ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13074.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY

摘要:

A study has been made of the relationship between conditions of specimen preparation and the tensile strength of small constricted soda‐lime‐silica glass rods. The preparation and testing techniques were basically the same as those used in a previous investigation' except that the drawing loads were systematically varied. It was found that different loads under which specimens were drawn resulted in significant changes in tensile strength values. The average strength values varied from 62,800 lb. per sq. in. to 88,400 lb. per sq. in., depending on the drawing loads used. Maximum strength values were obtained with the highest loads. The limits of error of the strength values did not change appreciably with different drawing conditions. Rubbing the specimens with the fingers reduced the strength by approximately

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13075.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY

摘要:

Production of fused stabilized zirconia directly from ores in an electric are fusion furnace is described. By this method, stabilized zirconia containing as low as 0.19% SiO2has been made in one furnacing from an ore containing 33% SiO2. Various properties of refractories made from fused stabilized zirconia are listed. Uses have included linings for furnaces operating to 2500°C., setters for firing titanates, containers for steel and platinum, and resistors for oxide resistor furnaces

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13076.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY

摘要:

Differential thermal analyses of samples of Kamec (N. C.) kaolin, Tako (Ala.) kaolin, an English kaolin, dickite (Ouray, Colo.), halloysite (Eureka, Utah), and diaspore (Chester, Mass.) were run under dynamic conditions in atmospheres containing water vapor of known partial pressures ranging from 5.0 to 760 mm. The differential thermal analysis curves of all kaolins showed the first indication of dehydration (that is, the beginning of the endothermic peak) at about 400°C., the halloysite at 320°C., the dickite at 500°C., and the diaspore at 465°C. in dry air. In steam atmosphere, the starting temperatures of the endothermic peaks were 470°, 485°, 585° and 510°C., respectively. The peak temperatures of the endothermic peaks were only slightly affected by the atmospheres, hence the peaks were more intense and covered a narrower temperature spread in the steam atmosphere. All kaolin‐group minerals showed the exothermic peak at 1000°C. in dry air and 970° to 980°C. in steam atmosphere. The data on InpH2O vs. 1/Tfor each mineral were plotted according to the van't Hoff equation. The straight line of dickite above InpH2O = 5.30 was used to calculate the heat of dehydration. The value is 137 cal. Per gm. The van't Hoff lines for the kaolinites and for diaspore, although straight lines, are in error since the recorded temperatures are considerably above the equilibrium temperatures because the rates of reaction are too slow at or near equilibrium. Actually kaolinite will decompose extremely slowly in the dry air at about 250°C., but in the steam atmosphere it will not decompose unti

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13077.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY

摘要:

The physical properties of some Na2O‐CaO‐GeO2and Na2O‐CaO‐SiO2glasses were compared. The glasses were compounded on a molecular basis with the RO2held constant. Physical properties determined were softening point, viscosity, annealing point, density, and refractive index. The possible constitution of these glasses is discussed in brief on the basis of their physical properties. Their optical and transmissive properties, which were also determined, indicate possible n

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13078.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY

摘要:

The fit of titania enamels as determined by warpage and the expansiometer ring tests is compared to torsion and cross‐bend failures. Tests were selected on the basis of normal use and acceptance by the industry. Titania enamels used for the tests cover a wide range of warpage values from low to high compression in the enamel. The major part of the work was conducted with the normal system of ground coat and cover coat. However, some comparative results are given for enamels applied directly on a titanium‐bearing steel. The data obtained are shown graphically.It was found that warpage values and expansiometer ring values vary directly with the weight of application, and expansiometer ring values and warpage values are proportional. Cross‐bend values vary inversely with weight of application, and higher warpage enamels have higher cross‐bend values. Cross‐bend values are lower when enamel is applied directly than when the cover coat‐ground coat system is used; they are not affected by adherence variations. Torsion values in either system vary inversely with thickness. Torsion values do not vary according to warpage, ring value, or

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1952.tb13079.x

出版商:Blackwell Publishing Ltd    

年代:1952

数据来源: WILEY