서지주요정보
$L1_2$ (Al,Cr)3Ti기 2상 금속간화합물의 기계적성질에 미치는 미세조직제어 효과 = Effects of microstructural controls on mechanical properties of two-phase intermetallic compounds based on $L1_2$ (Al,Cr)3Ti
서명 / 저자 $L1_2$ (Al,Cr)3Ti기 2상 금속간화합물의 기계적성질에 미치는 미세조직제어 효과 = Effects of microstructural controls on mechanical properties of two-phase intermetallic compounds based on $L1_2$ (Al,Cr)3Ti / 이재경.
저자명 이재경 ; Lee, Jae-Kyeong
발행사항 [대전 : 한국과학기술원, 1999].
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소장정보

등록번호

8009377

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 99036

휴대폰 전송

도서상태

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반납예정일

초록정보

Mechanical behavior of two-phase intermetallic compounds based on $L1_2$ $(Al,Cr)_3$Ti was investigated in view of microstructural controls. Al-21Ti-23Cr alloy has two phases consisting of mainly $L1_2$ phase and 20% $Cr_2Al$ phase. In this research, relationship between mechanical properties and microstructure was mainly studied by controlling the second phase, precipitation of third phase and grain size. The composition of Al-21Ti-23Cr alloy is located in two-phase region at temperature of 1150℃ but in three-phase region at 1000℃ in Al-Ti-Cr phase diagram. From this point, the microstructure was modified by aging treatment below 1000℃ and its influence on mechanical properties was examined. Aging at 800℃ leads to precipitate third phase refinedly in matrix and increases compressive yield strength drastically but decreases compressive strain to failure a little. These phenomena are understood by increasing amount of precipitation phase and it is expected that aging after decrease in second phase will increase strength and ductility of the alloy simultaneously. The Al-21Ti-23Cr alloy was recrystallized dynamically during isothermal forging at 1150℃, which refined the grain over ten times. Grain refinement increases tensile strength but don't have effect on ductility improvement at room temperature. However, this improves the ductility in 3-4% magnitude and changes fracture mode to intergranular fracture at 800℃. In order to change the distribution of second phase, boron and zirconium were added in Al-21Ti-23Cr alloy. Most of boron are dissolved in second phase and most of zirconium are dissolved in matrix, which is confirmed by SIMS analysis. The addition of boron and zirconium has different effects on the solidification of second phase. Adding of 0.1 wt.% boron homogenized the distribution of second phase and made second phase more ductile. Adding of 0.25 wt.% zirconium segregated second phase by increasing constitutional super-cooling of $L1_2$ dendrite.

서지기타정보

서지기타정보
청구기호 {MMS 99036
형태사항 iii, 72 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Jae-Kyeong Lee
지도교수의 한글표기 : 위당문
지도교수의 영문표기 : Dang-Moon Wee
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 70-72
주제 금속간화합물
Al-21Ti-23Cr 합금
시효처리
재결정
미량원소첨가
Intermetallic compounds
Al-21Ti-23 alloy
Aging
Recrystallization
Microalloying
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