ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14135.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

The tantalum‐silicon, molybdenum‐silicon, and tungsten‐silicon systems have been investigated for solid phases stable above 1900 °K. Three new tantalum silicide phases, two new molybdenum silicide phases, and one new tungsten silicide phase are reported besides the MSi2phases previously known. The crystal structure of MO3S is described. Lower limits for eutectic temperatures are given for these three systems, and the relative stabilities of metallic silicides of groups III through VII are dis

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14136.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

An instrument has been developed for the purpose of measuring the thickness of protective coatings of ceramic materials applied on nonmagnetic metal bases. This instrument provides a nondestructive method of measurement and can be used on metallic backings having a wide range of electrical conductivities. Also, the thickness measurement refers to a restricted area and is, therefore, applicable to curved surfaces. Although this instrument was developed primarily for the measurement of the thickness of ceramic coatings on turbine blades and other high‐temperature parts of aircraft power plants, it should be generally useful in thickness measurements of paint, plastic, and other nonconducting film

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14137.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Compositions of commercial amber glasses are reviewed briefly. Experimental results for variations in coloring ingredients are shown to affect not only the color, but also the fining. One of the major factors in determining color is the base composition which, contrary to previous reports, is shown to require high silica and low alkali contents for greatest intensity and stability of color. Other results show that color is intensified by the presence of fluorides and that added iron is unnecessary to the development of strong stable colors.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14138.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

The definition and scope of crystal chemistry are pointed out and the dependence of this new branch of science upon the well‐established fields of morphological and X‐ray crystallography is indicated. By correlation of elemental classification, based on the periodic system, with crystal geometry, the nature and strength of atomic binding forces are determined. The geometry and binding forces to be desired in refractory materials are evaluated, and methods for examination and preparation of compounds of this nature are discussed. Compounds in oxide and carbide systems are described, and correlation with physical properties is demonstrated wherever possi

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14139.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

The development of crystalline and glassy phases was traced in shale specimens fired over a range of temperatures. Two raw materials of distinctly different compositions were selected far study, namely; a high‐lime shale and an argillaceous shale. Mechanical separations and X‐ray analyses were used to isolate and identify the crystalline phases, whereas the development of glass was observed petrographically. The identification of the phases at various heat‐treatments was helpful in explaining the properties of fired shale pro

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14140.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

The resistance of some enamels to attack by citric and other acids is improved by prior exposure to certain weak acids, which do not appreciably attack the enamel themselves. The abrasion resistance of some enamels is markedly decreased by exposure to citric acid for IS minutes at room temperature. These effects, as well as the results of some exploratory experiments on the nature and extent of these effects, are reported.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14141.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

If strain is induced in disks of window glass by relatively rapid cooling in the annealing range (about 500 °C.), the birefringence seems to be permanent in its entirety at room temperatures (about 30 °C.). Even the most delicate polariscopes fail to detect any change in 11 years. At temperatures far below the annealing range, however, it is possible to remove some of this strain. Sometimes 5 to 10% can be removed at temperatures of 180° and 200 °C. in a period of 30 days. At 200 °C. a second 30‐day heating period produced no further change; at 250 °C., it produced another slight d

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb14142.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY