐Silica Glasses
Authors:   Owens‐Illinois Glass Company
Published: June 2006

In three base glasses, the first containing 18% Na2O & 10YO CaO · MgO, and 72% SiO2, the second, 14% Na2O, 12% CaO · MgO, and 74% SiO2, and the third, 14% Na2O, 16% CaO·MgO, and 70% SiO2, K2O was substituted for Na2O in amounts of 2, 4, and 6%. In two base glasses, the first containing 16%Na2O, 10% CaO·‐MgO, and 74% SiO2, and the second, 14% Na2O, 12% CaO·MgO, and 74% SiO2, Li2O was substituted for Na2O in amounts of 2, 4, and 6%. The effects of these substitutions on such properties as liquidus temperature, viscosity, deformation temperature, fiber softening point, coefficient of expansion, and the resistance of the glasses to dilute acid and to distilled water are presented.
Formation of a Sulfate Glass
Authors: FÖRLAND T. , WEYL W. A.
Published: June 2006

The highly symmetrical SO42‐ group is not easily distorted and consequently does not lend itself readily to glass formation, Vitreous sulfates of cations of the noble‐gas type are unknown. However, by combining a large cation with a weak positive force field (K+) with the strong field of the proton (H+), it became possible to distort the sulfate group sufficiently to delay crystallization on cooling and to obtain a potassium hydrogen sulfate glass.
Spodumene as a Flux Component in Sanitary Chinaware Bodies
Authors: COWAN C. A. , BOLE G. A. , STONE R. I.
Published: June 2006

Four groups of body compositions involving partial replacement of feldspar by spodumene were investigated. In the first group the firing temperature was maintained constant and the clay content was increased at the expense of the flux. In the second group the flint, clay, and total flux (flux was 20y0 of the body) contents were held constant and spodumene replaced 19, 30, and 40y0 of the total flux. In the third group the flux content containing varying proportions of spodumene was increased from 20 to approximately 40% of the body at the expense of flint and the firing temperature was lowered. In the fourth group miscellaneous bodies containing a variety of fluxes, including flotation soda feldspar, nepheline syenite, talc, and whiting in addition to the potash feldspar and spodumene, were tested. The spodumene appeared to have little advantage in lowering the maturing temperature of the 20% flux bodies; however, a spodumene: feldspar ratio of 30:70 appeared to lengthen the firing range. The effectiveness of the spodumene increased as the total flux was increased. A body containing 27% of flux matured at cone 11–12 when potash feldspar alone was used and at cone 8 when 8% of the feldspar was replaced by spodumene. A body containing spodumene, talc, and nepheline syenite matured at cone 3–4 and had a fired modulus of rupture in excess of 10,000 lb. per sq. in. The small amounts of spodumene (up to 8% of the body) had no apparent effect on the stability of the casting slips or similar properties.
Some Physical and Chemical Properties of Experimental Glazes for Vitrified Institutional Whiteware
Authors: KOCH W. J. , HARMAN C. G. , O'BANNON L. S.
Published: June 2006

The influence of the calculated oxide composition, batch composition, and application and firing techniques on the hardness, scratch resistance, resistance to attack by solutions of alkaline detergent materials, and other properties of glazes for vitrified institutional whiteware is discussed.

The Knoop hardness of a reference glaze was increased by (a) the removal of lead, (b) the replacement of lead, potassium, or sodium oxides by lithia or by lithia and beryllia, (c) the addition of zinc oxide or lithia to the composition, (d) the substitution of beryllia for calcium oxide, and (e) the direct addition of calcium oxide to the glaze formulation. The resistance to attack by solutions of alkaline detergent materials was improved by (a) the substitution of lithia and beryllia for the oxides of lead, potassium, and sodium, (b) the substitution of zirconia for alumina, (c) the substitution of lithia for potassium oxide and sodium oxide, and (d) the addition of beryllia to the composition. In general, glazes that had outstanding resistance to abrasion, as determined by means of a sandblast test, failed to show a corresponding increase in resistance to attack by solutions of alkaline detergent materials. Of particular interest was the observation that the hardness of a glaze did not appear to be the factor governing the resistance of the glaze to scuffing in a simulated service test.
Effect of Humid Conditions on Glass Surfaces Studied by Photographic and Transmission Techniques
Authors: STOCKDALE G. F. , TOOLEY F. V.
Published: June 2006

The progressive attack on polished glass surfaces caused by exposure to high humidity conditions was studied with photomicrographs and by measuring the visible–light transmissions. Carefully polished specimens of five commercial glasses representing a wide range of chemical durability were exposed to relative humidities of 95, 73, and 57% at 90°C. for a total of 1296 hours. Photomicrographs taken at frequent intervals show the degree of surface alteration as a function of time and humidity and furnish some basis for characterizing the course of weathering. For some glasses, the transmission losses did not correlate simply with the amount of visible attack; gains in transmission were noted frequently as the attack progressed. One glass in particular exhibited a general trapsmission gain of 1% after 24 hours of weathering and maintained this gain throughout the tests. Surface films produced on the least resistant glasses caused greater transmission loss in the blue region of the visible spectrum than in the red. Following a dilute‐acid wash, transmissions approached, or in some cases exceeded, values characteristic of the original polished condition.
Sintering Carbides by Means of Fugitive Binders
Authors: FOSTER L. S. , FORBES L W. , FRIAR L. B. , MOODY L. S. , SMITH W. H.
Published: June 2006

A method of sintering carbides has been evolved that permits fabrication of dense, strong pieces having accurate dimensions and containing no residual binder metal. To aid in sintering, a small percentage of a binder such as cobalt or nickel, or their oxides, is added, but this is later removed by volatilization during the high‐temperature vacuum sintering operation. The method has been applied to tungsten carbide, tantalum carbide, and columbium carbide. The good mechanical properties of the products are cited as evidence for the carbide‐skeleton theory advanced to account for the high strength of cemented carbides.
Effects of Acid Treatment on Acid and Abrasion Resistance of Porcelain Enamels
Authors: HARRISON WILLIAM N. , RICHMOND JOSEPH C. , CRANDALL JAMES R.
Published: June 2006

The resistance of some enamels to attack by citric and other acids is improved by prior exposure to certain weak acids, which do not appreciably attack the enamel themselves. The abrasion resistance of some enamels is markedly decreased by exposure to citric acid for IS minutes at room temperature. These effects, as well as the results of some exploratory experiments on the nature and extent of these effects, are reported.
Stability of Birefringence in Glass Articles
Authors: GHERING L. G. , PRESTON F. W.
Published: June 2006

If strain is induced in disks of window glass by relatively rapid cooling in the annealing range (about 500 °C.), the birefringence seems to be permanent in its entirety at room temperatures (about 30 °C.). Even the most delicate polariscopes fail to detect any change in 11 years. At temperatures far below the annealing range, however, it is possible to remove some of this strain. Sometimes 5 to 10% can be removed at temperatures of 180° and 200 °C. in a period of 30 days. At 200 °C. a second 30‐day heating period produced no further change; at 250 °C., it produced another slight decrease.
Leadless Opaque Glazes at Cone 04
Authors: DANIELSON R. R. , VAN GORDON D. V.
Published: June 2006

This investigation covered three systematic fields of composition of leadless, opaque, fritted glazes for cone 04. Studies were made of the effect of variations in the RO fluxes (calcium, barium, and zinc oxides), and in the alumina and the silica‐alumina ratio. Leadless glazes of low boric oxide content with either desirable mat textures or good gloss were obtained on both low and medium talc tile bodies. These glazes applied to tile of medium talc content withstood an autoclave test for crazing, but all glazes except those high in zinc oxide crazed on tile of low talc content. Zinc oxide improved the resistance to crazing. It also produced the most opaque glazes and those with the best gloss. Typical compositions for bright and mat glazes at cone 04 are recommended.
Thermal Diffusivity of Refractory Oxides
Authors: FITZSIMMONS E. S.
Published: June 2006

A method of measuring the thermal diffusivity of refractory materials is described. The experimental procedure is based on transient heat conditions requiring the measurement of only the time interval and the change in temperature. The results obtained for alumina, magnesia, zirconia, and alumina‐clay specimens show the variation of diffusivity with temperature. A comparison of the results with those of previous studies is given.
Sintering Reactions in MgO‐Tic Mixtures
Authors: UELTZ H. F. G.
Published: June 2006

Mixtures of MgO and Tic were sintered at four temperatures in an induction furnace using a helium atmosphere. X‐ray patterns of the sinters were made and interpreted. Colors and appearance were noted and weight losses determined for some samples. Observed changes in lattice dimensions are explained on the basis of the formation of titanium monoxide resulting from the partial reduction of magnesia by titanium carbide.
Preparation, Structure, and Applications of Thin Films of Silicon Monoxide and Titanium Dioxide
Authors: HASS GEORG
Published: June 2006

A material satisfying the chemical formula for silicon monoxide can be prepared by heating finely divided silicon and silica in vacuum. Silicon monoxide is structurally different from either silicon or silica and exists only in amorphous form. Vacuum‐deposited thin films of silicon monoxide decompose to silicon and silica when heat‐treated in an enert atmosphere and oxidize to silica when heated in air. Their oxidation rates in air at various temperatures have been measured by optical means. Silicon monoxide is especially suitable for depositing protective layers on first‐surface mirrors and for preparing replica and support films for electron microscope and electron diffraction studies. Titanium dioxide films prepared by evaporating titanium and oxidizing it in air at 400° to 500°C. have a rutile structure. Such rutile films can be used for splitting beams and for increasing the reflectivity of first‐surface mirrors.
Application of New Techniques to the Solution of an Efflorescence Problem
Authors: BROWNELL W. E.
Published: June 2006

The efflorescence of the products of a particular shale was studied. Sodium sulfate was found to be the major efflorescing salt. This salt was formed during firing by the action of sulfur gases, from the oxidation of pyrite, on sodium minerals in the shale. Additions of silica were effective in reducing efflorescence by reacting with the sodium sulfate under a slightly reducing atmosphere. Ammonium chloride additions destroyed the pyrite at a low temperature, thereby preventing the formation of sodium sulfate. These additions may be employed to solve similar efflorescence problems. The methods employed are applicable to all cases of efflorescence.
A Quenching Furnace for High‐Temperature Studies of Small Specimens
Authors: SOWMAN H. G. , ANDREWS A. I.
Published: June 2006

A high‐temperature, quenching furnace for study of small specimens is described. A heavy tungsten wire coil is used as a heat source. The furnace can be operated in a vacuum or in reducing or neutral atmospheres. This quenching furnace has been applied successfully to temperatures as high as 2300°C. in phase equilibrium studies of the systems ZrO2‐TiO2 and ZrO2‐TiO2‐SiO2.
Some Physical Properties of Eight Refractory Oxides and Carbides
Authors: GANGLER JAMES J.
Published: June 2006

An investigation of eight hot‐pressed refractory oxides and carbides for possible gas‐turbine application was undertaken. The properties, short‐time tensile strength at elevated temperatures, thermal‐shock resistance, coefficient of linear expansion, and density, were determined. The compositions of the ceramics included beryllium oxide, magnesium oxide, stabilized zirconia, zircon, boron carbide, 85% silicon carbide plus 15% boron carbide, titanium carbide, and zirconium carbide. The short‐time tensile strengths of these ceramics were determined at 1800° and 2200°F. Resistance to thermal shock was determined by rapid cooling in air to room temperature from 1800°, 2000°, 2200°, and 2400°F. The thermal‐expansion characteristics of these materials were studied from room temperature to 1100°F.

Zirconium carbide was the strongest material at 2200°F. with a maximum short‐time tensile strength of 15,850 lb. per sq. in.; however, it exhibited extremely poor resistance to oxidation. Boron carbide had a short‐time tensile strength of 22,550 lb. per sq. in. at 1800°F., and was the strongest material at this temperature. Boron carbide also had very poor resistance to oxidation and was among the worst compositions investigated in its ability to resist fracture by thermal shock. The evaluation of strength of boron carbide at 2200°F. was unsuccessful because it fluxed with the grips. Titanium carbide had the best resistance to thermal shock, and had strengths of 15,850 lb. per sq. in. at 1800°F. and 9400 lb. per sq. in. at 2200°F. It was the most promising of the eight compositions investigated. Hot‐pressing of these eight highly refractory bodies indicated that a density of at least 93% of theoretical density could be obtained by this fabrication method.
Determination of Ferric Oxide and Titania in Presence of Alumina
Authors: RUNNELS RUSSELL T. , UTTER MARJORIE G. , REED ALBERT C.
Published: June 2006

A study of cupferron reagent as applied to quantitative analyses of ceramic materials shows acceptable results in both precision and accuracy. The oxides Fe2O3, TiO2, ZrO2, and V2O5 are separated from Al2O3and P2O6; the ferric oxide is determined directly from the ignited mixed oxides by titration with K2Cr2O7. The oxide TiO2 is ordinarily the main constituent in the RO2, + R2O5 group and is reported as TiO2, by difference.
Recording Dilatometer for Measuring Thermal Expansion of Solids
Authors: TURNBULL JOHN C.
Published: June 2006

A recording dilatometer is described in which a resistance strain gauge is used to measure linear thermal expansion. The recording feature is obtained with a conventional recording potentiometer that prints the strain‐gauge output directly, together with the sample temperature. An accuracy of more than ± 0.5% of full scale is attainable.
Factors Influencing Oxidation of Iron During Firing of Ground‐Coat Enamels
Authors: KIMPEL ROBERT F. , COOK RALPH L.
Published: June 2006

The oxidation of the iron beneath a ground‐coat enamel was measured by recording the progressive weight change with a sensitive balance on heating a specimen from room temperature to 1550° F. and correcting for the volatile constituents. The permeability of the dry, unfired enamel films was correlated with the variables characteristic of ground‐coat enamel slips. Clays caused the greatest change in the permeability of the unfired films; the ball clays gave lower permeability than the kaolin clays. The results showed that the permeability of the unfired coating was not an index of the amount of oxidation that occurred when the coating was fired on iron. The oxidation studies indicated that (1) a kaolin clay in an enamel slip allowed less total iron oxidation than a ball clay, since with the latter a more permeable coating developed between 900 °F. and the fusion temperature, which is believed to be due to either the organic material or the free‐silica content of the ball clay, (2) the nickel deposited on the iron by nickel flashing caused a decrease in the total amount of iron oxidation, and (3) with low‐temperature ground coats the rate of metal oxidation was the same as with conventional ground coats up to the fusion temperature of the low‐temperature enamel, but owing to the lower fusion temperature the total amount of oxidation was considerably less than with regular ground‐coat enamels.
Relation of Microstructure to Translucency of Porcelain Bodies
Authors: GOODMAN GILBERT
Published: June 2006

The influence of various structural factors on the translucency of an unglazed porcelain body was studied. These included (u) total concentration of crystals, (b) relative proportions of quartz and mullite, (c) refractive index of the glass phase, (d) its degree of iron coloration, and (e) content and size of voids. Porcelain bodies in the compositional vicinity of a 50% clay, 25% flint, 25y0 feldspar base body and corresponding simulated bodies composed of suspensions of mullite and quartz mixtures in liquids were studied. Translucencies of several representative commercial bodies were also measured.
Thermal Expansion of Some Glasses in the System Li2O–Al2O3–SiO2
Authors: BRACKBILL C. E. , McKINSTRY H. A. , HUMMEL F. A.
Published: June 2006

The thermal expansion coefficients of five Lithia‐alumina‐silica glasses ranging in silica content from a 1:1:2 molecular ratio to a 1:1:10 ratio were found to vary from 76.0 × 10–7 cm./cm./°C. for the low‐silica glass to 39.3 × 10–7 cm./cm./°C. for the high‐silica composition in the interval 30° to 500°C. The relation of the data to the practical formulation of porcelain glazes is discussed.
The System Na2O–P2O5–Al2O3–B2O3 as a Possible Base for Low‐Temperature Titania‐Opacified Porcelain Enamels
Authors: BLAIR L. R. , BEALS M. D.
Published: June 2006

The region of glass formation in the system Na2O–P2O5–Al2O3–B2O3 has been established at levels of 10, 20, 30, 40, and 50 mole% Na2O. The compositions examined were restricted to those which could be melted easily (at temperatures < 1500°C.) and to those which could be compounded without the use of phosphoric anhydride or phosphoric acid as a source of P2O5. Sufficient titanium dioxide to develop opacity during firing was added to those four‐component glasses which possessed a reasonable degree of acid and water resistance. The resulting enamels were evaluated from a standpoint of firing temperature, acid resistance, color, and gloss. Compositions have been found which can be fired at temperatures in the range 675° to 725°C., have class AA acid resistance, good opacity, and whiteness. Their chief disadvantages axe poor alkali resistance and a high coefficient of thermal expansion.
Preparation and Tests of Refractory Sulfide Crucibles
Authors: EASTMAN E. D. , BREWER LEO , BROMLEY LeROY A. , GILLES PAUL W. , LOFGREN NORMAN I.
Published: June 2006

Crucibles have been prepared from all af the sulfides of barium, cerium, and thorium, and also from some of the mixed sulfides of cerium with thorium and uranium with thorium. The type of molds used, as well as the methods of pressing of the sulfide powders, are described in detail. Sintering procedures and techniques are listed for each of the various refractories. More than 800 refractory sulfide crucibles have been produced by the authors in the Berkeley laboratories. These crucibles have ranged from extremely small containers with 0.0026 cc. capacity to crucibles with 50 cc. capacity. Tests of these crucibles indicate that they are satisfactory refractories for a large number of metals and halides. Tests of the individual sulfide refractories as containers for various melts are summarized. The individual differences, as well as similarities, of the sulfide refractories are pointed out.
Effect of Grinding and Firing Treatment on the Crystalline and Glass Content and the Physical Properties of Whiteware Bodies
Authors: SANE S. C. , COOK RALPH L.
Published: June 2006

The quantitative determination of the amount of quartz, mullite, and glass resulting from varying grinding and firing treatments was correlated with the physical properties of a whiteware body. The body composition selected contained 20% potash feldspar, 30% flint, 7.5%, ball clays, and 42.5% kaolins. The body mix was ground for 8−, 25−, and 100−hour periods, and, in addition, the flint and feldspar were preground for 25 and 100 hours. Special fluxes such as talc and nepheline syenite were also tried. All bodies were heated to cones 5, 7, and 9, and the fired porosity, modulus of rupture, and volume shrinkage after firing were determined. The amounts of quartz, mullite, and glass (by difference) were determined quantitatively with a Geiger‐counter X‐ray spectrometer, using a powdered sample with an internal standard. The results showed that the finer grinding of the body, flint, or the potash feldspar reduced the quartz content, increased slightly the mullite formation, and increased the amount of glass. The combination of finely ground feldspar and flint gave a much higher mullite formation and a lower quartz content. The results showed that an increase of talc is unfavorable to mullite formation. The transverse strength of the bodies investigated was proportional to the total mullite and glass content.
Apparatus for Differential Thermal Analysis
Authors: McCONNELL DUNCAN , EARLEY J. W.
Published: June 2006

Information is furnished on newly designed, automatic, recording equipment* which has been combined with temperature‐control apparatus, Pt–Pt‐10% Rh thermocouples, a Globar furnace, and a newly designed sample holder, for the simultaneous production of three thermograms (differential thermal analysis curves). The recording apparatus has several advantages: (1) high sensitivity is obtained by a vacuum‐tube amplifier rather than by high‐sensitivity galvanometers with special mountings; (2) the thermograms can be examined during the run because photographic processing is not required for development of the record; (3) a special selector switch is employed in conjunction with a single amplifier and a multiple‐point recorder, thus eliminating the multiplicity of instruments which would otherwise be required in order to obtain adequate magnification. Platinum‐type thermocouples are desirable for several reasons. The apparatus described can be employed safely for temperatures up to 1100°C., above which it would be advisable to use a platinum sample holder rather than one made from Inconel. Complex interrelationships exist between the recording and the control circuits because of the existence of numerous sorts of heat transfer. These factors are briefly discussed in conjunction with their influence on the production of good reproducible thermograms.
Adsorption of Tagged Phosphute Ions on Glass Surfaces as Related to Alkaline Attack
Authors: HENSLEY JAMES W.
Published: June 2006

A preliminary investigation has been made of various factors involved in the sorption of phosphate ions on glass surfaces, particularly with reference to a possible utilization of phosphate sorption as an indicator of alkaline attack of the surface. Sorption has been measured by means of a tracer technique using radioactive phosphorus as trisodium phosphate, and tests have been made with two types of soft glass and with Pyrex‐brand glass, with and without alkaline pretreatments. Radioautographs have been prepared to determine the distribution of sorbed phosphate on soft‐glass specimens treated in various ways. The sorption of phosphate ions from dilute alkaline solutions at room temperature on fused soft glass and Pyrex‐brand glass has been found to be very slight, on the order of one‐thousandth of a μ gm. per sq. in. (roughly equivalent to a thousandth of a monomolecular layer on the macrosurface). Treatment of soft glass for a few minutes in sodium hydroxide solution at 80°C. results in a multifold increase in subsequent sorption of phosphate ions at room temperature. A much longer alkaline pretreatment is required in the case of Pyrex‐brand glass, but a similar increase in sorption is found. The different results obtained with soda‐lime and borosilicate glasses may be explained on the basis of different types of nonadsorbing surface films. Zinc ions in the alkaline pretreatment solution appear to cause an increase in subsequent sorption, and it is proposed that adsorption of polyvalent cations facilitates the adsorption of phosphate ions.
On the Fracture of Glass Which Is Subjected to Slowly Increasing Stress
Authors: GIBBS PETER , CUTLER IVAN B.
Published: June 2006

A single number called the “strength” does not serve to describe adequately the fracture properties of glass subjected to a slowly increasing tensile stress. Instead, it is found that the surface where fracture originates may be represented as a continuum over which flaws of differing “critical breaking stresses” are distributed. The distribution function for the flaws is given by Sσ where σ is the tensile stress initiating fracture and S and b are constants which are properties of the surface for slowly increasing stresses. The testing procedure and nature of the flaws are discussed.
The Cobalt‐Reduction Theory for the Adherence of Sheet‐Iron Ground Coats
Authors: HEALY J. H. , ANDREWS A. I.
Published: June 2006

On the basis of special techniques described, new data on the adherence phenomenon of cobalt ground‐coat enamels were obtained and the hydrogen‐ reduction theory developed. It was shown that cobalt oxide of the enamel is reduced to cobalt metal which forms a bond with the iron and the enamel
The Elements of the Third, Fourth, and Fifth Series as Possible Adherence‐Promoting Materials for Sheet‐Iron Enamels
Authors: HEALY J. H. , ANDREWS A. I.
Published: June 2006

The properties of the elements of the third, fourth, and fifth series of the periodic system were analyzed from the standpoint of their adherence‐promoting qualities. These elements were divided into five groups on the basis of such properties as heats of formation, melting points, vapor pressures, atomic radii, unit‐cell dimensions, and hydrogen solubilities.
Surface Conductivity of Lead Silicate Glass after Hydrogen Treatment
Authors: BLODGETT KATHARINE B.
Published: June 2006

Conductivity was developed in the surface layer of a lead silicate glass containing 61% lead oxide by certain prescribed hydrogen treatments. The conducting layer was found to be from 50 to 100 a.u. thick. The specific resistance was 800 ohm‐cm., or more, depending on the hydrogen treatment. The ratio of hot‐to‐cold resistance was constant for various values of cold resistance. This showed that the conducting substance was a semiconductor, probably with reduced lead atoms serving as the centers which supplied the electrons. Their density was found to be one‐millionth of the total density of lead atoms in the glass. The remainder of the lead gathered into aggregates which gave the glass a black color but made no contribution to the conductivity. A coating of this glass was applied to porcelain by powdering, spraying, and firing the glass. After hydrogen treatment the coating had a resistance of about 1000 megohms per square, which could be increased to higher values by treatment in boiling water. The coating was stable at voltage gradients up to 100 kv. per in. when the resistance was high enough to keep the wattage input below about 0.2 watt per sq. in. The resistance increased with increasing temperature, corresponding to bk= 0.065 e.v. at 25° to 100°C. and bk= 0.11 e.v. at 335° to 440°C.
Color Stability of Clear and Opaque Titania Enamels Containing Various Color Oxides
Authors: RUSSELL N. K. , FRIEDBERG A. L. , PETERSEN F. A.
Published: June 2006

A study was made of the spectrophotometric characteristics of a clear and an opaque titania‐bearing enamel. Three and six per cent additions of green, blue, brown, and red oxides were made to the base enamels. After firing the enameled samples over a range of time and temperature, spectrcphotometric and X‐ray data were obtained. The results indicate that the lack of stability of the opaque colored enamels is due to the change from a blue‐white to a cream‐white color on increased firing treatment. The addition of a cream component tends to shift the hue of the fired enamel toward the red end of the visible spectrum. The green and the blue colors were much less stable than the red. X‐ray data show that the total anatase present decreases, which is evidence that a cream‐white color developed. X‐ray data did not indicate any change in crystal structure of the anatase, rutile, or color oxide. Titania present in the glass of the clear enamel did not cause color instability.
Viscosity Studies of Titania Porcelain Enamels
Authors: HEIMSOETH WERNER , MEYER F. R.
Published: June 2006

The influence of TiO2 on the viscosity curve of various porcelain enamels, particularly B2O3‐free enamel frits, is examined by measuring the absolute viscosity at temperatures ranging from about 1300° to 1800°F. with the aid of a drawn‐ball viscosimeter. The viscosities measured lie between 250 and 25,000 poises. In general TiO2 decreases the viscosity. With enamels of low SiO2 content (phosphate enamel) the effect is the opposite. The viscosity‐temperature curves of the enamel frits studied are compared with those of standard B2O3 enamels. The fluxing effect of TiO2 in the silicate frits frequently makes a reduction of the B2O3 content of standard enamels possible, thus favoring the resistance to acid, the refractive index, and the scratch resistance.
Elastic and Flow Properties of Dense, Pure Oxide Refractories
Authors: WYGANT JAMES F.
Published: June 2006

Mechanical properties, including creep rates, were measured for slip‐cast magnesia, hydrostatically pressed magnesia, thoria, zircon, and mullite. None equaled alumina or zirconia in strength, rigidity, or creep resistance. Although mullite was found to have good properties, magnesia showed the best properties of the oxides tested. Thoria was very weak, zircon was highly plastic above 1000°C. Elastic and flow properties were determined primarily by the crystal structure and atomic bonding of the oxides and secondarily by grain boundary conditions.
Anelasticity of Glass: III, Effect of Heat‐Treatment on the Internal Friction of Tank Plate Glass
Authors: FITZGERALD J. V.
Published: June 2006

Heat‐treatment or annealing decreases the internal‐friction peak commonly attributed to sodium ion diffusion in tank plate glass, a typical soda‐lime‐silica glass. The peak is shifted to higher temperatures at constant frequency of vibration or to lower frequencies at constant temperature. The activation energy for the shift is greater in the annealed glass and agrees with the activation energy for the electrical conductivity and alkali durability of annealed glass. Heat‐treatment also decreases the internal friction caused by elastico‐viscous effects.
High‐Fire Opaque Glazes for Zircon Bodies
Authors: VAN GORDON D. V.
Published: June 2006

This investigation covers two systematic studies of raw, one‐fire, zirconium‐opacified glazes applied to two bodies of approximately 60% zircon content and fired to cones 11, 12, and 14. (1) Variations in alumina and silica were investigated in order to determine the best content and ratio of these refractory oxides. It was found that compositions having 0.6 molecular equivalents of alumina, with silica‐alumina ratios ranging from 9 to 11, gave the best results in gloss and texture at cones 11, 12, or 14. The best resistance to crazing was obtained when the glazes were fired to cone 14. (2) A triaxial series of glazes was investigated in which three fluxes, magnesium, calcium, and barium oxides, were varied. Glazes containing 0.55 to 0.65 equivalent of magnesium oxide had good gloss and texture and the best resistance to crazing over the entire range of firing. Glazes containing similar amounts of barium oxide had higher luster, but inferior texture, and were less resistant to crazing except when fired at cone 14. Glazes having calcium oxide contents in excess of 0.25 molecular equivalent crazed when fired at cones 11 and 12. Throughout the range of firing the glazes high in magnesium oxide maintained the best texture; the barium oxide glazes had the best gloss. The suitability of the better glazes developed in the investigation for bodies of very high zircon content was established by supplementary tests on four additional bodies containing from 72 to 90% zircon.
Some Further Observations of the Effects of Mill Additions on the Color Value of Titania Enamels
Authors: MARBAKER EDWARD E. , SAUNDERS HOLLIS S.
Published: June 2006

Experiments additional to those already described1 were carried out to determine the effect of smaller amounts of some of the electrolytes which had produced too much set. The influence of different amounts of clay with a given electrolyte and of urea as a mill addition was studied. The color stability was determined in high‐and low‐firing temperature ranges of enamels made from a given frit with different mill additions, and from different frits with the same mill addition.
Phase Equilibrium Relationships in a Portion of the System MgO–Al2O3–2CaO·SiO2
Authors: PRINCE A. T.
Published: June 2006

The system MgO–Al2O3–2CaO·SiO2 comprises a plane through the tetrahedron CaO–MgO–Al2O3–SiO2. A total of 108 compositions were prepared having an alumina content below the line joining 2CaO·Al2O3SiO2 (gehlenite) and MgO·Al2O3 (spinel). Quenching experiments were carried out on 96 of these compositions at temperatures up to 1590°C. Three binary eutectic systems and two ternary eutectic systems are described. Compositions on this plane are of significance in an investigation of the constitution of basic refractory clinkers made from Canadian dolomitic magnesites. They also concern the compositions of certain blast furnace slags.
Study of the Effect of Linear Pressure on Refractive Index Change in Glass
Authors: COLLYER P. W.
Published: June 2006

The possibility of accelerating the compacting1 of glass at constant temperature by application of linear pressure has been investigated. The study was limited to borosilicate optical glass. Pressures up to 31 atmospheres and temperatures within the transformation region were used. Several methods of applying pressure were tried. No difference in the compacting rate, as compared with samples not exposed to pressure, and as determined by critical‐angle refractometry or interferometry, was discerned.
Cone Deformation Study of a Portion of the System SrO–Al2O3–SiO2
Authors: WATTS ARTHUR S.
Published: June 2006

The results of a study of deformation temperatures and rates within the composition area 25 to 45% SrO, 5 to 25% Al2O3, 50 to 70% SiO2 are presented. A eutectic of the composition 30% SrO, 10% Al2O3, 60% SiO2 is indicated with “1 o'clock” deformation at 1155°C. and “6 o'clock” deformation at 1165°C. A low‐temperature area surrounding this eutectic includes 27.5 to 32.5% SrO, 10 to 12.5% Al2O3, 57.5 to 62.5% SiO2. Compositions within this range reach “6 o'clock” deformation at approximately 1180°C.
Study of Particle Size of the Opacifying Phase in Titania Enamels: I, Change of Particle Size with Change of Concentration of Dissolved TiO2
Authors: BEALS M. D. , BLAIR L. R. , FORAKER R. W. , LASKO W. R.
Published: June 2006

Variation of the particle size of the precipitated titanium dioxide with its change in concentration was indicated by reflectance data and substantiated by electron micrographs of these precipitated crystals. Possible correlation of the data with the precipitation laws of von Weimarn is discussed. Two methods were used for obtaining particle‐size data: the first was by the study of shadowed replicas of etched enamel disk surfaces, and the second and more important, by the study of TiO2 crystals removed from an enamel by selective solution with hydrofluoric acid.
A Study of the Phase Relations of ZrO2–TiO2 and ZrO2–TiO2–SiO2
Authors: SOWMAN H. G. , ANDREWS A. I.
Published: June 2006

The phase relations of the systems ZrO2–TiO2 and ZrO2–TiO2–SiO2 were investigated. X‐ray diffraction techniques served as the principal means of analysis. The binary system ZrO2–TiO2 was found to be one of partial solid solutions with no intermediate compounds. A eutectic point was found to exist at 50 to 55 weight % ZrO2 and 1600°C. A preliminary investigation of the ternary system ZrO2–TiO2–SiO2, although not extensive, resulted in a better understanding of this system, with a fairly accurate location of some of its boundary lines. A eutectic point was located at 2% ZrO2, 10% TiO2, and 88% SiO2 at approximately 1500°C.
A Study of Solid‐state Reaction in the Ternary System MgO–ZrO2,–SiO2
Authors: FOSTER WILFRID R.
Published: June 2006

A study has been made of solid‐state reaction at 1450°C. in the ternary system MgO–ZrO2–SiO2. Approximately 40 selected compositions have been sintered to obtain essentially complete reaction. The calcines have been analyzed by X‐ray diffraction methods, using a Norelco X‐ray spectrometer. The solid‐state compatibility relationships have been thereby established. The results are compared with those of some previous investigators. This study illustrates a general method of attack which, although old in principle, has long been neglected. It is recommended that the method be revived by ceramists and others engaged in phase equilibrium research.
Rigidity Modulus of Some Pure Oxide Bodies 8th Communication to Ceramography
Authors: RYSHKEWITCH EUGENE
Published: June 2006

Rigidity modulus of several sintered pure oxides was measured using specially prepared test pieces. A particular form of samples permitted an exact measurement of their dimensions and insured their proper elastic torsion deformation under a given load. Sintered alumina was tested up to 1550°C. Monocrystalline corundum, sintered stabilized zirconia, sintered pure beryllia, thoria, spinel, and zircon were tested at room temperature. Close agreement was noted between rigidity modulus values and Young's modulus values.
Anelasticity of Glass: II, Internal Friction and Sodium Ion Diffusion in Tank Plate Glass, A Typical Soda‐Lime‐Silica Glass
Authors: FITZGERALD J. V.
Published: June 2006

The internal‐friction peak observed near room temperature in tank plate glass at a period of the order of seconds and previously attributed to sodium ion diffusion is further discussed. The temperature of maximum internal friction is shown to vary with the frequency of vibration with an activation energy of about 16 kg.‐cal. Per mole for air‐chilled glass fibers. Likewise, the activation energy for the electrical resistivity of the chilled glass is about 16 kg.‐cal. Although the activation energy for sodium ion diffusion and alkali durability is about 21 kg.‐cal., it too can be properly interpreted to confirm that the internal friction peak is caused by sodium ion diffusion. The internal friction peak is much broader than can be accounted for by a single relaxation mechanism. However, a dispersion of relaxation mechanisms is consistent with the accepted theory of randomness in the silica network.
An Automatic Apparatus for Testing Refractories Under Tensile and Compressive Loads at High Temperatures
Authors: SCARLETT J. A. , ROBERTSON J. A.
Published: June 2006

Construction and operating details are given for an apparatus used for testing small refractory specimens under tensile or compressive loads up to 2200°C. An electrical resistance, graphite tube furnace can be made to heat at a uniform rate of 0° to 1000°C. per hour and to shut off at a predetermined specimen temperature or deformation. Temperature is measured by a radiation pyrometer and controlled by a duration‐adjusting, impulse‐type controller. Deformation is measured by means of a micrometer dial gauge and transmitted through a slide wire rheostat to a bridge‐type recorder. A standard deviation of 22°C. for compression failure and 24°C. for tensile failure was determined on a periclase refractory.
Reactions Accompanying the Firing of Brick
Authors: GRIM R. E. , JOHNS W. D.
Published: June 2006

Results are presented of an investigation of the reactions taking place when brick, particularly those made from fire clay containing some organic matter and sulfides, are fired. In making this investigation the differential thermal method was used. This method permitted a study of the temperature at which various reactions take place, the intensity of these reactions, and the speed with which they reach completion. The reactions for carbon are slow. The reactions for sulfur are also slow and somewhat different from those taking place when similar sulfur compounds are heated in air. The loss of (OH) lattice water from the clay mineral components is accompanied by an intense and abrupt reaction which shows slight relation to the heating rate. The structural change accompanying the loss of (OH) water fortunately causes little or no disruption of the brick.
Carbon Disintegration Test for Blast‐Furnace Brick
Authors: TROSTEL L. J.
Published: June 2006

An apparatus and a procedure using bottled carbon monoxide gas for testing the resistance of modern blast furnace brick are described. The apparatus is simple to operate, automatic even for protracted periods of exposure up to 1000 hours, and can handle 60 specimens at a time. The severity of the testing conditions has been augmented as much as present knowledge of the reaction involved permits.
Thermal Radiation Characteristics of Some Glasses
Authors: McMAHON HOWARD O.
Published: June 2006

The emissivity, reflectivity, and transmissivity have been studied for a number of glasses throughout the wave‐length region 2.2 to μ, and through a temperature range of 500° to 1500°F. In general it is found that, although the spectral emissivity varies considerably with wave length throughout the opaque portion of the spectrum, the emission spectrum is almost completely independent of temperature throughout the region of the spectrum studied. The most prominent feature of the emission spectrum of all silicate structures studied is the metallic‐reflection band at approximately 9.5 μ.
Note on the Thermal Conductivity of Synthetic Sapphire
Authors: WEEKS JAMES L. , SEIFERT RALPH L.
Published: June 2006

The thermal conductivity of synthetic sapphire in the direction 60 degrees from the c axis is shown to be 0.065 cal. per second per cm. per °C. at 90° to 100°C.
Some Factors Influencing the Dielectric Properties of Barium Titanates
Authors: EUBANK W. R. , ROGERS F. T. , SCHILBERG L. E. , SKOLNIK SOL
Published: June 2006

Capacity‐vs.‐temperature plots have been determined for two series of barium titanate ceramics prepared from (1) reagent‐grade and (2) spectrographic‐grade chemicals fired at various temperatures from 1100° to 1500°C. Dielectric constants in the spectrographic‐grade series were found to be as high as 12,000 and were, in general, 2 to 3 times as great as those in the reagent‐grade series. Also, the change of capacity (and dielectric constant) with temperature was larger for the purer titanates, amounting in some cases to 125% per °C. near the Curie point. Variations in firing temperature were observed to impart different properties to titanates of both series. The optimum firing temperature appears to be about 1400°C. A Curie point minimum was noted for materials fired near 1230°C. and a maximum for those fired near 1430°C. Shifts in Curie temperatures amounted to as much as 25°C. (111° to 136°C.). The rate of cooling from the firing temperature affects this shift in Curie point. In general, Curie points for the reagent‐grade titanates were about 10°C. lower than those for the purer material. Repeated cycling through the Curie point resulted in a progressive lowering of the dielectric constant. When subjected to temperatures above 150°C. these aged specimens were restored to their initial activity. Exposure to sunlight and ultraviolet radiations reduced the dielectric response.
A Preliminary Study of the Oxidation and Physical Properties of TiC‐Base Cermets
Authors: McBRIDE CLINTON C. , GREENHOUSE HAROLD M. , SHEVLIN THOMAS S.
Published: June 2006

The TiC‐base cermets investigated contained Cr, Fe, Co, Ni, NiAl, ferrosilicon, or Duriron as the metallic constituent. They were evaluated on the basis of strengths at 75° and 1800°F., oxidation resistance at 2000°F., and the degree of chemical reaction between the carbide and metal as determined metallographically. Metallographic and X‐ray studies were conducted on the oxide layers to determine a qualitative mechanism of oxidation. Results of these studies indicated Tic plus NiAl to be the most promising composition and oxygen diffusion to be the governing factor in the oxidation mechanism of all the cermets studied.
Borosilicate Glasses
Authors: ABE TOSIO
Published: June 2006

Various anomalous properties of borosilicate glasses are explained by the assumption that the atomic groups, each of which consists of one BO4 tetrahedron with four BO3 triangles bonded to it, are formed in these glasses. These atomic groups result from the reasonable postulate that BO4 tetrahedra cannot be bonded to each other, and that each BO4 triangle cannot be bonded to more than one BO4 tetrahedron owing to the disposition of the cation which neutralizes the –1 electronic surplus charge of the BO4 tetrahedron and prevents these tetrahedra from approaching each other.