ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12561.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Wide variations in particle‐size data from different laboratories for the same clay were thought to be due to dissimilar preparatory techniques. It was proposed to attempt to establish universally acceptable conditioning procedures based on determination of deflocculant requirement, most effective electrolyte, and method of dispersion. Three commonly employed dispersing agents were tested over a range of percentages on four selected whiteware clays. Both high‐intensity agitation and low‐intensity stirring were tried. It was found that all the sodium polyphosphate salts tested were equally effective and that with them complete dispersions could be attained by a minimum of agitation. Electrolyte requirements for complete dispersion were found to relate directly to points of minimum viscosity of deflocculated 50% clay‐wate

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12562.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Particle size control testing is limited in. application because of equipment cost and complexity of operation. A re‐evaluation of published techniques indicated the merits of simplicity inherent in hydrometer procedures. Certain features, however, restricted their application. Among these were elements of time and inaccuracy of measurement in the colloidal region. The application of log probability plotting of data was investigated and was found to be feasible. The extrapolation of data determined with a hydrometer was checked by centrifuge particle‐size data and was found to be accurate enough for routine testing. By elimination of the centrifuge, an inexpensive simple technique was evolved and was checked on seventy‐five representative whiteware

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12563.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

The effect of box and continuous enameling furnace firing schedules on the thermal deflection of enameled iron strips was studied. Effective coefficient of thermal expansion values were calculated from coefficient of thermal deflection data. Results indicate that the effective thermal expansion values for annealed and unannealed enameled iron agree with the expansion data obtained by an interferometer study of the same enamels. Variation in the cooling rate of the enameling furnaces studied is sufficient to produce a marked change in the development of thermal stress in the enameled iron. Residual compressive stresses in the enamel are increased by rapid cooling from firing temperatures. Tensile stress developed in the enamel during reheating is reduced by previous annealing.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12564.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

The discovery of readily sinterable BeO powder facilitated the production of dense, high‐strength BeO ceramics and created interest in the properties and preparation of sinterable BeO. BeO powders prepared by the thermal decomposition of Be(OH)2were studied in an effort to relate sinterability with other more basic characteristics of the oxide powder. Different BeO powders made from analyzed hydroxides showed a wide range of sinterability. The temperatures required for sintering the powder compacts to theoretical density ranged from 2300° to above 3200°F. Lattice parameters, thermal decomposition, surface areas, and refractive indices were determined on these powders after calcination in air at 750°, 1470°, 1830°, and 2190°F. Although unexpected variations in these properties were observed, no simple relation with sinterability was found. Occluded and surface impurities appeared to have a critical effect on sintering b

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12565.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Phase equilibrium data at liquidus temperatures are presented for mixtures in the system FeO–Fe2O3–Al2O3–SiO2. The volume located between the 1 and 0.2 atm. O2isobaric surfaces of the tetrahedron representing this system was studied in detail. Scattered data were obtained at lower O2pressures. Results obtained in the present investigation were combined with data in the literature to construct a phase equilibrium diagram, at liquidus temperatures, for the entire system FeO–Fe2O3–Al2O3–SiO2. Methods for interpretation of the diagram ar

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12566.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Available information on the thermodynamic stabilities of transition metal silicides is summarized and is used to demonstrate the calculation of the stability of silicide‐metal mixtures. The cause of the outstanding oxidation resistance of certain silicides is analyzed, and the results are used to predict high oxidation resistance for several untested disilicides. Thermodynamic and structural arguments are applied to the prediction of compositions of thermodynamically stable and oxidation‐resistant cerm

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12567.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Thermal expansion data are presented for two glasses for both heating and cooling at constant rates. Heating data were taken on samples with varying thermal histories brought about by either constant‐rate cooling or by constant‐temperature stabilization before the expansion test. The fictive temperature concept is discussed in regard to these data. Expansion data are correlated with density and refractive index at room temperature for a variety of heat‐treat

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12568.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1957.tb12569.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY