논문 해외 국제전문학술지(SCI급) Phase stability of L1(2)-based alloys in Al-Ti-Cr systems
- 학술지 구분 국제전문학술지(SCI급)
- 게재년월 2003-08
- 저자명 오민욱
- 학술지명 INTERMETALLICS
- 발행처명 ELSEVIER SCI LTD
- 발행국가 해외
- 논문언어 외국어
- 전체저자수 4
홈페이지논문 초록 (Abstract)
Compressive tests on Al-21Ti-23Cr (L1(2)+Cr2Al), Al-21Ti-15Cr (L1(2)+Al17Cr9) and Al-30Ti-15Cr (L1(2)+TiAl+TiAlCr) alloys were performed to investigate the effects of alloy compositions on the phase stability of L1(2)-based alloys at temperatures below 1000 degreesC. In Al-30Ti-15Cr alloy, yield strength increased significantly after exposure at 800 degreesC as compared to the other two alloys. Microstructure observation and phase identification confirmed that the Al-30Ti-15Cr alloy with Ti-rich composition exhibited complete decomposition of the L1(2) phase in contrast to partial decomposition of the L1(2) phase in Al-21Ti-23Cr and Al-21Ti-15Cr alloys under the same conditions. This results from the fact that the L1(2) phase field is shifted in the direction of the Al-rich corner with decreasing temperature in the Al-Ti-Cr phase diagram. The fracture toughness of Al-30Ti-15Cr alloy from three-point bend tests was more degraded after exposure at 800 degreesC than the other two alloys because the Al-30Ti-15Cr alloy exhibited poor phase stability due to its higher Ti content. Therefore, L1(2)-based alloys with higher Al-rich composition are more appropriate as coating materials when considering phase stability coupled with fracture toughness. (C) 2003 Elsevier Ltd. All rights reserved.