{"title":"Effect of Carbon Monoxide on the Sintering of SiC Whisker-Zirconia Composite","authors":"A. Mitsui, A. Kato","doi":"10.2109/JCERSJ1950.95.1106_1040","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.1106_1040","url":null,"abstract":"Reaction between silicon carbide and yttria-stabilized zirconia (YSZ) powders, ZrO2+3/2SiC=ZrC+3/2SiO(g)+1/2CO(g), was appreciable above 1400°C in argon atmospheres. The reaction was suppressed by adding an appropriate amount of carbon monoxide to the atmosphere. This finding was applied to the pressureless sintering of SiC whisker-YSZ composites. In CO (33%)-Ar atmosphere, 5vol% SiC whisker-YSZ composite densified to 97% theoretical density by pressureless sintering at 1550°C for 1h. At higher whisker contents, however, the sintered density of composite decreased with increasing whisker content in the same firing atmosphere, due to the formation of network structure by SiC whisker.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83891935","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}
T. Furusaki, G. Tei, K. Kodaira, S. Shimada, T. Matsushita
{"title":"Preparation and Properties of LiTaO3 Thin Films by Dipping Method","authors":"T. Furusaki, G. Tei, K. Kodaira, S. Shimada, T. Matsushita","doi":"10.2109/JCERSJ1950.95.1098_209","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.1098_209","url":null,"abstract":"Transparent and smooth LiTaO3 thin films 1000nm thick were prepared at 600°-800°C on platinum and fused silica substrates by the dipping method. Uniform grains were distributed in the films, and the grain size increased with increasing temperatures. Dielectric properties of the film depended on the defects of the film such as crack or pinhole. The crack-free film prepared at 800°C showed a symmetric D-E hysteresis loop. The spontaneous polarization was 0.6μC/cm2, remanent polarization was 0.4μC/cm2 and coercive field was 60kV/cm. Dielectric constant and dielectric loss angle were about 50 and 0.05, respectively. The optical transmission of the films was about 40-80% and refractive index was 2.1 in the visible region.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76232685","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":"Solid Particle Erosion of Brittle Materials (Part4)","authors":"S. Wada, Naoyoshi Watanabe","doi":"10.2109/JCERSJ1950.95.1105_835","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.1105_835","url":null,"abstract":"Erosive wear by solid particle impingement was tested for 13 kinds of commercial Al2O3 ceramics. The erosion rate of Al2O3 ceramics is inversely proportional to the specific gravity, Al2O3 content and Vickers hardness of the target ceramics. The erosion rates of high density Al2O3 ceramics composed of more than 99wt% of Al2O3 are 3.9-4.5×10-3cm3/cm3, the same order as those of gas pressure sintered and hot pressed Si3N4. The erosion rate (V) of Al2O3 ceramics is related to its hardness (H) and fracture toughness (KIC) by the equation V=0.56H-1.2KIC-0.94, derived from the multiple regression analysis. Indices for H and KIC in the equation are different from those for hot pressed Si3N4, -0.27 for H and=7.1 for KIC. These differences are caused by the differences in erosion mechanism.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90882730","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":"Si//3N//4 FORMATION IN THE CARBOTHERMAL REDUCTION PROCESS OF A MAGADIITE-POLYACRYLONITRILE INTERCALATION COMPOUND.","authors":"Y. Sugahara, Yasuyuki Nomizu, K. Kuroda, C. Kato","doi":"10.2109/JCERSJ1950.95.134","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.134","url":null,"abstract":"Silicon nitride was formed from a magadiite (layered polysilicate)-polyacrylonitrile (PAN) intercalation compound through a novel process of carbothermal reduction. SiO2 from magadiite was reduced above 1400°C without the formation of any crystalline oxides. On heating above 1400°C, both α-and β-Si3N4 were detected, and the additional formation of α-and β-SiC was observed by heating at 1600°C. On the other hand, the reactions for the synthesis from a magadiite-carbon mixture involved the formation of cristobalite as well as α-and β-Si3N4, and β-SiC. In addition, it was also indicated that the mixture was less reactive for the formation of Si3N4. These observations suggest that the reaction process of the magadiite-PAN complex was different from that of the magadiite-carbon mixture, and that the use of the intercalation compound was favorable for Si3N4 production.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84145848","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":"Synthesis of High-Purity ZrF4 by Chemical Vapour Deposition","authors":"K. Fujiura, Y. Ohishi, S. Sakaguchi","doi":"10.2109/JCERSJ1950.95.96","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.96","url":null,"abstract":"","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83335835","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}
Hiroshi Tanaka, T. Yazawa, H. Wakabayashi, H. Nakamichi, K. Eguchi
{"title":"Distribution of Impregnated Component and Nonuniformity of Colloidal Silica in Porous Glass","authors":"Hiroshi Tanaka, T. Yazawa, H. Wakabayashi, H. Nakamichi, K. Eguchi","doi":"10.2109/JCERSJ1950.95.1099_345","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.1099_345","url":null,"abstract":"Porous glass prepared by acid leaching of phase separated glass contains colloidal silica, resulting in the nonunif ormity in the porous glass. Porous glass rods were impregnated with aluminum nitrate solutions, and some of them were treated subsequently with ammonia to precipitate aluminum hydroxide. Then the porous glasses were sintered to form nonporous glasses. The concentration profile of aluminum in the sintered glasses was studied with reference to the nonunif ormity. The aluminum concentration in the impregnated and ammonia-treated specimens was high at the surface region and decreased toward the center. This fact coincides with the distribution of porosity which is high at the surface region. The concentration difference between the as-impregnated and impregnated and ammonia-treated specimens was large at the center and decreased toward the surface, in good correlation with the distribution of the surface area which is high at the center. A narrow gap with a low aluminum concentration was observed at the center of the impregnated specimen and was ascribed to the very densely deposited colloidal silica.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78786713","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}
Y. Kondo, Y. Kuroshima, Yutaka Hashizuka, A. Tsukuda, S. Okada
{"title":"Ground Surface of Y-TZP","authors":"Y. Kondo, Y. Kuroshima, Yutaka Hashizuka, A. Tsukuda, S. Okada","doi":"10.2109/JCERSJ1950.95.1108_1223","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.95.1108_1223","url":null,"abstract":"A monoclinic phase is frequently seen on fractured surfaces of yttria stabilized tetragonal ZrO2 polycrystals (Y-TZP). In this study, Y-TZP materials were ground by diamond grinding wheels of different grain sizes and the effects of grinding on the structure in the surface layers was examined from the viewpoint of the grinding mechanism. It was found that a compressive layer was formed on the ground surface and bending strength was increased by grinding under specific conditions.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87588394","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":"Enhancement of Frost Durability by Modification of Internal Surface of Clay Roofing Tiles","authors":"Masahiko Nakamura, S. Okuda","doi":"10.2109/JCERSJ1950.94.1096_1239","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1096_1239","url":null,"abstract":"The possibility of surface modification of a hydrophilic hydroxy group on silica surface to a hydrophobic butoxy group was investigated on clay roofing tile specimens, and the enhancement in frost durability was experimentally confirmed. The internal surface modification was undertaken by reflux-boiling of rectangular shaped specimens (2.5cm×2.5cm, 1.8cm in thickness) in pure n-butanol for 24 hours. The formation of butoxy group on the internal surface of clay roofing tiles was experimentally confirmed by comparing IR spectra and water absorption between surface-modified and non-modified specimens of clay roofing tiles. The surface modification enhanced the frost durability of clay roofing tiles.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77077303","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}
S. Tomura, Yasuo Shibasaki, Hiroyuki Mizuta, T. Maeda
{"title":"Exsolution of Mullite from Spherical Kaolinite","authors":"S. Tomura, Yasuo Shibasaki, Hiroyuki Mizuta, T. Maeda","doi":"10.2109/JCERSJ1950.94.1092_917","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1092_917","url":null,"abstract":"of mullite from the spherical kaolinite at 900°-1400℃ has been studied by means of electron microscopy and powder X-ray diffractometry. The starting kaolinite which has spherical shape with concentric layering has been synthe under hydrothermal condition. The following results in were to the difference in lattice deformation of the kaolinite","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82824422","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":"Physical Properties and Hydration Behavior of 3CaO⋅Al2O3 Composition by Quenching after Fusion","authors":"N. Tsuyuki, H. Otake, Tsugio Miyakawa, J. Kasai","doi":"10.2109/JCERSJ1950.94.1091_636","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1091_636","url":null,"abstract":"The melt of 3CaO⋅Al2O3 (G-C3A) composition in the presence of a small amount of SiO2 was synthesized by rapid quenching after fusion. Furthermore, the physical properties and the hydration behavior of G-C3A were investigated. G-C3A results in a lowering of lattice constant, a decrease of specific gravity and an increase of free CaO compared with C3A. The hydration was not completed even on 10 days curing, and 3CaO⋅Al2O3⋅6H2O hydrate grew very slowly. It is thought that Al(OH)4- eluted from G-C3A is remarkably depressed against Ca2+. The molar ratio (CaO/Al2O3) in case of G-C3A was given 2.7 after 10 days curing but closely approached to 1.0 after 6 hours curing in case of C3A. Namely, as glass phase is formed on G-C3A surface, the strain occurs in inner layer. Therefore, it is difficult to elute Al(OH)4- by breaking -Al-O-Al- bonds. Although the elution of Al(OH)4- by NaOH is considerable, the growth of the hydrate cannot be expected because of depression of the elution of Ca2+. The results of surface analysis by ESCA showed that the binding energy of inner shell electron of Ca, Al, and Si combined with O (oxygen) in G-C3A is 0.7-0.8eV higher than C3A. Consequently, as the elution of Ca2+ and Al(OH)4- is depressed, the hydration reaction becomes inactive.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81452917","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}