Abstract:The interfacial microstructure and joining properties of Titanium-Zirconium-Molybdenum (TZM) alloy joints were characterized by SEM, EDS, XRD and mechanical tests, etc. The results showed that the Ni-Ti brazing filler metal can efficiently realize high-temperature vacuum brazing of TZM. The formation MoNi4 phase from Mo of the base metal and Ni in the braze metal was the main reason for the metallurgical bond between the TZM and the Ni-13.7Ti / TZM interface region. Ti in Ni-44Ti braze metal dissolved in Mo to form an infinite solid solution in TZM / Ni-44Ti / TZM interface zone, forming a metallurgical bond between the braze metal and TZM. However, a serious inter-granular infiltration phenomenon was observed when Ni-44Ti braze alloy was used to braze TZM alloy. The degree of inter-granular infiltration and corrosion of the base material significantly reduced with a decrease of Ti content in the braze alloy. The average shear strength of TZM / Ni-13.7Ti / TZM brazed joints reached 193 MPa, while the average shear strength of TZM/Ni-44Ti/TZM brazed joints reached 167 MPa. The lower shear strength of TZM/Ni-44Ti/TZM was attributed to the inter-granular infiltration due to the higher content of Ti in the brazing filler.