An effective approach for bonding of TZM and Nb-Zr system: Microstructure evolution, mechanical properties, and bonding mechanism

Abstract

Abstract A novel method of liquid metallic film (LMF) bonding was developed to join titanium zirconium molybdenum alloy (TZM) and Nb-Zr alloy with a Ni interlayer. Using this method, a Ni-Zr liquid phase was formed by the eutectic reaction and then squeezed out from the gap due to a transient pressure, leaving an LMF. It not only achieved a reliable metallurgical bonding but also served as a transition layer between TZM and Nb-Zr alloy to reduce the mismatch between them thus further improving its performance. The bonding mechanism of the TZM and Nb-Zr system was discussed based on theoretical calculation and high–resolution microscopy analysis. The advantages of this method were established by comparing the microstructure and mechanical properties of LMF bonded joints with that of traditional contact-reaction brazing and direct diffusion bonding. Additionally, the feasibility of the LMF bonding method was also demonstrated by the reliable joining of other high-temperature and immiscible systems.