ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12926.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

The volatility of various lead silicate melts was determined by measuring the loss in weight at various temperatures from 800° to 1300° C. Platinum crucibles containing the melts were Suspended from an analytical balance into a vertical Global furnace. The crucible studies showed that the loss of lead oxide from melts could be decreased by as much as 80% when lead oxide was combined with silica in monosilicate melts and by as much as 95% when combined with silica in bisilicate melts. Comparative trials on raw lead glazes showed that most of the volatilization occurred in the early stages of glaze meltin

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12927.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Alkali test data were obtained for experimental and commercial porcelain enamels for test solutions of sodium hydroxide, sodium pyrophosphate, and commercial detergents. The effects of variations in volume and strength of solutions, time and temperature of testing, and the addition of bleaching agent were studied. The best correlation to detergent action was obtained with 1% sodium pyrophosphate. Results for sodium hydroxide varied greatly with solution strength. For some porcelain enamels the alkali resistance results, obtained with 5% sodium hydroxide, were contrary to those obtained with commercial detergents. The addition of a sodium hypochlorite type of bleach to detergent solution did not affect the degree of attack on porcelain enamels.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12928.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12929.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12930.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

The contact angle of liquid aluminum with recrystallized alumina and with sapphire, respectively, was measured using the sessile‐drop technique, The variation in contact angle with time was determined at temperatures of the order of 1200°C.in vacuoat 10‐4mm. Hg. A significant difference in spreading behavior was observed for aluminum on the respective aluminas. In the case of aluminum on recrystallized Al2O3the contact angle attained a steady value, whereas on sapphire the drop was observed to spread and contract repeatedly. The contact angle assumed after each contraction was essentially constant. The observations are discussed and an explanation is proposed for the effect in terms of changes in the interfacial geometry between liquid aluminum and the alumina due to dissolu

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12931.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

The oxidation of purified green silicon carbide in controlled atmospheres was studied by weight‐gain measurement and by observation of the surface reaction products, including optical measurement of the thickness of the oxide surface film. The rate of oxidation was much greater for silicon carbide in contact with fluid silicate glasses than for silicon carbide alone. In a vacuum of 0.1 mm., oxidation proceeded with loss of weight, because of the formation of volatile SiO2, and at a greater rate than at atmospheric pressure. It is postulated that the rate‐controlling process in the normal oxidation of silicon carbide is the formation of solid SiO2on the surf

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12932.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Alumina and magnesia compositions containing additions of titanium, chromium, manganese, iron, and zirconium oxides were sintered in atmospheres of oxygen, nitrogen, and hydrogen. Diffusion promoted by lattice defects was observed by measurements of bulk density. Color, atmosphere, and X‐ray diffraction indicated the nature of the structural defects resulting in increased rates of material transpor

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12933.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Results are presented of a study in air of mixtures in the system CaO‐Cr2O3‐SiO2. The phase equilibrium diagram shows relations at liquidus temperatures for all but the high‐lime part of the system. In this omitted part chromium in the mixtures oxidizes in air to higher valence forms. The compound Ca3Cr2Si3O12(uvarovite) occurs at subsolidus temperatures, decomposing at 1370°C. to α‐CaSiO3and Cr2O3. The inhibiting action of chromium oxide on the inversion of high‐temperature forms of Ca2SiO4to the low‐temperature γ‐Ca2SiO4is discussed in the light of new data. Evidence is presented for the existence of a pentavalent chromium compound, Ca3(CrO4)2, having solid‐solution rela

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12934.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Glasses were discovered in the system K2O‐Sb2O3b3Raw materials used in the preparation of these glasses were potassium pyroantimonate, potassium hydroxide, potassium nitrate, antimony oxide, and antimony trisulfide. Details of the methods of preparing the glasses and the compositions investigated are given. A glass, prepared by melting a mixture of potassium pyroantimonate and antimony trisulfide in air, was investigated in some detail. It was found to have an average infrared transmission of 42% in the range 2 to 7 μ. The glass annealed at about 150°C. and softened at about 230°C. Its coefficient of linear thermal expansion, in the range 240° to 200°C., was 20 × 10−6per °C. The glass had a specific gravity of 3.94, a modulus of elasticity of about 5 × 106lb. per sq. in., a Knoop hardness of about 135, and was highly resistant to attack by atmospher

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1958.tb12935.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY