Vacuum brazing of Ti₃Al and 316L stainless steel

Vacuum brazing of Ti₃ Al and 316 L stainless steel is realised with the Ag-Cu brazing filler. The interfacial microstructure of the joint is investigated by scanning electron microscopy（ SEM）,energy-dispersive X-ray spectroscopy（ EDS）,and X-ray diffraction（ XRD） and its forming mechanism is analysed. Meanwhile,effects of brazing temperature on interfacial microstructure and shear strength of the joint are studied. It is found that when holding time is fixed at 5 min,shear strength of the joint increases with the increase of brazing temperature. When the joint is brazed at 800 ℃,the highest joint strength of 343 MPa is achieved,and shear strength of the joint begins to drop with the further increase of brazing temperature. The typical microstructure of the joint is Ti₃ Al/Al Cu₂ Ti + Cu₂ Ti + Cu（ s,s） + Ag（ s,s） + Cu Ti + Fe₂ Ti/316 L stainless steel.