Showing papers in "Journal of the American Ceramic Society in 1933"
TL;DR: In this article, it was shown that the viscosity of a newly drawn fiber increases with time of heat treatment according to a definite law which may be explained on the basis of a change in the state of aggregation in the glass.
Abstract: Viscosity data published by the author in 1931 are discussed with reference to their limitations. New experiments on fiber elongation in a redesigned apparatus are described in which one of the glasses previously used is tested. The results show that the viscosity of a newly drawn fiber increases with time of heat treatment according to a definite law which may be explained on the basis of a change in the state of aggregation in the glass. A finite equilibrium viscosity is indicated a t each temperature, this limit being approachable from either side depending on previous heat treatment of the sample. This is taken to indicate an equilibrium average size of aggregate for any temperature, the groups starting to break up again if the temperature is increased after a long treatment. The expression of Sheppard and Houck is used for estimating effective molecular or aggregate weights in equilibrium at various temperatures, an example being 112,000 at about 500°C. The variation of viscosity with time is at least one reason why glasses fail to conform to Adams' and Williamson's annealing equation at low temperatures.
107 citations
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TL;DR: In this article, an apparatus was described for extracting the gas from glass at glass-furnace temperature and determining its composition, and results were given for glasses of various compositions and various melting histories.
Abstract: ARSTRACT
An apparatus is described for extracting the gas from glass at glass-furnace temperature and determining its composition. Results are given for glasses of various compositions and various melting histories. All ordinary glasses were found to contain appreciable quantities of dissolved (or chemically combined) gas, the amount varying from a few hundredths to a few tenths per cent. Water is frequently the most abundant gas, the content being highest in borosilicate glasses. Carbon dioxide is also usually present, the amount depending on the basicity of the glass. Nitrogen, carbon monoxide, and hydrogen were never found present in appreciable quantities. All oxidized glasses contain some oxygen. Glasses containing arsenic give off a comparatively large volume of oxygen. The effect of this oxygen on fining is discussed. It has been found that remelting a glass has little effect on the gas content. The gas content is greatly influenced by the size of the melt, being the lowest in small experimental melts.
37 citations
TL;DR: In this paper, a compilation of phase-rule diagrams for silicates and refractory oxides is presented, which may be useful to the ceramist and the silicate technologist.
Abstract: This paper is a compilation of phase-rule diagrams, principally of silicates and the refractory oxides, that may be useful to the ceramist and the silicate technologist. The text of the paper includes definitions of terms used in discussion of the Phase Rule, a description of methods used in the study of systems at high temperatures, and an interpretation of Phase-Rule diagrams for systems with one or more components.
16 citations
TL;DR: In this article, a short review is given of the results of measurements with such equipment on a series of glasses, including experiments on the effect of chilling, prolonged heat treatment, mechanical strains, and superposed radio-frequency currents on the conductivity of the glass at room temperature.
Abstract: New instruments and equipment are described for the measurement of the electrical conductivity of glass at room temperatures. The accuracy of the method is discussed and certain precautions are specified for this type of measurement. A short review is given of the results of measurements with such equipment on a series of glasses. In particular, experiments are described on the effect of (1) chilling, (2) prolonged heat treatment which produces an actual separation of phases, (3) mechanical strains, and (4) superposed radio-frequency currents on the conductivity of the glass at room temperature. In conclusion, i t is pointed out that the results of these measurements indicate that the electrical behavior of glass at room temperature is of importance.
14 citations
TL;DR: In this paper, a wide range of artificial alumina-silica products has been examined by the X-ray powder method and it has been shown that in each case in which the pattern has been sufficiently clear to permit a decision the pattern had been that of mullite, not that of sillimanite.
Abstract: A wide range of artificial alumina-silica products has been examined by the X-ray powder method. In each case in which the pattern has been sufficiently clear to permit a decision the pattern has been that of mullite, not that of sillimanite. The examination included a number of preparations made by heating clay minerals and clays at 1000°.
Mullite crystals containing alumina or the oxides of iron or titanium in solid solution give diffraction patterns in which the lines are slightly displaced toward the origin with respect to the corresponding lines in the diffraction pattern of the standard mullite (3Al2O3.2SiO2).
Mullite crystals, freed by HF treatment from the matrix in which they grew, often give diffraction patterns in which the intensities of certain lines arc strikingly different from normal. This is due to the orientation of the minute elongated crystals when mounted for photographing.
Finally, two recent papers proposing special names for certain similar materials are discussed and, on the basis of published data and the evidence presented here, these proposals are found to be unwarranted.
13 citations
TL;DR: In this article, the results of five years' research on refractory uses for a chemically purified grade of zircon and electrically fused zircons of high purity were described.
Abstract: This is a record of the results of five years' research on refractory uses for a chemically purified grade of zircon and electrically fmed zirconia of high purity. The products investigated included semi-permanent foundry molds, refractory brick and cements, ladle nozzles, and crucibles. Electric firing and a small oil-fired tunnel kiln are described. Sintered zircon grog was found superior to electrically fused grog. Zircon brick made with 50% grog, using 20% milled zircon for the permanent bond and fired at 1600°C for an hour, showed no firing shrinkage, very slight volume change, and high compressive strength at 1600°C. They were extremely resistant to spalling but did not resist basic slags or metallic oxides very well a t high temperature. Zircon-bonded magnesite brick were more refractory than ordinary magnesite, more resistant to spalling, and had about the same slag resistance magnesite. Zirconia was more refractory than zircon and had better slag resistance. Lime-bonded zirconia crucibles of good spalling resistance were made, but the cost was higher than that of zircon. The effects of various binders are discussed.
8 citations
TL;DR: The recent observations and generally accepted facts concerning the phenomenon of reboiling of enamels on sheet metals are listed concisely in this article, with no attempt at a final explanation, a series of the most obvious deductions to be drawn from the observations of the first portion of the paper is made.
Abstract: The recent observations and generally accepted facts concerning the phenomenon of reboiling of enamels on sheet metals are listed concisely. Six photomicrographs are presented to show the outstanding characteristics of the enamels obtained by some of the treatments described in the paper. With no attempt at a final explanation, a series of the most obvious deductions to be drawn from the observations of the first portion of the paper is made. In conclusion, some of the various theories that have been expressed to explain reboiling are mentioned and discussed.
8 citations
TL;DR: In this paper, a study of the propcrtics of English china clays in common use in the United States is presented, which may be useful in making substitutions for these clays, as well as furnishing a basis of correlation of some of the properties.
Abstract: A study is presented of soinc of the propcrtics of fiftecn English china clays in common use comrncrcially in the United States. Data are presented which may be useful in making substitutions for these clays, as well as furnishing a basis of correlation of some of the properties. A study of the base exchange capacities shows a general relationship to the transverse strciigths of the clays in the uiifired state.
7 citations
TL;DR: The drying shrinkage curves were accurately determined for a number of clays and Other finely divided substances as mentioned in this paper, which gave an insight into the nature of the surface film on the clay particles.
Abstract: The drying shrinkage curves were accurately determined for a number of clays and Other finely divided substances. Some clays show a secondary shrinkage and other do not. The latter are generally the less plastic ones. Other finely divided materials beside clay may show considerable plasticity, e.g., ferric oxide. The shrinkage curves give an insight into the nature of the surface film on the clay particles.
7 citations
TL;DR: In this article, two silica bricks were examined under the petrographic microscope for over ten years in a coke oven and it was concluded that in cooling a battery of ovens great care should be taken to cool slowly through the temperature range 200 to 300deg;C.
Abstract: Two silica brick which were in service in a coke oven for over ten years have been examined under the petrographic microscope. At the flue side the brick were almost completely converted to cristobalite, next comes a relatively thick layer which is mainly tridyinite, and finally mar the coke side quartz is found in addition. Measurements on small specimens taken from one of the brick show that the several layers have very different expanions. I t is concluded that in cooling a battery of ovens great care should be taken to cool slowly through the temperature range 200 to 300deg;C.
7 citations
TL;DR: In this article, a marked increase in the rate of vitrification occurred when bodies containing feldspar were fired in an atmosphere of H2O. This effect was explained on the basis of a feld'spar-water eutectic.
Abstract: Various types of ceramic bodies were fired in atmospheres of O2, N2, CO2, H2, And A marked increase in the rate of vitrification occurred when bodies containing feldspar were fired in an atmosphere of H2O. This effect was explained on the basis of a feldspar-water eutectic.
TL;DR: In this paper, the authors presented the data obtained in an extensive investigation on reinforced brick columns and the results furnished a basis for the development of rational design formulas, which were found to be made up of the effective strength of the masonry plus the yield point strength of longitudinal reinforcement.
Abstract: This paper presents the data obtained in an extensive investigation on reinforced brick columns. The results furnished a basis for the development of rational design formulas. The strengths of the columns were found to be made up of the effective strength of the masonry plus the yield-point strength of the longitudinal reinforcement. A study of the type of masonry mortars revealed the fact that Portland cement mortar containing 15% ordinary brick clay by weight of the cement gave better results than did any of the other types used.
A review of all known experiments on brick piers and columns is given.
TL;DR: In this paper, an investigation was made of the fusion behavior of the potash feldspar, soda and soda-lime felspar system, all materials being of commercial grade.
Abstract: An investigation was made of the fusion behavior of the potash feldspar, soda feldspar, and soda-lime feldspar system, all materials being of commercial grade. The potash feldspar had a pyrometric cone equivalent of cone 9 1/2, the soda feldspar, cone 6 1/2, and the soda-lime feldspar deformed at cone 11 l/2. Mixtures varying according to the triaxial diagram were made in the form of pyrometric cones. These were fired in groups along with standard Orton cones.
The 30% commercial potash fcldspar-70% commercial soda feldspar mixture reached 6 o'clock deformation when standard Orton cone 6 showed 2 o'clock deformation.
The mixture of 62 l/2% commercial potash feldspar with 37 1/2% soda-lime feldspar reached 6 o'clock deformation when cone 7 showed 1 o'clock deformation, the deformation of the cone 9 1/2 potash feldspar being reduced 3 cones by the addition of the proper percentage of the cone ll 1/2% soda-lime feldspar.
There was an increase in deformation temperatures (no indication of eutectic) in the plagioclase series, soda feldspar to soda-lime feldspar.
The mixture of 30% commercial potash feldspar, 60% commercial soda feldspar, 10% soda-lime feldspar showed 6 o'clock deformation when cone 6 showed 1 o'clock deformation, this being the lowest temperature at which any member of the system showed 6 o'clock deformation.
TL;DR: In this paper, the effect of previous history on the measurements was discussed, and an improved device for loading the specimens was described, and a logarithmic equation was suggested to fit the observations better than that of Adams and Williamson.
Abstract: Measurements of strain release1 showed that check results were obtained only when the previous history of the samples was the same. Moreover, it was found that the release of strain was more rapid at first than could be accounted for by the equation of Adams and Williamson.
This paper discusscs the effect of previous history on the measurements, describes an improved device for loading the specimens, and suggests a logarithmic equation which, in general, fits the observations better than that of Adams and Williamson. Tests of the equation are made both on data obtained from the modified apparatus described and on the data of Adams and Williamson. It is indicated that the Adams and Williamson equation gives too long an annealing time at higher temperatures and too short an annealing time at lower temperatures.
It appears that the rate of release of strain depends on some power of the strain which varies from unity at high temperatures where the glass is a viscous fluid to a higher power at low temperatures where the release of strain is elastico-viscous in character. With a siugle specimen at any fixed temperature in the annealing range, however, it appears that the release of strain in various parts of the specimen takes place at a rate which is proportional to the strain, but that the rate undergoes continual change with time.
TL;DR: In this article, a description of a furnace and accessories for the determination of the co-efficient of expansion of glasses is given, which may lead to the useful application of the method for determining the coefficient of expansion in the high-temperature range.
Abstract: A description is given of a furnace and accessories for the determination of the co-efficient of expansion of glasses. Suggestions are presented which may lead to the useful application of the method for the determination of the coefficient of expansion of materials in the high-temperature range.
TL;DR: Several bodies capable of being processed by usual manufacturing methods, with varying talc, clay, and mullite content, were studied to determine their relative resistance to thermal shock as mentioned in this paper.
Abstract: Several bodies capable of being processed by thc usual manufacturing methods, with varying talc, clay, and mullite content, were studied to determine their relative resistance to thermal shock. These bodies were fired a t various temperatures and submitted to quenching and transverse strength tests.
TL;DR: In this article, the thermal expansions of sheet-iron ground-coat enamels were determined by use of the interferometer, and the results showed that the calculated expansions based on the factors of Mayer and Havas were close to the actual expansions.
Abstract: The thermal expansions of sheet-iron ground-coat enamels were determined by use of the interferometer. The results showed that the calculated expansions based on the factors of Mayer and Havas were close to the actual expansions. It was also shown that variations of borax, feldspar, and quartz resulted in a fairly uniform change in the expansion. It was possible to interpolate between values for these constituents. The softening of the enamels in the interferometer test proved to be a characteristic change depending on the fusibility of the enamel. These data showed promise as a test for fusibility.
TL;DR: This Progress Report II is a continuation of the report presented before the Enamel Division in 1932 and concludes that nothing has developed which is inconsistent with the facts summarized in the 1932 report.
Abstract: This Progress Report II is a continuation of the report presented before the Enamel Division in 1932. The subjects discussed are (1) gases from metal, (2) possible reaction between enamel and iron, and (3) gases from the enamel itself. The author concludes in this report that nothing has developed which is inconsistent with the facts summarized in the 1932 report.
TL;DR: In this article, it was shown that tin is present in enamels as crystalline tin oxide and antimony as the crystalline antimony pentoxide, and other opacifiers and compounds such as zirconium oxide, zinc sulfide added to enamel were studied.
Abstract: The crystatline compounds present in vitreous enamels were determined by X-ray methods, particular reference being given to the opacifiers. It was shown that tin is present in enamels as crystalline tin oxide and antimony as the crystalline antimony pentoxide. Fluorspar added to the enamel contributes crystalline calcium fluoride. Cryolite and sodium silicofluoride contribute crystalline sodium fluoride. Other opacifiers and compounds such as zirconium oxide, zirconium silicate, calcium phosphate, arsenic oxide, and zinc sulfide added to enamels were studied. With the exception of the zirconium opacity the compounds causing opacity in enamels were identified alone and in the presence of other opacifiers.
TL;DR: The constituents produced were identified by petrographic-microscopic methods, and new optical data on sodium aluminate was obtained as mentioned in this paper, which was found to exist from temperatures below 1100 to above 1700°C.
Abstract: Crystalline sodium aluminate was prepared by heating monomolecular and other mixtures of Na2CO3 and A12O3.3H2O for varying periods to temperatures up to 1700°C.
The constituents produced were identified by petrographic-microscopic methods, and new optical data on sodium aluminate was obtained.
Sodium aluminate was found to exist from temperatures below 1100 to above 1700°C, its melting point being above 1700°C.
Small amounts of iron oxide aid the formation of sodium aluminate, especially at the lower temperatures.
TL;DR: By the use of X-ray methods, sheet-iron cover-enamel frits and fired enamels were investigated as discussed by the authors, and the results obtained show that tin oxide exists as tin dioxide in the enamel, antimony as antimony pentoxide, fluorspar as calcium fluoride, and cryolite as sodium fluoride.
Abstract: By the use of X-ray methods, sheet-iron cover-enamel frits and fired enamels were investigated. The results obtained show that tin oxide exists as tin dioxide in the enamel, antimony as antimony pentoxide, fluorspar as calcium fluoride, and cryolite as sodium fluoride. Zirconium oxide does not exist as the crystalline zirconium oxide even when present as a mill addition. Variations in the compositions of the ordinary sheet-iron cover enamels do not affect the identity of the crystals.
TL;DR: In this paper, the effect of ZnO on sheet-iron cover-enamel properties was studied by evaluation of the propcrties of a typical sheetiron cover enamel.
Abstract: The effect of ZnO on sheet-iron cover-enamel properties was studied by evaluation of the propcrties of a typical sheet-iron cover enamel in which ZnO was used as single- and double-partial replacements for the various ingredients. The fluxing action of ZnO was found to bc pronounced and i i was markedly effective in decreasing frit solubility in the mill liquor. Improvement in gloss resulted from its use without any adverse effect on enamel extensibility and resistance to thermal shock.
TL;DR: In this paper, the thermal conductivity of graphite bodies was investigated and the effect of varying percentages of graphites on the conductivity was discussed and an analysis of foreign and domestic graphites were tabulated.
Abstract: (1) Some properties or graphite are discussed and industrial applications as a refractory arc enumerated. (2) Previous work on graphite, particularly during the World War on graphite crucibles, is reviewed. That work was directed toward finding substitutes for imported graphites and clays. Since peace-time conditions were restored the manufacturers have returned to foreign sources, of raw materials and sonic reasons for this tendency arc advanced. (3) Analyses of Vera1 foreign and domestic graphites are tabulated. (4) Reports arc given on experiments 011 the thermal conductivity of clay-graphite bodies with the effect of varying percentages of graphite on the conductivity.
TL;DR: In this article, a preliminary investigation of the relation between particle size and some properties of china clays was undertaken, and measurements of grain size of a series of clays were made.
Abstract: Measurements of grain size of a series of china clays were made, and a preliminary investigation of the relation between particle size and some properties was undertaken.
TL;DR: In this article, a direct determination of alkali is often avoided in glass analysis because of the tedious nature of the method and the estimation by differcnce is not justifiable because of accumulating errors.
Abstract: A direct determination of alkali is often avoided in glass analysis because of the tedious nature of the method and the estimation by differcnce is not justifiable because of accumulating errors. The method proposed consists in HF-H2SO4 decomposition, removal of MgO and R2O3 by lime, conversion of sulfate to carbonates by Ba(OH)2 and CO2, boiling to precipitate CaCO3 and BaCO3, and titration of Na2CO3.