ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14162.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Phase‐equilibrium relations on the liquidus surface in the system Ba0‐A12O3‐SiO2have been investigated by the quenching method. The compositions investigated within the ternary area were those containing less than 30%, A12O3and more than 20% SiO2by weight. Petrographic and X‐ray techniques were employed in the determination of the crystalline phases.The crystal phases that separate from melts within the area investigated are barium orthosilicate (2BaO. SiO2,), barium metasilicate (BaO 2SO2,), solid solutions, sanbornite (BaO 2SiO2), tridymite and cristobalite (SO2), mullite (3A12O32SiO2), and celsian (BaO A12O3.2SiO2). Diagrams show the isotherms and indices of refraction of the glasses.Five quintuple points and eleven boundary curves have been determined within = .5yo compositional variations. The liquidus‐surface temperatures have been obtained within limits o

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14163.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Infrared reflection spectra of a number of glasses are presented. It is apparent that in some cases such a method may be a useful tool in determining the atomic arrangement in glasses, especially when combined with quantitative measurements of the refractive index and extinction coefficient. The dispersion curves of barium‐containing silicate glasses show that the network of these glasses contains metals in at least two different types of coordination. One is obviously the silica tetrahedron and the other is probably a octahedrally coordinated barium. The latter is concluded by comparison with the reflection spectrum of benitoite. Reflection spectra of boric oxide glasses are presented. These indicate that pure boric oxide glass is not 100% triangularly coordinated and that the pure glass contains much more tetrahedral coordination than was previously concluded from X‐ray‐scattering

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14164.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

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 V2O5are separated from Al2O3and P2O6; the ferric oxide is determined directly from the ignited mixed oxides by titration with K2Cr2O7. The oxide TiO2is ordinarily the main constituent in the RO2, + R2O5group and is reported as TiO2, by difference.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14165.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

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 attainab

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14166.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

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

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14167.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Methods are described for preparing lead zirconate and mixtures of lead and barium zirconate in ceramic form. These compositions are shown to constitute a new class of ferroelectric materials having dielectric constants as high as 11,000. Dielectric constants are measured at 1 mc. per second in a temperature range 25° to 350° C. Nonlinear dielectric properties and piezoelectric effects are demonstrate

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14168.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

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.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14169.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY