ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13969.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

A study was carried out to ascertain the effects of two forms of silica, quartz and silicic acid, the methods of mixing, and autoclaving conditions on the formation of the lime–rich crystalline hydrous calcium silicates designated as alpha–, beta–, and gamma–type hydrates. The alpha–type hydrates were synthesized from mixtures of lime slurry and quartz in compositions of 1.8 to 2.4 CaO/SiO2molar ratios (C/S ratios). This series of compounds, free of all contaminants, showed X–ray patterns containing many or nearly all lines of crystalline Ca(OH)2. The beta‐type hydrates, of which synthetic hillebrandite is a member, were prepared in 1.8 to 2.4 C/S ratios from mixes of CaO and silicic acid dispersed in water. This series of phases or closely related phases may extend in composition from 1.5 to 3.0 C/S and includes minerals and other synthetic solids previously believed to be distinctly separate phases. The gamma‐type hydrates having compositions of about 1.5 to 2.25 C/S were prepared from mixes of quartz and CaO dispersed in water and autoclaved at somewhat higher temperatures than the alpha‐type hydrates. The gamma‐type hydrates contained about 0.3 to 0.4 mol. of water per mol, of compound compared with values of 1.00 to about 1.25 for the other tw

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13970.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

A phase equilibrium study of the join lithium metasilicate–β–eucryptite in the system Li2O–Al2O3–SiO2was made by the quench method. The phase diagram was found to be a simple binary with a eutectic at 1070°C and 57% eucryptite. The relationship of these data to the ternary system is

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13971.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

The wettability and adherence of metal–ceramic systems were investigated, using a precise sessile–drop method. The surface tension and wettability of silicon, iron, and nickel in contact with various refractory materials were evaluated at elevated temperatures. Measurements were carried outin vacuo, in hydrogen, and in helium. Generally, nonwetting contact angles were observed for iron and nickel with oxides, whereas silicon was found to wet the oxides partially. In all cases the wettability was greater for the metal‐graphite and beryllium carbide systems than for the metal‐oxide systems. The nature of the atmosphere was found to have a significant effect on the wettability and surface tension of the metal. Wettability results are interpreted on the basis of surface tension and by the consideration of free‐energ

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13972.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

Some thermal and mechanical properties were measured for tin oxide‐matrix compacts which nominally were composed of 99% by weight tin oxide (SnO2) and 1% zinc oxide (ZnO). The sintered compacts were similar in strength to high–fire mullite porcelains, had superior resistance to thermal shock, and had high thermal conductivity. The tin oxide body might be expected to give good service under conditions of severe thermal shock and in an oxidizing atmosphere at temperatures up to 150

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13973.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY

摘要:

The heats of solution of glasses and devitrified alkali borates in the systems Li2O–B2O3, Na2O—B2O3, and K2O–B2O3were measured in 2 N nitric acid with a simple vacuum‐bottle calorimeter. The standard deviation was 0.35 cal. per gm. for approximately 130 determinations. From these data, together with available thermodynamic data, heats of formation were calculated for alkali borate glasses and devitrified alkali borates from two combinations of possible reactants. All the curves for the heats of solution of glasses showed minima at 20 mole % alkali oxide, but similar curves for devitrified alkali borates showed minima at 20 mole % for potassium and sodium borates only. The curve for devitrified lithium borates showed a minimum at 25 mole % alkali. The conclusion was drawn that there is probably no congruently melting Li2O.4B2O3c

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1954.tb13974.x

出版商:Blackwell Publishing Ltd    

年代:1954

数据来源: WILEY