논문 국내 국내전문학술지(KCI급) Microstructural Evolution in Cast and HIP’ed Ingot Material of Beta Gamma TiAl Alloy by Two Step Cooling
- 학술지 구분 국내전문학술지(KCI급)
- 게재년월 2018-05
- 저자명 Kwangsu Choi1 , Jeong Min Kim1 , Joon Sik Park1,*, and Young-won Kim2
- 학술지명 대한금속·재료학회지
- 발행처명 대한금속·재료학회
- 발행국가 국내
- 논문언어 한국어
- 전체저자수 4
홈페이지
논문 초록 (Abstract)
The beta gamma alloys of Ti-43.8Al - 4Nb - 2Cr - 0.2B - 0.2C at % (9CN) were prepared usinginduction skull melted (ISM) cast ingots. In order to make a fine fully lamellar structure with some minorphases, two step cooling was performed using two furnaces after heat treatments in the α + β phase region.The heat-treatments produced an ~50 μm fully lamellar structure with α2 / γ + γ + B2 (HIP) → α + β (heating)→ α / γ (FL) + γ + B2 → α2 / γ (FL) + γ + B2 phase change. For the two step heat treatment, the specimenwas heat treated at 1340oC(or 1350oC) and transferred to another furnace, which was maintained at 950oC,in order to minimize any phase transformations between the temperatures. Fully lamellar specimens withsome phases were compression-tested at RT, 700oC, 800oC, 900oC and 1000oC, and showed excellentcompressive strength at high temperature. The resultant material property determined via this coolingprocess was superior to that of other materials such as Ni based superalloys or commercial TiAl alloys. Themicrostructures associated with the cooling effect were discussed in terms of materials properties and phasetransformation.