Transient Liquid Phase Bonding of Nickel-Base Single Crystal Alloy with a Novel Ni-Cr-Co-Mo-W-Ta-Re-B Amorphous Interlayer

摘要

A novel Ni-Cr-Co-W-Mo-Ta-Re-B alloy consisting of plate γ and M_(23)B_6 phases was prepared as interlayer for the transient liquid phase (TLP) bonding of Rene' N5 nickel-base single crystal superalloy. The molten Ni-Cr-Co-W-Mo-Ta-Re-B alloy exhibited an excellent wettability on the nickel-base superalloy. The TLP bonding experiment has been carried out in vacuum furnace at 1,240 °C for 12 h and followed by post-weld heat treatment (PWHT) at 1,305 °C for 4 h. PWHT eliminated the intermetallic compounds and promoted the formation of γ precipitates in the bonding region. A more uniform microhardness profile of TLP joint was found after PWHT. The shear strength of the joint after PWHT significantly increased to 533.4 MPa compared with the value of 437.2 MPa without PWHT.