http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
TiAl-Nb 합금의 고온상변태와 일방향응고에 관한 연구
박종문 ( Jong-moon Park ),장호승 ( Ho-seung Jang ),김성웅 ( Seong-woong Kim ),김승언 ( Seung-eon Kim ),손지하 ( Je-ha Shon ),오명훈 ( Myung-hoon Oh ) 한국열처리공학회 2016 熱處理工學會誌 Vol.29 No.5
Phase transformation phenomenon at high temperature was investigated by using designed TiAl-Nb alloys with addition of the β stabilizer. Examination of dendritic morphologies in arc-melted button ingot could reveal the crystallography of the primary solidification phase. It was found that the addition of β stabilizer(Nb) shifted the high temperature region of the binary Ti-Al phase diagram to the high Al composition side so that β phase forms as a primary crystal even at higher Al composition compared with the binary Ti-Al system. The β was found to be the primary solidification phase for alloys with Al content less than about 52 at.%. The composition of β solidification in Ti-Al-Nb ternary system could be determined from the partial liquidus projection which was constructed by observing the microstructure of arc-melted buttons. The Ti-46Al-(6, 8)Nb composition was selected for β solidification and the directional solidification was performed by a floating zone-type DS apparatus at the growth rate 30 mm/hr respectively. (Received August 12, 2016; Revised August 30, 2016; Accepted September 9, 2016)
열간가공된 γ-TiAl 합금의 미세조직 제어 및 기계적 특성 평가
박성현 ( Sung-hyun Park ),김재권 ( Jae-kwon Kim ),김성웅 ( Seong-woong Kim ),김승언 ( Seung-eon Kim ),박노진 ( No-jin Park ),오명훈 ( Myung-hoon Oh ) 한국열처리공학회 2019 熱處理工學會誌 Vol.32 No.6
The microstructural features and texture development by both hot rolling and hot forging in γ-TiAl alloy were investigated. In addition, additional heat treatment after hot forging was conducted to recognize change of the microstructure and texture evolution. The obtained microstructural features through dynamic recrystallization after hot deformed γ-TiAl were quite different because two kinds of formation process were occurred depending on deformation condition. However, analyzed texture tends to be random orientation due to intermediate annealing up to α+β region during the hot deformation process. After additional heat treatment, microstructure transformed into fully lamellar microstructure and randomly oriented texture was also observed due to the same reason as before. Tensile test at room temperature demonstrated that anisotropy of mechanical properties were not appeared and transgranular fracture was occurred between interface of α2/γ. As a result, it could be suggested that microstructural features influenced much more than texture development on mechanical properties at room temperature. (Received October 22, 2019; Revised October 31, 2019; Accepted November 4, 2019)