ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14023.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

A new high‐temperature material with excellent stress‐sustaining characteristics at 1800°F. has been developed. The weight per cent composition of this Tic‐base cermet is 55.4 TIC + 17.9 TiB2+ 16.7 Co + 10 Si, and the principal phases present after sintering are Tic, TiB2, and CoSi. The research on and development of this material and some of its physical properties are dis

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14024.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Differential thermal analyses were made and weight losses were determined up to 1000°C. for a domestic and an imported high‐alumina hydraulic cement after hydrating. Refractory castables were prepared in the laboratory with these two cements and fire‐clay brick and flintclay aggregates. Compressive, transverse, and tensile strengths of these castables were obtained after heating 4,8, and 12 months at 300°C. and at other temperatures up to 1350°C. for shorter periods of time. Sixteen commercial brands of castables were tested for sieve analysis, P.C.E., and flow, on the material “as received”. The three types of strengths of the sixteen castables also were determined after treatments at 95% relative humidity and after heating at temperatures up to 1350°C. Some information on porosity and structural and linear changes after the heat‐treatments

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14025.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Various zirconium‐type opacifiers were used in a group of glazes maturing in the range cone 04 to cone 11 and the crystalline phase producing opacity in these fired glazes was studied by elevated‐temperature X‐ray diffraction techniques. The results definitely show that zirconium silicate is the major crystalline phase that promotes opacity regardless of the zirconium opacifying agent added. The foregoing conclusion pertains only to the opacifying particle; this should not be construed to mean that other important characteristics of glazes do not vary with the form of zirconium addition. These other aspects will be discussed in detail in another

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14026.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

A study of gypsum was made using the differential thermal analysis technique. Gypsum and mixtures of gypsum with silica, alumina, iron oxide, dialyzed kaolin, or carbon were analyzed. Furnace atmospheres of air, nitrogen, carbon dioxide, and carbon monoxide were used. Gases evolved at the decomposition temperature of gypsum were analyzed chemically and sample residues were anelyzed by X‐ray diffraction A slight amount of decomposition was observed when gypsum passed from the beta to alpha mineral form of CaSO4, but decomposition was not complete even after fusion had started. The addition of 20% carbon to the gypsum and heating in a nitrogen atmosphere caused decomposition, with evolution of CO2to start at a temperature as low as 615

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14027.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

An instrument has been developed to measure the thermal conductivity of dense ceramic materials over the temperature range 20° to 200°C. A cylindrical ceramic specimen 1/2 in. in m diameter by 1/2 in. long is used in the instrument. hessures lower than 1μ of mercury are used to reduce heat losses and to permit rapid attainment of steady‐state condit

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14028.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

The elastic moduli and speed of sound of twenty‐three optical glasses, a series of Na2O3, CaO3, SiO3, and B2O3glasses, and some specimens of fused silica were measured by a dynamic method. Each specimen, in the shape of a prismatic bar, was vibrated in four different ways: longitudinally, flexurally on the wide side, flexurally on the thin side, and torsionally. Good agreement was found on Young's modulus as determined by the first three methods. The torsional mode was used to obtain the shear modulus. Statically and dynamically determined values of Young's modulus for six sample glasses also showed good agreemen

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14029.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Use of the hydrogen flame attachment and the Beckman Model DU spectrophotometer to determine potassium in soda‐lime and boro‐silicate glasses in the order of 0.01 to 2.5% K2O is described. Data are presented showing the effect of varying concentrations of sodium, calcium, magnesium, barium, zinc, aluminum, and iron on the potassium flame emission. The potassium emission is relatively free from interference effects except from zinc and large amounts of barium. The method is rapid, precise, and accurate to 2% of the K2O present in the sam

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14030.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

It was first shown that the enamel slips which have the best suspnding characteristics contain equal amounts of Na2O and B2O3and at least a moderate amount of NaF. The solubilities of mixtures of Na2O, NaF, and B2O3were then investigated. The pH of these solutions and the primary crystalline phases separating on evaporation also were determined. The solubility data obtained at room temperature were summarized. When the solutions were evaporated, NaF was the first crystalline phase to separate from a large proportion of the mixtures investigated. It was concluded that the desirable handling characteristics of enamels whose mill liquors contain the proper proportion of Na2O, NaF, and B2O3are not due to the formation of complex salts but to the following combination of properties: (1) the presence of salts with a moderate solubility which changes very slightly with temperature, (2) a moderate pH of about 10 in a probably well‐buffered solution, (3) a relatively stable crystalline material, NaF, as a primary phase, and (4) a secondary phase which crystallizes slowly with relatively little shrinkag

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb14031.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY