{"title":"Glass-formation Range and Cooling Rate","authors":"M. Imaoka, H. Kurakata, S. Tai, Hiroshi Nonomiya","doi":"10.2109/JCERSJ1950.74.846_52","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.74.846_52","url":null,"abstract":"We have already studied the condition of glass-formation and the glass-formation range of borates, silicates and germanates. In these studies, however, we could not determine precisely the cooling condition which defines the glass-formation range, because the glassy stateis not a stable state, but a sub-stable one. These experiments were made under conditions which were determined for the sake of experimental convenience: namely, 1/80mols of specimen were melted and cooled naturally in a room. Therefore, it is necessary to examine to what extent the results of these experiments are effective in view of the glass structure. In this study experiments were carried out by changing the cooling rate, and the variation in the glass-formation range with various cooling rates was examined. These cooling processes included the followings: quick cooling by water, natural cooling in a room (cf. Curve I in Fig. 1), natural cooling in a furnace (cf. Curve II in Fig. 2) and slow cooling in a furnace controlled by a thermocontroller. These cooling rates are about 3×102, 10, 1.5×10-1 and 1.2×10-3°C/sec, respectively. The amount of molten glass is the same as that in the previous studies; crucibles employed are made of platinum or its alloy, which may have some effect especially in the case of the slow cooling in a furnace.Ternary borate systems have been chosen as the glass-forming system for the convenience of experiment, which have been divided into common systems and exceptional systems. The former include the B-type ternary system as the containing only the oxides of the a-group elements, the PbO-containing ternary system as the one containing both of the oxides of the a-group and the b-group elements, and the B2O3-Bi2O3-PbO system as the one containing only the oxides of the b-group elements. The results are shown in Fig. 1-19. These glass-formation ranges contain various critical lines of vitrification; the limit of the continuity of a network-structure (the AD-line in Fig. 2 and 3), the existing limit of necessary modifier ions for the network-formation (the B2O3-C line in Fig. 2 and 3), and the exchangeable limit of network ions represented by the number of b-group ions connecting B with B in the network-structure (the A1B2, A2B3, … lines in Fig. 8; cf. Table 1). The glass-formation range expressed by the above critical lines generally varies somewhat according to the variation in the cooling rate. Therefore the result of the glass-formation range under an arbitrary cooling condition has no absolute meaning. However, comparing Fig. 4 with Fig. 5, for example, we can see a similar variation in the glass-formation range in both cases. In the one case the modifier ions are not exchanged but the cooling conditions are changed, while in the other the modifier ions are exchanged but the cooling conditions are kept constant. This fact can be explained by assuming the 3-dimensional glass-formation range including the glass stability as shown in Fig. 7. When the m","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"67 1","pages":"52-60"},"PeriodicalIF":0.0,"publicationDate":"1966-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80699467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diffusion in Oxides","authors":"K. Hirano","doi":"10.2109/JCERSJ1950.74.851_215","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.74.851_215","url":null,"abstract":"","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"17 1","pages":"215-225"},"PeriodicalIF":0.0,"publicationDate":"1966-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73843215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the Device of Rotary Kiln for the Calcination of Lime","authors":"M. Takatsu","doi":"10.2109/JCERSJ1950.73.838_C359","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.73.838_C359","url":null,"abstract":"","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1965-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73281767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sintering in the Binary System MoSi2-WSi2","authors":"S. Matsuo, K. Homma","doi":"10.2109/JCERSJ1950.72.821_111","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.72.821_111","url":null,"abstract":"Molybdenum disilicide has recently been developed as an excellent heating element of high refractoriness and of high oxidation resistivity. The binary system of MoSi2-ZrO2 was studied for the purpose of improving the too low electrical resistivity of MoSi2 without changing the other favorable characteristics.ZrO2 used was previously stabilized by dissolving 10 mol % of Y2O3 at 1600°C. Samples of six different chemical compositions differing from each other by 20% in ZrO2 content, were formed under the pressure of 6ton/cm2 and sintered at five different temperatures between 1300° and 1650°C in H2 gas.The electrical resistivity, density and modulus of rupture were measured on sintered specimens and expressed as functions of sintering temperature, chemical composition and sintering time.The density becomes minimum at about 60% of ZrO2 content and the modulus of rupture varies approximately with the density.The electrical resistivity at a room temperature increases rapidly with the amount of ZrO2 above 60%. The change of the electrical resistivity was also investigated up to the surface temperature of 1700°C. The resistivity increases with temperature on the MoSi2 side, while decreases on the ZrO2 side.The thermal shock test by repeated rapid heating and cooling between a room temperature and 1400°C, showed that the samples of the medium composition had the least thermal shock resistance.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"20 1","pages":"111-117"},"PeriodicalIF":0.0,"publicationDate":"1964-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84798652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Casting Properties of Pottery Body due to Specific Base-Exchange Cations","authors":"Y. Shiraki","doi":"10.2109/JCERSJ1950.72.821_117","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.72.821_117","url":null,"abstract":"","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"39 1","pages":"117-122"},"PeriodicalIF":0.0,"publicationDate":"1964-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76681767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Some Observations on Cracking of Clay during steady Heating in a saturated Atmosphere","authors":"Y. Shiraki","doi":"10.2109/JCERSJ1950.72.827_169","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.72.827_169","url":null,"abstract":"","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"36 1","pages":"169-175"},"PeriodicalIF":0.0,"publicationDate":"1964-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88452059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Studies of the Glass-formation Range of Silicate Systems : Investigations on the Glass-formation Range, 2","authors":"M. Imaoka, T. Yamazaki","doi":"10.2109/jcersj1950.71.816_215","DOIUrl":"https://doi.org/10.2109/jcersj1950.71.816_215","url":null,"abstract":"Following a previous report “Studies of the Glass-formation Range of Borate Systems” (This Journal, 69, 282 (1961)), we studied the glass-formation range of silicate systems. Although silicate glasses have long been used, sufficient systematic studies of the glassformation ranges of silicate systems have not yet been made.In this experiment, 1/80 mole (about 1g.) of materials were melted in crucibles made of pure platinum or platinum containing 20% rhodium at temperatures from 1400° to 1750°C. The oxides used besides SiO2 were 16 kinds of the oxides of a-group elements namely Li, Na, K, Be, Mg, Ca, Sr, Ba, Al, La, Ti, Zr, Th, Nb, Ta and W.The glass-formation ranges of binary silicate systems are shown in Table 1. These ranges differ in some points from those of borate systems. For instance, the La-silicate system has no vitrified range, while the Mg-silicate system has a wider glass-formation range than the borate. Whether a component ion enters into the glass structure as a modifier or as a network-former depends on the acidity of the glass-former and on the electronegativity of the component ion. In silicate systems, however, the actual range of glass-formation equals the difference between the glass-formation range and the immiscible range. If the latter is equal to the former or somewhat wider, the vitrified range will disappear.The glass-formation ranges of ternary systems are shown in Fig. 1-34. The whole number of the studied systems reached about one hundred. The Experimental results show that the actual glass-formation ranges agree with the range (hatched areas in the figures) to be expected from the “Conditions of Glass-formation” (This Journaj, 67, 364 (1959)). Among these systems, the systems containing TiO2 (cf. Figs. 12 and 13) are remarkably different from the corresponding borate systems. In the borate systems, a glass-fromation range spreads on the right side of the SiO2-D line (cf. Fig. 10), and therefore it has been estimated that the co-ordination number of Ti4+ is 6. (In order for the Ti4+ ion to take 6-co-ordination as a network-former, the modifier of divalency must also be present, therefor, in the area on the left of the SiO2-D line glass-formation is impossible.) However, in the silicate system the limited line of SiO2-D is lacking. Consequently, it is concluded that the Ti4+ ion as well as the Si4+ ion takes the 4-co-ordination. The glass-formation range of the TiO2-containing systems are shown in the hatched areas of Figs. 12 and 13, which are limited by the AD line.The WO3-containing silicate systems have a remarkably narrow glass-formation range compared with borate systems. The vitrified range of the B2O3-WO3-alkali oxide system has two feet, but the silicate system, we suppose, lacks the left foot. Moreover, it is considered that the left foot consists of WO3 and alkali borate in borate systems, but that this part becomes immiscible in silicate systems.According to the devitrification of the binary system, La2O3 sy","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"28 1","pages":"215-223"},"PeriodicalIF":0.0,"publicationDate":"1963-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89311609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"X-Ray Study of Behaviors of Sesquioxides Depositing in a Chromite Grain","authors":"Eiji Anbo","doi":"10.2109/JCERSJ1950.71.810_109","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.71.810_109","url":null,"abstract":"It is well known that sesquioxides, Cr2O3, Al2O3 and Fe2O3, are liberated from chromite ore by heat treatment in air. But behaviors of the sesquioxides in ores fired at temperatures below 1000°C have not been studied systematically.In this report, influences of behaviors of the sesquioxides on lattice spacing of the chromite fired below 1300°C and diffusion phenomena of the sesquioxides in the fired chromite grain were examined by X-ray diffraction and fluorescent X-ray analysis. The followings were observed (1) The lattice spacing (440) of the chromite decreased with elevation of heating temperature up to 700°-900°C in air and increased over these temperatures. The diffracted line (440) was most broadened at 700°-900°C. The X-ray pattern of the sesquioxides in α-type appeared over 700°C, and the relative intensity of the diffracted line (014) increased with decrease of its lattice spacing (014) between 700° and 1300°C. (2) By fluorescent X-ray analysis of the chromite grain, ratio of Fe2O3/Cr2O3 on the surface of the grain fired was determined. The ratio increased in the temperature range between 700° and 1100°C, and over this range decreased. So diffusion of the liberated sesguioxides in the spinel phase which presumably consists of a single crystal, was ascertamed.It was concluded that by the liberation of the sesquioxides the chromite phase was made unstable at the heating temperature of 700°-900°C, but was brought into a stable state over 700°-900°C by isolation of two different crystal phases of the sesquioxides and the spinel, with formation of a solid solution of the sesquioxides. The degree of crystallization of the two different phases was raised by heating over 700°-900°C.The author considers that the behaviors, as described above, of the sesquioxide deposited on the surface of the chromite crysta will give a valuable explanation of reactions with the chromite grain.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"30 1","pages":"109-119"},"PeriodicalIF":0.0,"publicationDate":"1963-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89833002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the Influence of the Gamma-Irradiation upon the Electric Conductivity of Glasses","authors":"T. Sugiura, K. Murakami, Hirobumi Tanaka","doi":"10.2109/JCERSJ1950.70.122","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.70.122","url":null,"abstract":"Influence of gamma-irradiation upon properties of glasses have scarcely been studies excepting phenomena such as coloration and fluorescence caused by the irradiation. In this study, therefore, not only the influence of gamma-irradiation upon the electric conductivity of glasses, but applicability of glasses exposed by gamma-rays to semi-conductive glass or radiationdosimeter was studied.The electric conductivity for ten kinds of glasses were measured after irradiating gamma-rays up to the maximum dosage of 107r. using Co60.For the measurement of the electric conductivity, a vacuum tube voltmeter was used for the range of low resistance values and a vibration reed electrometer for the range of high resistance.The result of the measurement showed that no change in electric conductivity of the glasses occured by the irradiation of 107r. and consequently the gamma-irradiation to the glasses was found to be unapplicable in making semi-conductive glass and glass-dosimeter.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":"12 1","pages":"122-125"},"PeriodicalIF":0.0,"publicationDate":"1962-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84790766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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