A review on cracking mechanism and suppression strategy of nickel-based superalloys during laser cladding

Nickel-based superalloys are extensively utilized in the aerospace industry due to their exceptional corrosion resistance. Laser cladding as an advanced and effective technology has applied in the field of surface modification and additive manufacturing of nickel-based superalloys. However, crack is a challenging problem for nickel-based superalloys during laser cladding and crack issue has limited its specific application. This paper reviewed various types and mechanisms of cracks (solidification cracks, liquefaction cracks, ductility-dip cracks, etc.) in nickel-based superalloys during laser cladding. Some effective methods to suppress these cracks were also provided from two perspectives. On one hand, technological optimization can be considered from optimizing laser cladding process parameter and adopting heat treatment before laser cladding. On the other hand, metallurgical measure is also helpful and more attention can be paid on optimization of alloy composition and microstructure. Some suggestions for the further research direction on the cracking of nickel-based superalloys during laser claddings were also proposed so as to promote the development of laser cladding and widen its application.