ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13706.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Experiments to determine the effect of cold reduction on the behavior of hydrogen in high‐purity sheet iron were conducted using two laboratory‐melted heats. One heat was air‐melted and poured and contained 0.00470 carbon and 0.17% oxygen; the other was vacuum‐melted and poured and contained 0.003% carbon and 0.006% oxygen. An increase in hydrogen solubility (acid‐charged) with increasing cold reduction was observed for both lots. The hydrogen solubility increase occurring from 0 to 80% cold reduction was much more pronounced, however, for the lot containing the higher amount of oxygen. Ground‐coat reboiling tests were made on both lots of high‐purity iron. The material containing high oxygen exhibited light reboiling for all levels of cold reduction, whereas the material containing low oxygen exhibited light reboiling for intermediate levels of cold reduction and heavier reboiling for low and for high levels of cold reduction. For the cold‐reduced material containing high oxygen, the frequency of delayed defects decreased with increasing cold reduction. For the purer material, delayed defects were observed only for the specimens having the highest level of

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13707.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

An etching technique has been found which allows the devitrification phenomena in glass to be followed. Using this technique a study was made on 30 mole % Li2O‐SiO2glass at temperatures of 520°, 560°, and 600°C. By studying the average crystal size versus time at a given temperature, the growth rate was determined. It was found to be 7.5 × 10−4, 8 × 10−3, and 3 × 10−2cm. per hour for the three temperatures. The nucleation of crystals appeared to be linear with time at each temperature. An activation energy of 49 kcal. per mole was found for the growth process. Crystals were identifie

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13708.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

In order to study the cationic influence of lithium, if any, the constitution of variable lithium constant sodium‐potassium phosphate glasses was determined using paper chromatographic methods. It was possible to prepare glasses with very low ñ, the number average chain length value. Glasses with ñ values of 2, 1.75, and 1.5 could be prepared for glasses with Li:Na:K atomic ratios of 1:1:1 and 2:1:1. Attempts to prepare a glass with ñ= 1.25 were unsuccessful. At higher lithium concentrations, it was not possible to prepare glasses with low ñ values. The constitution of lithium phosphate glasses was reinvestigated. A comparison of the constitutions of mixed‐cation phosphate glasses and lithium glasses indicates a small but definite cationic effect. The significance of these results in relation to Van Wazer's polymer theory and distribution laws is di

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13709.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The strength and static fatigue behavior of abraded glass specimens tested in various surrounding media have been studied. The test media included distilled water, nitrogen atmospheres of varying humidity, methyl and isopropyl alcohol and mixtures of these with distilled water, and various acidic and basic solutions. For intermediate durations of load the strength values in atmospheres of 0.5 and 43% relative humidity were 45 and 20% greater, respectively, than in distilled water. The value oft0.5, the characteristic duration for static fatigue, under these three test conditions was 3500, 200, and 8 seconds, respectively, for the particular grit‐blast abrasion studied, indicating that liquid water is the most effective agent for promoting a high rate of static fatigue and very dry air with a small concentration of water vapor is least effective. In reagent‐grade methyl or isopropyl alcohol (0.01 to 0.05% H2O) the strength at an intermediate load duration of 10 seconds was about 40% greater than in distilled water and the slope of the static fatigue curve differed somewhat from that obtained for tests in water. With the addition of water to the alcohol solutions the fatigue curve became parallel to that for water, and as the water content was increased, the curves shifted toward the water curve. For tests in acidic and basic solutions the strength at an intermediate load duration was independent of pH over the range pH 1 to 13. For more acidic solutions the strength was slightly less and for more basic solutions slightly greater than in this range. The results are discussed in terms of possible mechanisms for static fatigue. It is concluded that the static fatigue of abraded glass results from changes in the shape or size of surface abrasion cracks under the combined action of stress and the surrounding medium. In general, water or water vapor is the primary agent in promoting fatigue, and, unlike the usual chemical attack, the interaction appears to involve primarily the neutral water molecule and the SiO2network of the glass. The presence of other ions or molecules is relatively unimportant except as it may serve to reduce the concentration of water and its availability to the tip of the abrasion cr

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13710.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

An induction furnace design which readily permits the determination of melting points and basic phase studies is described. The melting point of MgO was redetermined to be 2825°C., and the melting point of Cr2O3is reported as 2330° and 2315°C. in air and in nitrogen atmospheres, respective

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13711.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

In addition to the well‐known zinc orthotitanate (Zn2TiO4) and zinc metatitanate (ZnTiO3), the study of solid‐state reactions in the system ZnO‐TiO2disclosed a previously unrecognized compound, Zn2Ti3O8. This compound was obtained when sulfate‐containing hydrous titanium oxide of anatase structure was reacted with ZnO at 700° to 900° C. It crystallized in a defect spinel structure with eight Zn2+ions occupying the tetrahedral positions and twelve Ti4+ions distributed in sixteen octahedral positions (a0= 8.395 ± 0.002 a.u.). Crystallographic data are given for zinc orthotitanate and metatitanate.Formation of the latter compound appeared to be favored by rutile TiO2sources and those readily convertible to rutile under the reaction

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13712.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The plastic properties of calcium fluoride single crystals tested in compression were investigated in the temperature range 25° to 1000°C. Above 400° C., the crystals showed appreciable ductility. The critical resolved shear stress, t, decreased with absolute temperature,T, according to the equation t = t0e+K/T. The rate of work‐hardening decreased rapidly as the temperature increased but retained a relatively high value even as the melting point was approached. Air‐annealed crystals were harder than as‐cleaved crystals. Crystals with a (111) plane normal to the applied stress hardened less rapidly than crystals with a (110) plane normal to the applied stress. The dislocation density increased linearly with strain. (100), (110), and (111) fractures were

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13713.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The AlKα emission wave length is determined by the state of coordination of Al atoms and a clear distinction can be made between Al atoms in fourfold and in sixfold coordination to oxygen and also between Al atoms in fourfold coordination to oxygen and to nitrogen. Measurements of Δ(2θ) (the difference in diffraction angle for AlKα radiations from a sample and from metallic aluminum) are used to distinguish Al in fourfold and in sixfold coordination in normal and in heat‐treated kaolin minerals. The Al atoms in meta‐kaolin are shown to have fourfold coordination to oxygen in agreement with the structure proposed by Brindley and Nakahira. After heat‐treatment at 1024°C., the coordination of Al reverts toward sixfold, and this is more marked for disordered kaolinite and halloysite than it is for well‐crystallized kaolinite and dickite. Infrared absorption measurements by Stubičan and Roy provide further confirmation of the coordination changes of the Al ions in th

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13714.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Measurements have been made in the temperature range 750° to 1050°C. of the temperature dependence of the electromotive force of the solid‐electrolyte galvanic cellsand from these data the variation with temperature of the relative partial molar free energy of oxygen on the right side of the foregoing cells was calculated. In the case of the first of these cells, a favorable comparison was made between the present values of this thermodynamic quantity and those predicted from published thermodynamic data for this oxide mixture. The lack of gas equilibria data for the manganese oxide mixture prevented such a comparison in the second instance, however, and there were substantial discrepancies between the present values of the relative partial molar free energy of oxygen and those obtained from published calorimetric data. This disparity in results was rationalized on the basis of possible differences in the metal‐oxygen ratio for the manganese oxide specimens measured by the two different techn

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1961.tb13715.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY