서지주요정보
소결 질화 규소에 있어서 strength-probability-time diagram 에 관한 연구 = A study on the strength-probability-time(SPT) diagram for sintered silicon nitride
서명 / 저자 소결 질화 규소에 있어서 strength-probability-time diagram 에 관한 연구 = A study on the strength-probability-time(SPT) diagram for sintered silicon nitride / 하정수.
저자명 하정수 ; Ha, Jeong-Soo
발행사항 [서울 : 한국과학기술원, 1985].
Online Access 원문보기 원문인쇄

소장정보

등록번호

4103306

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 8547

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

During the past decade, $Si_3N_4$ has received considerable attention, primarily directed towards heat engine applications. Its intrinsic properties, i.e. low thermal expansion and high strength, minimize stress developed during severe thermal transient better than other structural ceramics. Despite its exceptionally high strength at room temperature, $Si_3N_4$ exhibits significant strength degradation at higher temperatures. In the present study, a composition containing $α-Si_3N_4$ with 5 W/O $Y_2O_3$ and 4W/O $Al_2O_3$ was hot-pressed at 1,650℃ and 350kg/㎠ for 1.5hr, and specimens of the same composition were pressureless-sintered at 1,750℃ for 1.5 and 5 hrs, in order to know the variations of the high temperature strength with the crystallization of grain-boundary phase. By X-ray diffraction, hot-pressed specimens consisted of α-and $β-Si_3N_4s$, and sintered specimens consisted of $β-Si_3N_4$ and $Si_3N_4ㆍY_2O_3$ which was crystallized out from grain-boundary phase. The 5-hr sintered specimens had higher degree of crystallization than the 1.5-hr sintered specimens. And all the hot-pressed and sintered specimens had microstructures interlocked by elongated β-grains. Among these three different specimens, the 5-hr sintered specimens showed the highest strength after MOR test at 1,000℃. This result assures that the crystallization of grain-boundary phase has a significant effect on the high temperature strength of $Si_3N_4$. The SPT diagram for the 5-hr sintered $Si_3N_4$ was generated by measurements of the stressing rate dependence of fracture strength. This diagram enables predictions of a safe working stress to be made for specific component lifetimes and survival probabilities.

서지기타정보

서지기타정보
청구기호 {MMS 8547
형태사항 [iii], 41 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Jeong-Soo Ha
지도교수의 한글표기 : 이준근
지도교수의 영문표기 : Jung-Gunn Lee
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 36-41
주제 Silicon nitride.
Metals at high temperatures.
Sintering.
Precipitation (Chemistry)
소결. --과학기술용어시소러스
고온 강도. --과학기술용어시소러스
결정화. --과학기술용어시소러스
질화규소.
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