Microstructure and corrosion behaviour of laser-cladded γ-Ni/Mo₂Ni₃Si alloy coating

ABSTRACT

Different γ-Ni/Mo₂Ni₃Si alloy coatings were fabricated on 0.45 wt-% C steel applying the DISTA300 semiconductor laser system. The microstructures, phase components and corrosion behaviour of the alloy coatings were investigated. Research results showed that laser-cladded coatings with different compositions were all composed of ductile phase γ-Ni and reinforced phase Mo₂Ni₃Si. Electrochemical parameters and anodic polarisation curves revealed that the γ-Ni/Mo₂Ni₃Si alloy coatings exhibited a good corrosion performance in 3.5% NaCl solution in comparison with 0Cr18Ni9Ti stainless steel. The corrosion current density of the laser-cladded layer increased first and then decreased with the increasing volume fraction of Mo₂Ni₃Si. Moreover, the addition of Cr can significantly improve the passivation and anti-pitting ability of the γ-Ni/Mo₂Ni₃Si alloy coating.

KEYWORDS:

• Laser cladding
• intermetallic alloy
• γ-Ni/Mo₂Ni₃Si
• microstructure
• corrosion resistance

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (Grant No. 51705028), Scientific Research Project of Colleges and Universities of Shandong Province (Grant No. J17KA025) and Natural Science Foundation of Shandong Province [grant nos ZR2016EEB36 and ZR2016EEP04].