Microstructural analysis of a (α+β) Ti alloy was investigated to consider phase transformation in each step of thethermo-mechanical process using by SEM and TEM EDS. The TAF (Ti-6Al-4Fe) alloy was thermo-mechanically treated withsolid solution at 880oC, rolling at 880oC and annealing at 800oC. In the STQ state, the TAF microstructure was composedof a normal hcp α and metastable β phase. In a rolled state, it was composed of fine B2 precipitates in an α phase, whichhad high Fe segregation and a coherent relationship with the β matrix. Finally, in the annealing state, the fine B2 precipitateshad disappeared in the α phase and had gone to the boundary of the α and β phase. On the other hand, in a lower rollingtemperature of 704oC, the B2 precipitates were more coarse in both the α and the boundary of α and β phase. We concludedthat microstructural change affects the mechanical properties of formability including rolling defects and cracks.

1. 서 론
 2. 실험 방법
 3. 실험 결과 및 고찰
  3.1 용체화처리 후의 미세조직
  3.2 열간압연 후의 미세조직
  3.3 어닐링 후의 미세조직
 4. 결 론
 Acknowledgement
 References

• 최병학(강릉원주대학교 신소재금속공학과) | Byung Hak Choe
• 최원열(강릉원주대학교 신소재금속공학과) | Won-Youl Choi
• 심종헌(강릉원주대학교 신소재금속공학과) | Jong Heon Shim
• 박찬희(재료연구소 타이타늄연구실) | Chan Hee Park
• 강주희(재료연구소 재료설계분석연구실) | Joo-Hee Kang
• 김승언(재료연구소 타이타늄연구실) | Seung Eon Kim
• 현용택(재료연구소 타이타늄연구실) | Yong Taek Hyun Corresponding author