Intermediate Phases of TiAl/GH3039 Friction Welding Joint

Abstract:

GH3039 superalloy was used as the third body metal to weld γ-TiAl with carbon steel, and the interface structure of the TiAl/GH3039 friction welding joint was analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the maximum tensile strength of the weld joint is more than 400 MPa after friction welding of γ-TiAl and GH3039 alloys. The plastic deformation of thermo-mechanically affected zone (TMAZ) on GH3039 side is larger than that on TiAl side, and dynamic recrystallization occurs on both sides. The Ni and Ti contents in the phase layer close to GH3039 and TiAl alloys hardly change, respectively. In the welding zone near GH3039 side, the distribution of Ni-rich and Cr-rich grains are complementary. Ti and Al are easily soluble in the Ni-rich crystal grains, and Mn is easily soluble in the Cr-rich crystal grains. A large number of Cr-rich grains formed in the bonding zone have body-centered cubic structure of α-Cr. The interface microstructure of the friction welding zone between γ-TiAl and GH3039 alloys is γ-TiAl+α₂-Ti₃Al/α₂+τ₃/τ₃-Al_1+x-yTi_1+yNi_1-x/τ₃+α-Cr/(Ni, Cr)_ss/GH3039.