ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14950.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

Isothermal compressibility data at 21°C. at pressures between 1000 and 10,000 atmospheres are reported for the binary alkali borate and silicate glass systems. In general, a decreasing compressibility is noted with increasing alkali content in both silicates and borates, the effect being much greater in the borates in the range of compositions studied. A maximum compressibility appears to be indicated for the potassium silicates at low potassium concentrations. In silicates and at high alkali contents in the borates, the order of compressibility is K>Na>Li. At low alkali contents in the borates, this order appears to be reversed. Possible interpretations of these data are discussed in terms of the concepts of the structura of glasses

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14951.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

Vanadium tetroxide and vanadium pentoxide were prepared and some of their physical properties were measured. A brief survey was then made of some of their binary oxide compounds. Various mixtures of V2O4or V2O6and BeO, MgO, CaO, SrO, BaO, Al2O3, SiO2, TiO2, CeO2, ZrO2, Nb2O6, and U3O8were heated. When compounds were formed, some of their properties were determined. Refractoriness, thermal expansion, and optical properties were considered of special interest. Vanadium pentoxide was found to have a linear thermal expansion of only 0.63 × 10−6per °C. from 30° to 4

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14952.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

The principal purpose of this investigation was to determine the creep behavior and strength at 1200° to 1850°F. of cermets which may be used in the high‐temperature areas of aircraft. Initially a series of bending tests was made on variations of Kennametal 150‐type Kentanium containing from 5 to 30% nickel binder. The 5, 15, and 20% compositions were the strongest and the most creep resistant. Because of the need for both thermal and mechanical shock resistance, tensile creep tests were then made on K150‐type Kentanium compositions containing 20, 25, and 30% nickel binder. A limited number of tests also were made on Kennametal composition K162B and on Firth Sterling composition FS‐27. The cermet K162B was the most creep resistant and the strongest. Linear thermal expansion determinations were made on Kennametal compositions K138A, K138, K151, and K151A. Their coefficients of expansion between room temperature and 1205°C. ranged from 8.1 × 10−6to 8.6 × 10−6per °C. Metallo‐graphic examinations were made of all the tensile‐tested specimens; in general, the test strains were too small to cause any noticeable deformation or chan

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14953.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

Evidence for the migration of the liquid phase in refractories is reviewed, and consideration is given to means of separating the liquid from refractory specimens to allow its study. Methods include absorption by porous media and gravity flow into platinum crucibles (the latter unworkable). Centrifuging at high temperatures is judged to be the most practical, and room‐temperature experiments are described which show that liquid (glycerine) of 1000‐centipoise viscosity can be removed by centrifug

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14954.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

A rotating‐type induction furnace with graphite heater was used to demonstrate the application of the principles developed in Part I. Rotation at 1200 to 1300 r.p.m. for 15 minutes at an average temperature of 2560°F. (1405°C.) separated a low‐melting slag from a silica brick which had been used in an open‐hear

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14955.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

Shivering of cone 8 zirconium‐opacifled glazes for use on one‐fire pyrophyllite wall tile and warping of the tile body were corrected by increasing the thermal expansion of the glazes. This was accomplished by (1) increasing the alkali content, (2) substituting strontium oxide for zinc oxide, (3) substituting calcium oxide for magnesium oxide, and (4) decreasing the silica‐alumina ratio. The last method appeared to be the most effective. It is shown that the calculated coefficient of cubic thermal expansion is often unreliable as a value for the actual expansion. Expansions were obtained with a quartz‐rod dila

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14956.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

Magnesium ferrite specimens made of unreacted (mixed oxides) and reacted (ground ferrite) materials were prepared to determine the effects of forming pressure, firing temperature, time at peak temperature, firing atmosphere, and quenching treatment on their magnetic and electrical properties. High firing temperatures (1450°C.), long holding times (8 hours), and quenching from the highest temperature (1200°C.) produced the highest μi, andBm, the lowestHc, and a decrease inBr. These changes were related to the change in the void volume and particle size of the specimens brought about by the fabrication techniques and to the alterations in the degree of inversion in the spinel lattice during quenching. Oxygen loss or gain from the stoichiometric amount caused a loss of magnetic properties. X‐ray and microstructure studies aided in the interpretation of the experimental

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14957.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14958.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1955.tb14959.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY