Direct bonding of bimetallic structure from Ti6Al4V to Ti48Al2Cr2Nb alloy by laser additive manufacturing

Abstract

A TC4/TiAl bimetallic structure (BS) was successfully fabricated by laser additive manufacturing (LAM) to investigate the microstructure evolution of the transition zone. The results presented that the microstructures of the transition zone consisted of α (α-Ti), α₂ (Ti₃Al) and γ (TiAl). The evolution rule of the microstructures was (more α + less α₂) → (more α₂ + less γ) → (more γ + less α₂) from the TC4 alloy side to the TiAl alloy side in the transition zone. The mechanical properties of the LAMed BS specimens revealed that the tensile strength reached that of the as-deposited TiAl alloy. The fracture was located at the TiAl alloy side near the transition zone and the fracture surfaces showed a quasi-cleavage fracture morphology.

KEYWORDS:

• Laser additive manufacturing
• bimetallic structure
• transition zone
• microstructure evolution
• tensile strength

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by PhD research startup foundation of Liaoning University of Technology [grant number XB2021005]; the Scientific Research Project of Liaoning Provincial Department of Education [grant number JJL202015408].