钎焊温度对TC4/Ti60接头组织及性能的影响

In order to study the effect of brazing temperature on the microstructure and mechanical properties of TC4/Ti60 joints, the contact reactive brazing of TC4 and Ti60 alloys using pure copper foil was performed and the brazing temperature ranged from 970 ℃ to 1 010 ℃. The microstructure and mechanical properties of the brazed joints were investigated by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and tension shear test. The results showed that the typical interfacial microstructure of TC4/Cu/Ti60 brazed joint was TC4/α-Ti+Ti₂Cu/Ti₂Cu/TiCu/Ti₂Cu/α-Ti+Ti₂Cu/Ti60. The thickness of reaction diffusion layers near substrates were increased with the increasing of brazing temperature, while the width of brazing seam with Ti-Cu intermetallic compounds were decreased. The composition of brazing seam tend to be uniform. The shear strength of joints first increased and then decreased with increasing the brazing temperature. The highest shear strength of 130 MPa was obtained when brazed at 1 000 ℃ for 10 min. Fracture analysis indicated that the quasi-cleavage fracture occurred between the center of brazing seam and the reaction diffusion layer.