Welding & Joining : Isothermal Solidification and Single Crystallization Behaviors during TLP Bonding of a Ni-Base Single Crystal Superalloy
김대업Dae Up Kim
Abstract
The isothermal solidification behaviors and single crystallization in bonded interlayer of a Ni-base single crystal superalloy, CMSX-2, during transient liquid phase (TLP) bonding were investigated employing MBF-80 and F-24 insert metals. TLP bonding of CMSX-2 was carried out at 1373∼1548K for 0∼19.6 ks in vacuum and the $lt;001$gt; orientation of each test specimen was always aligned perpendicular to the joint interface. The eutectic width diminished linearly with the square root of holding time during isothermal solidification. Electron back scattering patterns of completed joints revealed that the bonded layer had single crystallized during the TLP bonding process and matched the crystallographic orientation of the bonded substrates. It follows that epitaxial growth of the solid phase occurred from the base metal substrates during isothermal solidification.