摘要:

AbstractThe elements, Ni, Fe, Cr, and Mn, and their oxides, NiO, Fe2O3, Cr2O3, and MnO2, in a finely divided state, were brought into contact with granular fused MgO in loose form and in pressed disks and also into contact with slabs of high‐fired MgO and BeO. The maximum temperatures reached were 1000°C, 1100°C, and 1200°C in air firings. The degree of reaction was noted by the extent of discoloration of the MgO and BeO near the contact material. Ni showed the least reactivity, Fe and Cr came next, and Mn showed the most reaction. The oxides gave the same order of reactivity, NiO, Fe2O3and Cr2O3, and MnO2, the most. The elements in oxidizing caused more reaction than their oxides in all cases. There was less reaction with BeO than with MgO for corresponding contact material.Firings were also made with these elements and oxides in contact: with pressed disks of fused MgO but in a hydrogen atmosphere. Ni and Fe showed no reaction; Cr, a very slight reaction; and Mn, slightly more reaction. NiO and Fe2O3were reduced to their elements without reaction, whereas Cr2O3did not reduce and gave no reaction. MnO2became semi‐sintered and gave a very slight reaction.Other experiments were made by passing air or N2, dry or through water, into mixtures of granular fused MgO and Mn, MnO2, or Cr, respectively. At 1200°C, reaction was greatest with mo

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19786.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractThe new technique for the determination of the refractive indices of minerals, as developed by R. C. Emmons of the University of Wisconsin, is described. The paper contains a discussion of immersion media and a description of the double‐variation apparatus, the modified universal stage, and the smithsonite refractometer. Application of the technique to crystalline refractories is considere

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19787.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractThis paper describes the use of a specific type of tale in wall‐tile bodies and explains the effect of various percentages on shrinkage, absorption, modulus of rupture, moisture expansion, and resistance to delayed crazing. The data indicate the effects of talc with various combinations of wall‐tile body ingredients and the compositions and heat treatment of greatest potential resistance to craz

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19788.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractA base glaze was developed, using colemanite as the principal flux. A series of colors was produced by blending ten glazes containing different coloring materials.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19789.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractA firing procedure is formulated along the lines laid down by Seger for the production of copper red glazes and underglaze red. Possible methods of control of the liver red, cherry red, and purple‐redflambéglazes are giv

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19790.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractThe possibility of using the absorption of X‐rays or γ‐rays in a refractory brick as a measure of porosity has been tested experimentally for both kinds of radiation. It is found that the method is entirely practical in either case and when the necessary apparatus is set up it should yield results, with much less effort, better than those now obtained by the displacement method. Gamma‐rays from radium appear to have some advantages over

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19791.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractA loading device for use in making the standard load test on refractory brick is described. It consists of two steel shafts plus added weights, mounted in a simple steel frame to provide true direct vertical loads on the two test samples. Illustrations showing details of construction are included.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19792.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

AbstractViscosities and surface tensions of glasses and slags are properties of great practical importance but they are frequently difficult to measure. The methods which yield results in absolute units are time‐consuming and are not applicable to a study of the behavior of partly devitrified silicate melts.This paper describes an empirical method for estimating not only the relative fluidity of glasses and slags but also for determining the lowest temperature at which crystallization from a previously chilled vitreous slag will occur on reheating, the approximate rate at which devitrification proceeds at various temperatures, and the range of temperature within which devitrification is complete enough to prevent flow of the slag under its own weight.By an extension of the method to mixtures of crystalline substances, the behavior of such mixtures upon heating may be studied advantageously. By a further extension of the technique, the temperature at which the solid‐liquid interfacial tension becomes low enough to permit wetting of a solid by a glass or slag may be determined. The applicability of these techniques to vitreous enameling problems is indica

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19793.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

ABSTRACTThis paper contains a discussion of the well‐known Adams and Williamson annealing law which makes the rate of release of stress in glass proportional to the second power of the stress and points out certain fundamental objections to such a law. A new expression free from these objections and taking into consideration the change of viscosity with time at constant temperature is given as‐df/dt= Mfφ, whereMis a modulus and φ the instantaneous fluidity. Experiments made with an ordinary lime glass show that this law holds for the release of mechanical stresses imposed on strain‐free glass as well as for the release of thermal stresses in chilled samples. The value ofMfound for these two types of stress at two different temperatures is 5.9 (±0.5) × 1010d

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19794.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

ABSTRACTThe results are presented on work done to increase the opacity of enamels by mill practice and mill additions, such as milling to abnormal fineness, addition of opacifiers at the end of the milling period, the effect of the addition of feldspar, and the effect of different types of clays.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1936.tb19795.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY