Boundary liquation and interface cracking characterization in laser deposition of Inconel 738 on directionally solidified Ni-based superalloy

Laser deposition of Inconel 738 on directionally solidified (DS) Ni-based superalloy demonstrates a strong susceptibility to cracking. Cracks originate from the liquation of low melting point eutectic on the DS grain boundary. Five boundary liquation and interface cracking styles were identified. Sound Inconel 738 deposition layers were achieved free of cracks.