摘要:

AbstractAn exploratory study was made to determine possibilities of the Porcelain Enamel Institute rolling‐ball gouge test as well as to discover some of the factors influencing the gouge resistance of enamels as shown by the test. The test results compare favorably with deep‐scratch and gouge defects encountered in actual enamel practice. The accuracy of test results, moreover, compares favorably with other such physical tests designed for use with porcelain enamel. The gouge resistance is shown to be a function of enamel thickness and of bubble structure. Factors which increase or decrease bubble structure, such as mill additions, frit compositions, and firing treatment, are shown to affect gouge resista

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1943.tb15175.x

出版商:Blackwell Publishing Ltd    

年代:1943

数据来源: WILEY

摘要:

AbstractRelationships previously deduced and tested by the authors for the calculation of the density, refractive index, and. dispersion of a glass from its composition, expressed in terms of the “atomic fractions” of the components, are transformed into equivalent equations for the calculation of these quantities from the weight percentages or weight fractions. The necessary constants for use with these equations are tabula

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1943.tb15176.x

出版商:Blackwell Publishing Ltd    

年代:1943

数据来源: WILEY

摘要:

AbstractThe minerals found to have a stability range on the liquidus surface in the system MnO‐Al2O3‐SiO2are cristobalite and tridymite, SiO2; mullite, 3Al2O3. 2SiO2; corundum, Al2O3; rhodonite, MnO.SiO2; tephroite, 2MnO.SiO2; galaxite, MnO.Al2O3; spessartite, 3MnO.Al2O3.3SiO2; and a new compound, 2MnO.2Al2O3.5SiO2. The quintuple points and boundary lines found in that part of the MnO.Al2O3.SiO2system bounded by the systems 3MnO.Al2O3.3SiO2‐SiO2, 3MnO.Al2O3.3SiO2‐Al2O3, and Al2O3‐SiO2have been determined. Quintuple points and boundary lines involving the area inclosed by the systems 2MnO . SiO2‐3MnO . Al2O3. 3SiO2, 3MnO . Al2O3. 3SiO2‐SiO2, and 2MnO.‐SiO2‐SiO2are indicated. Isotherms and isofracts (lines of equal refractive index) are given for the portion of the system investigated.X‐ray data show that crystals of the compound 3MnO.Al2O3.3SiO2have the same structure as the garnet mineral spessartite (manganese garnet). The compound 2MnO. 2Al2O3. 5SiO2, which is shown by X‐ray data to have a basic structure similar to cordierite, 2MgO.2Al2O3.5SiO2, seldom crystallizes from the glass, but a third substance which has a high extinction angle crystallizes readily from the reheated glass. These high extinction angle crystals are replaced by 2MnO .2Al2O3.5SiO2when a proper heating cycle is employed, and they are not found again until the product is melted and crysta

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1943.tb15177.x

出版商:Blackwell Publishing Ltd    

年代:1943

数据来源: WILEY

摘要:

AbstractThe Tennessee Valley Authority has carried out small‐scale and large‐scale studies during the past five years, directed toward the development of refractories more resistant to corrosion by molten rock phosphate than the present commercial types.Small‐scale tests were made on refractories containing varying proportions of zirconium silicate and oxides of aluminum, beryllium, calcium, cerium, chromium, magnesium, thorium, and zirconium. Promising compositions were then tested by fabrication into standard 13l½‐in. and 9‐in. brick and by determining their resistance to corrosion by molten rock phosphate, basic open‐hearth slag, and electric phosphate‐smelting furnace slag. The most promising of the compositions tested were (1) Cr2O367%, CaO 30%, and Al2O33% and (2) ZrO233.5%, Cr2O333.5%, CaO 30%, and Al2O33%. A 25‐kw. Detroit rocking furnace was lined successively with brick of these two compositions, as well as a commercial superduty firebrick and a commercial unburned magnesite brick, and each lining was tested against molten rock phosphate until failure occurred.The tests show that the two new types of refractories are superior to the commercial refractories and that they may have promising possibilities for use where basic refractories are now

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1943.tb15178.x

出版商:Blackwell Publishing Ltd    

年代:1943

数据来源: WILEY

摘要:

AbstractThe plastic working properties of a number of clays and bodies were measured with a modified Endell body tester. The apparatus shows that various bodies may be adjusted to a similar consistency for a given molding process but differ in their tendency to crack on being deformed. It is possible to determine the extent to which plastic properties are affected by differences in raw materials, methods of body preparation, water content, aging, and deairing.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1943.tb15179.x

出版商:Blackwell Publishing Ltd    

年代:1943

数据来源: WILEY