서지주요정보
Lamellar 구조 TiAl 합금에서 lamellar spacing의 변화에 따른 크리프 변형기구에 대한 연구 = A study on the creep deformation mechanism of the lamellar TiAl alloys with lamellar spacing
서명 / 저자 Lamellar 구조 TiAl 합금에서 lamellar spacing의 변화에 따른 크리프 변형기구에 대한 연구 = A study on the creep deformation mechanism of the lamellar TiAl alloys with lamellar spacing / 배양호.
저자명 배양호 ; Bae, Yang-Ho
발행사항 [대전 : 한국과학기술원, 1999].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8009365

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 99024

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

리뷰정보

초록정보

TiAl alloy is regarded as a one of the strongest candidates for high temperature materials due to the superior properties, especially creep property, at high temperature. Creep resistance is known to be changed remarkably with lamellar spacing. Although the creep resistance seems to be improved by control of lamellar spacing, the study about controlling lamellar spacing has been limited. For the reason, the creep characteristics with lamellar spacing is investigated. The microstructure in TiAl alloy strongly depends on the heat treatment. The method to change only lamellar spacing is obtained by controlling the holding time(0.5hr and 2hr) near the α transus temperature(1380℃) and cooling rate(furnace cooling, air cooling). So, the lamellar spacing is 0.4㎛ in fine lamellar, 1.4㎛ in coarse lamellar. From the result of creep, It is found that fine lamellar has better creep resistance than coarse lamellar. As the creep strain increased within the primary regime, the activation for creep increases to the activation energy for diffusion and the dislocation density increases in general metal. However, EPM TiAl ally shows different behavior. : In case of fine lamellar, the dislocation density significantly decreases and the activation energy is changed from 300kJ/mol, the activation energy for diffusion, to 389kJ/mol. In case of the coarse lamellar, the dislocation density is not changed significantly in part of large lamellar spacing, but that of small lamellar spacing follows the trend of fine lamellar. The activation energy for creep in coarse lamellar changed from 300kJ/mol to 364kJ/mol which is smaller than fine lamellar. From the above result, it can be known that the rate controlling process for creep is the generation of dislocation by $α_2$ phase transformation in fine lamellar but balances between the generation of dislocation by $α_2$ phase transformation and dislocation climb in case of coarse lamellar.

서지기타정보

서지기타정보
청구기호 {MMS 99024
형태사항 ii, 55 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Yang-Ho Bae
지도교수의 한글표기 : 남수우
지도교수의 영문표기 : Soo-Woo Nam
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 50-55
주제 크리프
초기
활성화에너지
TiAl
층상
Creep
Primary
Activation energy
TiAl
Lamellar
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