Microstructure and mechanical properties of transient liquid phase bonding of A1_2O_3~p/A1 nanocomposite using copper interlayer

摘要

Transient liquid phase (TIP) bonding is one of the state-of-the-art joining processes. It is used for welding composites and advanced materials. Microstructure and mechanical properties of TLP bonding depends on the bonding time and temperature. In the current study, the effect of bonding time on the microstructure and bonding strength of the TLP diffusion bonded of A1_2O_3~p/Al nanocomposite were investigated. A thin layer of copper deposited by electroplating was used as interlayer. With increasing the bonding time from 20 to 60 min, at a constant bonding temperature of 580 ℃, the isothermal solidification was completed and the final joint microstructure consisted of soft a-Al phase with dispersed CuAl_2 precipitated particles. Decreasing the amount of brittle eutectic structures in the joint seam by increasing the bonding time was the main reason for improvement of the joint shear strength. The maximum joint shear strength was achieved at 580 ℃ for 60 min which was about 85% of the shear strength of the base material.