Bonding phenomena and joint properties of transient liquid phase bonding of Ni-base single crystal superalloys

摘要

The bonding and crystallization behaviors of Ni-base single crystal superalloys, CMSX-2 and CMSX-4 during transient liquid phase (TLP) bonding have been investigated using MBF-80 and F-24 insert metals. Joint strength was evaluated using tensileand creep rupture testing at the elevated temperature. TLP-bonding of Ni-base single crystal superalloys was carried out at 1373-1548 K for 0-19.6 ks in vacuum and the (001) plane of each test specimen was always aligned perpendicular to the jointinterface. The dissolution width at the bonding temperature increased when the bonding temperature and holding time increased. The eutectic width decreased linearly with the square root of holding time during isothermal solidification. Electron backscattering patterns of completed joints revealed that the bonded interlayer had single-crystallized during the TLP-bonding process and matched the crystallographic orientation of the bonded substrates. The elevated temperature tensile strength and creeprupture strength of the joints indicated the identical levels of the base metals.