摘要:

AbstractWhen definite types of white or clear enamel are milled with certain molybdenum compounds, light‐colored ground coats are produced. These ground coats show excellent adherence when applied in the usual manner to deeply pickled sheet steel. Firing may be done at 1600 °F. or at 1500 °F., according to the type of enamel. The paper also discusses the properties of molybdenum compounds, the problems involved in their use, the types of compounds which produce adherence, the type of enamels which work successfully, andapossible explanation of how these compounds function to produce adhere

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14191.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThe solubility of a zirconium oxide opacifier was determined by fusion in enamel glasses and then by heat‐treating at enameling temperatures and noting the amount of crystallization. An increase in the alumina, zinc oxide, and calcium oxide content in the glasses caused a decided decrease in the solubility of the zirconium oxide opacifier. The fusion temperatures of the enamels were raised by solution of zirconium oxid

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14192.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14193.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractAn attempt is made to apply the ideas of crystal chemistry to the problem of immiscibility in glass systems. Miscibility is favored by the tendency of the networkforming cations, Si, B, and P, to bond with all available oxygens in the melt. Immiscibility is favored in compositions which do not allow the other cations, such as Na+and Ca++, to be properly surrounded by unsaturated oxygens. The importance of this effect may be related to the valence and size of the cation. A qualitative discussion is given for a number of binary and ternary systems.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14194.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractFrom the standpoint of a strictly quantitative approach to the problem of measuring the chemical durability of glass, there is need for (1) a method to measure the surface area of irregularly shaped particles that is independent of their chemical composition and surface conditions and (2) methods to measure the actual ions present in extracts from durability tests. A method of measuring (1), that is, the surface of irregularly shaped particles, has been developed, based on the principle thatareas of projected images of a convex particle as measured fromnrandom positions approaches the absolute surface area of the particle asnincreases. Particles to be measured were mounted in random orientation by sprinkling them on a transparent plastic mounting medium applied in a thin film on a glass slide. After magnifying with a projection microscope and tracing the areas, the final areal measurements were made planimetrically. The procedures for measuring small concentrations of sodium and silica occurring in durability extracts were tested and were found to be applicable to the problem of measuring the extent of the attack. The procedure for determining sodium is to precipitate and weigh the triple salt, sodium zinc uranyl acetate, (UO2)3ZnNa(CH3COO)9.6H2O; the procedure for silica involves the production in acid solution of silicomolybdate blue by reduction of silicomolybdate yellow with sodium sulfite and by a photometric comparison of the color developed with a standard series. By the application of these methods in actual durability tests, it is shown that two equal volumes of the same glass collected between the same limiting screens exhibit a measured difference in surface per unit volume, which correlates closely both with chemical attack and with the positions of surface distribution curves. The evidence of this investigation corroborates the view that closer specification of the conditions under which the glass grains are prepared is desirable and that accurate determination of sodium and silica is practicable in very dilute solutions obtained in durability tests.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14195.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY