Elevated Temperature Static Fatigue in Silicon Nitride

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J. Korean Ceram. Soc. > Volume 36(1); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(1): 15.

질화규소의 고온정피로거동

최건, 최배호, 김기영¹

한국생산기술연구원 생산기반기술개발센터
¹한국기술교육대학 재료금속공학과

Elevated Temperature Static Fatigue in Silicon Nitride

ABSTRACT

Elevated temperature static fatigue behavior of silicon has been investigated by stress intensity/life test method. Static fatigue crack growth rate increase with the increase of temperature. Such tendency is found to be mainly related to the decrease of fracture toughness with the increase of temperature. That is, when static fatigue crack growth rate, da/dt is expressed by da/dt=AK1m, a constant A is a function of fracture toughness Kc and the exponent m is a constant which is independent of temperature or Kc. However, in the case of high temperature that glass phase is softened, the crack growth rate is found to be deviated from the above relation. This reason is, thus, discussed.

Key words: Static fatigue, Elevated temperatures, Silicon nitride, Fracture toughness, Stress intensity/life test