Since the directly bonded interface between TiAl alloy and SCM440 includes lots of cracks and generated intermetallic compounds(IMCs) such as TiC, FeTi, and Fe2Ti, the interfacial strength can be significantly reduced. Therefore, in this study, Cu is selected as an insert metal to improve the lower tensile strength of the joint between TiAl alloy and SCM440 during friction welding. As a result, newly formed IMCs, such as Cu2TiAl, CuTiAl, and TiCu2, are found at the interface between TiAl alloy and Cu layer and the thickness of IMCs layers is found to vary with friction time. In addition, to determine the relationship between the thickness of the IMCs and the strength of the welded interfaces, a tensile test was performed using sub-size specimens obtained from the center to the peripheral region of the friction-welded interface. The results are discussed in terms of changes in the IMCs and the underlying deformation mechanism. Finally, it is found that the friction welding process needs to be idealized because IMCs generated between TiAl alloy and Cu act to not only increase the bonding strength but also form an easy path of fracture propagation.

Abstracts
 1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
  3.1 접합계면의 미세조직 분석
  3.2 기계적 특성 변화
 4. 결 론
 References

• 박성현(금오공과대학교 신소재공학부) | Sung-Hyun Park (School of Materials Science and Engineering, Kumoh National Institute of Technology (KIT))
• 김기영(금오공과대학교 신소재공학부/A.F.W(주)) | Ki-Young Kim (School of Materials Science and Engineering, Kumoh National Institute of Technology (KIT)/Asan Friction Welding Co., Ltd)
• 박종문(금오공과대학교 신소재공학부) | Jong-Moon Park (School of Materials Science and Engineering, Kumoh National Institute of Technology (KIT))
• 최인철(금오공과대학교 신소재공학부) | In-Chul Choi (School of Materials Science and Engineering, Kumoh National Institute of Technology (KIT))
• Kazuhiro Ito(오사카대학교 접합과학연구소)
• 오명훈(금오공과대학교 신소재공학부) | Myung-Hoon Oh (School of Materials Science and Engineering, Kumoh National Institute of Technology (KIT)) Corresponding author