Direct bonding of bimetallic structure from Ti6Al4V to Ti48Al2Cr2Nb alloy by laser additive manufacturing
Zhanqi Liu, Xiaoou Zhu, Guili Yin, Qi Zhou
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), α 2 (Ti 3 Al) and γ (TiAl). The evolution rule of the microstructures was (more α + less α 2 ) → (more α 2 + less γ) → (more γ + less α 2 ) 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.