ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb12795.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

A precise instrument for measuring the torsion properties of refractories up to temperatures of 1500°C. is described. The twist is measured by sapphire mirrors mounted on the specimen itself. The mechanical properties of dense alumina and dense stabilized zirconia were measured at various temperatures. Higher ultimate strengths were reached than those reported for other bodies

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb12796.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

An improved kinetic test was devised by which the adherence of molten glass to metal may be evaluated. The results were expressed as the highest metal temperature at which the molten glass beads do not adhere. The variables of the test investigated were temperature of molten bead, height of fall of the molten bead, and slope and surface roughness of metal sample. The cumulative effect of the variables on the precision of measurement of the adherence temperature was found to be ±33° F. Several types of glass mold lubricants were investigated as to their effects on the adherence temperature and as to their persistence on heated metal surfaces. Several silicone lubricants were found to have high critical adherence temperatures while the graphitized oil base lubricant gave the best persistenc

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb12797.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

The phase relationships in the system zirconia‐ceria were investigated by X‐ray diffraction and dilatometric methods. The specimens were prepared by mixing and compacting the oxide powders and firing at 2000°C. At 2000°C. zirconia and ceria are miscible in each other from about 24 to 100 mole % ceria. The range of solid solubility decreases markedly with temperature, so that near 1000°C. the solubility of zirconia in ceria is only about 10 mole %. The addition of 0 to 1.5 mole % ceria lowers the temperature at which zirconia transforms from the tetragonal to the monoclinic form. Near 15%, therefore, this temperature is below room temperature and zirconia is stabilized. On the basis of these results, a tentative phase diagram of the system zirconia‐ceria is presented. Experiments also have been conducted with zirconia containing 13.8 mole % magnesia (stabilized zirconia). In this case the solubility between stabilized zirconia and ceria is complete at high temperature (2000°C.). At lower temperature, however, the solid solution breaks down and a two‐phase region appears in the center of

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb12798.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

A study was made of some possible causes of color fading of underglaze decalcomania used in the commercial production of semivitreous dinnerware, While the quality of the decalcomania employed is of primary importance, ware losses due to color fading can be minimized by careful control of glost firing procedures, adjustment of glaze composition, and proper fritting practice. Cone 2 dinnerware glazes identical in chemical composition but different in constituency were found to have widely different characteristics toward underglaze colors. Best results were obtained when lead oxide was fritted and 10% or more whiting was left unfritted and added as a mill addition. Low‐melting frits did not produce so good results as did the more refractory frits. Strontia, as a lead replacement, was effective in reducing color fading. Barium oxide also showed characteristics favorable to underglaze colors, but tin oxide, zinc oxide, and magnesia, even in small amounts, were decidedly harmful to most colors. When alumina and silica were varied and other oxides were kept constant, increases in alumina were decidedly unfavorable to most colors, resulting in extreme fading at the higher alumina contents. The effect of raising the silica content was generally favorable. For best results, glazes should be compounded to prevent the formation of low‐temperature melts. Adjustment of glaze composition to increase viscosity and lower surface tension of the molten glaze is suggested as a method of minimizing glaze attack on co

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1950.tb12799.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY