著者

幡中 憲治 藤満 達朗 安藤 隆之 橘 輝夫 中居 嘉一郎

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.55, no.512, pp.773-781, 1989-04-25

被引用文献数

1

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The test system was newly developed for evaluating precisely the strength of ceramics at elevated temperatures, being equipped with the laser beam-type displacement measuring system. Four-point bending tests were performed on the silicon-nitride ceramics at elevated temperatures from 800℃ to 1300℃. The linear relationship held between the load, P and the displacement, 6 at test temperatures below 1200℃. The P vs. δ plot, however, deviated from the linear relationship at temperatures above 1200℃, suggesting the occurrence of plastic deformation. The flexural strength remained unchanged in the test temperature range from room temperature to about 900℃, and then this decreased gradually with further increase in the test temperature. The fracture toughness measured by using the Chevron notch-type specimen was nearly constant in the temperature range from room temperature to about 1100℃. The fracture toughness obtained from the Knoop-indented specimen was discussed in comparison with that from the Chevron notch-type specimen.