摘要:

AbstractA continuously recording potentiometer, measuring accurately heat effects of from 0.1° to 500°C., is used to determine the differential temperature between a sample and a reference material. The temperature rise of sample and reference material is controlled to within 5° of a uniform rate (generally 400° per hour) by a continuous voltage adjustment‐type program controller. The sample holder differs from the usual holder described in the literature in that it has low heat capacity, high conductivity, and small mass. These properties necessitate a uniform temperature area in the fu

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1948.tb14245.x

出版商:Blackwell Publishing Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractA study has been made of the transmittance of near‐infrared energy by a number of binary glasses. Of the systems studied, the lithia‐silica and lead oxide‐silica glasses were found to have the highest transmittance of energy in the range of wave lengths from 3.0 to 5.0 microns. The transmittance of lithia‐silica glass is compared with that of the other alkali‐silica glasses. Values of transmittance are given for lead silicate glasses of higher lead content than previously reported in the l

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1948.tb14246.x

出版商:Blackwell Publishing Ltd    

年代:1948

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1948.tb14247.x

出版商:Blackwell Publishing Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractA method is described for testing ceramic specimens under torsional stresses at temperatures to 2500 °F. With simple apparatus and minimum time, consistent values are obtained for modulus of rigidity, Poisson's ratio (when the modulus of elasticity is known), tensile (torsion) strength, torque‐twist graph, approximate softening temperature, plastic deformation, and short‐time creep rate. The results are in satisfactory agreement with tensile test, bending test, and long‐time creep‐rate results and thus provide a quick means of making a preliminary selection of promising compositions for more extensive testing. Among the advantages of torsion testing are freedom from error caused by thermal expansion, absence of need for close dimensional tolerances, simplicity of specimen installation in grips, and the ability to make deformation measurements outside the furnace on the cool end of the specimen. Data for a sillimanite body and a beryl‐lia body illustrate the types of information given by the method. The beryllia body has more suitable high‐temperature cha

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1948.tb14248.x

出版商:Blackwell Publishing Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractPellets formed from dry‐milled ground‐coat frits of the conventional cobalt type were used to study the factors influencing the flow characteristics of enamel fusion buttons at temperatures above their softening points. To insure reproducible results it was necessary to control accurately (1) the materials being tested, (2) the temperature, (3) the time, and (4) the weight of the sample. Reasonable variations in the gauge of the metal holding plate and the coating applied to protect the plate did not greatly affect the dimensions of the fired buttons. Little difference in the flow of ground‐coat fusion buttons was noted for variations in either particle size, fineness distribution, forming pressures, or height of the pe

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1948.tb14249.x

出版商:Blackwell Publishing Ltd    

年代:1948

数据来源: WILEY