LOW-TEMPERATURE OXIDATION, HYDROTHERMAL CORROSION, AND THEIR EFFECTS ON PROPERTIES OF SIC (TYRANNO) FIBERS

被引:47
作者
GOGOTSI, YG [1 ]
YOSHIMURA, M [1 ]
机构
[1] TOKYO INST TECHNOL,ENGN MAT RES LAB,YOKOHAMA,KANAGAWA 227,JAPAN
关键词
D O I
10.1111/j.1151-2916.1995.tb08835.x
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
The effects of oxidation in air and corrosion in high-temperature, high-pressure water on the mechanical properties of three commercially available amorphous Si-Ti-C-O (Tyranno) fibers with different oxygen contents (12%-18%) and diameters (8-11 mu m) were investigated, The fibers were exposed to isothermal treatments at elevated temperatures and subsequently tested at room temperature. Structural changes in the fibers after oxidation and corrosion were also studied in order to understand better the degradation mechanisms of the fibers. Oxidation resulted in the formation of vitreous silica films and decreases of strength and Young's modulus of the fibers. Hydrothermal corrosion under 100 MPa water pressure started above 300 degrees C and resulted in the formation of a carbon layer on the surface of the fibers. Dissolution of silica in water during the treatment was observed. Corrosion at temperatures above 400 degrees C led to the formation of relatively thick carbon films which delaminated easily. It caused a decrease of strength and Young's modulus of the fibers. The hydrothermal method can be used for producing carbon coatings with thickness up to 2 mu m on the surface of silicon carbide fibers. The degrading of the mechanical properties after oxidation and corrosion was controlled by the thickness of the oxide or carbon layer. Based on this fact, it is possible to predict changes in the mechanical properties from the oxidation data.
引用
收藏
页码:1439 / 1450
页数:12
相关论文
共 39 条
  • [1] Okamura K., Ceramic Fibres from Polymer Precursors, Composites, 2, pp. 107-120, (1987)
  • [2] Yamamura J., Shibuya M., Ohtsubo H., Hiralsuka T., pp. 399-404, (1991)
  • [3] Yamamura T., Ishikawa T., Shibuya M., Nagasawa T., Okamura K., pp. 1084-1089, (1989)
  • [4] Gogotsi Yu.G., Lavrenko V.A., Corrosion of High‐Performance Ceramics, (1992)
  • [5] Pysher D.J., Goretta K.C., Hodder R.S., Tressler R.E., Strength of Ceramic Fibers at Elevated Temperatures, J. Am. Ceram. Soc., 72, pp. 284-288, (1989)
  • [6] Tressler R.E., Jia N.Y., Zheng Z., Takahashi H., pp. 167-176, (1991)
  • [7] Shimoo T., Kakimoto K., Okamura K., Mechanism of Oxidation of Tyranno Fiber, Journal of the Japan Society of Powder and Powder Metallurgy, 39, pp. 913-917, (1992)
  • [8] Shimoo T., Kakehi Y., Kakimoto K., Okamura K., Oxidation Kinetics of Amorphous Si‐Ti‐C‐O Fibers, (in Jpn.), J. Jpn. Inst. Metals, 56, pp. 175-183, (1992)
  • [9] Luthra K.L., Some New Perspectives on Oxidation of Silicon Carbide and Silicon Nitride, J. Am. Ceram. Soc., 74, pp. 1095-1103, (1991)
  • [10] Shimoo T., Chen H., Kakimoto K., Okamura K., Suppression of Pyrolysis of Si‐C‐O Fiber with Oxide Film, J. Ceram. Soc. Jpn., 101, pp. 295-300, (1993)